Chapter 15.01 GENERAL PROVISIONS

1. Facilitate the development of properly designed and constructed public and private roadways and utilities, so as to provide an efficient integrated roadway and utility system for Langley;

2. Protect public rights-of-way, natural resources, scenic and open space from undue degradation due to poor development practices;

3. Protect, to the greatest extent possible, life, limb and property from loss and damage by flooding, landscapes, accelerated soil creep, settlement and subsidence, abnormal erosion and other potential natural hazards;

4. Protect the public interest in management of surface water drainage, ground water recharge, and related functions of drainage basins, watercourses and shoreline areas. To this end, require reasonable and appropriate use of low-impact development measures;

5. Protect streams, creeks, ponds, wetlands, lakes, coastal areas, and drainage facilities from mechanical damage, excessive flows and other conditions which increase erosion turbidity, siltation, and other forms of pollution, or which reduce low water level and/or flow rates endangering aquatic and benthic life; and

6. Fulfill the objectives of comprehensive planning policies of Langley in promoting the health, safety and welfare of the general public, as well as fulfilling the city’s responsibilities as trustees of the environment as provided by law.

B. Satisfactory compliance with the provisions of this chapter shall be consistent with zoning and land use control provisions of Langley, as well as adopted planning policy. (Ord. 743, 1997)

15.01.010 Shortened designation.

These city of Langley construction development standards shall be cited routinely in the text as the “standards.” (Ord. 743, 1997)

15.01.015 Definitions.

“Access road” means a public or private road providing vehicular access to the boundary of a parcel of real property being proposed for development.

“Average daily traffic” or “ADT” means the average number of vehicles passing a specified point during a 24-hour period. “Annual average daily traffic (AADT)” denotes that daily traffic that is averaged over one calendar year. ADT to be calculated using standard methodology.

“APWA” means the adopted edition of the Washington State Chapter of the American Public Works Association.

“Best management practice” or “BMP” means physical, structural, and/or managerial practices that, when used singly or in combination, prevent or reduce pollution of water. BMPs are listed and described in the Manual.

“Building official” means the building official for the city of Langley.

“City engineer” means the city engineer for the city of Langley.

“Clearing” means (per DOE Tech Manual) the destruction and removal of vegetation by manual, mechanical, or chemical methods.

“Collector road” means a road whose function is to collect traffic from neighborhoods and local streets and which connects to another road of equal or greater classification. A collector also may provide direct access to adjacent properties.

“Commercial access” means an approach providing access to a commercial property.

“Common approach” means a shared approach serving no more than two lots/units. A common approach does not have to straddle a common property line.

“Complete street” means a road that is designed to be safe for drivers, bicyclists, transit vehicles and users, and pedestrians of all ages and abilities. The complete streets concept focuses not just on individual roads but on changing the decision-making process so that all users are routinely considered during the planning, designing, building and operating of all roadways.

“Critical drainage area” includes those mapped sensitive areas as hereinafter identified in the Langley Comprehensive Stormwater Management Plan, June 1994, and those areas where sufficient justification is demonstrated by the city engineer, in which flooding, drainage, erosion and/or instability hazards exist and the welfare and safety of the surrounding community would be threatened by increasing the volume and/or rate of surface water discharge from a developing parcel.

“Cul-de-sac” means a dead-end road having a primary function of serving adjoining land and constructed with a turn-around at its end (local access road).

“Design engineer” means an individual licensed by the state of Washington to practice civil engineering and who has been retained to design land development improvements.

“Design storm” means a rain storm of a particular intensity and duration used in storm drainage analysis and system design.

“Design storm frequency” means the probability of a design storm occurring, expressed in terms of a statistical probable yearly interval of occurrence.

“Developer” means any person, firm, partnership, association, joint venture, or corporation or any other entity responsible for a given project.

“Development coverage” means all developed surface areas within subject property, including but not limited to rooftops, driveways, carports, accessory buildings, and parking areas.

“Director of public works” means the city of Langley public works director or a duly authorized representative.

“Drainage area” means the watershed (acreage) contributing surface water within the subject property.

“Drainage plan” means a plan for receiving, handling, and transporting surface water within the subject property and may extend sufficiently downstream to assure adequate control of potential detrimental effects.

“Easement” means the right to use a defined area of property for a specific purpose/purposes as set forth in the easement document, on a plat or short plat, or as required for purposes as set forth herein, and recorded with the Island County auditor.

“Excavation” means the mechanical removal of earth material.

“Filling” means any deposit of earth material, rubble, or demolition wastes placed by artificial means.

“Generalized plan” means a plan delineating the contiguous property within one ownership and property delineating natural drainage ways and existing roadway systems as well as indicating a conceptual plan for drainage facilities or improvements thereto, and a suitable access plan for the remnant parcel(s) when topography/development and policies could reasonably be expected to limit locations and number of approaches to public roads. It is not to be construed as a binding site plan.

“Grading” means any clearing, excavating, or filling, exposing of soil by the removal of live vegetation and/or vegetative debris for nonagricultural purposes, or combination thereof.

“Grading permit” means the permit required under Section 15.01.680.

“Ground cover” means small plants such as salal, ivy, ferns, mosses, grasses or other types of vegetation which normally cover the ground and shall include trees less than four inches in diameter measured at 24 inches above the ground level.

“Half street” means a street constructed along an edge of development utilizing half the regular width of the right-of-way.

“Home site evaluation” means a report prepared by a qualified professional geologist/registered soils engineer which addresses the feasibility/safety of structural improvements within/adjacent to unstable slope areas, citing specific recommendations/conclusions, including but not limited to structure placement, foundation design, drainage and geological stability of the site for the intended use. Such reports shall be site- and development-specific.

“Impervious” means a surface which cannot be easily penetrated. For instance, rain does not readily penetrate paved surfaces.

“Interceptor” means a sewer that receives flow from a number of mains or trunk sewers, force mains, etc.

“Land clearing” means the act of removing or destroying trees or ground cover from any undeveloped or partially developed lot, public lands or public right-of-way.

“Land use coordinator” means the land use coordinator for the city of Langley.

“LID Manual” means the Low Impact Development Technical Guidance Manual for Puget Sound.

“LMC” means the Langley Municipal Code.

“Loop road” means a road of limited length forming a loop having a beginning and ending on the same road, having no other intersecting road, and having as its primary function the provision of direct access to adjoining properties (local access road).

“Low-impact development” means a stormwater management and land development strategy applied at the parcel and subdivision scale that emphasizes conservation and use of onsite natural features integrated with engineered, small-scale hydrologic controls to more closely mimic pre-development hydrologic functions.

“Neighborhood access” means a road whose primary function is to provide access to adjoining properties, but which also provides for traffic circulation within and/or through a neighborhood (local access road).

“Peak discharge” means the maximum surface water runoff rate (cfs) determined for the design storm frequency.

“Pervious surface” means a surface which can be easily penetrated. For instance, rain can easily penetrate gravelly soils.

“Planning official” means the planning official for the city of Langley.

“Potential number of lots or units served” means total possible users of a facility under current and/or contractual zoning, covenant restriction, and extensions to serve adjacent property.

“Private sewer” means any portion of the sewer system located on private property where no easements are granted to the city and/or the line has not been deeded to the city.

“Private street” means privately owned and maintained vehicular access provided for by an access tract, easement, or other legal means to serve more than two parcels.

“Project” is a general term encompassing all phases of the work to be performed and is synonymous to the term “proposal” or “work.”

“Public sewer” means that portion of the system located within public rights-of-way and/or easements and which is owned, operated and maintained by the city.

“Public street” means a publicly owned and maintained street.

“Residential/detention facilities” or “source control BMP” means a BMP that is intended to prevent pollutants from entering stormwater. A few examples of source control BMPs are erosion control practices, maintenance of stormwater facilities, and constructing roofs over storage and working areas.

“Right-of-way” is a general term denoting public land, property, or interest therein (e.g., an easement) acquired for or devoted to a public street, public access or public use.

“Roadside” means the portion of an easement or right-of-way lying on either side of the roadway, including curbs, sidewalks and ditches.

“Roadway” means the improved portion of an easement of right-of-way, excluding curbs, sidewalks and ditches.

“Side casting” means the act of moving excavated waste material and vegetative debris to the side and subsequently depositing or dumping such material over the side of a shoreline bluff or natural drainage way.

“Side sewer” or “building sewer” means that portion of the sewer line beginning two feet outside the outer foundation wall of the structure to the sanitary sewer main.

“Sidewalk” means a pedestrian access adjacent to or within the right-of-way of an adjoining public or private road.

“Special provisions” means road construction requirements peculiar to a specific project and which are not otherwise thoroughly or satisfactorily detailed and set forth in the standard specifications.

“Standard specifications” means those specifications adopted for municipal construction in Section 15.01.025.

“Street frontage” means the distance between the two points where the lot lines intersect the boundary of public or private street right-of-way.

“Structure” means that which is built or constructed, an edifice or building of any kind or any piece of work artificially built up or composed of parts joined together in some definite manner, but not to include utilities for the purpose of this chapter.

“Subject property” means the tract of land which is the subject of the permit and/or approval action.

“Technical Manual” means the Stormwater Management Manual for the Puget Sound Basin prepared by the Washington Department of Ecology.

“Trail” means an improved but natural path or way set aside for public and private use providing an access route to, from or between points of interest and intended for use by pedestrians, equestrians, bicycles and/or other nonmotor vehicular users.

“Tree” means any living woody plant characterized by one main stem or trunk and many branches, and having a diameter of four inches or more measured at 24 inches above the ground level.

“Undeveloped lot” means a lot or parcel of land upon which no structure exists.

Use of Pronoun. As used herein, the singular shall include the plural, and the plural the singular; any masculine pronoun shall include the feminine or neutral gender and vice versa; and the term “person” includes natural person or persons, firm, partnership, corporation or association, or combination thereof.

“Utilities” means those services provided for private or public use, including electric power lines, gas lines, telephone lines, television cables, sewer lines, water lines, and drainage facilities.

“Walkway” means a pedestrian access which is constructed of asphalt concrete pavement. Walkways may be located in right-of-way or on private property and may be connected to or separate from a street.

“Wetlands” means wetlands as defined in Chapter 16.20 as it now exists or is hereafter amended.

“WWHM3” means the Western Washington Hydrology Model, Version 3. (Ord. 970 § 1, 2012; Ord. 921, 2009; Ord. 862, 2005; Ord. 743, 1997)

15.01.020 Applicability.

A. This chapter shall apply to the following land development actions or permits, as applicable:

1. Subdivisions.

2. Short subdivisions.

3. Condominiums/multifamily developments.

4. Planned unit developments.

5. Business and commercial development.

6. Campgrounds and recreational facilities.

7. All building permits, except single-family residential and accessory structures with less than 5,000 square feet total of impervious surface area, except as provided for in Section 15.01.425 and Sections 15.01.680 through 15.01.715.

8. Grading and timber clearing.

9. Construction or development activity related to approval of rezones, conditional use permits, binding site plans, shoreline substantial development permits and other similar permits and/or approvals.

10. Access permits sought in conjunction with or subsequent to any of the above-mentioned land development actions or permits.

B. Commencement of construction work under any of the above-mentioned actions or permits, including the initial clearing of any proposed land development, shall not begin until such time as final approval of the drainage, erosion/sedimentation control, and/or grading plans is obtained, or a waiver therefrom is granted by the city in accordance with the provisions of this chapter.

C. These standards shall govern all new construction and upgrading of facilities both in the right-of-way and on site for transportation and transportation related facilities; storm drainage facilities; sanitary sewer and water improvements; and park, recreation, and open space facilities. (Ord. 743, 1997)

15.01.025 Standard specifications.

A. Design detail, workmanship, and materials shall be in accordance with the current edition of the “Standard Specifications for Road, Bridge and Municipal Construction,” the “APWA Amendments to Division One,” and the “Standard Plans for Road, Bridge and Municipal Construction,” all written and promulgated by the Washington State Chapter of the American Public Works Association and the Washington State Department of Transportation, except where these standards provide otherwise.

B. The most current edition of the following specifications shall also be applicable:

1. Conditions and standards as set forth in the city of Langley water system plan.

2. Conditions and standards as set forth in the city of Langley comprehensive sanitary sewer plan.

3. Conditions and standards as set forth in the Langley comprehensive plan.

4. Conditions and standards as set forth in the Langley comprehensive stormwater management plan.

5. Criteria set forth in the local agency guidelines as amended and approved by Washington State Department of Transportation (WSDOT).

6. City and County Design Standards for the Construction of Urban and Rural Arterial and Collector Roads Promulgated by the City Engineers Association of Washington.

7. Conditions and standards as set forth in the current WSDOT Design Manual as amended and approved by WSDOT.

8. United States Department of Transportation Manual on Uniform Traffic Control Devices (MUTCD), as amended and approved by Washington State Department of Transportation.

9. WSDOT Construction Manual as amended and approved by Washington State Department of Transportation.

10. Rules and regulations of the State Board of Health regarding public water supplies, as published by the State Department of Health.

11. Conditions and standards as set forth in the State of Washington Department of Ecology “Criteria for Sewage Works Design.”

12. Conditions and standards as set forth by the State of Washington Department of Labor and Industries.

13. Rules and regulations as adopted in the Langley Municipal Code.

14. Low-impact development measures as set forth in the Low Impact Development Technical Guidance Manual for Puget Sound (Puget Sound Action Team Publication No. PSAT 05-03 as it now exists or is hereafter amended).

15. Requirements as outlined by the Stormwater Management Manual for Western Washington (Department of Ecology Publication Nos. 05-10-029 through 05-10-033 as they now exist or are hereafter amended).

16. Requirements as outlined in the Langley six-year transportation plan.

17. Other specifications not listed above as may apply when required by the city of Langley.

18. The city engineer shall have the authority to establish additional standards, in accordance with accepted practice and in the city’s best interest.

C. The city council may impose such conditions upon the approval of any main extensions as the council may determine will promote the public health, safety and welfare of the users of the system. (Ord. 862, 2005; Ord. 743, 1997)

15.01.030 General policy – Utilities.

A. All development within city jurisdiction shall be served by the city water and sewer systems except where otherwise provided in Langley Municipal Code. Developers are required to extend the existing system across the full frontage of the property being developed and upon approval of construction and conveying or deeding the system so constructed to the city. Joint participation by the city may be applicable where oversizing is deemed appropriate in the city’s comprehensive water system plan and/or comprehensive sewer plan. City approval is required prior to construction. Latecomer agreements where appropriate will be administered by the city. (Ord. 798, 2001; Ord. 743, 1997)

15.01.035 Utilities – Construction.

A. The person(s) desiring to install a main extension shall apply to the public works department, requesting permission to extend the city’s utility system. The city shall review the application and make a decision regarding the requested extension.

B. If the requested main extension is determined to be an improper extension of the utility system, the application shall be denied.

C. Construction costs of all utility extensions to the city utility system shall be paid for by the property benefited thereby. Said costs shall include, without limitation, engineering fees, administrative expense, inspection fees, and the cost of any required appurtenances.

D. Main extensions may be made by private contract or through local improvement districts.

E. Any main extension shall be constructed by a licensed and bonded contractor in the state of Washington. (Ord. 743, 1997)

15.01.040 Design standards.

A. Detailed plans, prepared by a licensed engineer, must be submitted to the city for plan review and approval prior to the commencement of any construction. Applicant’s engineer shall be a professional engineer, registered as such in the state of Washington. All plans must be signed and stamped by the applicant’s engineer prior to submittal for plan review. Final plans shall be approved by the city engineer prior to the start of construction.

B. Five folded copies of the plans are required to be submitted along with a completed checklist. All drawings shall be on 24-inch by 36-inch sheet size.

C. Plans and profile drawings are required for all proposed transportation related improvements, street illumination, storm drainage facilities, and sewer and water improvements. For specific minimum requirements, see the plan checklist. Projects of a small scope (i.e., relocating one hydrant) may not require engineered plans and can instead be handled via a right-of-way use permit. This decision will be made by the city engineer during the pre-application meeting.

D. Specifications shall be submitted with the plans if general notes do not adequately cover the project requirements. (Ord. 743, 1997)

15.01.045 Plan review.

A. All plans are to be submitted to the city land use coordinator along with a plan review deposit in an amount as set by the land use coordinator. Any necessary easements or dedications shall be submitted for review along with the plans. A check of the plans against the plans checklist will be made by city staff. If the plans meet the minimum checklist requirements as to content, they will be routed to the appropriate city staff and the plan review process begins.

B. Initial review of plans submitted normally requires about two weeks. The design engineer is then requested to submit the original drawings for approval or if the plans are found to be incomplete, the design engineer is notified of additional required revisions. Additional review time will be required if revisions are necessary.

C. If plans require a third submittal, additional fees will be levied as established by resolution of the city council. “Third submittal” means the third and any subsequent submittal of construction drawings, specifications, drainage calculations, and/or other information that requires additional plan checking pertaining to the construction of proposed facilities.

D. Approved plans will be returned to the design engineer only after the plan checking fees have been paid in full.

E. Plans that have been approved for 365 days and construction has not started (i.e., a pre-construction meeting scheduled and inspection fees paid) shall be subject to additional review based on the hourly rate as established for third submittal. (Ord. 743, 1997)

15.01.050 Installation standards.

A. All setback requirements of the city of Langley must be sufficient to protect the public health, safety and welfare.

B. When only a portion of land having the same ownership, including contiguous property, is being developed, a generalized plan for the entire ownership shall be required at the time of application to indicate that the roadways, drainage and general design can be coordinated with the entire ownership when fully developed.

C. Roadway systems shall be planned and designed to facilitate the development of an integrated public roadway network. The number of external accesses, including emergency vehicle access, will be determined during preliminary plat review. Any right-of-way of less than city standards for public roads shall be retained permanently as privately owned and maintained; except when subsequently the street is developed to adopted city standards and specifications, and established as a city road in accordance with the provisions of law.

D. Maintenance responsibilities and the method of financing said maintenance for all privately owned and operated facilities, e.g., water, sewer, drainage, and road systems shall be established prior to approval of development actions.

E. Nothing herein shall be construed to preclude the imposition of additional requirements for offsite access road improvements as a condition of approving a preliminary plat, preliminary short plat, rezone, binding site plan, conditional use or other discretionary land use permit of approval, where such additional improvements are found by the city approving authority to be necessary in order to provide either adequate road access to the proposed development, or to mitigate traffic hazards caused or aggravated by the proposed development.

F. Future Public Right-of-Way Tracts or Trail Systems. The dedication of sufficient right-of-way may be required when it is necessary for public health, safety and welfare, consistent with the Langley comprehensive plan, to provide for future public street, or trail system right-of-way to assure the orderly development of neighborhood circulation. The dimensions of such tract, when required, shall be consistent with the adopted standards and plans for public streets, roads, and tracts attached. Such tracts may contain a private road consistent with the requirements of this chapter.

G. If the access road serving and/or adjoining a development is a state road, highway, or county road, required dedication and/or improvements thereto shall be governed by the provisions of this chapter as they relate to city roads, unless specified otherwise by the Washington State Department of Transportation, county engineer or city engineer.

H. In order to protect and preserve the function and character of adjoining public roadways, access to adjoining public roads may be restricted or denied by the city. In such circumstances, the developer shall be required to fulfill the access road requirements herein stated.

I. The city engineer may require the construction of individual or common lot accesses concurrent with roadway construction when said access requires excessive cutting or filling to meet the city’s standard requirements or to protect the public interest. (Ord. 743, 1997)

15.01.055 Construction control – Acceptance requirements.

A. Work performed for the construction or improvement of city roads and utilities, whether by or for a private developer or by a city contractor, shall be done to the satisfaction of the city and in accordance with approved plans. It is emphasized that no work shall be started until such plans are approved and the required bond posted (see Section 15.01.075). Any revision to such plans shall be approved by the city before being implemented. Failure to receive the city’s approval prior to construction can result in removal or modification of construction at the contractor’s or developer’s expense to bring it into conformance with approved plans.

B. The city reserves the right to reject any installation not inspected and approved by the public works director.

C. Upon satisfactory completion of all required tests and acceptance of the main extension, the city will allow the extension to be connected to the city system.

D. No water main extension shall be energized except for test purposes or sewer mains connected to the existing system until the new extension has been accepted by the city and all fees and charges have been paid. If energizing a water main is necessary to restore service to existing customers, fire hydrants will not be activated until city acceptance of the water main extension.

E. Upon completion of a main extension, the applicant shall provide the public works department with a reproducible mylar drawing that accurately indicates the main extension and appurtenances as actually installed in plan and profile. No main extension will be accepted until satisfactory “as-built” drawings are provided.

F. The permit holder shall provide the city with warranty bill of sale for all main extensions as a condition of acceptance of the main by the city. Forms are available from the public works department. (Ord. 743, 1997)

15.01.060 Inspection.

A. All work performed within the public right-of-way or easements, or as described in these standards, whether by or for a private developer or by a city contractor, shall be done to the satisfaction of the city and in accordance with the WSDOT/APWA Standard Specifications, any approved plans and these standards. Unless otherwise approved, any revision to construction plans must be approved by the city before being implemented.

B. It is the responsibility of the developer, contractor, or their agents to notify the city in advance of the commencement of any authorized work. A pre-construction meeting and/or field review shall be required before the commencement of work. Inspection fees shall be paid on or before the pre-construction meeting. Any necessary easements or dedications are to be reviewed and approved by the city prior to plan approval.

C. It is the responsibility of the developer, contractor or their agents to have an approved set of plans and any necessary permits on the job site whenever work is being accomplished.

D. The city shall have authority to enforce these standards as well as other referenced or pertinent specifications. The city will appoint project engineers, assistants and inspectors as necessary to inspect the work, at the developer’s expense, and they will exercise such authority as the city public works director may delegate.

E. All specific inspections, test measurements or actions required of all work and materials are set forth in their respective chapters herein. Tests shall be performed at the developer’s or contractor’s expense.

F. Failure to comply with the provisions of these standards may result in stop work orders, removal of work accomplished, or other penalties as established by ordinance.

G. A project is considered final when a letter of acceptance is issued by the city to the party responsible for the project.

H. No water meters shall be installed to any lot or building served by a project until final acceptance has been granted. (Ord. 743, 1997)

15.01.065 Fees.

A. Fees, charges or bonding requirements shall be as established by the city council by the passage of a resolution adopting a fee, charge, and bonding requirement schedule except where specifically set forth in the Langley Municipal Code (LMC). A copy of the fee schedule can be obtained at Langley City Hall. It is the applicant’s responsibility to verify that the fees in the schedule are current.

B. A plan check fee deposit is due at the time of plan submittal. Any balance due on the plan check fee is payable prior to release of the approved plans. Any excess deposit will be refunded to the applicant upon release of the approved plans.

C. After city approval of the plans and specifications, the public works director shall provide the applicant with an estimate of the utility construction inspection fee. A permit for construction will be issued after the inspection fees and estimated main connection charges have been deposited with the clerk-treasurer. At such time as the public works director determines the remaining funds are not adequate to provide necessary inspection for project completion, the applicant shall be notified of such, and an estimate of additional inspection fees required will be provided. The additional fees shall be deposited with the clerk-treasurer prior to depletion of the funds on deposit. Any moneys unexpended from the inspection deposit upon completion of the project shall be returned to the applicant.

D. In addition, there are various miscellaneous service and connection fees and charges. It is strongly urged that all applicants request an estimate of these fees and charges from the city’s public works department at the pre-application meeting. (Ord. 743, 1997)

15.01.070 Permits.

A. Before any person, firm or corporation shall commence or permit any other person, firm or corporation to commence any work to grade, pave, level, alter, construct, repair, remove, excavate or place any pavement, sidewalk, crosswalk, curb, driveway, gutter, drain, sewer, water, conduit, tank, vault, street banner or any other structure, utility or improvement located over, under or upon any public right-of-way or easement in the city of Langley, or place any structure, building, barricade, material, earth, gravel, rock, debris or any other material or thing tending to obstruct, damage, disturb, occupy, or interfere with the free use thereof or any improvement situated therein, or cause a dangerous condition, a right-of-way use permit shall be obtained. A separate permit shall be obtained for each separate project.

B. In the case of work contracted for by the department of public works, the signing of the contract shall constitute a right-of-way use permit.

C. Much of the work covered under these standards will require multiple permit authority review and approvals. Several types of permits and approvals require prior approval from the authority before a building or other permit can be issued. Any questions regarding information about permits, approvals and agreements should be directed to the land use coordinator.

D. The following general categories describe some of the permits, approvals and agreements, along with issuing permit/code authority identified in parentheses:

1. Environmental Review. For some projects, an environmental checklist must be completed by the applicant and submitted along with plans, specifications, and other information when approval or permits are being requested for a project. The planning official conducts the environmental review and issues a SEPA threshold determination for the city. An applicant should consult with the land use coordinator to determine if an environmental checklist is required.

2. Construction Permits.

a. A fill and grading permit (building department) is required for all significant tree alterations, including plats. A land clearing, fill and grading permit is typically issued separately. A strict inventory and landscaping plan is required for all land clearing and grading permits.

b. Building Permit (Building Department). A building permit is required for most construction work. Demolition permits for structures greater than 4,000 total square feet require the submittal of an environmental checklist.

c. Right-of-Way Use Permit (Public Works Department). A right-of-way use permit is required for any work within the right-of-way as outlined at the beginning of this chapter. Such work may include utilities work, lane closures, curbs, sidewalks, and haul routes. Permission to temporarily close a street or portion thereof for construction activities is obtained through the right-of-way use permit.

d. Access Permit (Public Works Department). An access permit is required prior to construction or alteration of any driveway or road approach onto a city street or road.

3. Approvals and Other Permits.

a. There are several other permits or approvals which may be required and referred to in these standards: site plan review, plat and short plat approvals, water service and side sewer permits, building permit and certificate of occupancy.

b. In addition, there are several other city approvals (land use) which may have to be obtained prior to the above listed permits and which may affect the standards as contained in this document, including reclassification, conditional use, planned residential development, planned unit development, shoreline substantial development permit, and design review board approval. This list is not meant to be all inclusive. Consult with the land use coordinator to determine exact permit requirements. (Amended during 2013 reformat; Ord. 743, 1997)

15.01.075 Performance and maintenance bonds.

Bonds or other allowable securities may be required by the city to guarantee the performance or maintenance of required work. The type and amount of security shall be per city code, or, if not specified, at the discretion of the city. Types of securities include but are not limited to a bond with a surety qualified to do a bonding business in this state, a cash deposit, an assigned savings account, or a set aside letter. The following are the most frequent bonds required:

A. Performance Bond. No building permit shall be issued until all public improvements are completed and final acceptance granted or, with the approval of the director of public works, the permittee or the contractor for the permittee may post a performance bond naming the city as obligee or a cash surety may be posted with the city in an amount equal to 115 percent of the cost of the public works improvements prior to issuance of a building permit. A certificate of occupancy shall not be issued until all public works improvements are completed in accordance with approved plans and accepted by the city.

B. Maintenance Bond. Prior to final public works approval of any major improvements, the permittee or the contractor for the permittee shall post with the city a maintenance bond warranting materials and workmanship, naming the city as obligee, or a cash surety for the guarantee of the public works improvements in an amount equal to 10 percent of the total cost of the improvements for a period of one year after the completed improvements are accepted by the city. (Ord. 743, 1997)

15.01.080 Utility locations.

A. Utilities as defined in Section 15.01.015, within a right-of-way or easement on new roads or in roadways where existing utilities are not in conflict, shall be located as shown in typical sections in the standard drawings. Where existing utilities are in place, new utilities shall conform to these standards as nearly as practical and yet be compatible with the existing installations. Deviations of location shall be approved by the director of public works. Existing utilities shall be shown using the best information available. This verification may require exploration/excavation (pot holing) by the developer, if utilities are in conflict with proposed design. A street use permit shall be required for any exploration/excavation in city right-of-way.

The contractor/developer shall be responsible for requesting utility locates in conjunction with their project.

B. All new private utilities located in existing right-of-way within an existing subdivision or on easements within a subdivision shall be installed underground by the utility owning said facility and new and existing facilities shall comply with provisions as set forth in these standards and as directed by the public works director. Easements for public utilities shall be as set forth in franchise agreements between the city and the utility.

C. A right-of-way use permit is required of any utility, except city owned facilities and utilities, who hold a franchise agreement with the city for any work done within the right-of-way, and shall comply with all provisions of these standards. (Ord. 743, 1997)

15.01.085 Easements.

A. Where city owned utilities and/or their conveyance systems cross private lands, an easement must be granted to the city. The city will generally process, record and file all easements on city initiated projects. The cost of recording and filing shall be paid by the developer. If the property is platted, the easement may be conveyed when the short plat or final plat is filed. All easements not shown on a plat must be prepared by a licensed land surveyor or engineering firm capable of performing such work.

B. Easement widths shall be a minimum of 20 feet for utilities. An easement as narrow as 15 feet may be allowed under special conditions as determined by the city engineer. Construction easements shall be 30 feet minimum in total width, including the permanent easement. When trench depths dictate or where pipe diameter or vault widths exceed four feet, a wider easement may be required by the city engineer.

C. Easements are required to be prepared by the applicant and submitted in draft, unsigned for review and approval prior to plan approval. Signed copies are required prior to final city acceptance of a project. Any change in design which places an amenity, i.e., water, sewer, sidewalk, etc., outside of the easement may necessitate stopping of construction until plans and easements can be resubmitted and approved. Plan review fee shall be based on the rate as established for third submittal fee. Easements will be recorded by the developer upon satisfactory completion of the work. (Ord. 743, 1997)

15.01.090 Latecomer agreement – New streets, street extensions, sewer, storm sewer and water main extensions and related improvements.

A. Purpose. This section is intended to implement and thereby make available to the city and the public the provisions of Chapters 35.72 and 35.91 RCW as presently constituted or as may be subsequently amended.

B. Application Authorized – Term. Any applicant (developer) utilizing private funds to install street, water, sewer (sanitary and/or storm) or other related improvements and appurtenances may apply to the city to establish a latecomer agreement for recovery of a pro rata share of the cost of constructing said public improvements from the owners of the other properties that will later derive a benefit from said improvements. No reimbursement agreement or latecomer agreement shall extend from a period longer than 15 years from the date of final acceptance by the city of the applicable public improvement. The city council shall have discretion to authorize or not to authorize latecomer agreements on a case-by-case basis.

C. Rights and Nonliability of City. The city reserves the right to refuse to enter into any latecomer agreement or to reject any application therefor at the city’s sole discretion. No latecomer agreement shall be legally effective until the city council adopts an ordinance approving the latecomer agreement at a public meeting of the city council. All applications for latecomer agreements shall be made on the basis that the applicant releases and waives any claims for any liability of the city in the establishment and enforcement of any latecomer agreements. The city shall not be responsible for locating any beneficiary or survivor entitled to benefits by or through latecomer agreements.

D. Application Requirements. All applications, procedures and policies for latecomer agreements shall be approved and established by the mayor or his/her designee, and shall be accompanied by all nonrefundable application fees set forth in the city’s land use fee schedule or in any fee schedule subsequently adopted by the city. The latecomer agreement application must be submitted for city review prior to city acceptance of the improvements for which reimbursement is sought.

E. Eligibility of Applicants. In order to be eligible to apply for a latecomer agreement, the applicant shall be in compliance with all city ordinances, rules and regulations relating to any development application or project associated with the proposed latecomer agreement.

F. Procedures for Latecomer Agreements.

1. The applicant (developer) proposing to establish a latecomer agreement shall submit a preliminary estimate and proposed reimbursement/benefit area (“benefited area”) boundaries as part of the engineering drawings submitted as part of the initial project application. Following utility/street installation/construction and city acceptance of same, the applicant (developer) requesting a latecomer agreement shall submit detailed construction plans and drawings for the project together with a site plan, map or diagram of the proposed benefited area which documents shall be prepared and stamped by a licensed professional civil engineer and which shall identify the proposed boundaries of the benefited area and each separately owned parcel of real property located within the benefited area and the location of the project in relation to all parcels of real property located within the benefited area, and an itemized cost estimate for the entire project based upon the plans of the civil engineer from which reimbursable costs shall be estimated, together with assessor’s reports (including names and mailing addresses) of all real properties within the benefited area, and such other information and documents as the city may require.

2. The applicant (developer) requesting a latecomer agreement shall submit, along with the application, the nonrefundable application fee set forth in the city’s land use fee schedule, which application fee shall be applied to the city’s legal, engineering and administrative costs in processing the application for the latecomer agreement, which costs shall be included as reimbursable costs in the latecomer agreement; provided, that whenever the city’s actual engineering, legal, administrative or other costs exceed the amount of the initial nonrefundable application fee, the applicant shall be required to pay to the city the estimated cost of said excess costs and the city shall not be obligated to continue to process the application until such costs have been paid to the city in full. In addition, the city will charge a 10 percent administrative fee for handling each transaction, said fee to be deducted from all latecomer fees collected.

3. The mayor or his designee will determine the boundaries of the benefited area based upon a determination of which parcels of real property are within the benefited area and which of such parcels will not contribute to the original cost of street and utility system improvements and who may subsequently connect to, drain to or use the same including uses connected to laterals or branches connecting thereto.

4. The mayor or his designee, based on information submitted by the applicant with the application for the latecomer agreement, will establish an estimate of the pro rata share of costs. The mayor or his designee may require the applicant to supply the city with engineering costs and/or competitive construction bids prior to the establishment of the estimate.

5. The mayor or his designee, at his/her discretion, shall have the right to require the applicant to pay, in advance, the costs of an appraiser retained by the city to assist the mayor or his designee in formulating the assessment reimbursement area and the estimate of the proration of costs.

6. Prior to the execution of a contract with the applicant for a latecomer agreement, the mayor or his designee shall deliver by certified mail a notice required by the applicable state law to all property owners within the benefited area stating the preliminary boundaries of the benefited area and pro rata share of assessments for costs of the project, and stating that each property owner has the right to request a public hearing to be held before the city council to consider the application for the latecomer agreement, including the preliminary boundary of the benefited area and preliminary assessment of costs to the affected property owners. If no hearing is requested, the city council may consider and take final action on the latecomer agreement at any public meeting held more than 20 days after notice was mailed to the affected property owners. If the city receives a request for a public hearing, a public hearing will be held by the city council thereafter, with notice of the public hearing given to all affected property owners at least 20 days in advance of the hearing. At the hearing, the city council shall determine whether to accept, reject or modify the proposed latecomer agreement, or any provision thereof, including but not limited to the boundaries or proration of costs. If the city council accepts the latecomer agreement, the council shall establish the boundaries of the benefited area; provided, that the city council may only modify the boundary of the benefited area upon prior notice to the owners of the property affected by the modification. The decision of the city council shall be final and determinative.

7. The latecomer agreement shall have no legal effect and shall be null and void unless it is recorded with the Island County auditor within 30 days of the final execution of the agreement. It shall be the sole responsibility of the applicant for the latecomer agreement to record said agreement at his expense.

8. Once recorded, the latecomer agreement shall be binding on all owners of record of all real properties located within the benefited area who are not party to the latecomer agreement.

9. The city shall neither issue a building permit or similar development permit or approval nor grant permission to use water or sewer service unless the city has received full payment of the assessment applicable to the property connecting to or using the street and/or utility system improvements constructed by the applicant (developer); provided, if the validity of the latecomer agreement is challenged, the city reserves the right to issue a permit, approval or permission without liability or prejudice to the city, and without prejudice to any other rights or remedies available to the applicant (developer) under this section or otherwise at law or in equity.

G. Segregation. The public works director shall, upon the request of any property owner within the benefited area, segregate the assessment among portions of a particular parcel that is legally subdivided. The segregation shall be based upon the same factors applied when the assessments were originally established. The property owner seeking segregation of the assessment shall pay all costs to record the segregation as well as an administrative fee to the city based upon a segregation fee schedule to be established by the city from time to time. (Ord. 874, 2006; Ord. 820, 2002; Ord. 743, 1997)

15.01.100 Traffic control.

A. The developer/contractor shall be responsible for interim traffic control during construction on or along traveled roadways. Traffic control shall follow the guidelines of the WSDOT/APWA Standard Specifications. All barricades, signs and flagging shall conform to the requirements of the Manual on Uniform Traffic Control Devices (MUTCD).

City utilities constructed within Island County right-of-way shall follow all traffic control requirements as set forth by Island County department of public works and MUTCD. The contractor/developer shall be responsible for obtaining any required county permits.

Signs must be legible and visible and shall be removed or covered at the end of each work day if not applicable after construction hours.

B. Road closures will not be allowed in normal circumstances. One lane of travel is to remain open to traffic at all times. When road closures and detours can not be avoided, the contractor/developer shall notify the public works director 48 hours in advance. The city may require a detour plan to be prepared, submitted and approved prior to closing any portion of a city roadway.

C. A right-of-way use permit shall be required before work in the right-of-way can commence. See requirements in Sections 15.01.070 and 15.01.075 and contact the department of public works for specific permit information. (Ord. 743, 1997)

15.01.105 Call before you dig.

All developers/contractors are responsible for timely notification of all utilities in advance of any construction in right-of-way or utility easements. The utilities one-call Underground Location Center phone number is 1-800-424-5555. (Ord. 743, 1997)

15.01.110 Sanitary sewer system – General.

A. Sanitary sewerage refers to waste water derived from domestic, commercial and industrial pretreated waste to which storm, surface, and ground water are not intentionally admitted. Pre-treatment shall follow all the requirements as set forth by Washington State Department of Ecology (DOE) and the Langley Municipal Code.

B. Any extension of Langley’s sanitary sewer system must be approved by the department of public works and must conform to the city of Langley comprehensive sanitary sewer plan, Department of Ecology (DOE), and Department of Health (DOH) requirements.

C. New construction within the corporate city limits is required to connect to the city sewer system as outlined in Title 18 and Ordinance 696 as they currently read or are hereafter amended.

D. Anyone who wishes to extend or connect to the city’s sewer system should contact the department of public works for a sewer extension/connection fee estimate of the costs due the city for a sewer extension or connection.

E. Prior to the release of any water meters, or occupancy, all public works improvements must be completed, approved, as-built drawings submitted to the city and all applicable fees must be paid.

F. See Section 15.01.015 for definitions of specific sewers. Maintenance of the side sewer, from the main line tee to the building, shall be the responsibility of the property owner. (Ord. 743, 1997)

15.01.115 Marking side sewers.

If curbs are present, the location of all side sewers shall be marked on the face or top of the cement concrete curb with an “S” one-quarter inch into concrete. (Ord. 743, 1997)

15.01.120 Sanitary sewer/water main separation.

See Section 15.01.370 for requirements regarding sewer and water separation. (Ord. 743, 1997)

15.01.125 Staking.

A. All surveying and staking shall be performed by an engineering or surveying firm capable of performing such work. The engineer or surveyor directing such work shall be licensed as such by the state of Washington.

B. A pre-construction meeting shall be held with the city prior to commencing staking. All construction staking shall be inspected by the city prior to construction.

C. The minimum staking of sewer lines shall be as directed by the city engineer or as follows:

1. Stake location of mainline pipe and laterals every 50 feet with cut to invert of pipe.

2. Stake location of all manholes for alignment and grade with cut or fill to rim and invert of pipes. (Ord. 743, 1997)

15.01.130 Trench excavation.

See Section 15.01.385 for requirements regarding trench excavation. (Ord. 743, 1997)

15.01.135 Backfilling.

See Section 15.01.395 for requirements regarding backfilling. (Ord. 743, 1997)

15.01.140 Street patching and restoration.

See Sections 15.01.540 and 15.01.545 for requirements regarding street patching and trench restoration. (Ord. 743, 1997)

15.01.145 Testing.

Prior to acceptance and approval of construction, the following tests shall apply to each type of construction:

A. Gravity Sewer.

1. Prior to acceptance of the project, the gravity sewer pipe shall be subject to a low pressure air test per WSDOT/APWA Standards. The contractor shall furnish all equipment and personnel for conducting the test under the observation of the city inspector. The testing equipment shall be subject to the approval of the city.

The contractor shall make an air test for his own purposes prior to notifying the city to witness the test. The acceptance air test shall be made after trench is backfilled and compacted and the roadway section is completed to subgrade. The developer shall be responsible for paying city costs for inspections as set by council resolution.

All wyes, tees, and ends of side sewer stubs shall be plugged with flexible joint caps, or acceptable alternates, securely fastened to withstand the internal test pressures. Such plugs or caps shall be readily removable and their removal shall provide a socket suitable for making a flexible jointed lateral connection or extension. Immediately following the pipe cleaning, the pipe installation shall be tested with low pressure air.

2. Testing of the sewer main shall include a television inspection by the contractor. Television inspection shall be done after the air test has passed and before the roadway is paved. Immediately prior to a television inspection, enough water shall be run down the line so it comes out the lower manhole. A copy of the video tape and written report shall be submitted to the city. Acceptance of the line will be made after the tape has been reviewed and approved by the inspector.

3. A water test of all manholes may also be required. The water test shall be made by the contractor first by filling the manhole up with water and letting it sit for 24 hours to allow the water to saturate the concrete. After 24 hours the manhole shall be filled to the top of the cone. The water cannot drop more than 0.05 gallons in 15 minutes per foot of head above invert to pass. Upon completion of the water test, the water shall be pumped out of the manhole and not allowed to be released to the system.

4. A mandrel test may be required on all mainline sewers as defined in Section 15.01.015.

B. Force Main.

1. Prior to acceptance of the project, the pressure line and service lines shall be subjected to a hydrostatic pressure test of 200 pounds for four hours and any leaks or imperfections developing under said pressure shall be remedied by the contractor. No air will be allowed in the line. The main shall be tested between valves. Insofar as possible, no hydrostatic pressure shall be placed against the opposite side of the valve being tested. The pressure test shall be maintained while the entire installation is inspected.

The contractor shall provide all necessary equipment and shall perform all work connected with the tests. Tests shall be made after all connections have been made. This is to include any and all connections as shown on the plan. The contractor shall perform all tests to assure that the equipment to be used for the test is adequate and in good operating condition and the air in the line has been released before requesting the city to witness the test.

2. A water test for all wet wells in accordance with the manhole water test for gravity sewer shall be required.

3. A mandrel test in accordance with Section 7-17.3(2)G of the Standard Specifications is required.

4. Pump operation, alarms, and electrical inspection of all lift stations is required. (Ord. 743, 1997)

15.01.150 Gravity sewer – General.

All sewers shall be designed as a gravity sewer whenever physically feasible or as outlined in the comprehensive sanitary sewer plan. (Ord. 743, 1997)

15.01.155 Design standards.

A. The design of any sewer extension/connection shall conform to city standards, Department of Ecology’s “Criteria of Sewage Works Design,” and any applicable standards as set forth herein and in Sections 15.01.025 and 15.01.040.

B. The layout of extensions shall provide for the future continuation of the existing system as determined by the city.

C. Sewer systems shall be designed to current Department of Ecology standards.

D. The city of Langley general notes on sewer installation shall be included on any plans dealing with sanitary sewer design. (Ord. 743, 1997)

15.01.160 Main line – Gravity.

A. Size. Sewer mains shall be sized for the ultimate development of the tributary area. Nothing shall preclude the city from requiring the installation of a larger sized main if the city determines a larger size is needed to meet the requirements for future service.

The minimum size for submains and mains shall be eight-inch inside diameter. The minimum size for a side sewer in the right-of-way (from the sewer main to the property line) shall be six inches. See definitions in Section 15.01.015.

A. Six-inch diameter lateral is required for all commercial or general business applications or for multifamily connections. The design is subject to all other design requirements as noted in this chapter.

B. Material. Sewer main shall be PVC, ASTM D 3034, SDR 35 with joints and rubber gaskets conforming to ASTM D 3212 and ASTM F 477.

C. Depth. Gravity sewer will typically have a minimum cover of five feet to provide gravity service to adjoining parcels, adequate head room within manholes for maintenance personnel and vertical clearance between water and sewer lines. Actual depth will be determined by slope, flow, velocity and elevation of existing system.

D. All building sewer connections to the main shall be made with a wye connection. All new mains connecting to existing mains shall require the installation of a new manhole if the connection is not made at an existing manhole. If a new connection is made at an existing manhole, the manhole shall be re-channeled per city standards and specifications. (Ord. 743, 1997)

15.01.165 Connection to existing system.

A. At connection to existing system, all new sewer connections shall be physically plugged until all tests have been completed and the city approves the removal of the plug.

B. Connection of new pipelines to existing manholes shall be accomplished by using provided knock outs. Where knock outs are not available, the manhole shall be core drilled for connection. The transition of connecting channels shall be constructed so as not to interrupt existing flow patterns.

C. Connection of a pipeline to a system where a manhole is not available shall be accomplished by pouring a concrete base and setting manhole sections. The existing pipe shall not be cut into until approval is received from the city.

D. Connections to manholes requiring a drop shall follow the criteria as outlined in Section 15.01.190.

E. Connections where a new building sewer is the same size as the existing main shall be accomplished by the installation of a new manhole.

F. Taps shall not be allowed to protrude into the existing main. A city inspector shall be notified 48 hours prior to any tap of a city sewer. A city inspector shall be present to witness the tap. (Ord. 743, 1997)

15.01.170 Manholes.

A. Precast manholes shall meet the requirements of ASTM C 478 with either a precast base or a cast in place base made from 3,000 psi structural concrete. Manholes shall be Type 1, 48-inch diameter minimum. The minimum clear opening in the manhole frame shall be 24 inches. Joints shall be rubber gasketed conforming to ASTM C 443 and shall be grouted from the inside. Lift holes shall be grouted from the outside and inside of the manhole. Manholes constructed of other materials may be approved by the city engineer, provided they meet the requirements of Section 2.318 of the Department of Ecology’s “Criteria for Sewage Works Design.” Material specifications need to be submitted for review before an alternate material will be considered.

B. Eccentric manhole cone shall be offset so as not to be located in the tire track of a traveled lane.

C. Manhole frames and covers shall be cast iron casting marked “Sewer” conforming to the requirements of ASTM A 30, Class 25, and shall be free of porosity, shrink cavities, cold shuts or cracks, or any surface defects which would impair serviceability. Repairs of defects by welding or by the use of smooth on or similar material will not be permitted. Manhole rings and covers shall be machine finished or ground on seating surfaces so as to assure nonrocking fit in any position and interchangeability. Manholes located in areas subject to inflow shall be equipped with a PRECO sewer guard watertight manhole insert or approved equal.

D. Where lock type castings are called for, the casting device shall be such that the cover may be readily released from the ring and all movable parts shall be made of noncorrosive materials and otherwise arranged to avoid possible binding.

E. All castings shall be coated with a bituminous coating prior to delivery to the job site.

F. Safety steps shall be fabricated of polypropylene conforming to an ASTM D 4101 specification, injection molded around a one-half inch ASTM A 615 grade 60 steel reinforcing bar with anti-slip tread. Steps shall project uniformly from the inside wall of the manhole. Steps shall be installed to form a continuous vertical ladder with rungs equally spaced on 12-inch centers.

G. Gravity sewers shall be designed with straight alignment between manholes.

H. Manholes shall be provided at a maximum of 300-foot intervals where six-inch sewer is allowed, 400-foot intervals for eight-inch to 15-inch sewers, 500-foot intervals for 18-inch to 30-inch sewers, at intersections, and at changes in direction, grade or pipe size. (See also Section 15.01.180.) Greater spacing may be permitted in larger sewers.

I. Minimum slope through the manhole shall be one-tenth of one foot from invert in to invert out.

J. Manhole sizing shall be determined by the following criteria:

1. Forty-Eight-Inch Manhole.

a. Two connecting pipes, eight-inch to 12-inch diameter.

b. Three connecting pipes, eight-inch to 10-inch diameter, perpendicular.

c. Four connecting pipes, eight-inch diameter, perpendicular.

2. Fifty-Four-Inch Manhole.

a. Two connecting pipes, eight-inch to 12-inch with more than 45 degrees deflection.

b. Three connecting pipes, 10-inch to 12-inch diameter, perpendicular.

c. Four connecting pipes, 10-inch to 12-inch diameter, perpendicular.

3. Seventy-Two-Inch Manhole.

a. Two connecting pipes, 15-inch to 18-inch diameter with less than 45 degrees deflection.

b. Three connecting pipes, 15-inch diameter, perpendicular.

c. Four connecting pipes, 15-inch diameter, perpendicular.

4. In the above criteria “deflection” refers to the angle between any two pipe channels in the manhole. For other pipe configurations, the size of the manhole shall be approved by the city. The above configurations will provide adequate shelves and room for maintenance and performing TV inspections. (Ord. 743, 1997)

15.01.175 Slope.

A. All sewers shall be designed and constructed to give mean velocities, when flowing full, of not less than 2.0 feet per second based on Manning’s formula using an “n” value of 0.013. Use of other practical “n” values may be permitted by the city if deemed justifiable on the basis of research or field data submitted. The following minimum slopes should be provided; however, slopes greater than these are desirable.


Sewer Size (Inches)	Minimum % Slope
	% (Feet per 100')
6	1.00 (0.0100 Ft/Ft)
8	0.40 (0.0040 Ft/Ft)
10	0.28 (0.0028 Ft/Ft)
12	0.22 (0.0022 Ft/Ft)
14	0.17 (0.0017 Ft/Ft)
15	0.15 (0.0015 Ft/Ft)
16	0.14 (0.0014 Ft/Ft)
18	0.12 (0.0012 Ft/Ft)
21	0.10 (0.0010 Ft/Ft)
24	0.08 (0.0008 Ft/Ft)
27	0.07 (0.0007 Ft/Ft)
30	0.06 (0.0006 Ft/Ft)
36	0.05 (0.0005 Ft/Ft)

B. Under special conditions, slopes slightly less than those required for the 2.0 feet per second velocity may be permitted by the city engineer. Such decreased slopes will only be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. Whenever such decreased slopes are proposed, the design engineer shall furnish with the plans his computations of the depths of flow in such pipes at minimum, average, and daily or hourly rates of flow. Larger pipe size shall not be allowed to achieve lesser slopes.

C. Sewers shall be laid straight and true with uniform slope between manholes. (Ord. 743, 1997)

15.01.180 Increasing size.

A. Manholes shall be provided where pipe size changes occur.

B. Where a smaller sewer joins a larger one, the invert of the larger sewer should be lowered sufficiently to maintain the same energy gradient. An approximate method for securing these results is to place the 0.8 depth point of both sewers at the same elevation. (Ord. 743, 1997)

15.01.185 High velocity protection.

Where velocities greater than 15 feet per second are expected, special provisions such as thrust blocking and piping materials shall be made to protect against displacement by erosion and shock. (Ord. 743, 1997)

15.01.190 Drops.

A. Straight grades between invert out of last manhole and connection to existing are preferred over drops whenever possible. Care must be taken when designing steep grades or sweeps so as not to create a situation of excessive velocity. Grade changes associated with “sweeps” shall not be allowed unless otherwise approved by the city engineer.

B. An outside drop connection shall be provided for a sewer entering a manhole at an elevation of 24 inches or more above the manhole invert. Where the difference in elevation between the incoming sewer and the manhole invert is less than 24 inches, the invert shall be filleted to prevent solids deposition. Outside drop structures shall be constructed per city of Langley standard drawings.

C. Inside drop connections will not be allowed. (Ord. 743, 1997)

15.01.195 Cleanouts.

A. Cleanouts are not an acceptable substitute for manholes. A manhole shall be installed at the end of any public sewer extension.

B. Location of cleanout for building sewer is governed by the Uniform Plumbing Code as adopted by the Langley Municipal Code.

C. All cleanouts in city right-of-way shall be extended to grade and have a cast iron ring and cover. A three-foot-square by four-inch concrete pad shall be installed around all cleanouts that are not in a pavement area. The concrete pad shall be sloped to drain away from the cleanout. (Ord. 743, 1997)

15.01.200 Side sewer.

A side sewer refers to the extension from a building sewer beginning two feet outside the outer foundation wall at the structure to the sanitary sewer main. Side sewers from the sewer main to the right-of-way line shall be minimum six-inch diameter on single-family residences, multifamily and commercial buildings. Side sewers from the right-of-way line to the building shall be minimum four-inch for single-family residential and six-inch for multifamily and commercial buildings. Minimum slope shall be two percent on four-inch side sewers and one percent on six-inch side sewers. Maintenance of the side sewer is the responsibility of the property owner. Prior to connection of a side sewer to the public sewer a side sewer permit must be obtained from the city. Materials and design criteria for a side sewer are covered by the Uniform Plumbing Code (UPC) as adopted by the city of Langley. Inspection of the side sewer installation and test will be done by the public works department inspector. Testing shall be performed by the contractor. The side sewer test shall consist of either a water or air test at four psi for 15 minutes. It is the contractor’s responsibility to contact the city 24 hours in advance of test. (Ord. 743, 1997)

15.01.205 Lift stations – General.

All lift stations will be designed to serve the appropriate basin as identified in the Langley comprehensive sanitary sewer plan. (Ord. 743, 1997)

15.01.210 Design standards.

A. The design of any lift station shall conform to city standards, the Department of Ecology’s “Criteria of Sewage Works Design” and applicable standards as set forth herein and in Sections 15.01.025 and 15.01.040. In addition, the plans shall include the following:

1. An overall site drawing of the lift station showing the location of all components including elevations;

2. Service size, voltage and enclosure type and location in relation to the pump station;

3. A list of specific materials used including quantity, description and manufacturer name;

4. A schematic and line diagram of the service and motor control center and lift station;

5. The electrical shall be designed to meet state and local electrical code requirements;

6. All applicable telemetry installation with schematics; and

7. An operation and maintenance manual from the lift station manufacturer shall be supplied.

8. A lift station emergency bypass connection shall be installed.

B. A design report shall be submitted with each lift station demonstrating conformance with the standards as outlined above and shall address the following items:

1. Pump Data.

a. Size and type (no variable speed pumps allowed);

b. Horsepower;

c. Pump curves;

d. Head capacity;

e. Velocity.

2. Motor.

a. Size and type;

b. Cycle length;

c. Type of mount.

3. Controls: type.

4. Telemetry: alarm system (must be compatible with city system).

5. Housing.

a. Size and type;

b. Ventilation;

c. Humidity control;

d. Interior lighting;

e. Access.

6. Auxiliary power: provision for connection required of all lift stations and may be required to furnish auxiliary generator at the direction of the city.

7. Well Sizing.

a. Type;

b. Storage capacity.

8. Maintenance.

a. Warranty;

b. Tools and equipment required.

9. Electrical Service.

a. Size and type;

b. Source.

10. Corrosion Protection.

a. Type of materials;

b. Coatings;

c. Linings;

d. Maintenance.

11. Site layout: location of lift station on property, right-of-way or easement.

12. Testing.

a. Operational;

b. Pressure.

13. Piping and Valves.

a. Size and type;

b. Bypass.

See Sections 15.01.215 through 15.01.250, Pressure Sewer, for additional information regarding force mains. (Ord. 743, 1997)

15.01.215 Pressure sewer (force main) – General.

Low pressure systems, i.e., force mains, may be considered for situations where high ground water table or topography makes gravity sewer impractical. (Ord. 743, 1997)

15.01.220 Design standards.

A. The design of any sewer extension/connection shall conform to city standards, the Department of Ecology’s “Criteria of Sewage Works Design,” and any applicable standards as set forth herein and in Sections 15.01.025 and 15.01.040.

B. The layout of extensions shall provide for the future continuation of the existing system as determined by the city. In addition, main extensions shall be extended through the side of the affected property fronting the main.

C. The system shall be designed at full depth of flow on the basis of an average daily per capita flow. A friction factor of 0.013 shall be used for Manning’s “n” value.

D. New sewer systems shall be designed by methods in conjunction with the basis of per capita flow rates. Methods shall include the use of peaking factors for the contributing area, allowances for future commercial areas, and modification of per capita flow rates based on specific data. Documentation of the alternative method used shall be provided along with plans.

E. The applicable general notes shall be included on any plans dealing with pressure sanitary sewer design. (Ord. 743, 1997)

15.01.225 Force main.

A. Material. Force mains for sizes up to 12 inches shall be ductile iron AWWA C151 Class 50 or PVC C900 with ductile iron fittings and gasketed joints. For 14- to 24-inch mains, pipe shall be ductile iron AWWA C151 Class 50 or PVC C905 with ductile iron fittings and gasketed joints. A more rigid pipe may be required where unlimited trench widths occur. All ductile iron pipe and fittings shall be epoxy coated or PE lined and designed for use with corrosive materials.

B. Depth. Force mains shall have a minimum 36 inches of cover to top of pipe. See Section 15.01.370 for sanitary sewer/water main separation requirements.

C. Velocity. The minimum velocity allowed is two feet per second (fps) at average dry weather flow. Two fps is required to maintain solids in suspension although three fps is desired to scour settled solids. Maximum velocity allowed shall be eight fps. (Ord. 743, 1997)

15.01.230 Surge protection.

PVC is subject to fatigue failure due to cyclic surge pressures. Systems utilizing PVC pipe materials shall be constructed to minimize rapid changes in velocities and a properly sized surge tank provided. (Ord. 743, 1997)

15.01.235 Air/vacuum valves.

Air release valves and air/vacuum valves shall be located at the high points of the line within a standard 48-inch manhole or a comparable sized, approved vault. Air release valves shall be fitted with an activated carbon canister to absorb compounds with disagreeable odors prior to releasing the air to the surrounding area. Grades shall be designed to minimize the need for air/vacuum valves when practical. Vehicular access to valve is required for maintenance. (Ord. 743, 1997)

15.01.240 Force main drain.

Provisions to drain a force main to facilitate repairs or to temporarily remove force main from service shall be provided. This may be accomplished through the use of a valved tee connected to a drain line at the low point of the line. A manhole shall be set over the force main at the valved tee. (Ord. 743, 1997)

15.01.245 Thrust blocking.

A. Location of thrust blocking shall be shown on plans. Thrust block concrete shall be poured against undisturbed earth. A plastic barrier shall be placed between all thrust blocks and fittings.

B. Designed and approved restraining joint systems may be allowed in lieu of thrust blocking. Restraining joint brand, type, and size shall be specified on the plans. (Ord. 743, 1997)

15.01.250 Force main termination.

Hydrogen sulfide odors (H2S) and the buildup of sulfuric acid (H2SO4) occur in the operation of a force main. To mitigate these conditions some type of control method(s) shall be used. This may include chemical addition at the pump station and/or the re-aeration of the waste water at or near the terminus. Re-aeration may include the following:

A. Construction of a vault housing an aspiration assembly.

B. The use of hydraulic fall (vertical siphon) within the terminal manhole.

C. High velocity discharge with smooth transition so as to not cause splashing of force main into the down stream gravity sewer.

These methods all require an adequate source of fresh air at the vault or manhole. At a minimum, the manhole at the terminus and the first manhole downstream of the terminus shall be coated with Tnemic 120 vinyl ester, Quantum polymorphic resin or approved equal which is resistant to sulfuric acid and hydrogen sulfide. (Ord. 743, 1997)

STEP System

15.01.255 General.

A septic tank effluent pump (STEP) system may be installed, when approved by the city, to serve residential and light commercial locations where allowed by Chapter 13.50. A STEP application with a proposed site plan is required for each individual onsite system. A STEP application may be obtained from the public works department.

A STEP system is a facility consisting of a tank or tanks for settling and digesting wastewater solids, and a pressure piping system for conveying the supernatant liquid into the sewer system.

Only sanitary wastewater shall be discharged into the tank. Roof drains and other stormwater sources shall be strictly excluded.

The installer shall be responsible for providing an as-built drawing for the entire system.

Power shall be provided by the customer. The customer shall be responsible for notifying the city when the control panel alarm buzzer is activated. All sewer pipe, drains and plumbing between the tank and the building shall be the responsibility of the customer. The customer shall be responsible for curtailing water usage until city forces respond to the customer’s notification. The city will accept no responsibility for damages resulting from a plumbing backup, such as may occur if water usage is not curtailed during an alarm condition or if the customer disables the alarm.

The specifications for a STEP system must be submitted to the city for review and approval. (Ord. 749, 1997)

15.01.260 Design standards.

The design of any STEP sewer system shall conform to city standards and any applicable standards as set forth herein and in Sections 15.01.025 and 15.01.040.

The layout of STEP system mains shall not interfere with the continuation of the sewer system as outlined in the city of Langley comprehensive sewer plan.

Pump and pipeline sizing shall conform to the criteria as set forth in the Langley comprehensive sanitary sewer plan, most current edition, and Department of Ecology standards.

The applicable general notes shall be included on any plans dealing with pressure sanitary sewer design. (Ord. 749, 1997)

15.01.262 Pipe.

A. Mainline. The minimum pipe size allowed is two-inch inside diameter. This is based on maintenance requirements rather than flow. Pipe shall be PVC Class 200, Schedule 80 PVC or ASTM D 2241, SDR 21 with rubber gasketed joints. Gaskets shall comply with ASTM D 1869. STEP mains shall have a minimum 36 inches of cover to top of pipe. See Section 15.01.370 and DOE criteria for sewage works design G1-1.4(D) for sanitary sewer/water main crossing requirements.

B. Service Line. Service connection pipe shall be minimum one-inch diameter, Schedule 40 PVC water pipe, solvent weld joint located at 90 degrees to the mainline unless otherwise approved by the city. Solvent cements and primer for joining PVC pipe and fittings shall comply with ASTM D 2564 and shall be used as recommended by the pipe and fitting manufacturers. Services shall have a minimum 24 inches cover to top of pipe. Pressure services crossing over any water line shall follow DOE requirements.

C. Building Sewer. The gravity building sewer between the building and the tank shall be designed and installed in accordance with the Uniform Plumbing Code as adopted in the Langley Municipal Code.

D. All pipe shall be installed with continuous tracer tape installed 12 to 18 inches under the proposed finished grade. The marker tape shall be plastic, nonbiodegradable, metal core or backing which can be detected by a standard metal detector. Tape shall be Terra Tape “D” or approved equal. In addition to tracer tape, install 14-gauge coated copper wire, wrapped around the pipe, brought up and tied off at the valve boxes. (Amended during 2013 reformat; Ord. 749, 1997)

15.01.264 Fittings.

All pipe fittings shall have a minimum working pressure rating equal to the pipe with which they are connected. Fittings shall be PVC 1120, rubber joint complying with ASTM D 1784, D 2466, or D 2467, for pipe larger than one inch. Solvent weld fittings for one-inch pipe shall be socket type Schedule 40 and shall comply with ASTM D 1784 and ASTM D 2466. (Ord. 749, 1997)

15.01.266 Valves.

A. Ball and Gate Valves. All valves from one to three inches shall be PVC ball valves with preloaded EPDM stem seals, microfinished PVC ball and self adjusting polyethylene ball seat to compensate for wear and prevent over tightening. Valves shall be designed for use with corrosive fluids, for low torque manual operation, and for a working pressure of 150 psi. One- or two-inch valves shall be LT-1000-S or LT-2000-S as manufactured by KBI (King Brothers Industries) or GF500 as manufactured by George Fisher Signet, Inc. Three-inch valves shall be BTU-3000-E as manufactured by KBI or GF346 as manufactured by George Fisher Signet, Inc.

Valves four to 12 inches shall be resilient wedge gate M&H style 820 or Waterous Series 500 plug valves with an epoxy coating to resist corrosion. A ball or gate valve shall be located at every intersection and at a maximum of every 500 feet. Valves may be installed in conjunction with required pigging ports.

B. Air/Vacuum Valves. Air release valves and air/vacuum valves shall be located at the high points of the line. Profiles for each pipe run shall be submitted with the hydraulic gradeline for both static and dynamic flow conditions to show where the critical points are for air release valves. Vehicular access to air/vacuum valves is required for maintenance.

Because the air released by these valves will contain hydrogen sulfide, the valves and their enclosures shall be constructed of corrosion resistant materials. The valve vaults shall have insulated lids to prevent freezing. Vents shall be equipped with an odor control system such as activated carbon filters impregnated with sodium hydroxide.

C. Check Valves. Check valves used on service lines shall be a tee or wye pattern swing check, PVC, with a working pressure of 150 psi. Valves shall be designed for use with corrosive fluids. A check valve shall be installed at the end of the service stub-out at the property line to be installed in a valve box located at the center of the lot. Check valves shall be King Brothers, KSC or approved equal.

D. Pressure Sustaining Valve Assembly. Pressure sustaining valves are sometimes required in the design of STEP systems to keep the pipeline full during periods of low or no flow or when siphoning conditions exist.

E. Valve Box Lids. Valve box lids shall be specified to be marked with “SEWER” so they can quickly be distinguished from valves in the water system.

All service connect boxes shall be Carson Model 1419 with hinged bolt down cover and 1419E extension box as required, or approved equal. (Ord. 749, 1997)

15.01.268 Pigging ports.

A pipeline pig is a projectile that is forced through the inside of a pipe to clean pressure pipelines. A pigging port is used as a point to send or retrieve the pig.

Pigging ports may be required:

A. At every change in pipeline size;

B. At the end of every dead-end line;

C. No farther than every 3,000 feet.

These locations are subject to review and approval by the city. (Ord. 749, 1997)

15.01.270 Septic tank.

Approved STEP tanks are as follows: 1,000 gallon, Evergreen Precast and Northwest Cascade, Inc.; 1,200 gallon, Central Reddi-mix, Inc.; and 1,700 gallon, Evergreen Precast.

Tanks for single-family residential use shall be rectangular, 1,000-gallon precast concrete, single chamber, and shall have been designed by a registered structural engineer. Fiberglass or polyethylene tanks shall not be allowed. Dual chamber tanks may be allowed in certain instances as approved by the director of public works. All tanks shall be manufactured for acceptance of pump assemblies or effluent filters and have a precast groove one inch wide by one-half inch deep, 24 inches in diameter to allow positive attachment of the riser. The manufacturer shall provide the structural design and certification to the city for review. The design or analysis shall be in accordance with accepted engineering practice. Tanks up to four feet in depth shall be designed for the following loading conditions:

A. Top of tank 400 pounds per square foot.

B. Lateral load of 62.4 pounds per square foot.

C. The tank shall be designed to support a 2,500-pound wheel load.

D. The tank shall be designed to withstand hydrostatic loading equal to the maximum depth of bury, in addition to the soil loading. Maximum depth of bury shall be measured from the ground elevation to the invert of the sewer line entering the tank.

Deeper installations, if required by local conditions, will require special consideration, as will tanks located where a vehicle might be driven over them. Tanks approved as traffic bearing tanks shall be designed to withstand an H-20 live load with a minimum soil cover of 18 inches.

All tanks shall be guaranteed in writing by the tank manufacturer for a period of two years from the date of delivery to the project. Manufacturer’s signed guarantee shall accompany delivery.

Systems installed on a site where an existing septic tank exists may use the existing tank if it meets DOH and/or city requirements.

Concrete material and construction shall meet the requirements of section 6-02 of the WSDOT/APWA Standard Specifications for Road, Bridge, and Municipal Construction, most current edition.

Walls, bottom and top of reinforced concrete tanks shall be designed across the shortest dimension using one-way slab analysis. Stresses in each face of monolithically constructed tanks may be determined by analyzing the tank cross section as a continuous fixed frame. The walls and bottom slab shall be poured monolithically. Concrete shall achieve a minimum compressive strength of 5,000 psi in 28 days.

Reinforcing steel shall be ASTM A 615, Grade 60, fy = 60,000 psi. Details and placement shall be in accordance with ACI 315 and ACI 318.

The concrete mix shall not be modified unless the mix design is reviewed and approved by the city.

Tanks shall be protected by applying a heavy cement-base waterproof coating, Thoroseal or equal, on both inside and outside surfaces.

Tanks shall be manufactured and furnished with 18-inch diameter access openings of the size and configuration shown on the standard drawings. Modification of completed or existing tanks will not be permitted for structural, warranty, and liability reasons. Tanks shall be furnished without concrete access hole lids. In order to demonstrate watertightness, tanks shall be tested prior to acceptance. Each tank shall be tested at the factory, by filling with water to the base of the riser and letting stand. After 24 hours, the tank shall be refilled to the soffit and the exfiltration rate shall be determined by measuring the water loss during the next two hours. The two-hour water loss shall not exceed one gallon.

Tanks shall not be moved from the manufacturing site to the job site until the tank has cured for seven days and has reached two-thirds of the design strength.

Tanks shall be bedded on six inches sand or pea gravel. Sides shall be compacted in two-foot lifts to the same or greater density than the surrounding area.

After the tanks have been set in place and the riser installed, but prior to backfilling, each tank shall be tested by filling the tank to two inches above the base of the riser for a two-hour period. Water loss shall not exceed one gallon.

Tanks installed where ground water levels are above tank bottom require precautions to prevent flotation. In general, tanks shall immediately be filled with water and shall not be pumped down more than three feet below top of tank.

Tank excavation shall be backfilled with select material free of boulders and compacted to a dry density equal to or greater than that of the adjacent, undisturbed soil. City inspection shall be required of the backfill and compaction of any tank that is abandoned in place. Finish grading, cleanup, and restoration shall be completed prior to final acceptance by the city. (Ord. 749, 1997)

15.01.272 Tank riser.

Outlet risers shall be fiberglass or ribbed PVC as manufactured by Orenco Systems, Inc., 2826 Colonial Road, Roseburg, Oregon 97470, or approved equal. Outlet riser shall be a minimum of 18 inches high or as otherwise shown on the engineering drawings, and have a diameter of 24 inches. Outlet risers shall be factory equipped with the following:

A. Two one-inch or one one-quarter-inch diameter (IPS) neoprene grommets, one for the pump discharge, installed no less than eight inches from the top of the riser and one for the splice box conduit.

B. A PVC splice box, with four cord grips and one-inch outlet fitting, Orenco Model No. SB4i or approved equal.

A lid shall be furnished with each riser. It shall be latching and shall be constructed of fiberglass with an aggregate finish. Riser and lid combination shall be able to support a 2,500-pound wheel load. PVC risers are not allowed in traffic areas.

Each riser shall be bonded to the top of the concrete tank with a two-part epoxy that shall be supplied with the riser by the manufacturer. The epoxy shall be applied in accordance with the manufacturer’s recommendations. A generous bead of epoxy shall be laid completely around the bottom of the riser prior to mounting the riser on the top of the tank. After the riser is in place, a generous fillet shall be run completely around the inside base. The epoxy shall be allowed four hours curing time at 64 degrees Fahrenheit; otherwise a greater time shall be allowed based on the manufacturer’s recommendations before backfill is placed over tank. Care shall be exercised during the curing period to avoid dislodging the riser or disrupting the watertight seal between the riser and tank. (Ord. 749, 1997)

15.01.274 Pumping tank equipment.

Pumps shall be stainless steel, thermoplastic, or coated inside and out with baked-on epoxy paint, UL listed for use in effluent. All pumping systems shall be Orenco Systems Model OSI S 4000 Series High Head Pumping Assemblies or approved equal comprised of:

A. Standard vault: 15-inch by 48-inch PVC Vault and Flow Inducer, Orenco Model No. SV 1548FI with eight one-and-three-eighths-inch diameter inlet holes or approved equal.

B. Hose and valve assembly includes one-inch diameter flexible PVC hose with quick-disconnect fittings and PVC ball valve. Orenco Model No. HV 100 Bfc or approved equal.

C. Mercury Switch Float Assembly, Model MF-ABR or approved equal, with three mercury floats mounted on a PVC stem which attaches to vault.

D. Pump: OSI High Head, 1/3 hp or 1/2 hp, 115V, single phase Model 8 OSI 03 HH or 8 OSI 05 HH, with eight-foot cord and one-eighth-inch bypass orifice for effluent application, or approved equivalent.

All pumping systems shall be installed in accordance with the manufacturer’s recommendations. (Ord. 749, 1997)

15.01.276 Controls and alarms.

All STEP systems shall be wired to a dedicated 20-amp breaker which supplies power to the STEP system control box only. This is required to avoid damage or overload to system and appliances. All buried power shall be installed with continuous tracer tape installed 12 inches above the buried power. The marker tape shall be plastic nonbiodegradable, metal core backing marked “Power.”

Positions on the PVC 3 float assembly are to be set at the following levels: High tank level alarm is to be set nine inches below underside of tank top, “on” at three and one-half inches below alarm, and “off” in same float as “on” set three and one-half inches below “on,” and redundant off with low level alarm set four inches below off.

Control panels shall be Orenco Systems Model S-IRODS (redundant off with disconnect assembly) or approved equal with the following features:

A. Rating: 1 hp/115 VAC, 2 hp/230 VAC, single phase, 60 Hz. Motor start contact shall be rated for 25 FLA, single phase, 60 Hz.

B. Audible alarm, panel mount with a minimum of 80 db sound pressure at 24 inches continuous sound.

C. Oil-tight visual alarm, red lens, with push-to-silence feature.

D. Automatic audio-alarm reset.

E. Fifteen-amp motor rated toggle switch, single-pole, double-throw with three positions: manual (MAN), automatic (AUTO) and center (OFF).

F. NEMA 4X-rated fiberglass enclosure with gasketed, hinged cover, and locking latch. Padlock will be installed by city at time of city’s acceptance of the completed installation and shall signify final acceptance.

G. Alarm circuit shall be wired separately from the pump, so that if the internal pump overload switch is tripped, the alarm will still function.

H. Twenty-amp power disconnect assembly toggle switch to de-energize entire control panel, to permit servicing panel without access to the customer’s breaker switches. The pump control panel shall be mounted on the side of the house nearest the tank and pump, within sight of the tank in all cases and of the street where practical at no less than four feet but no more than five feet above finished grade.

I. There shall be a dedicated 20-amp circuit breaker serving the pump control panel.

J. Control panel shall contain hour meter and event counter bases so the meter and counter may be moved from one installation to another. (Ord. 749, 1997)

Alternative Holding Tank Systems

15.01.280 Holding tanks.

A. The size of the proposed tank shall be designed by a licensed engineer and must take into consideration the estimated daily flow and the estimated pumping frequency. These shall be submitted to the public works department for approval.

B. Tank specifications shall be submitted to the public works department with the plans for review and approval by public works. (Ord. 749, 1997)

15.01.282 Pipe.

The gravity building sewer between the building and the holding tank shall be six-inch PVC, SDR 3034, gasketed pipe. (Ord. 749, 1997)

15.01.284 Alarm system.

Two alarm systems shall be required on all holding tank installations. The first alarm is to be set at 70 percent capacity. The second alarm is to be set at 80 percent of tank capacity.

Alarm systems shall have the following features:

A. Audible alarm, panel mount with a minimum of 80 db sound pressure at 24 inches continuous sound.

B. Oil-tight visual alarm, red lens, with push-to-silence feature.

C. Automatic audio-alarm reset.

D. Alarm circuits shall be wired separate of each other and of other fixtures.

15.01.305 Water – General.

A. Any proposed extension of the Langley water system must be approved in advance by the department of public works. All extensions must conform to Washington State Department of Health, city of Langley water system plan, as adopted or hereafter amended, and Langley fire department requirements.

B. In designing and planning for any development, it is the developer’s responsibility to see that adequate water for both domestic use and fire protection is attainable. The developer must show, in the proposed plans, how water will be supplied and whether water flow and pressure will be adequate in case of fire. An analysis of the system shall be required if it appears that the system is inadequate.

C. Anyone who wishes to extend or connect to the city’s water system should contact the department of public works for a water extension/connection fee estimate. This fee estimate is an estimate of the costs due the city for a waterline extension or connection.

D. Prior to the release of any water meters, all public works improvements must be completed and approved including granting of right-of-way or easements, and all applicable fees must be paid.

E. Issuance of building permits for new construction of single-family subdivisions shall not occur until final public works approval of utility installation is given.

F. For commercial projects, building permits may be issued upon completion and acceptance of the required fire protection facilities. A performance bond, in accordance with Section 15.01.075, will be required for the remaining public works improvements. Certificate of occupancy will not be issued until final public works approval is given for all improvements. (Ord. 743, 1997)

15.01.310 Design standards.

A. The design of any water extension/connection shall conform to city standards and any applicable standards as set forth herein and in Sections 15.01.025 and 15.01.040.

B. The layout of extensions shall provide for the future continuation and/or “looping” of the existing system as determined by the city. In addition, main extensions shall be extended as required in Section 15.01.030.

C. A copy of the general notes for water line installation may be obtained from the Langley public works department. (Ord. 743, 1997)

15.01.315 Main line.

A. Water mains shall be sized to provide adequate domestic plus fire flow at the required residual pressure. See Section 15.01.415 for fire flow requirements.

The minimum water main size shall be eight inches diameter as long as fire flow requirements can be met. Larger size mains are required in specific areas outlined in the Langley comprehensive water system plan. Nothing shall preclude the city from requiring the installation of a larger sized main in areas not addressed in the comprehensive water system plan if the city determines a larger size is needed to meet fire protection requirements or for future service. No dead-end eight-inch main shall be longer than 800 lineal feet unless approved by the city engineer.

B. All pipe for water mains shall have flexible gasketed joints and shall comply with one of the following types:

Ductile iron pipe: Ductile iron pipe shall conform to AWWA C151 Class 52 and have a cement mortar lining conforming to AWWA C104. All pipes shall be joined using nonrestrained joints which shall be rubber gaskets, push-on type or mechanical joint, conforming to AWWA C111.

PVC pipe: All PVC pipe shall conform to the latest revision of the following specifications: Four-inch through 12-inch pipe shall meet AWWA C900 standards.

C. All fittings for ductile iron pipe or PVC pipe shall be ductile iron compact fittings conforming to AWWA C153 or Class 250 gray iron conforming to AWWA C110 and C111. All fittings shall be cement mortar lined conforming to AWWA C104. Plain end fittings shall be ductile iron if mechanical joint retainer glands are installed on the plain ends. All fittings shall be connected by flanges or mechanical joints.

D. All nonmetallic pipe and services shall be installed with continuous tracer tape installed 12 to 18 inches under the final ground surface. No breaks or splices will be allowed. A continuous loop shall be placed from the main line to the meter box and back to the main line. The marker shall be plastic nonbiodegradable, metal core or backing which can be detected by a standard metal detector. Tape shall be Terra Tape “D” or approved equal. In addition to tracer tape, install 14-gauge coated copper wire, taped to the top of pipe, brought up and tied off at valve body.

E. The minimum cover for all water mains from top of pipe to finish grade shall be 36 inches unless otherwise approved by the city engineer. (Ord. 743, 1997)

15.01.320 Connection to existing water main.

A. The developer’s engineer shall be responsible for determining the scope of work for connection to existing water mains.

B. It shall be the contractor’s responsibility to field verify the location and depth of the existing main and the fittings required to make the connections to the existing mains. (Ord. 743, 1997)

15.01.325 Service interruption.

A. The contractor shall give the city (public works, fire department and police department) a minimum of 72 hours’ notice of any planned connection to an existing pipeline. This includes live taps. Notice is required so any disruptions to existing services can be scheduled. The contractor shall notify customers involved or affected of the water service interruption 24 hours in advance of the interruption. The contractor shall make every effort to schedule water main construction with a minimum interruption of water service.

B. In certain situations, the city may dictate scheduling of water main shutdowns to avoid shutdowns during specific periods to existing customers. (Ord. 743, 1997)

15.01.330 Hydrants.

A. The lateral from the service main to the fire hydrant shall be ductile iron cement mortar lined Class 52 no less than six inches in diameter.

B. Fire hydrants shall have two two-and-one-half-inch outlets and one four-and-one-half-inch pumper port outlet. All outport threads shall be National Standard thread. The valve opening shall be five-and-one-quarter-inch diameter. The hydrant shall have a positive and automatic barrel drain and shall be of the “safety” or break away style. Hydrants shall be Mueller Centurion or approved equal. All hydrants shall be bagged until system is approved.

C. Fire hydrants shall be set as shown in the standard drawings.

D. Fire hydrants must be installed, tested, and accepted prior to the issuance of a building permit. (Ord. 743, 1997)

15.01.335 Valves.

A. All valves and fittings shall be ductile iron with ANSI flanges or mechanical joint ends. All existing valves shall be operated by city employees only.

B. Valves shall be installed in the distribution system at sufficient intervals to facilitate system repair and maintenance, but in no case shall there be less than one valve every 1,000 feet. Generally, there shall be two valves on each tee and three valves on each cross. Specific requirements for valve spacing will be made at the plan review stage.

C. Gate Valves, Six-Inch to 12-Inch. The design, materials and workmanship of all gate valves shall conform to, or exceed the requirements of AWWA C509-80 latest revision. Gates valves shall be resilient wedge nonrising stem (NRS) with two internal O-ring stem seals. Gate valves shall be Mueller A-2360. Gate valves shall be used on all six- to 12-inch lines.

D. Butterfly Valves. Butterfly valves shall conform to AWWA C504, Class 150B, with cast iron short body and O-ring stem seals. Butterfly valves shall be Mueller, Lineal III, Kennedy, Pratt Groundhog, or Allis Chalmers. Butterfly valves shall be used on all lines 14 inches and larger.

E. Valve Box. All valves shall have a standard cast iron water valve box set to grade. If valves are not set in paved area, a three-foot by three-foot by four-inch concrete pad shall be set around each valve box at finished grade. In areas where valve box falls in road shoulder, the ditch and shoulder shall be graded before placing asphalt or concrete pad.

F. Valve Marker Post. Valve marker posts shall be four-inch by four-inch reinforced concrete or schedule 40 steel posts five feet long stamped with “W” and distance to valve. Post shall be painted with one base coat and two coats blue oil base enamel. (Ord. 743, 1997)

15.01.340 Casing.

Steel casing pipe shall be schedule 20 steel or equal. Pipe spacers shall be Cascade style CC5 with eight-inch runners or equal. Casing pipe and spacers shall be sized for pipe being installed. Install minimum of three spacers per section of pipe. (Ord. 743, 1997)

15.01.345 Air and vacuum release valve.

A. Air and vacuum release valves (ARV) shall be Crispin combination air release valve or approved equal.

B. The installation shall be set at the high point of the line when required. Where possible, pipes are to be graded to prevent the need for an air release valve. Air release valves may not be required when services or hydrants are in the vicinity. (Ord. 743, 1997)

15.01.350 Blowoff assembly.

If a fire hydrant is not located at the end of a dead-end main, a blowoff assembly shall be required. On water mains which will be extended in the future, the valve which operates the blowoff assembly shall be the same size as the main and provided with a concrete thrust block. The pressure rating for blowoff assemblies shall be 200 psi. Installation shall be as shown on standard drawings. (Ord. 743, 1997)

15.01.355 Backflow prevention.

A. All water system connections to serve buildings or properties with domestic potable water, fire sprinkler systems, or irrigation systems shall comply with the minimum backflow requirements as established by the State of Washington Department of Health (DOH) and the city of Langley.

B. The installation of all backflow devices is required to protect the existing water system and users from possible contamination.

C. The developer shall provide public works with the certificate for testing of any backflow prevention device before releasing the certificate of occupancy on any building. A list of approved testers may be obtained from Washington Environmental Training Resource Center (WETRC) located in Auburn, Washington.

D. The building official will witness the test of the fire line. The contractor shall provide the city with a copy of the certificate for underground piping. In any situation, the building official will not witness the test of the fire protection supply line until public works has tested and approved the water main up to the fire line. (Ord. 743, 1997)

15.01.360 Service connection.

A. All service connections relating to new development shall be installed, at a minimum depth of 36 inches, to the property line by the developer at the time of mainline construction. After the lines have been constructed, tested and approved, the owner may apply for a water meter. The city will install a water meter after the application has been made and all applicable fees have been paid. Water meters will be set only after system is inspected and approved.

B. When water is desired to a parcel fronting an existing main but not served by an existing setter, an application must be made to the city. Upon approval of the application and payment of all applicable fees, the city will tap the main, and install the meter, box, and setter. The developer shall be responsible for excavating the main line for tapping, ditch preparation for service installation (including boring if required) and backfilling the excavation upon completion of the installation by city forces. On installations that require a street crossing, boring and conduit installation may be required by the director of public works at the developer’s expense.

C. Service lines shall be three-quarter-inch minimum, high density polyethylene pipe, minimum pressure class 200 psi, iron pipe size. Service lines one and one-half inch and larger shall be minimum pressure class 200 psi, copper tube size. Service lines shall be installed 90 degrees off the main. Tracer tape and wire wrapped around the pipe shall be installed on all service lines.

D. Service saddle shall be all bronze with stainless steel straps and shall be Romac style 202S, Rockwell 317 or approved equal. All clamps shall have rubber gasket and iron pipe threaded outlets.

E. Corporation stop shall be all bronze and shall be Mueller type H15005 or approved equal with iron pipe threads conforming to AWWA C 800.

F. Meter setters shall be Mueller B-2404-2 (locking angle valve with dual check) with dual purpose end connections, 15-inch minimum.

G. Meter boxes shall be Brooks Standard Series 1419, Carson Series 1419 (plastic) or Fogtite #1D. (Ord. 743, 1997)

15.01.365 Marking service lines.

The location of all service lines shall be marked on the face or top of the cement concrete curb, where curbs are available, with a “W” one-quarter inch into concrete. (Ord. 743, 1997)

15.01.370 Water main/sanitary sewer separation.

A. The contractor shall maintain a minimum of 18 inches of vertical separation between the top of sanitary sewers and the bottom of water mains. The minimum cover for water main of 36 inches may be reduced to 24 inches upon approval by the city engineer to provide for acceptable vertical separation.

B. The longest standard length of water pipe shall be installed so that the joints will fall equidistant from any sewer crossing. In some cases where minimum separation cannot be maintained, it may be necessary to encase the water pipe and/or sewer service in pipe or concrete as required by the director of public works. No concrete shall be installed unless specifically directed by the city. (Ord. 743, 1997)

15.01.375 Irrigation.

A. All irrigation systems shall be installed with an approved backflow prevention assembly approved by AWWA and the Department of Health.

B. Irrigation sprinklers shall be situated so as to not wet any public street or sidewalk. (Ord. 743, 1997)

15.01.380 Staking.

A. All surveying and staking for main extensions shall be performed by an engineering or surveying firm capable of performing such work. The engineer or surveyor directing such work shall be licensed as a professional engineer or professional land surveyor by the state of Washington.

B. A pre-construction meeting shall be held with the city prior to commencing staking. All construction staking shall be inspected by the city prior to construction.

C. The minimum staking of waterlines shall be as directed by the city engineer or as follows:

1. Stake centerline alignment every 50 feet with cut or fill to invert of pipe maintaining 36 inches of cover over pipe. Cuts are normally not required when road grade has been built to subgrade elevation.

2. Stake alignment of all fire hydrants, tees, water meters, setters and other fixtures and mark cut or fill to hydrant flange finished grade. (Ord. 743, 1997)

15.01.385 Trench excavation.

A. Clearing and grubbing where required shall be performed within the easement or public right-of-way as permitted by the city and/or governing agencies. Debris resulting from the clearing and grubbing shall be disposed of by the owner or contractor in accordance with the terms of all applicable permits.

B. Trenches shall be excavated to the line and depth designated by the approved plans to provide a minimum of 36 inches of cover over the pipe. Except for unusual circumstances where approved by the city, the trench sides shall be excavated vertically and the trench width shall be excavated only to such widths as are necessary for adequate working space as allowed by the governing agency. The trench shall be kept free from water. Surface water shall be diverted so as not to enter the trench. The contractor shall maintain sufficient pumping equipment on the job to ensure that these provisions are carried out.

C. The contractor shall perform all excavation of every description and whatever substance encountered and boulders, rocks, roots and other obstructions shall be entirely removed or cut out to the width of the trench and to a depth six inches below water main grade. Where materials are removed from below water main grade, the trench shall be backfilled to grade with material satisfactory to the city and thoroughly compacted.

D. Trenching and shoring operations shall not proceed more than 300 feet in advance of pipe laying without approval of the city, and shall be in conformance with Washington Industrial Safety and Health Administration (WISHA) and Office of Safety and Health Administration (OSHA) safety standards.

E. The bottom of the trench shall be finished to grade with hand tools in such a manner that the pipe will have bearing along the entire length of the barrel. The bell holes shall be excavated with hand tools to sufficient size to make up the joint. (Ord. 743, 1997)

15.01.390 Thrust blocking.

A. Location of thrust blocking shall be shown on plans. Thrust block concrete shall be Class B poured against undisturbed earth. A plastic barrier shall be placed between all thrust blocks and fittings.

B. See standard drawings for thrust block locations and calculations. (Ord. 743, 1997)

15.01.395 Backfilling.

Backfilling and surface restoration shall closely follow installation of pipe so that not more than 300 feet is left exposed during construction hours without approval of the city. Selected backfill material shall be placed and compacted around and under the water mains by hand tools to a height of six inches above the top of the water main. The remaining backfill shall be compacted to 95 percent of the maximum density in traveled areas, 90 percent outside traveled area. Where governmental agencies other than the city have jurisdiction over roadways, the backfill and compaction shall be done to the satisfaction of the agency having jurisdiction. Native material may be used for backfill only upon the approval of the director of public works. If suitable backfill material, as determined by the director of public works, is not available from trenching operations, the city may order the placing of bedding conforming to Section 9, 30.7A of the Standard Specifications around the water main and gravel base conforming with Section 9, 30.7(3) of the Standard Specifications for backfilling the trench.

15.01.400 Street patching.

See Sections 15.01.540 and 15.01.545 for requirements regarding street patching and trench restoration. (Ord. 743, 1997)

15.01.405 Hydrostatic tests.

A. Prior to the acceptance of the work, the installation shall be subjected to a hydrostatic pressure test of two and one-half times the static pressure or 250 psi minimum, for 15 minutes. Any drop in pressure must be within the allowable limits set by the State of Washington Department of Health. Any leaks or imperfections developing under said pressure shall be remedied by the contractor. No main shall be hydrostatically tested until the lines are flushed. The main shall be tested between valves. Insofar as possible, no hydrostatic pressure shall be placed against the opposite side of the valve being tested. Test pressure shall be maintained while the entire installation is inspected.

B. The contractor shall provide all necessary equipment and shall perform all work connected with the tests. Tests shall be made after all connections have been made and the roadway section is constructed to subgrade. This is to include any and all connections and hydrants as shown on the plan. The contractor shall perform the test to assure that the equipment to be used for the test is adequate and in good operating condition and the air in the line has been released before requesting the city to witness the test.

C. Testing against existing valves shall not be allowed.

D. See Section 15.01.355 for testing responsibilities for backflow prevention devices. (Ord. 743, 1997)

15.01.410 Sterilization and flushing.

A. Sterilization of water mains shall be accomplished by the contractor in accordance with the requirements of the Washington State Department of Health and in a manner satisfactory to the city. At no time shall chlorinated water from a new main be flushed into a body of fresh water. This is to include lakes, rivers, streams, drainage ways, and any and all other waters where fish or other natural water life can be expected.

B. When a chlorine concentration has been established throughout the line, the valves shall be closed and the line left undisturbed for 24 hours. The line shall then be thoroughly flushed and water samples taken by the city at least 24 hours after flushing and disinfecting. Should the initial treatment result in an unsatisfactory bacteriological test, the original chlorination procedure shall be repeated by the contractor until satisfactory results are obtained. Testing and sampling shall take place after all underground utilities are installed and compaction of the roadway section is complete. The developer shall be responsible for all testing and testing costs. (Ord. 743, 1997)

15.01.415 Fire protection.

A. All subdivisions/developments/buildings served by the city’s water systems shall be required to provide for fire flow as hereinafter specified. Nothing herein shall be construed to preclude the imposition of fire flow requirements for water systems, where such consideration is found to be necessary by the fire chief to mitigate fire hazards.

B. When the subdivision/development/building is determined by the land use coordinator to be commercial in nature, fire flow requirements for the servicing water system will be set by the building official consistent with provisions hereinafter.

C. All modification or extension of the existing system, and those developments of a commercial nature, shall provide fire flow as stated below. In the case of existing systems, incremental improvements toward complete compliance may be stipulated, reflecting the concurrence of the Health Department, the engineer, and the fire chief. The “Insurance Service Office Guide for Determining Fire Flow” may be used in setting the fire flow requirement, but the minimum requirement for new development shall be as follows:

1. Fire Flow Requirements. The following minimum fire flow requirements are hereby imposed:

a. Residential units: 500 gallons per minute for 30 minutes.

b. Commercial units: 1,000 gallons per minute for 60 minutes. Higher flow requirements may be required after evaluation by the fire chief.

c. The water system providing the above fire flows to commercial/multifamily class buildings shall do so with a minimum residual pressure of 20 pounds per square inch.

2. Fire Hydrants. Fire hydrants shall be provided in accordance with WAC 248-57-600.

3. Hydrant Spacing.

a. Residential: 600 feet maximum, except that additional hydrants may be required by the fire chief to permit all dwellings to be reached by hose lays of no greater than 500 feet.

b. Commercial/industrial/multifamily: as determined by the fire chief, but not to exceed 300 feet maximum.

c. Where geographically or otherwise physically possible, the spacing intervals for hydrants shall commence at street intersections.

d. Hydrant spacing shall be measured along the improved portion of the roadway.

D. 1. For requirement regarding use, size and location of a fire department connection (FDC) and/or post indicator valve, contact the Langley building department. Location of FDC shall be shown on water plans.

2. The property owner installing a fire sprinkler line to a building shall be responsible for maintenance of the fire line, for the life of the project, from the building to the water main, including the appurtenances utilized in the connection to the water main.

E. Where needed, the department of public works or Langley fire department may require hydrants to be protected by two or more posts, each four inches in diameter by five feet in length made of either reinforced concrete or steel. (Ord. 743, 1997)

15.01.420 Erosion control and drainage plans – Submission.

A. Application for any of the permit/approvals specified in Section 15.01.020 shall be accompanied by an interim erosion/sedimentation control plan and a drainage plan or a waiver therefrom granted by the city engineer in accordance with the provisions of subsection (C) of this section.

B. The plan submitted during one permit approval process may be subsequently submitted with further required applications.

C. The plan requirement established in this section will not apply when the engineering department determines that the proposed permit and/or activity:

1. Will neither seriously nor adversely impact the water quality conditions of any affected receiving bodies of water.

2. Will not alter the drainage patterns, increase the peak discharge and cause adverse effects in the drainage area.

3. Will not seriously nor adversely impact ground water quality, the recharge of a ground water aquifer and/or the capacities of nearby springs and wells. (Ord. 862, 2005; Ord. 743, 1997)

15.01.425 Plan contents.

A. All persons applying for any of the permits and/or approvals specified in Section 15.01.020 shall provide an interim erosion/sedimentation control plan and drainage plan for surface and pertinent subsurface water flows entering, flowing within, and leaving the subject property. Said plans shall present the following required information:

1. Interim Erosion/Sedimentation Control Plan. An interim erosion/sedimentation control plan will be required as set forth in the Langley comprehensive stormwater plan. At the discretion of the city engineer, plans prepared in conjunction with those actions not identified as categorical exemptions under SEPA, WAC 197-10-170 and/or occurring in lands classified as sensitive lands per Section 16.04.170 shall be prepared under the direction of a civil engineer, soil scientist, or other qualified individual(s). The plan for a proposed construction site shall describe:

a. Soils, topography, existing vegetation, the areas to be cleared and graded, and the location of major cuts and fills covered by the permit and/or approval for which application is made;

b. Computations and hazards associated with the area covered by the permit and/or approval for which application is made, the anticipated schedule of construction, and the proposed measures, including site management practices (such as check dams, slash removal, reseeding, or mulching) as appropriate for controlling erosion/sedimentation and runoff;

c. The city engineer may require interim erosion/sedimentation control measures to account for seasonal changes, alterations of the topography and watercourse during construction, and other such factors affecting site conditions which need to be constructed to ensure complete siltation control on the subject property. It shall be the obligation and responsibility of the person required to provide and maintain temporary erosion/sedimentation facilities pursuant to this section to address any new conditions that may be created by his activities and to utilize additional control measures as may be needed;

d. The interim erosion/sedimentation control facility shall be constructed prior to any grading or extensive land clearing in accordance with the approved temporary plan. These facilities must be satisfactorily maintained until construction and landscaping is completed and the potential of onsite erosion has passed.

B. Small Projects. All persons applying for and doing grading in conjunction with building permits for development or redevelopment with less than 5,000 square feet of impervious surface area shall employ one or more of the best management practices (BMPs) identified in Appendix A of this code prior to commencement of grading.

C. Preliminary Drainage Plan. A preliminary drainage control plan will be required unless waived by the city engineer. The preliminary drainage plan shall describe:

1. Background computations for sizing drainage facilities.

a. Depiction of the drainage area and the natural surface drainage system on a topographical map, with acreage indicated. A contour interval of two feet or five feet shall be required as directed by the city engineer.

b. Indication of the peak discharge and amount of surface water currently entering and leaving the subject property.

c. Indication of the peak discharge and amount of runoff which will be generated within the subject property if development is allowed to proceed.

d. Indication of how low-impact development measures will be incorporated into the site design in an effort to eliminate offsite discharge and mimic natural hydrologic functions.

e. For applications in which onsite detention is required, the preliminary drainage plan shall include the required storage volume, method of storage and an accurate cost estimate associated with furnishing and installing the detention facility. The cost estimate shall exclude the drainage conveyance system to the detention facility.

2. Proposed improvements for handling the additional computed runoff, and providing water quality treatment of runoff.

3. Arrangements by the developer to provide for continuing maintenance of the project drainage facilities.

D. As an alternate to onsite detention, upon the approval of the city engineer, the applicant may contribute to the city a sum of money equivalent to the estimated costs for furnishing and installing the sized detention facility for the proposed development. The cost estimate for the detention facility submitted by the applicant shall be reviewed by the city engineer for accuracy. This estimate, with any modifications by the city engineer, shall be the sum of money contributed to the storm drainage fund.

E. Modifications. The requirements of this section may be modified if, in the city engineer’s professional opinion, such additional or reduced amount of information is necessary or appropriate to carry out the expressed purpose and intent of this chapter.

F. Large tract subdivisions shall be exempt from the detailed drainage plan requirements in subsection (C) of this section, except in critical drainage areas. (Amended during 2013 reformat; Ord. 921, 2009; Ord. 862, 2005; Ord. 743, 1997)

15.01.430 Detailed drainage plan – Mandatory requirements.

A. A detailed drainage plan shall be prepared by a registered civil engineer based upon the city engineer’s determination as provided in Section 15.01.425(E). Detailed drainage plans are not required for single-family or duplex development or redevelopment that includes the creation of less than 5,000 square feet of impervious surface area. Detailed drainage plans are also not required for commercial/industrial or multifamily development or redevelopment that includes the creation of less than 5,000 square feet of impervious surface area except if the development is located in the critical drainage sub-basins DB-3B-3East.

B. The use of all reasonable and appropriate low-impact development measures shall be required prior to consideration of conventional stormwater management methods.

C. Surface water entering the subject property shall be received at the naturally occurring location, and surface water exiting the subject property shall be discharged at the natural location, with adequate energy dissipaters within the subject property to eliminate downstream damage and with no diversion at any of these points. Deviations consistent with law may be permitted.

D. The peak discharge from the subject property due to the design storm may not be increased due to the proposed development. Further control may be required as specified in Section 15.01.440. See alternative to detention, Section 15.01.425(D).

E. Retention/detention facilities or other drainage facilities shall be in accordance with Section 15.01.445.

F. Provide stormwater quality treatment facilities to accommodate runoff produced by the design storm, defined as the six-month, 24-hour return period storm event which is approximately equal to 64 percent of the two-year, 24-hour storm. The first priority for treatment shall be to infiltrate as much as possible of the storm, if site conditions are appropriate and ground water quality will not be impaired. Direct discharge of untreated stormwater to ground water is prohibited. All treatment BMPs shall be selected, designed, and maintained according to the Department of Ecology’s Stormwater Management Manual for Western Washington (Publication Nos. 05-10-029 through 05-10-033 as they now exist or are hereafter amended).

G. All development projects shall conduct an analysis of offsite water quality impacts resulting from the project and shall mitigate these impacts. The analysis shall extend a minimum of one-fourth of a mile downstream from the project. The existing or potential impacts to be evaluated and mitigated shall include, at a minimum, but not be limited to: excessive sedimentation, stream bank erosion, discharges to ground water contributing or recharge zones, violations of water quality standards, and spills and discharges of priority pollutants.

H. Source Control of Pollution. Source control BMPs shall be applied to all projects to the maximum extent practicable. Source control BMPs shall be selected, designed and maintained according to the DOE Technical Manual.

I. Wetlands. The following requirements apply only to situations where stormwater discharges directly or indirectly through a conveyance system into a wetland.

1. Stormwater discharges to wetlands must be controlled and treated to the extent necessary to meet the State Water Quality Standards, Chapter 173-201 WAC, or Ground Water Quality Standards, Chapter 173-200 WAC, as appropriate.

2. Discharges to wetlands shall maintain the hydroperiod and flows of existing site conditions to the extent necessary to protect the characteristic uses of the wetland. Prior to discharging to a wetland, alternative discharge locations shall be evaluated, and natural water storage and infiltration opportunities outside the wetland shall be maximized and shall be subject to review by the planning official and the city engineer.

3. Created wetlands that are intended to mitigate for loss of wetland acreage, function and value shall not be designed to also treat stormwater.

4. In order for constructed wetlands to be considered treatment systems, they must be constructed on sites that are not wetlands and they must be managed for stormwater treatment. If these systems are not managed and maintained in accordance with the Department of Ecology’s Stormwater Management Manual for Western Washington (Publication Nos. 05-10-029 through 05-10-033 as they now exist or are hereafter amended) for a period exceeding three years these systems may no longer be considered constructed wetlands. Discharges from constructed wetlands to waters of the state (including discharges to natural wetlands) are regulated under Chapter 90.48 RCW and Chapters 173-200 and 173-201 WAC.

5. Stormwater treatment BMPs shall not be built within a natural vegetated buffer, except for necessary conveyance systems as approved by the city of Langley.

J. Operation and Maintenance. An operation and maintenance schedule shall be provided for all proposed stormwater facilities and BMPs, and the party (or parties) responsible for maintenance and operation shall be identified.

K. The developer will obtain the necessary easements from all affected properties for the flow of storm drainage between the development and a drainage way or receiving body of water necessary to comply with the foregoing requirements.

L. Drainage from roofs, downspouts, surface drains, and sub-drains shall not be discharged into a city road or drainage ditch without first having received approval from the city engineer.

M. Variances from any or all of the foregoing requirements of this section may be permitted only after a determination by the city engineer and the planning official, employing the following criteria: (1) capacity of downstream facilities, (2) acceptability of receiving bodies of water, (3) possibility of adverse effects of retention, (4) utility of regional retention facilities, and (5) capability of maintaining the system.

N. Exceptions:

1. Those areas designated in the city of Langley comprehensive stormwater plan as not benefiting from stormwater runoff control (sub-basins C and D2 which discharge directly to the Sound and have short travel times in comparison to uphill basins) may be exempt from the runoff control/detention requirements of this chapter and eligible for the alternative described in Section 15.01.425(D).

2. Increased mitigation measures may be required based on downstream flooding problems or the limited capacity of the downstream conveyance system. (Ord. 921, 2009; Ord. 862, 2005; Ord. 743, 1997)

15.01.435 Drainage.

Development in a critical drainage area shall meet special drainage conditions set by the city engineer until such time as the community hazard is alleviated. Such conditions may include the limitations of the volume of discharge from subject property to predevelopment levels, preservation of wetlands or other natural drainage features, or other controls necessary to protect against community hazard. (Ord. 743, 1997)

15.01.440 Design criteria.

A. The methods for predicting runoff from a given basin that are acceptable to the city are the Soil Conservation Service (SCS) method or the Santa Barbara Urban Hydrograph (SBUH) method. In addition, for basins smaller than 25 acres, the rational method is acceptable for sizing conveyance systems.

B. Stormwater quantity conveyance systems connected to the present piping system shall be designed to convey a 25-year, 24-hour storm as computed using the Soils Conservation Service (SCS) method or the Santa Barbara Urban Hydrograph (SBUH) method. In basins smaller than 25 acres the Rational Method is acceptable. Stormwater runoff that is discharged directly or indirectly to a stream shall be regulated as follows:

1. The peak rate of runoff from individual development sites shall be limited to 50 percent of the existing condition two-year, 24-hour design storm while maintaining the existing condition peak runoff rate for the 10-year, 24-hour, and 100-year, 24-hour design storm. In cases where discharge is directly to Puget Sound and the downstream conveyance system has adequate capacity to carry the 25-year, 24-hour peak flow the requirement to limit peak rates to pre-development values may be waived based on the city engineer’s approval. In cases where discharge is directly to Puget Sound but the downstream conveyance system has limited capacity, post-development peak runoff rates shall be limited to the magnitudes of the pre-development 10-year, 24-hour and 100-year, 24-hour peak runoff rates.

C. Water Quality Facilities. Water quality facilities shall be designed for the six-month, 24-hour storm event which is approximately equal to 64 percent of the two-year, 24-hour storm. (Amended during 2013 reformat; Ord. 743, 1997)

15.01.445 Onsite detention and infiltration.

A. All reasonable and appropriate low-impact development measures shall be incorporated into site design before conventional onsite detention and infiltration methods are considered.

B. Open retention/detention facilities and infiltration facilities shall not be located in public road right-of-way. The city engineer is authorized to require all persons, associations, and/or corporations constructing new or maintaining retention/detention facilities to secure a liability insurance policy for the duration of the operation of the facility.

C. An emergency overflow system is required for all retention/detention facilities.

D. Detention basin design must account for antecedent conditions which may contribute to a partially full basin at the beginning of the design storm, i.e., a minimum of one foot of freeboard above the maximum design water surface.

E. Existing wetlands may function as both a control feature in the natural surface drainage system and as areas of ground water recharge. Any reduction of such features shall be replaced with equivalent drainage controls.

F. Infiltration is preferred where practical because it reduces the demand for conveyance capacity and hence, reduces potential flooding. It also recharges the aquifer and has water quality benefits. Figure 2.7 of the City of Langley Comprehensive Stormwater Management Plan and Section 5 of that document discuss areas where infiltration shall be considered. The Low Impact Development Technical Guidance Manual For Puget Sound (Puget Sound Action Team Publication No. PSAT 05-03 as it now exists or is hereafter amended) and the Department of Ecology’s Stormwater Management Manual for Western Washington (Publication Nos. 05-10-029 through 05-10-033 as they now exist or are hereafter amended) provide general guidelines for analyzing the feasibility of the infiltration systems, which shall be recognized as minimum standards. The basic design shall follow the Stormwater Manual for Western Washington.

Infiltration may be restricted or disallowed, as determined by the city engineer, in those areas designated and defined in the Langley Municipal Code as sensitive areas.

G. Detention systems shall be designed in accordance with Chapter III-4 of the Stormwater Manual for Western Washington. Water shall be released at a rate not to exceed the runoff which occurred before development. (Ord. 921, 2009; Ord. 862, 2005; Ord. 743, 1997)

15.01.450 Maintenance of facilities.

A. Publicly Owned Stormwater Facilities Located in City Rights-of-Way. Facilities are maintained by the city public works department. These facilities include catch basins, road side ditches, storm drains, detention facilities, and infiltration facilities.

B. Existing Privately Owned Stormwater Facilities Located on Private Property.

1. Facilities located on single lot private property shall be maintained by the property owners.

2. When a facility serves several properties, a homeowners association will provide an O&M agreement that the facilities will be inspected, with notice, by the city and paid for by the homeowners association. The facility shall be located in a tract or easement dedicated to that association.

3. Should private stormwater facilities not be maintained in accordance with city standards, then the city may choose to perform the necessary maintenance and charge the property owner/association or the city may condemn the property as a health and safety nuisance and assume ownership.

C. Public facilities shall be inspected by the city annually and cleared of debris, sediment and vegetation, when they affect the functioning and/or design capacity of the facility. All stormwater facilities shall be maintained in accordance with the DOE Technical Manual. (Ord. 921, 2009; Ord. 743, 1997)

15.01.455 Storm sewer system – Minimum requirements.

A. Mainline Storm Sewers.

1. Minimum diameter of storm drain pipe shall be 12 inches except that a maximum length of 60 lineal feet of eight-inch diameter pipe may be used between inlet and catch basin.

2. Minimum slope of storm drain pipe shall be 0.005 ft./ft.

3. Minimum velocity at design flow shall be three feet per second.

4. Maximum depth of liquid in culvert shall be d/D = 0.8.

5. Maintain line and grade between all catch basins/manholes.

6. Install catch basins/manholes at all changes of line or grade, at all pipe intersections and at both ends of all storm drain pipe, except driveway culverts and at maximum spacing of 300 feet.

7. Extend mainline storm sewers to boundary of project to serve adjacent upstream properties.

8. Design location of pipe shall be south and west of street centerline under street curb, except as required to match existing utilities.

9. Maximum depth of cover over top of pipe into catch basins shall be four feet except where approved by the city engineer. Where the depth to pipe invert is five feet or more, a manhole shall be installed at grade breaks and pipe intersections.

10. Provide six-inch tees to serve each adjacent land parcel or future lot. Extend service lines to property line where under future paving, curbs or sidewalks.

11. Note pipe size, length, slope and invert elevations in profile on each run between catch basins.

12. Drainage facilities must be designed to convey the surface water entering a drainage area at the naturally occurring location.

B. In areas where ditches are allowed, they shall be constructed with maximum depth of three feet, minimum side slope of one and one-half horizontal to one vertical, with driveway culverts 12-inch minimum diameter.

C. Footing and Downspout Drain.

1. Preference is to keep stormwater on site, through installation of rain gardens, or infiltration drywell next, over connection to the storm drain.

2. Minimum diameter shall be six inches to property line.

3. Minimum slope shall be one percent.

4. Provide three-foot minimum depth at property line, or deeper if required by lot topography.

5. Provide individual drain for each house or lot.

6. All drain lines shall enter mainline at a tee or catch basin.

7. Under no circumstances shall storm drain be connected to the sanitary sewer system.

8. In no event shall footing drains and downspout drains be allowed to be tied together within 10 feet of a structure.

D. Minimum materials requirements shall be as follows:

1. Pipe materials shall be in accordance with Section 7-04 of the APWA Standard Specifications.

2. Catch basins, inlets and grates shall be in accordance with the APWA Standard Plans. (Ord. 921, 2009; Ord. 743, 1997)

15.01.460 Transportation – General considerations.

A. The overall goal of this chapter is to encourage the uniform development of an integrated, fully accessible public transportation system that will facilitate present and future travel demand with minimal environmental impact to the community as a whole.

B. This chapter provides minimum construction standards supplementing the applicable standards as set forth in Section 15.01.025; provided, that applicants shall, to the maximum extent practicable, apply low-impact development alternatives where site conditions are favorable and upon a recommendation by the city engineer and approval by the city council. (Ord. 862, 2005; Ord. 743, 1997)

15.01.465 Streets – General – Complete streets.

A. The city of Langley will plan for, design and construct all new transportation projects to provide appropriate accommodation for bicyclists, pedestrians, transit users and persons of all abilities in comprehensive and connected network with the following exceptions:

1. Where their establishment would be contrary to public health and safety; or

2. Where there is no identified long-term need; or

3. Where there are significant adverse environmental impacts to streams, wetlands, steep slopes, or other critical areas; or

4. Where there are significant adverse impacts on neighboring land uses, including impacts from right-of-way acquisition; or

5. Where the public works director grants a documented exception which may only be authorized in specific situations where conditions warrant. Such site-specific exceptions shall not constitute general changes to the standards set in Section 15.01.470.

B. Except in unusual or extraordinary circumstances, complete streets principles may not apply to the following:

1. Repairs made pursuant to pavement opening and restoration allowed by approval of the public works director.

2. Ordinary maintenance activities designed to keep assets in serviceable condition (e.g., mowing, cleaning, sweeping, spot repair and surface treatments such as chip seal, or interim measures on detour or haul routes).

C. Complete streets may be achieved through single projects or incrementally through a series of smaller improvements or maintenance activities over time. All sources of transportation funding should be drawn upon to implement complete streets. Maximum financial flexibility is important to implement complete streets principles.

D. Street design must provide for the maximum loading conditions anticipated. The width and grade of the pavement must conform to specific standards set forth herein for safety and uniformity. (Ord. 970 § 2, 2012; Ord. 743, 1997)

15.01.470 Design standards.

A. The design of streets and roads shall depend upon their type and usage. The design elements of city streets shall conform to city standards as set forth herein and current design practice as set forth in Section 15.01.025. Standard design structures are shown in the standard drawings.

B. The layout of streets shall provide for the continuation of existing streets in adjoining subdivisions or of their proper projection when adjoining property is not subdivided by providing street design 200 feet beyond the subdivision boundary. Streets which serve primarily to provide access to abutting property shall be designed to discourage through traffic. See the table of the Minimum Street Design Standards.

C. Alignment. Alignment of new streets shall meet the intent of that shown in the comprehensive plan.

D. Grade. Street grade should conform closely to the natural contour of the land. The minimum allowable grade shall be 0.5 percent. The maximum allowable grade shall be 15 percent, depending upon the street classification. Any deviation from this standard shall require review and approval of the city engineer.

E. Width. The pavement and right-of-way width depend upon the street classification. The table of Minimum Street Design Standards shows the minimum widths allowed. Upon a determination by the city engineer and approval by the city council, standards in the Low Impact Development Technical Guidance Manual for Puget Sound (Puget Sound Action Team Publication No. PSAT 05-03 as it now exists or is hereafter amended) may be substituted.

F. The street construction general notes shall be included on any plans dealing with street design in addition to all applicable requirements in Section 15.01.040. A copy may be obtained from the public works department.


MINIMUM STREET DESIGN STANDARDS Table T-15.01.470
DESIGN STANDARD	MAJOR COLLECTOR	MINOR COLLECTOR	LOCAL	PRIVATE
DESIGN LIMITATIONS				3 LOTS MAXIMUM
MINIMUM STRUCTURAL DESIGN	SEE STANDARD DRAWINGS
MINIMUM RIGHT-OF-WAY	60'	60'	56'	N/A
MINIMUM PAVEMENT WIDTH (INC. PARKING)	42'	42'	42'	SEE SECTION 15.01.495
PARKING LANE	BOTH SIDES	BOTH SIDES	BOTH SIDES	SEE SECTION 15.01.495
GRADE
MINIMUM	0.5%	0.5%	0.5%	0.5%
MAXIMUM	10.0%	15.0%	15.0%	15.0%
CURB	REQUIRED IN CB ZONE AND AS OUTLINED IN SECTION 15.01.560 CEMENT CONCRETE CURB AND GUTTER			N/A
SIDEWALKS	MIN. 6' WIDE CB ZONE	MIN. 6' WIDE CB ZONE	MIN. 6' WIDE	SEE SECTION 15.01.495
WALKWAY	BOTH SIDES 6' ALL OTHER ZONES	BOTH SIDES 6' ALL OTHER ZONES	ONE SIDE 6' RS ZONE	SEE SECTION 15.01.495 RS ZONE
CUL-DE-SAC RADIUS	N/A	N/A	40'	40' OR HAMMER HEAD
INTERSECTION CURB RADIUS	35'	30'	25'	25'
DESIGN SPEED (MPH)	30	30	25	10

(Amended during 2013 reformat; Ord. 862, 2005; Ord. 743, 1997)

15.01.475 Functional classification.

City streets are divided into major collector, minor collector and local access streets in accordance with regional transportation needs and the functional use each serves. Function is the controlling element for classification and shall govern right-of-way, road width, and road geometrics. The following list is provided to assist the developer in determining the classification of a particular street. Streets not listed are classified as local access streets. New streets will be classified by the city public works department.

A. Major Collector.

1. Second Street (DeBruyn to Cascade).

2. Third Street (City limits to Park Avenue).

3. Sixth Street (Park Avenue to Cascade Avenue).

4. Park Avenue (Sixth Street to Third Street).

5. Camano Avenue (Sandy Point Road to Sixth Street).

6. Cascade Avenue (Sixth Street to Second Street).

B. Minor Collector.

1. Wharf Street (Cascade to end).

2. Decker Avenue (Edgecliff Drive to Sandy Point Road).

3. Saratoga Road (City limits to DeBruyn Avenue).

4. Edgecliff Drive (Camano Avenue to Decker Avenue).

5. Anthes Avenue (Sixth Street to Second Street).

6. First Street (DeBruyn Avenue to Second Street/Camano Avenue).

7. Park Avenue (Third Street to First Street).

8. DeBruyn Avenue (First Street to Second Street – proposed). (Ord. 743, 1997)

15.01.480 Naming.

A. The developer may submit proposed street names at the time the preliminary plat is submitted and again upon approval of the final plat. The public works department will ensure that the name requested for a new street is consistent with policies of the city. Street name approval will occur with final plat approval.

B. An address number will be assigned to all new buildings at the time the building permit is issued. It is then the owner’s responsibility to see that the house numbers are placed clearly and visibly at the main entrance to the property or at the principal place of ingress prior to occupancy. (Ord. 743, 1997)

15.01.485 Signing.

A. The developer is responsible for providing all traffic control signs. Traffic control signing shall comply with the provisions as established by the United States Department of Transportation Manual on Uniform Traffic Control Devices (MUTCD).

B. Street designation signs, including poles and hardware, will be paid for by the developer but will be designed, furnished and installed by the city to establish uniformity. The developer will be billed upon installation. Street designation signs shall display street names. (Ord. 743, 1997)

15.01.490 Right-of-way.

A. Right-of-way is determined by the functional classification of a street. Collectors shall have a right-of-way width of not less than 60 feet. See Minimum Street Design Standards for specific widths. Local access streets shall have a right-of-way of not less than 56 feet. See Table T-15.01.470 for radius requirements at cul-de-sac “bulb.”

B. Right-of-way requirements may be increased if additional lanes, pockets, transit lanes, bus loading zones, operational speed, bike lanes, utilities, schools or other factors are required as determined by the city engineer.

C. Right-of-way shall be conveyed to the city on a recorded plat or by a right-of-way dedication deed. (Ord. 743, 1997)

15.01.495 Private streets.

See definition of private street in Section 15.01.015.

A. The following general requirement is applicable to all private streets.

1. Private streets will be allowed only for such streets that have no public interest for traffic circulation, and are to be built in accordance with the standards adopted herein for public streets, except that a gravel street surface may be allowed in the case where the maximum number of lots that can be served by a private street is three lots. For driveway standards, see Section 15.01.525.

B. The potential number of lots or units used for determination of applicable standards shall be based on the potential number of lots or units that could reasonably be served, using the city comprehensive land use plan and existing zoning to calculate density.

C. Design and construction standards and general specifications for private streets shall be as follows:

1. Subdivision standards;

2. Road width easements shall be 25 feet minimum.

A cul-de-sac easement with a radius of 40 feet, or an equivalent turn-around area, shall be required.

3. Access easements shall extend at least 30 feet into the interior lot(s) when deemed necessary by the city engineer.

4. Private street construction width shall be 16 feet.

5. All private streets shall require a minimum of six-inch gravel base consistent with the general requirements of this chapter. Suitability of in-place material to fulfill all or part of this requirement is subject to the approval of the city engineer.

The intent is to provide an “all weather street” capable of supporting the traffic characteristics for which the road is proposed and emergency access.

6. Private streets shall be constructed in accordance with the applicable typical section adopted as part of this chapter.

D. Cottage Housing, Planned Residential Developments, Mobile Home Parks, Condominiums and Multifamily Developments. Except where needed for public circulation, internal accesses within subject developments may be private. In such circumstances, streets shall be built in accordance with the provisions specified herein for city street (Section 15.01.535) except as follows:

Private internal accesses serving eight or less total units, having street and right-of-way widths consistent with subsection (C)(1) of this section and a structural cross section consistent with subsection (C)(5) of this section, may be permitted. (Ord. 743, 1997)

15.01.500 Street frontage improvements.

A. All commercial and residential (including multifamily) development, plats, and short plats shall install street frontage improvements at the time of development as required by these city construction standards. Such improvements may include curb and gutter; walkway or sidewalk; storm drainage; street lighting; utility installation or relocation; landscaping and irrigation; and street widening and overlaying. Plans shall be prepared and signed by a licensed civil engineer registered in the state of Washington.

B. A half street improvement is the minimum acceptable roadway section modified to conform to limited right-of-way on the boundary of property subject to development.

C. A half street may be permitted subject to approval by the city engineer when:

1. There is reasonable assurance of obtaining the prescribed additional right-of-way from the adjoining property suitable for completion of a full-section roadway; and

2. Such alignment is consistent with or will establish a reasonable circulation pattern; and

3. The right-of-way width of the half street shall equal at least 30 feet; and

4. The traveled way shall be surfaced the same as the designated street classification to a width not less than 24 feet; and

5. The half street shall be graded consistent with locating centerline of the ultimate roadway section on the centerline of the right-of-way; and

6. Property line edge of street may be required to be finished with permanent curb and gutter to ensure proper drainage, bank stability and traffic safety. (Ord. 743, 1997)

15.01.505 Cul-de-sac.

Streets designed to have one end permanently closed shall be no longer than 400 feet. At the closed end, there shall be a widened “bulb” having a minimum paved traveled radius as shown in the Minimum Street Design Standards table, or a “T” which provides sufficient turning area. (Ord. 743, 1997)

15.01.510 Temporary dead-ends.

Any temporarily dead-ended street shall have turn-around provisions where the street serves more than one lot. The turn-around may be a hammerhead with a minimum distance on both sides at the centerline intersection of 60 feet to facilitate emergency vehicle turn-around. (Ord. 743, 1997)

15.01.520 Intersections.

A. Traffic control will be as specified in the Manual on Uniform Traffic Control Devices (MUTCD) or as modified by the city engineer as a result of appropriate traffic engineering studies.

B. Street intersections shall be laid out so as to intersect as nearly as possible at right angles. Sharp-angled intersections shall be avoided. For safe design, the following types of intersection features will not be allowed:

1. Intersections with more than four intersecting streets;

2. “Y” type intersections where streets meet at acute angles.

C. Spacing between adjacent intersecting streets, whether crossing or “T,” shall be a minimum centerline offset of 125 feet.

D. On sloping approaches at an intersection, landings shall be provided with grade not to exceed one foot difference in elevation for a distance of 20 feet approaching a collector or local access street, measured from nearest right-of-way line (extended) of intersecting street in all directions. (Ord. 743, 1997)

15.01.525 Driveways.

A. General.

1. Details of driveway sections are located in the standard drawings.

2. All abandoned driveway areas shall be restored to current city standards.

3. All approach aprons constructed in the right-of-way shall be subject to the same testing and inspection requirements as street construction or curb, gutter, and sidewalk construction.

4. Asphalted approach aprons are required on all new construction and shall be constructed, at a minimum, from the edge of the existing street to the property line.

5. Common approach driveways serving two adjacent parcels may be built upon formal written agreement by both property owners and approval of the city. The agreement shall be a recorded easement for both parcels of land specifying joint usage and maintenance.

6. No commercial access shall be approved where backing onto the sidewalk or street will occur.

B. Collector Streets.

1. No driveway may access a collector street within 50 feet (measured along the collector) of any other such collector street access on either side of the street; provided, that such access may be located directly opposite another access.

2. No driveway access shall be allowed to a collector street from parcels platted after the effective date of the ordinance codified in this chapter.

3. Within the limitations set forth above, access to collector streets within the city shall be limited to one driveway for each tract of property separately owned. Properties contiguous to each other and owned by the same person are considered to be one tract.

C. Width.

1. The maximum driveway width for two-way access drives onto a collector shall be 30 feet for commercial uses. Maximum driveway widths for one-way access drives shall be 24 feet for residential, and 24 feet for commercial. A road approach or wider driveway width may be approved by the city engineer where a substantial percentage of oversized vehicle traffic exists, where divisional islands are desired, or where multiple exit or entrance lanes are needed.

2. Parking lot circulation and signing needs shall be met on site. The public right-of-way shall not be utilized as part of a one-way parking lot flow.

3. Road approaches and/or ingress and egress tapers shall be required in commercially zoned areas, designed to meet current standards. (Ord. 743, 1997)

15.01.530 Sight obstruction.

The following sight clearance requirements take into account the proportional relationship between speed and stopping distance.

The sight distance area is a clear-view triangle formed on all intersections by extending two lines of specified length (A) and (B) as shown below from the center of the intersecting streets along the centerlines of both streets and connecting those endpoints to form the hypotenuse of the triangle. See detail 2-1 at the end of this chapter. The area within the triangle shall be subject to said restrictions to maintain a clear view on the intersection approaches.

Sight Distance Triangle.

A. Stop or Yield Controlled Intersection.


	Sight Distance (Ft.)
	(A)	(B)
Speed Limit	Major Collector	Minor Collector
20 mph	200	*
25 mph	250	*

* Sight distance measured from a point on the minor road 15 feet from the edge (extended) of the major road pavement and measured from a height of eye at 3.50 feet on the minor road to height of object at 4.25 feet on the major road.

B. Uncontrolled Intersection.


	Sight Distance (Ft.)
	(A)	(B)
Speed Limit	Major Collector	Minor Collector
20 mph	90	90
25 mph	110	110

C. The vertical clearance area within the sight distance triangle shall be free from obstructions to a motor vehicle operator’s view between a height of three feet and 10 feet above the existing surface of the street.

D. Exclusions. Sight obstructions that may be excluded from these requirements include: fences in conformance with this code, utility poles, regulatory signs, trees trimmed from the base to a height of 10 feet above the street, places where the contour of the ground is such that there can be no cross visibility at the intersection, saplings or plant species of open growth habits and not in the form of a hedge which are so planted and trimmed as to leave at all seasons a clear and unobstructed cross view, buildings constructed in conformance with the provisions of appropriate zoning regulations and preexisting buildings. (Ord. 743, 1997)

15.01.535 Surfacing requirements.

A. The following are the surfacing requirements for each application listed. These designs are based on Washington stabilometer subgrade R-value of five. Alternate structures will be accepted based on soil tests to determine the actual Washington stabilometer R-value. Soil tests and a completed worksheet for each road classification shall accompany plans submitted if other than the structures shown below are used.

1. Major Collector Streets.

a. Surfacing: 0.50 feet Class B asphalt concrete.

b. Top course: 0.17 feet crushed surfacing top course.

c. Base: 2.0 feet ballast.

2. Minor Collector Streets.

a. Surfacing: 0.33 feet Class B asphalt concrete.

b. Top course: 0.17 feet crushed surfacing top course.

c. Base: 2.0 feet ballast.

3. Local Access Streets.

a. Surfacing: 0.33 feet Class B asphalt concrete.

b. Top course: 0.17 feet crushed surfacing top course.

c. Base: 1.36 feet ballast.

4. Sidewalks.

a. Surfacing: 0.33 feet commercial concrete.

b. Base: 0.17 feet crushed surfacing top course (0.50 feet commercial concrete required in sidewalks at driveway approaches).

5. Approach Apron.*

a. Surfacing: 0.17 feet Class B asphalt concrete.

b. Base: 0.33 feet crushed surfacing top course.

* Required from property line to street edge.

6. Alley.

a. Commercial Zone.

(1) Surfacing: 0.34 feet Class B asphalt concrete.

(2) Base: 0.34 feet crushed surfacing top course.

b. Residential Zone.

(1) Surfacing: 0.34 feet crushed surfacing top course.

(2) Base: 0.34 feet ballast.

7. Walkway/Bikeway (When Not Subject to Vehicular Traffic Loading).

a. Surfacing: 0.17 feet Class B asphalt concrete.

b. Base: 0.17 feet crushed surface top course.

B. One soil sample per each 500 LF of centerline with three minimum per project representative of the roadway subgrade shall be taken to determine a statistical representation of the existing soil conditions.

C. Soil tests shall be performed by an engineering firm specializing in soils analysis.

D. The soils report, signed and stamped by a soils engineer licensed by the state of Washington, shall be based on actual soils tests and submitted with the plans. All depths indicated are a minimum compacted depth. (Ord. 743, 1997)

15.01.540 Temporary street patching.

A. Temporary restoration of trenches shall be accomplished by using 0.17 feet Class B asphalt concrete pavement when available or 0.17 feet medium curing (MC-250) liquid asphalt (cold mix), 0.17 feet asphalt treated base (ATB), or steel plates. Steel plates shall not be used for more than 24 hours without permission of the public works director.

B. ATB used for temporary restoration may be dumped directly into the trench, bladed and rolled. After rolling, the trench must be filled flush with asphalt concrete pavement to provide a smooth riding surface.

C. All temporary patches shall be maintained daily by the contractor until such time as the permanent pavement patch is in place.

D. If the contractor is unable to maintain a patch, with 24 hours’ notice, for whatever reason, the city will patch it at actual cost plus overhead and materials. (Ord. 743, 1997)

15.01.545 Trench backfill and restoration.

A. Trench restoration shall be either by a patch or patch plus overlay as required by the city.

B. All trench and pavement cuts shall be made by spade bladed jackhammer or saw cuts. The cuts shall be a minimum of six inches outside the trench width.

C. All trenching shall be backfilled with crushed surfacing materials conforming to Section 4-04 of the WSDOT/APWA Standard Specifications. Upon the approval of the public works director screenings may be used for backfill. The trench shall be compacted to 95 percent maximum density, as described in Section 2-03 of the WSDOT/APWA Standard Specifications.

If the existing material is determined by the city to be suitable for backfill, the contractor may use the native material except that the top eight inches of trench shall be two and one-half inches minus ballast. All trench backfill materials shall be compacted to 95 percent density. Backfill compaction shall be performed in six-inch lifts. Replacement of the asphalt concrete or Portland concrete cement shall be of existing depth plus one inch or three inches total, whichever is greater. Controlled density backfill may be required in collector streets, as determined by the public works director.

D. Tack shall be applied to the existing pavement and edge of cut and shall be emulsified asphalt grade CSS-1 as specified in Section 9-02.1(6) of the WSDOT/APWA Standard Specifications. Tack coat shall be applied as specified in Section 5-04 of the WSDOT/APWA Standard Specifications.

E. Asphalt concrete Class B shall be placed on the prepared surface by an approved paving machine whenever available or as directed by the director of public works and shall be in accordance with the applicable requirements of Section 5-04 of the WSDOT/APWA Standard Specifications, except that longitudinal joints between successive layers of asphalt concrete shall be displaced laterally a minimum of 12 inches unless otherwise approved by the city engineer. Fine and coarse aggregate shall be in accordance with Section 9-03.8 of the WSDOT/APWA Standard Specifications. Asphalt concrete over two inches thick shall be placed in equal lifts not to exceed two inches each.

All street surfaces, walks or driveways within the street trenching areas affected by the trenching shall be feathered and shimmed to an extent that provides a smooth riding connection and expeditious drainage flow for the newly paved surface. Shimming and feathering as required by the city engineer shall be accomplished by raking out the oversized aggregates from the Class B mix as appropriate or by using class G mix. Surface smoothness shall be per Section 5-04.3(13) of the WSDOT/APWA Standard Specifications. The paving shall be corrected by removal and repaving of the trench only.

F. All joints shall be sealed using paving asphalt AR4000W.

G. When trenching within the roadway shoulder(s), the shoulder shall be restored to its original or better condition. A minimum of two inches crushed rock shall be placed on all shoulder repairs.

H. The final patch shall be completed as soon as possible; however, no longer than 30 days after first opening the trench. This time frame may be adjusted if delays are due to inclement paving weather, or other adverse conditions that may exist. However, delaying of final patch or overlay work is allowable only subject to the city engineer’s approval. The city engineer may deem it necessary to complete the work within the 30 days’ time frame and not allow any time extension. If this occurs, the contractor shall perform the necessary work as directed by the city engineer. (Ord. 743, 1997)

15.01.550 Staking.

B. A pre-construction meeting shall be held with the city prior to commencing staking. All construction staking shall be inspected by the city prior to construction.

C. The minimum staking of streets shall be as directed by the city engineer or as follows:

1. Stake centerline every 50 feet in tangent sections and 25 feet in curved sections plus grade breaks, PVCs, PVTs, high points and low points, with cut and/or fill to subgrade.

2. Stake top of ballast and top of crushed surfacing at centerline and edge of pavement at the above-described intervals.

3. Stake top back of curb at the above-described intervals with cut or fill to finished grade. (Ord. 743, 1997)

15.01.555 Testing.

A. Testing shall be required at the developer’s or contractor’s expense. The testing shall be ordered by the developer or contractor and the chosen testing lab shall be approved by the city construction inspector. Testing shall be done on all materials and construction as specified in the WSDOT/APWA Standard Specifications and with frequency as specified herein.

B. In addition, the city shall be notified at least 48 hours prior to each phase of street construction commencing (i.e., staking, grading, subgrade, ballast, base, top course, and surfacing). (Ord. 743, 1997)

15.01.560 Sidewalks, curbs and gutters – General.

All properties within CB zones of the city shall, in conjunction with new construction on such properties or alterations or improvements which constitute 25 percent or more of the assessed value of the existing structures on the property, have sidewalks, curbs and gutters constructed or reconstructed along abutting streets as required in the Langley Municipal Code.

Curbs and gutters must also be constructed, in residential zones, along the abutting street when the city engineer determines that the conditions of drainage require curbs and gutters. (Ord. 743, 1997)

15.01.565 Design standards.

A. Plans for the construction of sidewalks, curbs and gutters are to be submitted as part of the street plans when applicable.

B. The city has set forth minimum standards as outlined in Section 15.01.040 which must be met in the design and construction of sidewalks, curbs and gutters. Because these are minimum standards, they may be modified by the city engineer should he feel circumstances require increased or decreased widths. (Ord. 743, 1997)

15.01.570 Sidewalks.

A. Sidewalks shall be constructed as outlined in Section 15.01.535. Sidewalks through a driveway approach shall be six inches thick paving with a four-inch base course.

B. Subgrade inspection by the city is required before a sidewalk is poured.

C. Monolithic pour of curb, gutter and sidewalk will not be allowed. (Ord. 743, 1997)

15.01.575 Curb and gutter.

A. Cement concrete curb and gutter shall be used for all street edges in the CB zone. All curbs and gutters shall be constructed of commercial concrete as shown in the standard plans. No rolled curb will be allowed.

B. Extruded curb and gutter per WSDOT/APWA Standard Specifications is allowed upon approval of the city engineer.

C. Form and subgrade inspection by the city are required before curb and gutter are poured.

D. The face or top of all new curbs shall be embossed to denote the location of water and sewer services crossings. Water services shall be marked one-quarter inch into concrete with a “W” and side sewers shall be marked with an “S.” (Ord. 743, 1997)

15.01.580 Curb ramps.

A. All sidewalks must be constructed to provide for curb ramps in accordance with the standards of WAC 51-30-1106.4.7.

B. Curb ramps shall be constructed of commercial cement. Form and subgrade inspection by the city are required before curb ramp is poured. (Ord. 743, 1997)

15.01.585 Staking.

B. A pre-construction meeting shall be held with the city prior to commencing staking. All construction staking shall be inspected by the city prior to construction.

C. The minimum staking of curb, gutter and sidewalk shall be as directed by the city engineer or as follows:

D. Stake top back of curb every 50 feet in tangent sections and 25 feet in curved sections plus grade breaks, PVCs, PVTs, high point and low points, with cut or fill to finished grade. (Ord. 743, 1997)

15.01.590 Testing.

A. Testing shall be required at the developer’s or contractor’s expense on all materials and construction as specified in the WSDOT/APWA Standard Specifications.

B. At a minimum, one slump test and two test cylinders shall be taken once per day.

C. In addition, the city shall be notified 48 hours in advance of each phase of sidewalk, curb and gutter construction commencing. (Ord. 743, 1997)

15.01.595 Walkways – General.

Walkway or trail construction is required in conjunction with any new development or redevelopment where the estimated cost of improvements on such properties exceeds 25 percent of the assessed value of the existing structures, or plat or short plat approval, when the need for such a bikeway is indicated in either the Langley comprehensive plan or the Island County trails plan. (Ord. 743, 1997)

15.01.600 Design standards.

A. The design of walkways shall depend upon their type and usage. Walkway surfacing shall be as outlined in Section 15.01.535.

B. All minimum design standards as set forth in Section 15.01.040 shall apply.

C. Normally, walkways are shared with other transportation modes, although they may be provided exclusively for pedestrian use. Walkways are categorized as follows:

1. Class I: Facilities are separated from automobile traffic. This class includes independent paths both inside and outside of the roads’ rights-of-way. In effect, the system is exclusive. For pedestrian facilities, Class I includes sidewalks.

2. Class II: Pedestrians and bicyclists use the existing roadway, but are set off by a painted stripe or curb. These facilities include shoulders signed as bikeways, shoulders signed for both bicyclists and pedestrians, and gravel shoulders signed for equestrian travel. This class is best thought of as restrictive.

3. Class III: Bicyclists share the roadway with either pedestrians or automobiles. Pedestrians share gravel shoulders with equestrians. It is a minimal system of signed routes along shoulders.

D. New Development.

1. Local Access Streets. Walkways shall be required on both sides of local access streets interior to the development and on the development side of local access streets abutting the exterior of said development including cul-de-sacs.

2. The design and construction of all walkways shall meet the following minimum standards:

a. The width of walkways shall be as shown in the street design drawings. Those walkways designated in the bike plan of the city as bike paths shall in addition meet the minimum width requirements established for said bike paths. The design of all walkways shall provide for a gradual rather than an abrupt transition between walkways of different widths or alignments. (Ord. 743, 1997)

15.01.605 Staking and testing.

Staking and testing shall be done in accordance with street staking and testing as outlined in Sections 15.01.550 and 15.01.555. (Ord. 743, 1997)

15.01.610 Illumination – General.

All new commercial or residential subdivisions, short plats or property development requiring review by the city engineer and planning official shall provide street lights in accordance with the standards for such improvements of the city and they shall be owned and operated by the city. (Ord. 743, 1997)

15.01.615 Design standards.

A. A street lighting plan submitted by the applicant and approved by the city engineer shall be required for all street light installations. Type of installation shall be as set forth in WSDOT/APWA Standard Specifications and as directed by the city except where noted herein.

B. All public street light designs shall be prepared by an engineering firm capable of performing such work. The engineer shall be licensed by the state of Washington. All developments shall submit the lighting plan on a separate sheet. After system is completed and approved, a set of “as built” mylars shall be submitted to the city as a permanent record.

C. All street light electrical installations including wiring conduit and power connections shall be located underground.

D. The general notes, available from the public works department, need to be included on any plans dealing with street design in addition to all applicable requirements as set forth in Section 15.01.040. (Ord. 743, 1997)

15.01.620 Staking.

B. A pre-construction meeting shall be held with the city prior to commencing staking. All construction staking shall be inspected by the city prior to construction.

C. The minimum staking of luminaries shall be as follows:

1. Location and elevation to the center of every pole base.

2. Location and elevation of each service disconnect. (Ord. 743, 1997)

15.01.625 Testing.

All illumination systems shall be subject to an electrical inspection which shall include megger testing and functional test. Lamp, photocell and fixture shall be under warranty for a period of one year. (Ord. 743, 1997)

15.01.630 Roadside features – General.

Miscellaneous features included herein shall be developed and constructed to encourage the uniform development and use of roadside features wherever possible. (Ord. 743, 1997)

15.01.635 Design standards.

The design and placement of roadside features included herein shall adhere to the specific requirements as listed for each feature, and, when applicable, to the appropriate standards as set forth in Sections 15.01.025 and 15.01.040. (Ord. 743, 1997)

15.01.640 Staking.

B. A pre-construction meeting shall be held with the city prior to commencing staking. All construction shall be inspected by the city prior to construction. (Ord. 743, 1997)

15.01.645 Testing.

Testing shall be required at the developer’s or contractor’s expense on all materials and construction as specified in the WSDOT/APWA Standard Specifications and with a frequency as specified in the WSDOT Construction Manual. (Ord. 743, 1997)

15.01.650 Survey monuments.

A. All existing survey control monuments which will be disturbed or destroyed during construction shall be referenced prior to construction and replaced after construction by a professional land surveyor licensed by the state of Washington. All applicable RCWs and WACs will be complied with, including, but not limited to, Chapters 332-120 and 332-130 WAC and Chapter 58.09 RCW. The monuments shall be replaced with the proper type as outlined in subsection (B) of this section at the expense of the responsible builder or developer.

B. Street Type – Major Collector, Minor Collector, and Local. A precast concrete monument with cast iron monument case and cover installed per city of Langley standards is required.

C. Monument Locations. Appropriate inner-visible monuments as outlined in subsection (A) or (B) of this section shall be placed:

1. At all street intersections;

2. At the PC and PTs of all horizontal curves or at the PI if it lies in the traveled roadway;

3. At all DLC corners, section corners, quarter corners and sixteenth corners that fall within the subdivision. Where these points fall outside of the pavement or sidewalks, a poured-in-place monument per city of Langley standards shall be set so that the top of the monument is one foot below the surface of the ground.

4. At all corners of a subdivision.

D. The monument case shall be installed after the final course of surfacing has been placed. (Amended during 2013 reformat; Ord. 743, 1997)

15.01.655 Mailboxes.

A. During construction, existing mailboxes shall be accessible for the delivery of mail or, if necessary, moved to a temporary location. Temporary relocation shall be coordinated with the U.S. Postal Service. The mailboxes shall be reinstalled at the original location or, if construction has made it impossible, to a location as outlined below and approved by the U.S. Postal Service.

B. Location.

1. Bottom or base of box shall be 36 to 42 inches above the road surface.

2. Front of mailbox 18 inches behind vertical curb face or outside edge of shoulder.

3. New Developments. Clustered mailboxes are required. Contact the U.S. Postal Service for details. See detail 2-18.

C. Mailboxes shall be set on posts strong enough to give firm support but not to exceed four-by-four-inch wood or one one-and-one-half-inch diameter pipe, or material and design with comparable breakaway characteristics. (Ord. 743, 1997)

15.01.660 Guard rails.

For purposes of design and location, all guard rails along roadways shall conform to the criteria of the “Washington State Department of Transportation Design Manual” as may be amended or revised. (Ord. 743, 1997)

15.01.665 Retaining walls.

A. Rock walls may be used for erosion protection of cut or fill embankments up to a maximum height of eight feet in stable soil conditions which will result in no significant foundation settlement or outward thrust upon the walls. For heights over four feet or when soil is unstable, structural wall of acceptable design stamped by a licensed structural engineer shall be used. Rock walls over four feet high shall be subject to inspection by a geotechnical engineer as outlined in the following paragraph.

Any rock wall over 30 inches high in a fill section shall require an engineered design by a geotechnical engineer. The geotechnical engineer shall continuously inspect the installation of the wall as it progresses and shall submit inspection reports, including compaction test results and photographs taken during the construction, documenting the techniques used and the degree of conformance to the geotechnical engineer’s design.

In the absence of such a rock wall design, walls having heights over four feet or walls to be constructed in conditions when soil is unstable require a structural wall having a design approved by the public works department or the building department if outside the right-of-way. The design of structural walls shall be by a professional engineer qualified in retaining wall design. Structural walls require issuance of a building permit prior to construction.

B. The rock material shall be as nearly rectangular as possible. No stone shall be used which does not extend through the wall. The rock material shall be hard, sound, durable and free from weathered portions, seams, cracks and other defects. The rock density shall be a minimum of 160 pounds per cubic foot.

C. The rock wall shall be started by excavating a trench having a depth below subgrade of one-half the base course or one foot (whichever is greater).

D. Rock selection and placement shall be such that there will be minimum voids and, in the exposed face, no open voids over six inches across in any direction. The final course shall have a continuous appearance and shall be placed to minimize erosion of the backfill material. The larger rocks shall be placed at the base of the rockery so that the wall will be stable and have a stable appearance. The rocks shall be placed in a manner such that the longitudinal axis of the rock shall be at right angles or perpendicular to the rockery face. The rocks shall have all inclining faces sloping to the back of the rockery. Each course of rocks shall be seated as tightly and evenly as possible on the course beneath. After setting each course of rock, all voids between the rocks shall be chinked on the back with quarry rock to eliminate any void sufficient to pass a two-inch square probe.

E. The wall backfill shall consist of quarry spalls with a maximum size of six inches and a minimum size of four inches or as specified by a licensed engineer. This material shall be placed to a 12-inch minimum thickness between the entire wall and the cut or fill material. The backfill material shall be placed in lifts to an elevation approximately six inches below the top of each course of rocks as they are placed, until the uppermost course is placed. Any backfill material on the bearing surface of one rock course shall be removed before setting the next course.

F. Perforated drainage pipe and filter fabric shall be installed as per city of Langley standard drawings. This pipe requirement may be waived by the engineer upon a showing by the developer that no subsurface water problem exists. (Ord. 743, 1997)

15.01.670 Landscaping.

Maintenance. All developments required to plant landscaping in the right-of-way will also be required to maintain the landscaping for the life of the project, regardless of ownership. (Ord. 743, 1997)

15.01.680 Grading – Applicability.

No person shall do any excavating or filling in excess of 50 cubic yards over the lifetime of the fill or excavation or do any grading or filling in a sensitive area prior to having first obtained a grading permit from the city. This section is applicable to any of the permits/approvals specified in this section, including all building and sewage permits in sensitive areas, and these requirements are in addition to the city’s shoreline permit requirements for grading in shoreline areas. Areas designated as sensitive are, for the purpose of this chapter:

A. Wetland and stream areas. All lands within 100 feet of wetlands or streams as defined in Chapter 16.20 as it now exists or is hereafter amended.

B. Steep/unstable slope areas.

1. All lands having greater than 15 percent slopes on which grading is proposed as a part of a land development action.

2. Those lands designated in the Department of Ecology Coastal Zone Atlas of Island County dated April 1979, as having recent or historical slide and/or indicative of intermediate or unstable slope conditions, and those lands within 100 feet thereof, or supplemental information related thereto.

C. Flood hazard/high-water table areas. (Ord. 743, 1997)

15.01.685 Permit – Exempt activities.

A. Grading in an isolated, self-contained area if there is no danger apparent to private or public property when approved by the building official.

B. Refuse disposal sites controlled by other regulations.

C. Grading not to exceed an area of one acre incidental to a city of Langley residential building permit unless otherwise specified in Section 15.01.680.

D. Excavations and filling of cemetery graves.

E. Grading, mining, or extractions which are regulated by the city of Langley zoning ordinance, provided such provisions do not affect the lateral support or increase the stress in or pressure upon any adjacent or contiguous property.

F. Grading pursuant to an approved public road access permit wherein the provisions of this chapter have been considered for the entire scope of the grading proposal.

G. Work required for the repair, replacement, reconstruction, or widening of an existing public road or utility in an existing right-of-way/easement when project plans/departmental policies govern the activity consistent with this chapter, except that disposal of excavated material outside the project area must either occur at an approved public site or the property owner of the disposal site must have received an approved grading permit from the city, as applicable.

H. Work required for the construction of private roadways/utilities necessitated by and/or being reviewed as those actions specified in Sections 15.01.680 through 15.01.720, where erosion control, drainage, and slope stability reports/plans are pre-approval requirements.

I. Exploratory excavations under the direction of a registered soils engineer or professional geologist.

J. Exploratory excavations performed as a prerequisite of septic drain field approval so long as work is performed more than 40 feet from the top of identified unstable slopes.

K. Grading incidental to construction/repair of a bulkhead for protection of an existing single-family residence; provided, that the applicant has an exemption from a shoreline management substantial development permit.

L. Grading activities which are regulated by this section, but for which review has occurred, and conditions specified in compliance with this section, as applicable, as a requirement for approval of a land development action of permit listed in Section 15.01.020. (Ord. 743, 1997)

15.01.690 Required information for permits – Preliminary plan.

Every person, corporation, etc., who desires to undertake grading activities subject to the requirements of this chapter shall first make application to the city. A preliminary grading plan shall be submitted, specifying the construction site, soil profile, waste disposal areas, erosion control methods, schedule of operation, existing and proposed topography, composition of fill or waste, location of physical features, property boundaries, drainage control plans, intended use of the property and other such information as the city may deem necessary. The city may waive specific items due to the simplicity and relative safety of the proposed project. The city shall either grant, deny, or specify any additional requirements within a 15-working day period, commencing on the date a complete application is received by the city. (Ord. 743, 1997)

15.01.695 Homesite evaluations (when required).

A. A homesite evaluation shall be prepared by a geotechnical engineer, licensed in the state of Washington, for structural development which is proposed to occur within sensitive unstable slope areas as defined by Section 15.01.680(B)(2), except in those instances wherein the structure is set back from the line of the uppermost scarp a horizontal distance of no less than one-third the height of the scarp, plus 40 feet, at the time of construction, and except in those cases when not required by the city after suitable investigation. Homesite evaluations are to be submitted as addendums to the grading permit application and in lieu of a detailed grading plan.

B. Applications for developments wherein the stability of the property has been evaluated by qualified consultants, in compliance with this section, as a requirement for approval of a previous application, shall be able to fulfill this requirement with a suitable addendum to the original homesite/development evaluation prepared and submitted by the same consultant/firm, wherein a specific proposal is compared to the original proposal/concept. Approved subdivisions or development plans which required an analysis of stability in compliance with this section as a prerequisite of approval, for example, would not require new homesite/development evaluations for each lot, if setbacks and similar considerations were adequately addressed in the original report and site conditions remain essentially the same. (Ord. 743, 1997)

15.01.700 Detailed grading plan (when required).

The city may require that a detailed grading/drainage plan be prepared by a soils engineer/engineering geologist/hydrologist with demonstrated qualifications to develop a specific report citing the adequacy of the site to support the proposed immediate and long-term intended use of the property. Such plans shall be submitted to the city engineer for review and approval and shall include a soil engineering and engineering geology report with specific conclusions, recommendations, implementation, inspection, and certification procedures. (Ord. 743, 1997)

15.01.705 Completion of grading work.

Upon completion of all work authorized/required by these provisions, the responsible consultant shall certify that the grading is complete in accordance with the grading plan as approved or modified. Projects involving complex slopes and drainage conditions shall require submittal of an “as-built” grading plan to certify compliance with these provisions. (Ord. 743, 1997)

15.01.710 Prohibitions.

Side casting over shoreline bluff areas is expressly prohibited by this chapter. (Ord. 743, 1997)

15.01.715 Performance bond – Grading permit.

The city engineer may require, as a condition to the granting of a permit, that the applicant furnish a performance bond, naming the city as obligee. The bond shall secure the applicant’s obligation, after the approved land clearing has been accomplished, to complete the restoration and replanting of the property in accordance with the terms of his permit and within the term thereof. The bond shall be in an amount equal to the estimated cost of such restoration and replanting and with surety and conditions satisfactory to the city engineer. (Ord. 743, 1997)

15.01.720 Appeals.

Any person or persons aggrieved by any action of the city engineer may within 10 days of such action file a notice of appeal with the hearing examiner setting forth the reasons for such appeal. The hearing examiner shall hear and determine the matter and may affirm, modify or disaffirm the administrative decision within 45 days of the filing of notice of appeal. (Ord. 957 § 3, 2011; Ord. 743, 1997)

15.01.725 Land clearing – Intent.

A. Intent. It is the desire of the city to preserve and enhance the physical and aesthetic character of the community, to promote land development practices that minimize disturbance to vegetation and soils, minimize surface water and ground water runoff and diversion, prevent erosion, and reduce risk of slides.

B. Requirements. No person shall remove any significant tree from a parcel of land without first obtaining approval of a land clearing permit for an approved timber harvest or other specified use requiring the land clearing. Clearing and removal of significant trees may be approved as part of a development action or permit as set forth in Section 15.01.020, or consistent with an approved plat.

C. Tree Protection Encouraged. Developers are strongly encouraged to retain as many native trees and as much undergrowth as feasible in support of the city’s policy of promoting native landscape retention. (Ord. 1004 §§ 2 (Exh. C), 4 (Exh. E), 2014; amended during 2013 reformat; Ord. 966 § 1, 2012; Ord. 743, 1997)

15.01.730 Tree protection during construction.

A. Intent. It is the desire of the city to protect trees designated for preservation during construction projects.

B. Applicable Projects. The standards in this section shall apply for any construction project where one or more trees or a group of trees have been designated for preservation, including such trees located within the public right-of-way adjacent to the project site.

C. Tree Protection Plan. For all applicable projects, the applicant is required to prepare a tree protection plan that maps all trees or groups of trees designated for preservation, the drip line for individual trees and/or groups of trees, the building footprint for all proposed structures, all proposed impervious surfaces and existing and proposed overhead and underground utilities (including irrigation systems).

D. Tree Valuation and Bond Requirement. Each tree designated for preservation shall be assigned a monetary valuation based upon standards available from national arborist associations, such as the ISA Council of Tree and Landscape Appraisers (CTLA). Project proponents are required to submit a bond or other form of surety acceptable to the city equal to the total valuation of the trees designated for preservation.

E. Protective Fencing. To protect trees during construction, the developer must install and maintain throughout the life of the development a temporary chain link or durable plastic net fence over an area one and one-half times the radius of the average drip line of the individual or group of trees to be protected. No filling, excavation, clearing, vehicle or equipment use or storage of construction materials shall be permitted within the areas defined by protective fencing. All requests to vary from this standard based on specific site circumstances must be proposed as part of the tree protection plan and approved by the planning official. Depending on species, permanent retaining walls at the drip line may be used to maintain grade level around individual or stands of protected trees.

F. Signage on Fence. No fewer than two signs shall be affixed to the protective fence citing the ordinance codified in this section and penalties for violation. Exact language shall be provided by the planning official.

G. Alternative Methods. Alternative methods of tree protection that provide equal or greater protection than the standards in this section that have been approved by a certified arborist may be used subject to approval by the planning official.

H. Inspection and Enforcement. The city planning official or his/her designee is authorized to enforce the provisions of this section. Regular inspections of the project site will be performed by the planning official to confirm that the requirements and conditions of the tree management plan are being followed.

I. Violations and Penalties. Violations shall be investigated by the planning official or designee and penalties assessed according to the following:

1. Actions Removing or Severely Damaging Trees Designated for Protection. Violations that result in the removal of or severe damage to a tree or trees designated for protection shall result in the forfeiture of that portion of the bond corresponding to the valuation of the trees so removed or severely damaged. “Severely damaged” shall be defined as the severing of three or more major roots or the tap root, the greater than incidental stripping of bark from a tree, the greater than incidental application of herbicides within the drip line, topping the tree, or removal of more than one-third of the live crown. The determination that a tree has been severely damaged shall be made by an ISA-certified arborist hired by the city and the costs of the determination shall be paid for by the developer. Moneys collected by the city as a result of bond forfeiture shall be used solely to plant new trees or maintain existing trees.

2. Actions Causing Damage to Trees Designated for Protection. Damage to trees that is not covered in subsection (I)(1) of this section shall be subject to a fine of $500.00. In addition, the planning official may require that the developer retain an ISA-certified arborist to prepare and implement mitigation measures to repair the damage.

J. Enforcement Action and Appeal.

1. Any enforcement action for violation of this section shall follow the procedures set forth in Chapter 1.14; provided, however, that any fine that is imposed as part of an enforcement action shall be in accordance with subsection (I) of this section, and any appeal of an enforcement action shall be to the hearing examiner in a manner consistent with Section 15.01.720. (Ord. 966 § 2, 2012)

15.01.735 Modifications and appeals.

A. In cases where unusual topographic conditions, nature of existing construction, unique development design or similar factors would make adherence to the width, design or alignment standards of this chapter undesirable or impracticable, the requirements may be modified, if not otherwise provided herein, upon written request as follows:

1. Up to 10 percent variation from any numerical standard contained within this chapter by the planning official in cases involving short subdivisions.

2. By final approval of the city planning official approving any development actions or permits listed in Section 15.01.020 over which the planning official has final authority. Conditions may be attached to an approval which are necessary to protect the public interest and carry out the purpose of this chapter.

3. By the hearing examiner of Langley in approving any development actions listed in Section 15.01.020 over which the hearing examiner of Langley has final approval authority. (Ord. 957 § 4, 2011; Ord. 743, 1997)

15.01.740 Changes to standards.

From time to time, changes may be needed to add, delete, or modify the provisions of these standards. These standards may be changed and, upon adoption by the city council, shall become effective and shall be incorporated into the existing provisions. (Ord. 743, 1997)

15.01.745 Applications – Forms.

The applications and forms for work as outlined in Section 15.01.020 shall be on forms as prescribed by the city administration. (Ord. 743, 1997)

15.01.750 Caveat and disclaimer.

It is the specific intent of this chapter to place the obligation of complying with its requirements upon the owner of the property or land within its scope, and no provisions or term used in this chapter are intended to impose any duty whatsoever upon the city or any of its officers or employees running to any specific person or entity. Nothing contained in this chapter shall be construed as a guarantee or warranty on the part of the city that site development has been or will be accomplished in accordance with the provision of this chapter, nor shall it be construed to create or form the basis for any liability on the part of the city or its officers, employees or agents for any injury or damage resulting from the failure of an owner of property or land to comply with the provisions of this chapter, or by reason or in consequence of any inspection notice, order, certificate, permission or approval authorized or issued or done in connection with the implementation or enforcement of this chapter, or by reason of any action or inaction on the part of the city related in any manner to the enforcement of this chapter by its officers, employees, or agents. (Ord. 743, 1997)

15.01.755 Enforcement and penalties.

A. Enforcement responsibilities lie with the city agencies responsible for administration of the permits and/or approvals identified in Section 15.01.020 unless otherwise provided herein.

B. Any enforcement action, for violation of this chapter, shall follow the procedure outlined in Sections 1.15.010 and 1.15.020 as they currently exist or are hereafter amended. (Ord. 743, 1997)

15.01.760 Fees and charges.

The city of Langley council shall levy such fees and charges as are necessary for the administration or review of the applications, plans, or permits required, to the end that the individuals benefiting from said actions will bear the costs of administration and review. (Ord. 743, 1997)

15.01.765 Codification.

This ordinance shall be codified as a separate chapter in Title 15, said chapter to be entitled “General Provisions.” Each codified section shall be in the same order as set forth in this ordinance. (Ord. 743, 1997)