Chapter 18A.60
AIRPORT OVERLAYS Revised 3/18

Sections:

18A.60.010    Purpose.

18A.60.020    McChord Air Force Base Area of Influence.

18A.60.030    Pierce County Airport – Thun Field Airport Area of Influence.

18A.60.040    Noise Insulation.

18A.60.050    Performance Criteria.

18A.60.060    Intensity of Use Criteria.

18A.60.070    Divided Properties.

18A.60.080    Airport Overlays – Small Airports. Revised 3/18

18A.60.090    Rural Airport Overlay.

18A.60.010 Purpose.

The purpose of the Airport Overlay is to minimize land use incompatibilities for McChord Air Force Base and Pierce County Airport/Thun Field. Provisions of this Section address reduction of incompatibilities with these airports through performance standards, building coverages, limitations on the number of persons on site at any one time, limitations on allowed uses and/or construction of buildings with noise attenuation features, depending upon the situation. Uses permitted and reviews required for activities within the Airport Overlay vary depending on the designation given to the particular airport. (Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.020 McChord Air Force Base Area of Influence.

A.    McChord I (Accident Potential Zone (APZ) I).

1.    The following specific civic uses as defined by PCC 18A.33.220 which result in large concentrations of people are prohibited: Administrative Government Facilities and Services, Community and Cultural Services, Education, Health Services, specifically hospitals and institutional facilities, Recreation, specifically regional parks, Religious Assembly and Public Safety Services, specifically correctional facilities.

2.    All non-residential uses within McChord I shall comply with the performance and intensity of use criteria set forth in PCC 18A.60.050 and 18A.60.060.

3.    No new residential dwelling units shall be permitted in McChord I, unless building permits were submitted prior to July 21, 1995. On lots in McChord I containing residential dwellings as of July 21, 1995, no additional dwelling units, including accessory dwelling units, shall be permitted. Remodeling and expansion of existing dwelling units or common areas is permitted as long as the number of dwelling units is not increased over that existing on July 21, 1995.

(Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.030 Pierce County Airport – Thun Field Airport Area of Influence.

A.    Pierce County Airport-Thun Field Area of Influence. Thun Field Aircraft Accident Safety Zones 1-6.

1.    All non-residential uses within Thun Field Area of Influence, Aircraft Accident Safety Zones 1-6, shall be subject to PCC 18A.60.050, Performance Criteria, and PCC 18A.60.030 A.3. through 7. below.

2.    No new residential dwelling units shall be permitted in the Thun Field Area of Influence, with the exception of Zones 4 and 6, unless building permits were submitted prior to June 16, 2003. On lots in the Thun Field Area of Influence, with the exception of Zones 4 and 6, containing residential dwellings as of June 16, 2003, no additional dwelling units, including accessory dwelling units, shall be permitted. Remodeling and expansion of existing dwelling units or common areas is permitted as long as the number of dwelling units is not increased over that existing on June 16, 2003.

3.    Large concentrations of people shall be prohibited within the Pierce County Airport Area of Influence Aircraft Accident Safety Zones 1-6. Non-residential uses or activities shall meet this standard by complying with either (1) or (2) below:

a.    Large concentrations of people shall be calculated by the number of people the proposed building(s) would accommodate per gross acre. The concentration standard varies by Accident Safety Zones (see (b) below).

(1)    Calculation Method. To determine the number of people that a building or use would accommodate, the following methods shall be used depending on the type of use:

(a)    Other Than Education Use Type. The number of people that a building(s), other than those associated with an Education Use Type, can accommodate shall be calculated by multiplying the total number of proposed parking stalls by two.

Example:

500

(proposed parking stalls)

x 2

 

1,000

(assumed number of people for the site)

(b)    Education Use Type. The number of people that a site associated with an Education Use Type can accommodate shall be the building's maximum occupancy load per the County's adopted Building Code divided by two.

Example:

1,600

(calculated building codes, Title 17C PCC), maximum occupancy load)

÷ 2

(reduction figure)

800

(assumed number of people for the site)

(c)    Combination of Education and Religious Assembly Use Types on One Site/Building. The number of people that a site can accommodate if it has buildings that facilitate both Education Use Types and Religious Assembly Use Types shall be the total number of proposed parking stalls multiplied by two, or the maximum occupancy load per the County's adopted Building Code for the identified Education Use Type building divided by two, whichever is greater.

Examples:

Educational Use Type Building

900

(calculated building codes, Title 17C PCC) maximum occupancy load)

÷ 2

(reduction figure)

450

(assumed number of people for the site)

 

 

Religious Assembly Use Type Building

75

(proposed parking stalls)

x 2

 

150

(assumed number of people for the site)

In this example, 450 would be the assumed number of people for the site, and used in determining if the use met the standard below.

(2)    Standard. The concentration standard for each Safety Accident Zone is defined as follows:

Safety Accident Zone 1, 2, 5 – greater than 5 people per gross acre

Safety Accident Zone 3 – greater than 25 people per gross acre

Safety Accident Zone 4 – greater than 40 people per gross acre

Safety Accident Zone 6 – greater than 100 people per gross acre

Example: Zone 6

1,000

(assumed number of people for the site per PCC 18A.60.030 A.3.a.(1)

÷ 8

(site acreage)

125

(concentration of persons per gross acre)

Since 125 persons per gross acres is higher than the standard for Zone 6, 100, the proposed use in this example would not meet the standard and is not allowed; or

b.    Alternatively, the prohibition of large concentrations of people within the Pierce County Airport Area of Influence can be accomplished by limiting the building coverage portion of the site. The building coverage associated with a non-residential activity within the Pierce County Airport Area of Influence cannot exceed 20 percent of the site in Safety Accident Zones 1-5, and 25 percent in Safety Accident Zone 6.

4.    Any buildings and structures that would penetrate the imaginary airspace surfaces for the Pierce County Airport (Thun Field) as defined in Title 14 CFR (Code of Federal Regulations) FAR (Federal Aviation Regulations) Part 77 "Objects affecting navigable airspace" shall be prohibited. The imaginary airspace surfaces (maximum elevations) are identified on the Pierce County Airport – Thun Field Airport Airspace Drawing.

5.    No use, building or structure that promotes large concentrations of bulk storage of flammable/hazardous substances or materials shall be permitted within Accident Safety Zones 1-5.

6.    Prior to issuance of a Building Permit for new construction within the Pierce County Airport Area of Influence, the property owner must sign an airport proximity disclosure statement and record it in the Pierce County Auditor's office. The disclosure statement acknowledges that the property is located within 4,500 feet of the Pierce County Airport as indicated on the Pierce County Airport Area of Influence map and that the property may be impacted by low flying aircraft, noise, vibration, odors, and other associated aviation activities.

7.    The expansion of an existing business within the Pierce County Airport Area of Influence shall comply with PCC 18A.60.050, Performance Criteria, and 18A.60.030 A.4. and 5.

(Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.040 Noise Insulation.

Provisions for noise insulation apply to uses within the 65 Ldn Noise Contour for McChord Air Force Base, Thun Field and the following airport designations: McChord Air Force Base: Clear Zone, APZ I, and APZ II; and Thun Field: Object Free Area, Runway Protection Zone, and Transitional Surface Area.

A.    Noise Insulation Required. All new residential dwelling units and the portion of new non-residential structures where the public is received or where offices are proposed must be constructed with sound insulation or other means to achieve a day/night interior noise level (Ldn) of no greater than 45 dB. A remodeling project where the total cost of improvements is 75 percent or more of the valuation of the existing building must also meet this standard.

B.    Certified by an Acoustical Expert. An engineer registered in the State of Washington who is knowledgeable in acoustical engineering, an architect registered in the State of Washington who is knowledgeable in acoustic design, or an industrial hygienist must certify that the building plans comply with the performance standard for sound insulation prior to the issuance of a Building Permit.

C.    Noise Contour Maps. A set of noise contour maps, known as the Pierce County 65 Ldn Noise Contour Maps, is available for review at the Department.

D.    Noise Disclosure Statement. Prior to the issuance of a Building Permit for new construction or remodeling where the total cost of improvements is 75 percent or more of the valuation of the existing building, the property owner must sign a noise disclosure statement and record the statement with the title of the property. The noise disclosure statement acknowledges that the property is located within the 65 Ldn contour, as indicated on the Pierce County Noise Contour Maps, and that noise attenuation is required of any new construction or remodeled structure where it meets the threshold.

(Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.050 Performance Criteria.

The following performance criteria shall be used by the Director or Examiner in determining the compatibility of a use, the project design, and any mitigation measures with aircraft operations within Clear Zones, "FAR Part 77 Imaginary Surfaces," or within the Accident Potential Zones, as required in PCC 18A.60.020 A.:

A.    Prohibit any new use which involves release of airborne substances, such as steam, dust, and smoke which interfere with aircraft operations;

B.    Prohibit any new use which emits light, direct or indirect (reflections), which interfere with a pilot's vision;

C.    Facilities which emit electrical currents shall be installed in a manner that does not interfere with communication systems or navigational equipment;

D.    Prohibit any new use which attracts concentrations of birds or waterfowl (i.e., mixed solid waste landfill disposal facilities, waste transfer facilities, feeding stations, and the growth of certain vegetation); and

E.    Prohibit any use which would have structures within 100 feet of aircraft approach-departure or transitional surfaces.

(Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.060 Intensity of Use Criteria.

The intensity of use criteria shall be used by the Director or Examiner in determining the compatibility of a non-residential use with aircraft operations, as required in PCC 18A.60.020 and 18A.60.030. Provisions for the intensity of use criteria are as follows:

A.    One of the following criteria must be met:

1.    The building coverage cannot exceed 20 percent; or

2.    The number of persons on site during any particular hour cannot exceed that permitted by the following formula: an average of 25 persons per hour-per acre in a 24-hour period; provided, there shall be no more than 50 persons per acre during any hour of the day.

B.    It is the applicant's burden to provide adequate information to indicate that the operation will comply with the formula in PCC 18A.60.060 A.2. above. If an applicant can demonstrate that they can comply with the formula, a notice shall be required to be recorded with the County Auditor prior to issuance of Building Permits.

C.    Existing developments that exceed the 20 percent building coverage may not expand the building coverage without complying with the limitation on the number of persons on site during any particular hour.

(Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.070 Divided Properties.

Where the Pierce County 65 Ldn Noise Contour divides a lot of record, the entire lot shall be subject to the noise insulation requirements of PCC 18A.60.040. The applicant may be exempted from noise insulation requirements on divided lots if an acoustical engineer provides documentation that the portion of the site in question has a noise level below 65 Ldn. (Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.080 Airport Overlays – Small Airports. Revised 3/18

A.    Purpose. The purpose of the Airport Overlay-Small Airports zone classification, AIR SA, is to minimize land use incompatibilities for small airports, such as the Shady Acres Airport in Graham/Frederickson and Eatonville Airport (Swanson Field) in Eatonville. Provisions of this Section address reduction of incompatibilities through limitations on usage intensity and other land use characteristics which could affect the severity of an aircraft accident. Mitigation and attenuation features may be appropriate, depending upon the situation.

B.    Height Standard. For each airport, any buildings or structures that would penetrate the imaginary airspace surfaces as defined in Title 14 CFR (Code of Federal Regulations) FAR (Federal Aviation Regulations), Section 77.25 "Civil Airport Imaginary Surfaces, Objects affecting navigable airspace," or would otherwise be required to file FAA Form 7460-1 in accordance with Title 14 CFR FAR 77.13 "Construction or alteration requiring notice," and are determined by the FAA to both exceed obstruction standards and to pose a hazard to air traffic, shall mitigate the hazard through lighting or other means acceptable to the FAA. Hazards which cannot be mitigated shall be prohibited. These height standards are in addition to other compatibility standards required within the overlay classification.

C.    Compatibility Standards by Safety Compatibility Zones. Compatibility standards within the Airport Overlay – Small Airports zone classification vary depending on the specific safety compatibility zone (zones 1 through 6) within the overlay and are in addition to and supersede the standards for the underlying zone.

1.    Zone 1, Runway protection zone.

a.    Prohibit new structures, residential or non-residential, unless needed as an accessory to an existing use.

2.    Zone 2, Inner approach/departure zone.

a.    Allow new residential uses at rural densities only. Accessory uses to residential are permitted.

b.    New nonresidential civic uses where people congregate, such as day care centers, schools and educational facilities,, churches, hospitals and nursing homes:

(1)    Shady Acres Airport. Prohibit these uses unless below the threshold of 40 people per acre for the total acreage of the development site or up to 80 people for any single acre within the development site in the rural zones and 60 people per acre for the total acreage of the development site or up to 120 people for any single acre within the development site in the urban zones.

(2)    Eatonville Airport. These uses are prohibited.

c.    Allow new nonresidential utility, commercial and industrial uses only at no higher intensity than 60 people per acre for the total acreage of the development site or up to 120 people for any single acre within the development site in the urban non-residential zone classifications.

d.    Prohibit hazardous material handling and storage, other than incidental small scale uses accessory to primary use, except that underground storage tanks are allowed.

3.    Zone 3, Inner turning zone.

a.    Allow new residential uses at rural densities or as infill up to the average density of surrounding residential area.

b.    New nonresidential civic uses where people congregate, such as large day care centers, schools and educational facilities, churches, hospitals and nursing homes:

(1)    Shady Acres Airport. Prohibit these uses unless below the threshold of 80 people per acre for the total acreage of the development site or up to 160 people for any single acre within the development site in the rural zones and 100 people per acre for the total acreage of the development site or up to 200 people for any single acre within the development site in the urban zones.

(2)    Eatonville Airport. Same as Shady Acres Airport, except schools and daycare centers are prohibited.

c.    Allow new nonresidential utility, commercial and industrial uses at no higher intensity than 100 people per acre for the total acreage of the development site or up to 200 people for any single acre within the development site in the urban nonresidential zone classifications.

d.    Allow aboveground hazardous material handling and storage uses that store greater than 6,000 gallons only if no feasible alternative is available and the facility is designed for risk reduction.

4.    Zone 4, Outer approach/departure zone.

a.    Allow new residential uses at rural densities or as infill up to the average density of surrounding residential area.

b.    New nonresidential civic uses where people congregate, such as large day care centers, schools and educational facilities, churches, hospitals and nursing homes:

(1)    Shady Acres Airport. Prohibit these uses unless below the threshold of 80 people per acre for the total acreage of the development site or up to 240 people for any single acre within the development site in the rural zones and 100 people per acre for the total acreage of the development site or up to 300 people for any single acre within the development site in the urban zones.

(2)    Eatonville Airport. Same as Shady Acres Airport, except schools are prohibited.

c.    Allow new nonresidential utility, commercial and industrial uses at no higher intensity than 100 people per acre for the total acreage of the development site or up to 300 people for any single acre within the development site in the urban nonresidential zone classifications.

5.    Zone 5, Sideline zone.

a.    Allow residential uses on properties linked to the airport at rural densities. Other new residential uses are allowed only at rural densities or as infill up to the average density of surrounding residential area.

b.    Prohibit new nonresidential civic uses where people congregate, such as large day care centers, schools and educational facilities, churches, hospitals and nursing homes:

c.    Allow new nonresidential utility, commercial and industrial uses only if they are related to aviation or airport operations, and at no higher intensity than 20 people per acre for the total acreage of the development site or up to 40 people for any single acre within the development site in the urban nonresidential zone classifications.

6.    Zone 6, Traffic pattern zone.

a.    Allow residential uses consistent with underlying zone.

b.    Prohibit new nonresidential civic uses where people congregate, such as large daycare centers, schools and educational facilities, churches, hospitals and nursing homes, and stadia unless below the threshold of 150 people per acre for the total acreage of the development site or up to 450 people for any single acre within the development site.

c.    Allow industrial and commercial uses consistent with the underlying zone.

D.    Split Parcels. When the zoning overlay splits a parcel, the overlay restrictions will only apply to those portions of the parcel within the overlay.

E.    Disclosure. Prior to issuance of a Building Permit for new construction within the Airport Overlay-Small Airport, the property owner must sign an airport proximity disclosure statement, provided by the Pierce County Department of Planning and Public Works, at the time permits are applied for, and record it in the Pierce County Auditor's office. The disclosure statement acknowledges that the property is located within the Airport Overlay for the specific airport and that the property may be impacted by low flying aircraft, noise, vibration, odors, and other associated aviation activities.

F.    Airport-Related Uses. On the airport property, airport-related uses needed to support aircraft operations are allowed; provided all building, fire, health, and other State and Federal regulations are met.

G.    Lighting. Lighting, other than that used for marking potential hazards to air navigation, should be directed downward so it does not cause glare for pilots, and should be arranged such that it does not approximate runway lighting.

(Ord. 2017-12s § 2 (part), 2017; Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)

18A.60.090 Rural Airport Overlay.

A.    Purpose. The purpose of the Rural Airport Overlay is to function as a safety buffer adjacent to the Tacoma Narrows Airport on rural land. The overlay provides restrictions on the use of land, which are intended to protect the airport from neighboring land uses that are incompatible with aviation activities. The area also provides buffering between those more intensive uses related to aviation activities and the uses authorized in the rural-residential classifications.

B.    Restriction on Uses Permitted. The following uses shall be permitted in the Rural Airport Overlay pursuant to the process described in Table 18A.60.090-1.

Table 18A.60.090-1. Rural Airport Overlay

Use Category and Use Type

Permit Process

Residential Use Category

Single-family Detached Housing

P

Civic Use Category

Community and Cultural Services

C1

Public Safety Services

C1

Recreation, Non-Profit

P1;C2,3,4

Transportation

P1;C2,3

Utilities Use Category

Telecommunication Towers or Wireless Facilities

P1;C2,3

Electrical Facilities

P

Natural Gas Facilities

P1,2;C3,4

Organic Waste Processing Facilities

C

Pipelines

P

Sewage Collection Facilities

P*

Stormwater Facilities

P

Waste Transfer Facilities

P1

Water Supply Facilities

P1;C2

Utilities or Public Maintenance Facilities

C

Resource Use Category

Agritourism

C

Agricultural Supply Sales

C1

Agricultural Services

C

Animal Production, Boarding and Slaughtering

P1

Crop Production

P1

Forestry

P1

Surface Mines

C

Commercial Use Category

Amusement and Recreation

C4,5,6

Building Materials and Garden Supply

C5

Lodging

C1

Industrial Use Category

Contractor Yards

C

C.    General Standards.

1.    Any new use that involves the release of airborne substances that could interfere with aircraft operations is prohibited.

2.    Any new use that emits light that interferes with a pilot's vision is prohibited.

3.    Any new use that attracts concentrations of birds is prohibited.

4.    Uses that emit electrical currents shall be installed in a manner that does not interfere with communications systems or navigational equipment.

D.    Residential density shall be limited to 1 dwelling unit per 10 acres. A bonus density that provides for 2 dwelling units per 10 acres is permitted when 50 percent of the development is retained in open space. A minimum lot size of 5 acres is required for new lots.

1.    Prior to approval of a residential building permit in this overlay, title notification describing the presence of the airport shall be required.

E.    Buildings and structures that would penetrate the imaginary airspace surfaces for the Tacoma Narrows Airport as defined in Title 14 CFR (Code of Federal Regulations) FAR (Federal Aviation Regulations) Part 77 "Objects affecting navigable airspace" are prohibited. Examples of such obstructions may be cell towers, radio broadcast towers, water towers, etc. when the height of the structure would exceed the lower limits of navigable airspace.

(Ord. 2014-42 § 2 (part), 2014; Ord. 2013-85 § 1 (part), 2013; Ord. 2013-30s2 § 5 (part), 2013)