Division 13-09-008
Micro-Trenching
Sections:
13-09-008-0001 Micro-Trench Fiber-Optic Cable Installation
13-09-008-0002 Planning
13-09-008-0003 Ground Equipment (Cabinets, Meters, and Miscellaneous Equipment)
13-09-008-0004 Construction
13-09-008-0005 Pavement Matching Modifications
13-09-008-0006 Citywide Maintenance Program
13-09-008-0007 Relocations
13-09-008-0008 Alternatives
13-09-008-0009 Citizen Complaint Resolution
13-09-008-0001 Micro-Trench Fiber-Optic Cable Installation
Micro-trenching is a construction technique used for placing micro-conduits and fiber-optic cables. Micro-trenching may be permitted for the installation of fiber-optic cables in small-diameter conduit or micro-duct pathways by a franchise utility or licensee authorized to place telecommunication, video, broadband or similar facilities within City of Flagstaff rights-of-way or by a contractor or provider authorized to install fiber infrastructure serving public facilities within the City of Flagstaff. These pathways aim to provide broadband internet or communication services to residential neighborhoods, commercial buildings and public facilities throughout the area. Micro-trenching methods (where authorized) must adhere to these standards and may not be permitted within all roadways due to site-specific constraints such as conflicting existing facilities or locations where micro-trenching is otherwise not authorized. A valid permit is required for the installation of fiber-optic facilities within rights-of-way or public utility easements. For the purposes of this division, "permittee" shall refer to the fiber provider and their authorized contractor(s) named on a valid permit authorizing the installation of fiber-optic facilities within City of Flagstaff rights-of-way or public utility easements. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0002 Planning
A. Concept plan submittal shall be prepared in accordance with Section 13-09-001-0001(B). The City may limit the areas of simultaneous construction in order to minimize conflicts with other projects, maintain acceptable levels of traffic service and to ensure the availability of inspection and project management staff to adequately monitor and manage the project. Per MAG Section 107.11, permittees shall not commence construction until all arrangements are made for the protection of others’ facilities and property if necessary. The permittee shall coordinate with other projects (private development, private utilities, City projects, etc.) to avoid construction conflicts, minimize impacts to traffic, and otherwise ensure the integrity of the rights-of-way. The permittee shall submit plans to the private utilities and pay for any required design services and approvals, if applicable to the project. Private utility companies will need time to design new services, evaluate clearance requirements, and identify possible conflicts with the proposed work.
B. Micro-trenching is authorized in local roads and minor collectors. Micro-trenching is not authorized in major collectors or arterials. Micro-trenching in any roadway paved or overlaid within a period of five (5) years prior to the permit application date must demonstrate that other pathways or methods are not available for the fiber installation which would result in a lower impact to public infrastructure.
C. Each permit shall be one (1) contiguous area, and shall encompass an area no more than one hundred (100) acres as measured using bounding streets and/or subdivision boundaries. Each permit shall involve installation of no more than thirty thousand (30,000) feet of micro-trench, trench, directional bore, aerial lashing, or a combination thereof. The City Engineer may require the permittee to divide large projects into multiple smaller permits based on the complexity or anticipated community impact of a given permit.
D. During the preliminary planning stages of larger network rollouts, the permittee shall provide broad maps of proposed permit areas prior to submittal of individual permit applications. The City will provide guidance on permit requirements for the proposed area.
E. Where permittee proposes micro-trenching in a street in which no other micro-trench has been installed, permittee shall plan and place all micro-trench in the preferred location at the lip of curb as indicated on standard details reserving the secondary offset micro-trench location for future fiber providers who may utilize the secondary location when the preferred location is previously occupied. Where more than two (2) providers proposed micro-trenching in a given street, the City Engineer may require installation by methods other than micro-trenching unless a modification to the Engineering Standards is approved.
F. Permittees undertaking projects involving the installation of one thousand (1,000) feet or more of micro-trench, trench, directional bore, or a combination thereof, shall adhere to the following procedure:
1. Permitting. Permittees will be allowed a maximum of five (5) active permits at any given time. Permits in review and finalized permits shall not count against this limit. Permits of less than one thousand (1,000) feet of micro-trench, trench, directional bore, aerial lashing, or a combination thereof may be exempt from this limit where the additional impact to the public is demonstrated to be minimal.
2. Permit Holds. City staff will continue to review permit applications, regardless of the number of active permits issued to the permittee. If the permittee has five (5) active permits, applications that are ready for approval will be placed on hold until an active permit has been finalized by the City Inspector.
3. Preconstruction Meeting. If the permittee has four (4) or fewer active permits and has an approved permit application that is on hold, the permittee may request a preconstruction meeting for that permit. At the preconstruction meeting, the permittee shall provide a construction schedule that includes, at a minimum, contractor and subcontractor contact information, proposed start and end dates, and proposed phasing and milestone dates. The permittee will also provide construction logistics information, including where vehicles, equipment, and materials will be staged.
4. Final Inspection. Upon completion of work under a permit, permittee must promptly schedule and conduct a final inspection walk-through with the City Inspector. During this inspection, the permittee must demonstrate that all restoration work, including but not limited to landscaping, irrigation systems, concrete, pavement, and any related infrastructure, is completed in accordance with all applicable standards. Any public complaints related to the work under the permit must be addressed prior to permit closeout. Permit closeout final inspection walk-through will include data deliverables and previous punch list items.
5. The contractor is required to maintain continuous work during construction. Construction should proceed day by day, with sufficient equipment and workforce to ensure the project progresses effectively, maintaining public ways in satisfactory condition. Failure to adhere to the restoration timelines outlined in this section or neglecting to implement underground damage prevention methods will result in a reduction in maximum allowed active permits. The City may withdraw authorization for micro-trench installations after written notification with opportunity to cure where continuing failure to adhere to restoration timeline occurs.
6. Permittee may request approval of additional concurrent permits by the City Engineer where the permittee demonstrates that adverse public impacts will not result. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0003 Ground Equipment (Cabinets, Meters, and Miscellaneous Equipment)
The following guidelines govern the placement of equipment in public highways:
A. Equipment shall be designed and installed to:
1. Minimize the visual impact on the public;
2. Blend with the visual context and character of the rights-of-way, surrounding neighborhood, and development; and
3. Adhere to the highest standards of visual and functional quality. Equipment colors shall generally be earth tones and shall be indicated in the APL.
B. Equipment shall be flush or low-profile and pad-mounted unless City approval states otherwise.
C. Equipment shall be positioned two (2) feet away from sidewalks, ramps, and walkways and located behind sidewalk unless other locations are approved in writing by the City Engineer. The width of the existing travel route shall not be reduced. Vaults, handholes, junction boxes and similar facilities shall not be placed in pavement, sidewalk, driveways or similar hardscape unless during plan review the permittee demonstrates that there are no other viable locations to place such facilities behind sidewalk or in parkways. In all circumstances the permittee shall be responsible to ensure compliance with PROWAG, ADA and other applicable standards in accordance with Section 13-09-008-0006.
D. Equipment location should be inconspicuous. Equipment proposed in front of windows, doors, etc., requires alternative placement. Equipment should be positioned as close as possible to existing structures and property lines.
E. Equipment shall be placed in a manner that does not hinder the sight visibility triangle or clear view zone requirements outlined in Section 13-10-006-0002; plans must show the sight triangle, including calculations where any equipment is proposed that is more than thirty-six (36) inches higher than the adjacent roadway pavement surface elevation.
F. Equipment should maintain a minimum clearance of fifty (50) feet from business and monument signs (or similar structures), based on equipment height, to prevent view obstructions.
G. Equipment cabinets with air-conditioning or fans (used intermittently or continuously) should be screened and set back at least twenty (20) feet from livable and residential property lines. Noise emitted should not exceed the ambient noise level of the surrounding rights-of-way, which can be confirmed with a noise analysis. For instance, such equipment should be as quiet as or quieter than a typical, well-maintained residential air-conditioning unit, or equivalent to twenty (20) decibels, akin to whispering from five (5) feet away.
H. Equipment that could generate audible noise beyond the property line must be enclosed or equipped with noise attenuation devices.
I. Shelters or shade structures will not be permitted in the rights-of-way or easements.
J. Three (3) photographs of the proposed equipment site are required, showing different viewpoints. (Google Earth or similar snapshots do not meet this requirement due to outdated imagery.) Provide one (1) photograph at a ninety (90) degree angle and the other two at forty-five (45) degree angles on either side of the proposed location.
K. Photographs must clearly identify the location of all proposed structures. Mark the location using white paint, an orange traffic cone, or a similar method. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0004 Construction
A. The permittee shall follow City of Flagstaff Standard Detail 9-08-004 for micro-trenching construction.
B. The permittee shall visually inspect the condition of all locations proposed for micro-trenching construction methods to ensure that the adjacent curb and pavement are structurally sound without significant cracking, deflection or failures that would negatively affect the micro-trenching installation. It shall be the responsibility of the permittee to replace any such existing infrastructure in order to prepare the location for micro-trenching or shall select a different installation method. The trench path may not be varied from those typical locations indicated in the standard details in order to avoid any areas of unsuitable curb or pavement.
C. All work performed under this standard shall be completed in compliance with the Uniform Standard Specifications and Details for Public Works Construction published by the Maricopa Association of Governments ("MAG"), as amended, City amendments to MAG, Engineering Standards and the APL.
D. The permittee shall retain an independent testing company, approved by City at its reasonable discretion, to test all materials used for restoring the rights-of-way. The testing company and materials testing methods are subject to, and shall be done in accordance with, MAG standards and City amendments to MAG. Material testing does not apply to materials that will be owned by permittee.
E. The permittee shall comply with MAG Section 105.5 regarding a competent superintendent. The superintendent shall be authorized to receive and fulfill instructions from the City Inspector related to the requirements set forth in this section. No less than fourteen (14) days prior to the scheduled/planned construction, the permittee or contractor shall submit to the City Inspector the name and contact information of the superintendent.
F. Permittee shall prepare and distribute construction door hangers to each residential and commercial property prior to requesting Arizona 811 locates.
G. Ground-penetrating radar may be used as a secondary method of identifying existing utilities but will not replace the requirements, as set forth in A.R.S. Section 40-360 et seq., to expose and uncover existing utilities in a careful and prudent manner. The permittee shall cross-check the record drawings and plans with field locate marks to determine discrepancies before micro-trenching. The permittee shall immediately notify the City Inspector if existing utilities are damaged or unknown utilities are encountered. Subject to and in accordance with A.R.S. Section 40-360.21 et seq., if permittee damages, disturbs, or alters the surface or subsurface of any public highway or adjoining public property, any public improvement, landscaping, or property of third parties, then the permittee shall promptly, at its own expense, and in a manner reasonably acceptable to the City, repair and restore the damage or disturbance to a condition substantially comparable to its prior state.
H. Throughout the entire duration of the license agreement, it is the responsibility of the permittee to promptly safeguard and address any subsidence issues that are identified to have been caused by or resulting from the permittee’s construction activities. Vertical measurement is taken from the adjacent road surface, in accordance with MAG Section 336.2.4.1. It is the responsibility of the permittee to identify any subsidence problems. Failure to initiate repair work in a timely manner could result in the City performing the repairs, with costs borne by the permittee.
I. The contractor shall comply with MAG Section 107.6.1.2 regarding public convenience and safety.
J. It is the responsibility of the contractor to ensure the conduits do not shift horizontally or float vertically in the trench during CLSM application. Spot pouring CLSM or using conduit restraints may be required due to shallow depth. Conduit restraints shall be placed at a maximum distance of ten (10) feet apart along the alignment to prevent the conduit from rising from the bottom of the micro-trench. No metal shall be placed in the trench to restrain conduit. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0005 Pavement Matching Modifications
A. The slurry seal coat, as required by MAG Section 336 or chip seal fee in Section 13-10-009-0001, will not be assessed for the micro-trench path, ten (10) inch diameter or smaller core for junction with service lateral, and ten (10) inch diameter or smaller potholes that reside in the micro-trench path. The chip seal coat fee applied during the permit process will not be assessed due to the asphaltic sealant material, also known as the overband seal, placed over the entire top of the micro-trench, lateral service, and core holes. The overband seal must meet MAG Section 337 to be exempt from MAG Section 336.2.2 and the chip seal fee.
B. Potholes, bore pits, receiving pits, and excavations that adhere to MAG Section 336 will incur the chip seal fee. This fee encompasses junctions with service laterals and pothole patches, exceeding ten (10) inch diameter.
C. All license holders electing to utilize micro-trenching within City of Flagstaff roadways will be responsible to warrant, maintain and repair micro-trench and mastic overband installations for the duration of the license and any renewals until such time that any roadway receives a mill and overlay or full-depth replacement after the completion of the micro-trench installation. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0006 Citywide Maintenance Program
A. The City has a substantial governmental interest in ensuring that existing facilities do not cause harm to its citizens and public or private property. The safety of the general public and the ability of the City to provide City services is a priority. To that end, permittee agrees to the following:
1. Maintain backfill and/or overband seal from subsidence in the pavement of one-quarter (1/4) inch or more, vertically measured from the adjacent road surface per MAG Section 336.2.4.1.
2. Maintain overband seal from deterioration, damage or failure due to ordinary use of the roadway including snow removal operations.
3. Protect curb and gutter, sidewalk, concrete structures, etc., from any damage, disturbance, or alteration caused or as a result of construction by the permittee or their contractors.
4. Follow all the requirements of the permit when addressing temporary cables.
5. The permittee will annually inspect facilities to determine compliance with the license agreement and this section. Permittee shall submit an annual inspection report and location exhibits identifying the maintenance activities within the City to the City Engineer without City prompting for report. If the permittee determines that it must provide proprietary information in order to respond to the City’s request for documentation and inspection, then it shall designate such documents as proprietary or confidential prior to its submittal to the City.
B. Upon receiving notice from the City about facilities failing to meet the requirements of this division, the permittee will address those conditions within a reasonable time following such notice. The permittee shall reimburse the City for all documented costs incurred as a result of noncompliant conditions not cured after a reasonable time following notice. However, if noncompliant conditions damage the rights-of-way, damage City property, disrupt City services, or require the dispatch of emergency personnel, the permittee shall reimburse the City for all documented costs incurred as a result. This includes but is not limited to: inspection fees identified on the City’s schedule of fees, police and fire services, idled solid waste equipment, and repair of damage to the City’s real and personal property. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0007 Relocations
If the permittee is required to relocate its communications network facilities due to the construction of a public improvement, the City shall provide the permittee with a minimum of sixty (60) calendar days’ notice before any required action of the permittee to relocate affected portions of the communications network. The City shall cooperate with permittees to identify replacement and alternative public highways for the relocation of affected portions of the communications network. Promptly after receiving notice from the City, the City and the permittee shall cooperate to agree on a removal schedule and alternative public highways for the relocation of the affected portions of the communications network. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0008 Alternatives
A. In accordance with Section 13-06-002, the City Engineer may, in their sole and absolute discretion, approve alternatives to the requirements and specifications contained herein based upon a specific finding that the proposed alternative:
1. Will provide an equivalent level of service for the health, safety, and welfare of the general public;
2. Adequately protect public and private property;
3. Would not reasonably increase the City’s future maintenance or replacement costs; and
4. Is not otherwise contrary to the public interest. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))
13-09-008-0009 Citizen Complaint Resolution
A. The permittee shall respond to all customer/citizen calls or complaints resulting directly or indirectly from this project within one (1) business day of receipt and shall provide the City notice of any customer/citizen calls or complaints that cannot be resolved within three (3) business days. The required door hanger shall provide contractor and permittee contact information where citizens may contact for information and complaints. Failure to resolve citizen complaints in a timely manner will result in a reduction of the number of allowed active permits, or loss of authorization for micro-trench installation, as described in Section 13-09-008-0002(F)(5).
B. The contractor shall comply with MAG Section 107.9 regarding protection and restoration of property and landscape. (Ord. 2025-20, Enacted, 10/21/2025 (Res. 2025-52))