Last Updated 07/16/2026
Excerpt from Arlington Municipal Code
Chapter 13
13.28.220 Inspection and Maintenance of Stormwater BMPs/Facilities
(a) Maintenance Responsibility.
- The utility is responsible for maintaining, repairing, and replacing public drainage facilities.
- Owners of private drainage facilities, including but not limited to detention facilities, runoff treatment facilities and conveyance facilities, are responsible for the operation, maintenance, repair, and replacement of those facilities.
- In new subdivisions and short plats, maintenance responsibility for private drainage facilities shall be specified on the recorded subdivision or short plat.
- If a private stormwater treatment and flow control BMP/facility serves multiple lots and the responsibility for maintenance has not been specified on the subdivision plat, short plat or other legal document, maintenance responsibility shall rest with the homeowners association, if one exists, or otherwise with the properties served by the facility, or finally, with the owners of the property on which the facilities are located.
(b) Inspection and Maintenance Standards. Drainage facilities shall be maintained so that they operate as intended. Stormwater maintenance standards shall be in accordance with the stormwater manual, the engineering standards, and in accordance with the O&M manual approved for the stormwater treatment and flow control BMP/facility.
(c) Ongoing Inspections. The regular inspection of privately owned storm drainage facilities or controls is essential to enable the city to evaluate the proper operation of the storm and surface water system and the environment. The city shall have access to private stormwater facilities for inspection to ensure they are properly operated and maintained in accordance with the stormwater manual per Section 13.28.080. Annual inspections will be conducted by city staff on all stormwater treatment and flow control BMPs/facilities that discharge to the storm and surface water system that have been built since the date listed in the city’s current NPDES II permit, unless available maintenance records can be used to justify a reduced inspection frequency.
(e) When an inspection identifies an exceedance of the maintenance standard, maintenance shall be performed:
- Within one year for typical maintenance of facilities, except catch basins
- Within six months for catch basins
- Within two years for maintenance that requires capital construction less than twenty-five thousand dollars
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Frequently Asked Questions
Who is responsible for maintaining private stormwater facilities in Arlington?
Under AMC Section 13.28.220(a), owners of private drainage facilities are responsible for the operation, maintenance, repair, and replacement of those facilities. This includes detention facilities, runoff treatment facilities, and conveyance facilities. In new subdivisions and short plats, maintenance responsibility is specified on the recorded plat document. If a private stormwater facility serves multiple lots and no maintenance responsibility is specified in a plat or other legal document, responsibility rests with the homeowners association if one exists, or otherwise with the properties served by the facility, or finally with the owners of the property on which the facility is located. The City’s utility is responsible only for public drainage facilities located within the public right of way or public easements.
What are the maintenance timeframes for private stormwater facilities in Arlington?
AMC Section 13.28.220(e) establishes specific timeframes for completing maintenance once an inspection identifies an exceedance of the maintenance standard. Typical maintenance of stormwater facilities, other than catch basins, must be completed within one year. Catch basin maintenance must be completed within six months. Maintenance that requires capital construction of less than $25,000 must be completed within two years. Drainage facilities must be maintained so that they operate as intended, consistent with the stormwater manual, the City’s engineering standards, and the operation and maintenance manual approved for the specific BMP or facility.
What maintenance standards apply to private drainage facilities in Arlington?
Under AMC Section 13.28.220(b), drainage facilities must be maintained so they operate as intended. Specific maintenance standards are set by the City’s stormwater manual, the engineering standards, and the operation and maintenance manual approved for each stormwater treatment and flow control BMP or facility. Property owners who are unsure what maintenance standards apply to their facility should contact the City of Arlington Public Works Department or review the operation and maintenance manual associated with their stormwater approval. AQUALIS provides annual stormwater inspection and maintenance services for commercial properties in Arlington to help property owners meet these standards before a City inspection identifies deficiencies.
How is the Arlington stormwater fee calculated?
Arlington uses an Equivalent Service Unit (ESU) system to calculate stormwater fees. One ESU is equal to 6,000 square feet of impervious surface, which represents the base unit established by the City Council and the Stormwater Rate Structure Committee as the standard for a single-family residential property. Every residential home or equivalent residential unit is charged one ESU. For non-residential properties, the total impervious surface area on the property is measured and divided by 6,000 square feet to determine the number of ESUs billed. The City used GIS mapping to determine impervious surface measurements across the service area.
Does the City of Arlington inspect private stormwater facilities?
Yes. Under AMC Section 13.28.220(c), the City conducts annual inspections of all stormwater treatment and flow control BMPs and facilities that discharge to the City’s storm and surface water system and have been built since the date specified in the City’s current NPDES Phase II permit. Where available maintenance records can demonstrate proper maintenance, the City may justify a reduced inspection frequency. The City’s authorized representatives have the right of entry to private property at all reasonable times to conduct inspections, provided the property owner is notified beforehand. Under AMC Section 13.28.240, the City also conducts source control inspections on existing commercial developments as required by the NPDES Phase II permit.
What happens during a City stormwater source control inspection in Arlington?
During a typical stormwater source control inspection conducted under AMC Section 13.28.240, the City inspector will visit outdoor and indoor loading, storage, and process areas, observe facility operations, and review pertinent documents including as-built drawings, stormwater pollution prevention plans (SWPPP), chemical storage inventories, spill logs, and spill response plans. The purpose of these inspections is to identify potential sources of stormwater pollution at existing commercial and industrial developments and to ensure best management practices are in place to prevent pollutants from entering the storm drain system. Property owners should maintain current records of their stormwater facilities, BMPs, and any maintenance activities.
What stormwater records should commercial property owners maintain in Arlington?
Commercial property owners with private stormwater facilities in Arlington should maintain an operation and maintenance manual for each BMP or facility, records of all inspections performed on stormwater facilities, records of all maintenance activities including dates, scope of work performed, and any materials or conditions found, copies of any as-built drawings for stormwater improvements, and any stormwater pollution prevention plans or source control BMPs required as a condition of development approval. These records support City inspections conducted under AMC Section 13.28.220 and 13.28.240 and demonstrate compliance with the City’s NPDES Phase II permit requirements. AQUALIS provides inspection documentation formatted to meet Arlington’s maintenance record requirements.
What stormwater services does AQUALIS provide for properties in Arlington?
AQUALIS provides comprehensive stormwater management services for commercial properties, HOAs, and institutional facilities in Arlington and throughout Washington State. Services include annual stormwater inspections and maintenance documentation that satisfy AMC Section 13.28.220 requirements and support City source control inspections under Section 13.28.240, catch basin cleaning within the required six-month timeframe, stormwater facility condition assessments, storm drain jetting and vactor services, CCTV pipe inspection, NOV response and corrective action documentation, and BMP installation and maintenance. AQUALIS documentation is prepared to meet the standards required by the City of Arlington Public Works Department and the City’s NPDES Phase II permit. Contact AQUALIS to get started.
The information on this page is provided for general informational purposes only and is not legal advice. Regulations change frequently — AQUALIS makes no warranty as to the accuracy or completeness of this content, and any reliance on it is at your own risk. Consult a qualified professional or your local regulatory authority to confirm requirements applicable to your specific property.
