City of Anchorage

Anchorage Stormwater Laws & Regulations

City of Anchorage regulations are compliant with the Alaska Pollutant Discharge and Elimination System (APDES) permit requirements for the city’s Municipal Separate Storm Sewer System (MS4.) The city’s MS4 permit requires Anchorage to administer and enforce compliance with stormwater discharge permits in an effort to decrease stormwater pollutants and increase overall water quality.

EXCERPT- Storm Water Treatment Plan Review Guidance Manual, September 2010

1. Introduction

MOA regulations regarding storm water pollution control are set forth in the Anchorage Municipal Code (AMC) Title 21. The AMC requires the development, implementation, and maintenance of a Storm Water Treatment Plan Review Guidance Manual (SWTPRGM). The AMC further requires anyone who constructs, installs, modifies, or operates a storm water treatment or disposal system to comply with the SWTPRGM regarding storm water runoff system plan requirements and plan reviews.

Developers of both new and redeveloped sites are required to prepare and submit a Storm Water Treatment Plan (SWTP) to the MOA for review and approval prior to the start of construction. This requirement applies to anyone who will disturb the ground or discharge or route storm water within municipal boundaries.

2. State Regulations

2.3.3 Municipal Separate Storm Sewer System (MS4) Permit

The MOA and the Alaska Department of Transportation and Public Facilities (ADOT&PF) are copermittees under an MS4 permit issued by the EPA and now administered by ADEC. The MS4 permit allows the MOA and ADOT&PF, as operators of a MS4, to discharge storm water meeting specified requirements into waters of the United States. The MS4 permit requirements are implemented through the Storm Water Management Program and include a program substantially similar to the CGP program discussed above.

In compliance with the MS4 permit, the MOA developed the SWTP program and associated guidances describing MOA storm water treatment requirements, reviews, and inspections. The SWTP program is the basis for this guidance document, which will continue to be updated periodically as EPA and ADEC regulations change or as the MOA revises its program. The MOA SWTP review requirements outlined in this manual apply to all land areas and land disturbances within the corporate limits of the MOA and / or served by the MS4, and refer to those portions of the MS4 that are owned and operated by the MOA or ADOT&PF, and that discharge to receiving waters.

3. SWTP Requirements Overview

Storm water treatment plan approval is required under AMC 21 prior to the commencement of land clearing or ground disturbing activities; the discharge of surface water (including meltwater from snow disposal sites); the construction, alteration, installation, modification, or operation of a storm water treatment or disposal system; demolition or utility work; connection to the municipal storm sewer system; work in waterways or watercourse; or dewatering activities. All construction, development, and maintenance activities shall be in accordance with the approved Storm Water Treatment Plan. The Storm Water Treatment Plan is a comprehensive report containing all of the technical information and analysis necessary for regulatory agencies to evaluate proposed BMPs and determine if minimum requirements will be met. Contents of the plan vary with the size of the parcel, size and type of proposed development, individual site characteristics, and activities and land use associated with the site.

Supplemental Documents:

Anchorage stormwater website

Watershed Management Services Utility Permit

State of Alaska Documents:

APDES Stormwater Website

Alaska Storm Water Guide