Clean Water Act, Section 402 - National Pollutant Discharge Elimination System (NPDES) Permits

The information on this page will help you determine if you need to apply for a permit or how to comply with a permit already issued to WSDOT.

These permits regulate sources of pollutants that could make their way to surface waters like streams, lakes, and the Puget Sound. They contain limits on what we can discharge, monitoring and reporting requirements, and other requirements to protect water quality. Complying with these permits helps Washington State Department of Transportation (WSDOT) ensure that our construction, maintenance, and operation work results in minimal impacts to surface waters.

Issued by: Department of Ecology (Ecology), or Environmental Protection Agency (EPA) if in Indian Country
Relevant Statutes: 33 USC 1342 ; 40 CFR Parts 122 , 123 & 124 Subchapter D; WAC 173-226 

 

Construction Stormwater General Permit

A construction stormwater general permit is required if a construction project has the potential to discharge stormwater to surface waters and will either disturb one or more acres of soil, or is part of a larger plan that will end up disturbing one or more acres of soil.

Use the following links to access details on this permit, how to apply it, and how to comply with its conditions.

 

WSDOT Municipal Stormwater General Permit

Compliance with specific conditions in this permit may be required depending on your location. WSDOT has coverage under this permit within areas covered by a Phase I or Phase II Municipal Stormwater General Permit. It authorizes the discharge of stormwater from stormwater systems owned or operated by us along highways, at ferry terminals, rest areas, park and ride lots, maintenance facilities, vactor decant and street sweepings facilities, and winter chemical storage facilities.

Use the following links to access details on this permit and how to comply with its conditions:

 

Industrial Stormwater General Permit

A permit may be required if you engage in certain industrial activities. It authorizes stormwater and conditionally approved non-stormwater discharges associated with industrial activities. WSDOT has coverage under this permit at the Washington State Ferries Eagle Harbor Repair Facility.

Use the following links to access details on this permit and how to comply with its conditions:

 

Sand & Gravel General Permit

This permit may be required if a pit site is being used by a project. WSDOT has coverage under this permit for several pit sites, but the site needs to be in active status before being used for a project. The material engineering programs for each WSDOT region manage this permit. It authorizes discharges of process water, stormwater, and water from mine dewatering into surface water, groundwater or both at permitted locations associated with sand and gravel operations, rock quarries, and similar mining operations.

Use the following links to access details on this permit and how to comply with its conditions:

 

Bridge & Ferry Terminal Washing General Permit

A permit is required when you discharge water associated with work on bridges, ferry terminal transfer spans, or associated overwater structures, including:

  • Spot cleaning
  • Low pressure maintenance washing
  • High pressure preparatory washing
  • Painting

Use the following links to access details on this permit and how to comply with its conditions:

 

Aquatic Noxious Weed Control General Permit

A permit is required for herbicide applications made near surface water to manage noxious and quarantine weeds. It authorizes the indirect discharge of specific herbicides, adjuvants, and markers dyes into surface water. WSDOT has permit coverage statewide for all aquatic herbicide applications on our property.

Use the following links to access details on this permit and how to comply with its conditions:

 

Aquatic Plant & Algae Management General Permit

A permit is required for herbicide applications made in or near surface water to manage nuisance vegetation not on the state noxious weed list. It authorizes direct and indirect discharges of specific herbicides and other chemicals into surface waters. WSDOT has permit coverage statewide for all aquatic herbicide applications on our property.

Use the following links to access details on this permit and how to comply with its conditions:

 

Aquatic Mosquito Control General Permit

A permit is required for pesticide applications in or near surface water to control mosquitos. It authorizes discharges of specific adulticides and larvicides into surface waters. WSDOT has permit coverage statewide for all pesticide applications for mosquito control on our property.

Use the following links to access details on this permit and how to comply with its conditions: