In 2004, Clean Water Services received the nation’s first watershed-based National Pollutant Discharge Elimination System (NPDES) permit. Issued under the federal Clean Water Act, this watershed-based NPDES permit combines the permits for our four water resource recovery facilities and the Municipal Separate Storm Sewer System (MS4) into a single integrated permit that can be managed across facilities and the Tualatin River Watershed.
CWS, Washington County, and our 12 partner cities work collaboratively to consider the entire watershed when managing water resources.
CWS is required to report annual progress on attaining measurable goals and tracking measures.
Illegal Storm Drain Dumping
If you see someone dumping paint, oil, soap, fertilizer, or other waste into a storm drain, notify Environmental Services. Someone from our team will follow up to gather information about the location and possible source to determine next steps.
Contact
Contact Us – Illegal Storm Drain Dumping, Permits, Field Ops
Report a Problem – Illegal Storm Drain Dumping, Industrial Discharge
Stormwater Management Program
When it rains, stormwater washes over streets, roofs, lawns, and parking lots — picking up oil, sediment, bacteria, grease, and chemicals that can pollute our streams and the Tualatin River. Clean Water Services, Washington County, and our 12 partner cities are responsible for the system that carries the flow of stormwater, or runoff, from one location to another — known as stormwater conveyance.
The Municipal Separate Storm Sewer System (MS4) portion of the permit is aimed at protecting and improving water quality and requires implementation of a broad range of stormwater pollution reduction measures including swale maintenance, street sweeping, education, and more. These measures are documented in a Stormwater Management Plan (SWMP). The permit also requires water quality monitoring as documented in a Stormwater Monitoring Plan.
Clean Water Services and partner cities collect fees to operate, maintain, and improve the community’s stormwater management system. Residential and business customers pay monthly or bi-monthly fees and developers pay a one-time fee to connect to the stormwater system.
- Learn more about neighborhood stormwater
- Learn more about business and industrial stormwater
Program Components
The Stormwater Management Plan identifies best management practices according to permit requirements into the following sections:
Public Education and Outreach
Programs that inform and educate the public, business, industry, and government about the causes of stormwater pollution, the effects on local streams and rivers, and encourage behavior change that will reduce stormwater pollution and promote the health of the Tualatin River Watershed.
Public Involvement and Participation
Programs that provide opportunities for the public to effectively participate in the development, implementation, and modification of the permittee’s stormwater management program.
Illicit Discharge Detection and Elimination
Programs that improve water quality by preventing, proactively investigating (detecting, characterizing, and tracing), and removing illicit discharges to the stormwater system.
- IDDE Program Description guidance document
Construction Site Runoff Control
Programs that improve water quality by reducing or preventing soil erosion and implementing sediment control measures at construction sites through regulation, inspection, enforcement, and education.
Post-Construction Site Runoff for New Development and Redevelopment
Programs that improve water quality by developing and applying appropriate design and construction standards to development.
Pollution Prevention and Good Housekeeping for Municipal Operations
Programs that improve water quality and reduce impacts associated with municipal operations such as facilities used for the storage, transport, and treatment of green waste (yard clippings, leaves). Programs under this BMP also address operations related to pesticide application, fleet maintenance, and other elements of an associated Stormwater Pollution Control Plan.
Industrial and Commercial Facilities
Programs that improve water quality by regulating select industrial and commercial discharges to the stormwater system. This includes identifying facilities subject to industrial permitting requirements, reviewing stormwater pollution control plans, conducting inspections, reviewing discharge monitoring data, and providing technical assistance.
Infrastructure Retrofit and Hydromodification Assessment Update
Since 2019, CWS has been implementing its Hydromodification and Stormwater Retrofit programs. These programs continue to focus on working closely with co-implementers to address water quantity management issues as well as areas with insufficient stormwater management.
- Private Water Quality Facilities Management Program
- Hydromodification Assessment Report
- Stormwater Retrofit Program Plan
Authorization
As a county service district enabled under Oregon Revised Statute (ORS) 451, CWS is charged with providing, among other services, the “treating and disposing of sanitary or storm sewage.” ORS 451.550 grants CWS the authority to “adopt storm and surface water management plans, programs, and regulations relating to the quality and quantity of such waters and conduct water quality studies.” Using this authority, the elected CWS Board of Directors has passed ordinances and resolutions and orders regulating the discharge of stormwater, development (including design and construction standards for post-construction runoff quality and quantity), and construction site discharges. In addition, CWS operates under agreements with DEQ to administer construction site permits and industrial stormwater discharge permits. Below are documents relating to CWS’ authority to regulate stormwater as well as documents that outline standards, studies, and other elements of our program.
- Ordinances 27, 29, and 40
- Stormwater Monitoring Plan
- Performance Standards
- Mercury TMDL Implementation Plan
History
Clean Water Services has been implementing stormwater pollution reduction measures since the Surface Water Management (SWM) utility for water quality and drainage was established with city partners in 1990. The permit has been re-issued three times since then: in 2004, 2016, and most recently January 2023.
In 1998, the industrial stormwater program was implemented to address runoff from businesses and industry in Washington County.
With each iteration of the permit, and at certain times between the issuance of permits, updates to the Stormwater Management Plan and Stormwater Monitoring Plan are required to ensure continued compliance with changing regulations and to reflect improved program effectiveness through adaptive management.
Subbasin Planning
Sub-basin planning is a process and framework CWS uses to provide recommended solutions to address issues such as: water quality impairments, the effects of urbanization, and adapting to a changing climate. Using a smaller watershed approach, CWS can tailor these solutions to fit specific watershed and community needs, visions, challenges, and opportunities. Through sub-basin planning, CWS is better able to consider a range of environmental outcomes when developing recommended solutions. Sub-basin planning can also provide a pathway to integrating our work with that of cities and other partners.
A First-in-the-Nation Approach to Protecting Our Water
Our permit, like our river, is unique. In 2004, we worked with the Oregon Department of Environmental Quality (DEQ) to create the nation’s first integrated watershed-based NPDES permit. This kind of permit remains a rarity, and none of the watershed-based permits that exist today are as complex as the one regulating the Tualatin River Watershed. Learn more.