Water quality assessment & 303(d) list
The federal Clean Water Act requires states to perform a water quality assessment every two years to track how clean the rivers, lakes, and marine water bodies are. We place assessed water bodies in categories that describe the quality of the water and status of any needed cleanup. The assessment helps us use state resources more efficiently by focusing our limited resources on water bodies that need the most work.
2022 Water Quality Assessment call for data
We are beginning our next update to the Water Quality Assessment and we need recent water quality data from Washington’s rivers, streams, lakes, and marine waters. We are seeking data collected between January 1, 2012 and December 31, 2021.
To make sure your data is included in this next Water Quality Assessment, please submit before September 30, 2022. Water quality data can be submitted to Ecology's Environmental Information Management (EIM) database. Narrative information and studies, such as published research and peer-reviewed reports, can be submitted directly to Water Quality Assessment staff at 303d@ecy.wa.gov.
All data submitted must have been collected under a quality assurance project plan, or similar guidance document. Data must be representative of ambient water quality conditions. Submitters must be able to confirm that quality assurance procedures were followed and must be prepared to provide a copy of the plan upon request. If you previously submitted data to us, you do not need to submit it again.
View our online database for the latest assessment results.
2018 Water Quality Assessment submittal to EPA
The 2018 Water Quality Assessment was submitted to EPA for approval on Aug. 31, 2021. This version of the assessment can be viewed through the Candidate Water Quality Assessment Review search tool or map tool.
See the timeline below for more information about how we developed this Water Quality Assessment.
EPA decision
On June 8, 2022, EPA issued a partial approval of our 2018 Water Quality Assessment. EPA is currently seeking public comment on portions of the Water Quality Assessment that they disapproved.
We proposed placing certain impaired waterbodies in Category 4A (impaired with a cleanup plan or TMDL) rather than Category 5 (impaired without a cleanup plan), because these waterbodies were within the boundary of an already existing TMDL. EPA did not approve some of these proposed changes to Category 4A because they said there was not enough information to support the change. EPA is taking comments on their decision to keep these specific listings in Category 5. For more information or to provide comment on their decision, visit EPA’s website.
Draft assessment documents
What is the water quality assessment?
The water quality assessment is our process of collecting data and assessing the quality of surface water in the state. This includes all rivers, lakes, and marine water. You can view the results of the assessment in our online database.
The federal Clean Water Act requires that all states restore their water bodies to be “fishable and swimmable.” Section 303(d) of the Clean Water Act establishes a process to identify and clean up polluted water.
What is the Water Quality Atlas?
We also have a mapping tool called the Water Quality Atlas. The Water Quality Atlas is an interactive search and mapping tool that includes additional layers of information in an easy-to-use mapping application.
Users can map the water quality assessment category results, view water quality standards for a location, identify areas addressed by Total Maximum Daily Loads (TMDLs), and see permitted wastewater discharge outfalls.
The current assessment
The current water quality assessment — called the 305(b) report and 303(d) list of impaired waters for the state of Washington — was approved by the U.S. Environmental Protection Agency (EPA) on July 22, 2016. See below for more information about the current process to update the assessment.
Read the 2016 EPA approval letter.
Key changes that were made in 2016
- Updated freshwater listings based on data collected between 2000 and 2010.
- Updated how we map polluted rivers, lakes, and streams — moving from a land-based system (township/range/section) to a water-based (National Hydrography Database) system. The mapping change helps us be consistent with other agencies and states, and is strongly recommended by EPA.
The process to update the Water Quality Assessment
The following timeline provides information on each step of the current assessment cycle. Because we have been working on a large data automation project (see Assess the data section below) we have not submitted an assessment since 2016. However, this automation of our data should now allow us to meet our requirement for submittal every two years. This new assessment will serve as Washington's past due submittals.
The opportunity for early tribal review of the assessment is part of a 1997 cooperative agreement between the tribes, Ecology, and EPA that recognizes the government-to-government relationship between Washington and tribes in managing water quality.
To develop the revised assessment, we first needed to review and update our water quality assessment policy (Policy 1-11). The purpose of the update was to include several revisions to Washington's surface water quality standards and respond to comments received in the public review of the policy.
Next, we gathered readily available data and narrative information to help us understand the condition of state water bodies. To do this we used federal databases and asked other groups to submit their data to our Environmental Information Management System (EIM). Our call for data and narrative information happened in 2018 and we recieved approximately 116 million pieces of data. The updated assessment will reflect all data and information collected through 2017. Water quality condition determinations based on data prior to 2006 are only reassessed if newer data and information are available.
We applied the updated Policy 1-11 to evaluate the data quality and used the data to review all of Washington's water bodies to determine where designated uses are impaired. The result is the draft revised water quality assessment.
Due to the large volume of data that are available for Washington, we developed new data tools to automate much of our process. These tools will help us gather data more frequently and provide the Assessment to EPA every two years. The development and testing of these new automation tools was completed in Spring 2020 and are now being used to create the draft Water Quality Assessment.
We held a public review of the draft assessment from April 8 to June 4, 2021. On April 20, 2021, we held a workshop to walk through the draft assessment. We highlighted the assessment process, key changes in this assessment, and provide a demonstration of how to use review tools and submit comments.
View presentation slides (pdf)
Next steps
EPA has 30 days from the time we submit the assessment to take action. We are working diligently with EPA to ensure a quick and smooth approval process. Following approval, the candidate list will become the new, approved Water Quality Assessment for Clean Water Act regulatory purposes. We will then announce a Call for Data for the next Water Quality Assessment cycle.
How are water bodies assessed?
We compile our own water quality data, and invite other groups to submit water quality data they have collected. We only assess data that meets high quality assurance and credible data requirements. Our goal is to accurately determine if water bodies are polluted based on the best available data.
The assessed water bodies are placed into one of five categories that describe the water quality. Once the assessment is complete, we provide the public a chance to review and give comments. We submit the final assessment to the Environmental Protection Agency for approval of the category 5 listings, also called the 303(d) list.
Assessment categories
Category 1 means a water body meets the state water quality standards. Being placed in this category does not necessarily mean that a water body is free of all pollutants.
Most water quality monitoring is designed to detect a specific array of pollutants, so placement in this category means that the water body met standards for all the pollutants for which it was tested. Specific information about the monitoring results may be found in the individual listings.
Water bodies in this category have some evidence of a water quality problem, but not enough to show persistent impairment. These are water bodies that we want to continue to test.
There are several reasons why a water body would be placed in this category. A water body might have pollution levels that are not quite high enough to violate the water quality standards. Or there may not have been enough violations to categorize it as impaired according to our listing policy.
According to Policy 1-11, Category 3 water bodies have insufficient data to place them into any of the other categories.
Category 4 means water bodies that have impairment problems are being resolved in one of three ways:
- Category 4a — already has an EPA-approved TMDL plan in place and implemented.
- Category 4b — has a pollution control program, similar to a TMDL plan, that is expected to solve the pollution problems.
- Category 4c — is impaired by causes that cannot be addressed through a TMDL plan. Impairments in these water bodies include low water flow, stream channelization, and dams. These problems, while not pollutants, require complex solutions to help restore water bodies to more natural conditions.
Water quality assessment Category 4b
We recognize that communities do not have to wait for a formal TMDL planning process to begin improving water quality. They can take the initiative to clean up polluted water. Because these efforts are locally controlled, there is an opportunity to reduce overall costs, and the communities can exert greater control over the cleanup process.
Category 4b is intended for water bodies with a pollution control program in place that is expected to solve the pollution problems. While pollution control programs are not TMDLs they must have many of the same features. There must also be some legal or financial guarantee that the program will be implemented.
To be placed in the "has a pollution control project" category, the pollution control project must meet all of the following criteria:
- Be problem-specific and water body-specific
- Have reasonable time limits established for correcting the specific problem, including load reduction or interim targets, when appropriate
- Have a monitoring component to evaluate effectiveness
- Have adaptive management built into the plan to allow for course corrections, if necessary
- Have enforceable pollution controls or actions stringent enough to attain the water quality standard or standards
- Be feasible, with enforceable legal or financial guarantees that implementation will occur
- Be actively and successfully implemented and show progress on water quality improvements in accordance with the plan
In addition to the conditions above, the project is more likely to gain approval if the following elements are included:
- A description of management measures
- An implementation schedule and measurable milestones
- A description of criteria that are used to determine loading reductions achieved over time
- An information/education component
This is the list of impaired water bodies traditionally known as the 303(d) list. Starting with the 2004 Water Quality Assessment, Washington’s 303(d) list of polluted waters were placed under category 5 in the approved assessment. Total Maximum Daily Loads (TMDLs) or other approved water quality improvement projects are required for the water bodies in this category.
If a water body is in this category it means that we have data showing that the water quality standards have been violated for one or more pollutants, and there is no TMDL — or pollution control program — in place.
303(d) list
Water bodies whose designated uses (such as for drinking, recreation, aquatic habitat, and industrial use) that are impaired by pollutants are identified in the water quality assessment as "Category 5: Polluted water that requires a water improvement project." The 303(d) list, so called because the process is described in Section 303(d) of the Clean Water Act, lists water bodies in the polluted water category.
Federal laws, state water quality standards, and water quality assessment policy 1-11 guide our assessment of which water bodies to place on the 303(d) list.
To view the list, go to the water quality assessment database and select Category 5 (under Categories).
What happens to polluted water bodies?
If water bodies are polluted, we develop a water cleanup plan, also called a Total Maximum Daily Load or TMDL, to reduce pollution sources throughout the surrounding watershed. After pollutant controls are in place, we monitor in the watershed to see if the water meets state water quality standards.
Translated content
El departamento de ecología está buscando datos nuevos de la calidad del agua para actualizar nuestra Evaluación de la Calidad del Agua. La Evaluación de la Calidad del Agua determina la salud de los ríos, lagos y arroyos basado en los datos disponibles. Estamos buscando datos que representen condiciones ambientales de la calidad del agua y datos coleccionados bajo planes de manejo de agua de alta calidad.
Los datos deben ser presentados a ecología antes del 30 de septiembre de 2022.
Para más información, favor de comunicarse con Jeremy Reiman al 360-819-0197 y solicite un intérprete.
華盛頓州生態管理署正在尋找新的水質數據來更新我們全州的水質評估。水質評估根據現有數據確定河流、湖泊和溪流的健康狀況。我們正在尋找代表環境水質狀況的數據以及在高質量監測計劃下收集的數據。
數據應在 2022 年 9 月 30 日之前提交給 生態管理署。
如需更多信息,或需口譯員,請致電 360-819-0197 聯繫 Jeremy Reiman
Bộ Môi Sinh đang tìm kiếm dữ liệu mới cho chất lượng nước để cập nhật Đánh Giá Chất Lượng Nước trên toàn tiểu bang. Đánh Giá Chất Lượng Nước xác định tình trạng của sông, hồ và suối dựa trên dữ liệu có sẵn. Chúng tôi đang tìm kiếm dữ liệu tượng trưng cho các tình trạng chất lượng nước xung quanh và dữ liệu được thu thập theo kế hoạch giám sát chất lượng cao.
Dữ liệu phải được gửi cho Bộ Môi Sinh trước ngày 30 tháng 9 năm 2022.
Để biết thêm thông tin hoặc yêu cầu thông dịch viên, vui lòng gọi Jeremy Reiman theo số 360-819-0197.
주 환경부는 주 전체의 수질평가 업데이트를 위한 새로운 수질자료를 구하고 있습니다. 수질평가는 가용한 자료를 기반으로 강과 호수, 하천의 건강성을 평가하는 것입니다. 우리가 찾는 자료는 주변의 수질조건을 나타내는 것으로, 고품질 모니터링 계획에 의해 수집된 자료들입니다.
관련자료는 September 30, 2022까지 주 환경부에 제출되어야 합니다.
보다 많은 정보를 위해서는 담당자 (Jeremy Reiman, 360-819-0197)에게 연락하여 통역을 요청하세요.
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Contact our Language Access team: civilrights@ecy.wa.gov
Contact information
Jeremy Reiman
Water Quality Assessment Scientist
303d@ecy.wa.gov
360-819-0197