Water Quality Assessment & 303(d) List

The 2018 Water Quality Assessment evaluated data collected between 2006 and 2017. The candidate 2018 Assessment was submitted to EPA on Aug. 31, 2021. EPA issued a partial approval of our candidate 2018 Assessment on June 8, 2022 and their final approval on Aug. 26, 2022.

After the 2018 Water Quality Assessment was approved by the EPA, we started work on the 2022 Assessment. We began by reviewing and updating our Water Quality Assessment policy (Policy 1-11). This update included a new methodology for evaluating freshwater harmful algae blooms, a temporary suspension of the natural conditions methodology, and non-substantial edits to improve clarity of the Water Quality Assessment, largely focused on narrative standards based listings. Policy 1-11 was also shifted to an updated, accessible format. We held a public comment period for the policy update from Nov. 2022 – Jan. 2023 and finalized updates in March 2023.

The call for data helps us gather credible water quality data and information to use with the Assessment. We held a call for data for the 2022 Water Quality Assessment from July 7, 2022 – Sept. 30, 2022 and requested data collected between Jan. 1, 2012 and Dec. 31, 2021.

During the call for data, water quality data was submitted to Ecology's Environmental Information Management (EIM) database. Narrative information and studies, such as published research and peer-reviewed reports, were submitted directly to Water Quality Assessment staff at 303d@ecy.wa.gov.

For this Assessment, we evaluated over 85 million data points from many water bodies across the state, including 9,322 miles of streams, 449 lakes, and 633 square miles of marine water. Data analysis began in the Fall 2023 and was completed in Summer 2024. Following Policy 1-11, we compiled, reviewed, and assessed water quality data to determine where designated uses of Washington's waters were being met or were impaired. The end result is the Draft 2022 Water Quality Assessment.

The public comment period is an opportunity for people to comment on draft Assessment results. Before and throughout the public comment period we also seek feedback from Tribes. Our public comment period for the Draft 2022 Water Quality Assessment was open from Nov. 4, 2024 - Jan. 10, 2025.

During the public comment period, we hosted a workshop on Nov. 13, 2024 where we discussed the Assessment process, key changes in the Assessment, data results, and provided a demonstration of how to use review tools and submit comments.

We are now reviewing the comments received during the public comment period and will make any necessary changes to the Draft 2022 Water Quality Assessment. We will prepare a response to comments document that will be posted on our webpage and submit the updated candidate Water Quality Assessment to the EPA. EPA has 30 days from the time we submit the Assessment to take action. Once approved, the candidate Water Quality Assessment will become the new, approved Water Quality Assessment for Clean Water Act regulatory purposes. We will then begin the next Assessment – starting with reviewing Policy 1-11 and announcing the call for data for the next Assessment cycle.

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.