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Guest Post: Aspect Consulting’s Discussion of the Washington Department of Ecology’s Efforts to Update Its Water Quality Assessment for Freshwaters

Posted in Clean Water Act, Emerging Policy, Guest Posts, Water Quality

This is another in the series of guest posts authored by the consultants we work with and trust. Owen Reese is a Water Resources Engineer at Aspect Consulting approached us and offered to provide Aspect’s perspective on Ecology’s efforts to update its Water Quality Assessment for freshwater. We eagerly took Owen up on the offer because this work by Ecology has the potential to impact a number of dischargers throughout Washington State and fits well into Science Law and the Environment’s editorial goal of analyzing the intersection of science, law, and policy.

-Doug Steding

The Washington State Department of Ecology (“Ecology”) recently proposed updates to Washington’s Water Quality Assessment for freshwater, as required by sections 303(d) and 305(b) of the Clean Water Act. This list is important because it identifies which waters require water cleanup plans and could result in additional requirements for NPDES permit holders discharging to waters identified as impaired.

Ecology is seeking public comment until May 15, and is currently hosting a series of listening sessions to introduce the proposed changes in the Water Quality Assessment. The remaining sessions are: April 15 in Yakima, and April 16 in Spokane Valley. I attended the first session in Edmonds on April 7. This article summarizes my key takeaways from the presentations, with particular attention to potential effects to NPDES permittees.

Background on the Water Quality Assessment Process
The Water Quality Assessment categorizes the quality of Washington’s waters based on available data. A key purpose of the assessment is to identify waters that are not meeting the State Water Quality Standards (WAC 173-201A) for freshwaters. Water bodies not meeting standards are assigned Category 5 if no Total Maximum Daily Load (“TMDL “) or other water cleanup plan is in place, or Category 4 if one is in place. The Water Quality Assessment is submitted to EPA for review and the list of Category 5 waters, known as the 303(d) list, requires EPA approval.

Performing the Water Quality Assessment involves dividing water bodies into assessment units based on their designated uses and water quality criteria, as well as reach lengths where water quality is likely to be consistent. Where water quality data is available for an assessment unit, it is compared to the water quality standards and assigned a category for each medium (water, sediment, fish tissue, habitat) and parameter (temperature, dissolved oxygen, etc.). Policy 1-11 provides guidance for performing the assessment, including evaluating data quality and determining how many exceedances of a standard are required before a water body is listed as impaired.

The Water Quality Assessment is presented as an online database and mapping tools that allow users to query the specific locations, parameters, or previous listings of interest. The information available includes a map of the listing, an explanation of the basis for the listing, and, in some cases, a link to the dataset in the evaluation for that specific listing. It also includes a comparison tool for illustrating the changes between the current and proposed Water Quality Assessments.

What Has Changed Since the Last Assessment Was Completed?
Three notable changes resulted in significant differences between the proposed assessment and the 2012 EPA-approved assessment (the last freshwater update was in 2008):

  • More data — The proposed assessment is based on a much larger data set, resulting primarily from data collection efforts by Ecology, tribes, local governments, and nonprofits. Ecology estimates that approximately 13 percent of the miles of rivers and streams in Washington have monitoring data for at least one parameter. Ecology put out a call for data in 2011 and based the assessment on data collected from 2001 to 2010 that meets data quality objectives.
  • Different approach for defining reaches — Previously, Ecology based the reaches for rivers and streams on the Public Land Survey (i.e., township, range, and section boundaries). For the 2015 update, Ecology shifted to the National Hydrography Dataset (NHD) which establishes reaches based on confluences with major tributaries. Generally, reaches are now longer than in the previous assessment. In addition, Ecology shifted away from the grid system for large open waters like large rivers, lakes, and reservoirs.
  • Revisions to water quality standards — The extent of lower temperature standards to protect salmonid incubation and spawning was significantly updated in 2011.

The net effect of these three changes is a 43 percent increase in the number of Category 5 listings. The proposed freshwater assessment includes 3,847 Category 5 listings, the majority of which are for temperature, dissolved oxygen, and bacteria. Toxics listings comprise 13 percent of the total, most of which are related to concentrations of toxins observed in fish tissue that exceed criteria for protection of human health. Ecology attributes the growth in Category 5 listings to the larger data set and more stringent temperature criteria. Many of the new listings were related to temperature.

The switch to the defining reaches according to the NHD, by itself, would have resulted in fewer listings because the reaches are generally larger and in some cases combine adjacent Category 5 waters. Here is an example of how one water body’s categorization will change as a result of applying reaches based on the NHD:

303(d) example

Example of a comparison between the current and proposed assessment for a single listing to illustrate the difference in reach definition methodology.

 

Takeaway’s from Ecology’s Meeting on Tuesday
At the meeting in Everett this past Tuesday, Ecology asked parties to review the listings in their local waters. Given the highly technical and data-intensive nature of this process, parties whose operations may be impacted by the new assessment should take some time to review the Draft Assessment, and should do so soon. The comment period ends on May 15 and Ecology is hoping to submit the assessment to EPA in July. EPA’s timeline for approval is difficult to estimate, but may occur in fall 2015.

Of course, one of the overlays in this process is Ecology’s ongoing efforts to revise its water quality standards to account for higher fish consumption rates. A question was asked about whether EPA may incorporate any changes in water quality standards resulting from modification of the fish consumption rate as part of their approval of the assessment. Ecology is seeking to avoid this issue by completing the assessment ahead of the rulemaking to change the fish consumption rate and related human health-based water quality standards.

Finally, Susan Braley, Ecology’s Water Quality Management Unit Supervisor, shared Ecology’s vision for future assessments as reintegrating marine and freshwaters into a single assessment, and automating the process to allow future assessments to occur more frequently, ideally achieving the Clean Water Act requirement of every two years. Braley acknowledged the lag between the period of data considered in an assessment (2001 to 2010, in this case) and the completion of the assessment (2015), and stated that Ecology hoped to launch the start of the next assessment shortly after EPA acceptance of the current one. Finally, while the freshwater assessment changed methodologies for defining reaches, Ecology does not envision altering the grid used for marine waters.

Implications for NPDES Permit Holders
Water Quality Assessments have direct effects on NPDES permit holders, for both individual and general permits; however, any changes would be delayed until the next permit cycle. When asked, Ecology clarified that NPDES permits are based on the current Water Quality Assessment at the time the permit is issued, and the 303(d)-related requirements won’t be updated until the permit is reissued.

The Industrial Stormwater General Permit (ISGP) requires dischargers to impaired waters to increase monitoring and comply with effluent limits for the listed parameter. There are also significant restrictions on allowing new discharges to impaired waters. Generally, bacteria, solids (turbidity and TSS), and sediment-related listings have the greatest effect on ISGP permittees. However, the ISGP does not have increased requirements for the most common 303(d)-listed parameters — temperature and dissolved oxygen.

Ecology did consider and evaluate the potential impacts to NPDES permit holders. They examined each individual permit, working with the permit writer to determine whether changes would be required in the next permit cycle. Of the hundreds of individual permits reviewed, they found that about 40 that discharged to waters newly classified as impaired and would have new requirements in their next permit. Similarly, Ecology selected 100 ISGP permit holders at random and evaluated the effects of the new Water Quality Assessment, finding that only a handful would be on newly impaired waters and face new requirements in the 2020 ISGP.

It’s possible that this proposed Water Quality Assessment won’t directly affect ISGP permittees at all. The latest ISGP recently took effect on January 2, 2015 and won’t be reissued until late 2019. If Ecology is successful in moving to a two-year schedule for future assessments, then this proposed freshwater assessment would be superseded by the time the ISGP is reissued.

Nonetheless, I recommend that all NPDES permit holders use the online tools to check if their receiving water is included as Category 4 or 5 on the proposed Water Quality Assessment. Now is the time to catch errors or present additional information if a listing appears erroneous.