Washington’s Proposed Water Quality Assessment: New Data, New Techniques May Trigger New Discharge Requirements


Washington State has proposed an updated water quality assessment that identifies state waters that do not meet water quality standards.  Failure to meet the standards can trigger more stringent regulations for dischargers.  The proposal, if adopted, may have significant consequences for water-dependent businesses.  Comments on the proposal are due May 15.

The Proposed Water Quality Assessment

Under EPA regulations, a list of impaired water bodies must be submitted to EPA every two years.  Washington’s proposed listings depart from previous water quality assessments.  Historically, the Department of Ecology used a land-based segmentation system to characterize waters that did not meet the standards.  The proposed listings rely on a water-based segmentation system, which is a “confluence-to-confluence” mapping technique recommended by EPA.  According to Ecology, this new method will increase the lengths of impaired stream segments.

In addition, monitoring changes, updated standards, and policy revisions since the last assessment will increase the number of impaired segments and water bodies by 43 percent.  These developments may lead to stricter discharge requirements at more facilities.

Total Maximum Daily Loads

CWA § 303(d) establishes Total Maximum Daily Loads (TMDLs) as the mechanism for improving water quality in impaired waters.  In light of the expanded list of impaired water bodies and recent case law, greater reliance on TMDLs can be expected in the future.  TMDLs set the maximum effluent that a water body can receive and still meet applicable standards.  Once in place, TMDLs inform permitting for point sources of pollutants, including pipes and culverts, and best management practices for non-point sources of pollutants, including runoff from impermeable surfaces and farmland.

TMDLs are mandatory.  Last week, in a case involving PCB loading to the Spokane River, a Washington federal district court affirmed that “nothing in the CWA provides that states may pursue…[alternative] courses in place of, or as a means of indefinitely delaying, a TMDL.  To the contrary, the CWA expressly requires states to produce a TMDL for each pollutant of concern in each 303(d) water segment.”  Sierra Club v. McLerran, 2015 WL 1188522, at *10 (W.D. Wash. Mar. 16, 2015).

Potential Regulatory Burden

Pollutant sources and available data will affect how the burden for achieving TMDLs is allocated across watershed users.  Where nonpoint source control is not achievable, for instance, implementation plans may focus on point source discharges.  These additional performance requirements can be expensive for businesses already complying with technology-based effluent limits.

Discharge requirements also may be tightened for impaired waters without a TMDL.  Ecology’s 2015 industrial stormwater general permit, for example, imposes more rigorous sampling obligations in these circumstances.  And, following a Ninth Circuit decision, Friends of Pinto Creek v. EPA, 504 F.3d 1007 (9th Cir. 2007), new discharges to an impaired segment or water body without a TMDL may be disallowed.

Novel Water System Management Options

While the potential impacts of TMDLs on businesses cannot be overstated, TMDLs also may generate unique regulatory approaches for achieving water quality improvement goals.  TMDLs have been an impetus for water-quality trading schemes and for comprehensive watershed planning initiatives that manage a broader range of effluent sources.

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