Clean Water Consent Decree

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Elliott Bay 1976

Seattle and the US Environmental Protection Agency (USEPA) have completed negotiations on a historic consent decree that opens the door for a more thoughtful and effective approach to promoting clean water in Seattle and Puget Sound.  The Council is now reviewing this decree, and will vote on whether to endorse it in the near future.

Cities around the country are required to meet standards for cleaning up Combined Sewer Overflows (CSO’s).  CSO’s take place when a single pipe carrying both sewage and stormwater to the treatment plant becomes overwhelmed by a rain event.  Under this circumstance, the pipes are designed to spill the untreated sewage and stormwater into the city’s waterways, threatening human and aquatic health and the region’s quality of life.  While it would be prohibitively expensive to completely eliminate these events,  state regulators have set a standard of an average of no more than one such event per year for each outfall as an achievable goal to meet the objectives of the Clean Water Act.

sewer pump 4, 1924

For decades, cities have been working to build the expensive holding tanks and other systems that will attain that goal.  Seattle has reduced its overflows by more than 80%.  However, the ones that remain to be managed are  those that are the most expensive,  and/or most difficult to manage.

At the same time, over these decades there has been growing  evidence that the toxic materials carried by stormwater  exceed the effects of CSO’s on water quality.  Cities have also been struggling to find ways to effectively manage stormwater, and Seattle has been a leader in developing new green infrastructure that can be both effective and affordable.

The problem is that there has not been a way to set priorities that integrates the issues of stormwater and CSO’s so that the most cost effective strategies for clean water can be implemented as rapidly as possible.  That’s why for years Seattle and other cities around the country have been asking EPA to rethink the way it regulates such investments.  Finally, last fall, EPA issued a letter indicating that it was open to looking at doing the best investments first, rather than relying on a more prescriptive set of rules that don’t always deliver the most effective and immediate water quality improvements that could be optimum.

The proposed agreement allows SPU to integrate the full set of tools — rain gardens, street swales, low-impact development, larger diameter pipes, larger storage tanks, and treatment — with street sweeping and best operation and maintenance practices.  Seattle continues to have the obligation to clean up sewage overflows under a specific and regulated schedule, to the regulatory standard of an average of one overflow per outfall per year.  But this schedule is supplemented by being able to mix and match clean water actions to deliver pollution prevention.  Seattle’s plan will be the first in the nation to give flexibility to set priorities for both stormwater and combined sewage overflow control measures.

Over the next 13 years, the city estimates it will spend about $500 million on capital construction projects — including retrofits, green infrastructure, and large underground storage tanks — to implement the proposed agreement, but will save approximately $375 million in future operating and maintenance costs over the next 13 years — primarily because Seattle Public Utilities (SPU) has been able to demonstrate it uses best practices for inspecting and managing its existing sewer pipes and systems.  Using some of the most advanced technology and system analytics available, Seattle’s maintenance program has significantly reduced the risk of pipe breaks and sewage spills.  Recognizing this, the proposed plan allows SPU to take a much less prescriptive approach for maintaining its system.

Cleaning up environmental pollution and getting the best water quality in our streams and Puget Sound as quickly as possible is a challenging and costly endeavor.  There is no perfect path to get there and certainly no inexpensive way.  There will be questions about the new strategic approach, such as how this impacts other considerations like specific neighborhoods where priorities might change, especially low income communities.  These will  be taken into account as new plans and priorities are developed.  Overall, however, the emphasis on doing the most cost effective environmental projects and the widest range of effective measures as a priority makes a lot of sense for the environment and ratepayers.