Seattle To Shell Out $600 Million For Record CSO Problems

As water managers across the country struggle with drought, Seattle officials have a different problem: The city experienced its wettest October on record this year, reports said. 

Wet weather, population growth in the city, and an outdated wastewater system are prompting severe sewer challenges in the form of wastewater overflows. 

“Seattle’s sewer and stormwater systems were designed for a much smaller city decades ago. Back then, engineers designed a system that moved sewage water and the street runoff into the same pipes. Those pipes are still there and lead to wastewater treatment plants. But it rains in Seattle — a lot. And those pipes can only hold so much. So when heavy rain hits, the pipes overflow into the nearest body of water — Elliott Bay, Lake Union, or Lake Washington. This is all the sewage from house and office toilets, sinks, showers, etc. And it’s also rainwater,” KIRO 7 reported. 

Here’s how KUOW described the problem: “Big storms mean big water pollution as heavy runoff carries toxic crud into local waters, and as city sewer systems can't keep up.” At one point in October, the city experienced 12 simultaneous overflows. 

The city is implementing a major plan to upgrade its sewer infrastructure, but completion remains a long way off. 

“A Seattle utility unveiled a $600 million plan to stop millions of gallons of untreated wastewater and polluted runoff from flowing into the area's creeks, lakes, the Duwamish river and the Puget Sound,” Reuters reported last year. 

“The 15-year plan aims to fulfill promises Seattle made in a 2013 consent decree with the U.S. Environmental Protection Agency and the state's Department of Ecology to reduce sewer overflows to comply with state and federal law,” the report said. 

“The legal mandate is to have these pipes only discharge untreated sewage once a year, after the biggest storms,” KUOW reported. 

Nevertheless, the problem may continue to worsen in the coming years. 

“Climate change, expected to bring more-intense rainfall to the region, could make that mandate even more difficult to reach,” KUOW reported. 

To read more about how wastewater plants deal with heavy rainfall visit Water Online’s Stormwater Management Solutions Center.