Rain, rain, come this way

September 24, 2019 / / No Comments

By Cari Simson, Stormwater Programs Director

Rain has returned to Seattle and with it, the acute awareness of the region’s pollution challenges. Recently, the Duwamish River was declared unsafe due to a sewage spill. Spills like this have repercussions for swimming, fishing and other aquatic activities and communities are not always made aware of the dangers. While this particular spill was resolved in just a day, the incident reminds us why stormwater pollution is Puget Sound’s #1 source of pollution.

The size of the Georgetown Wet Weather Treatment Plant reflects the magnitude of the stormwater pollution challenge. Photo Credit: Cari Simson / ECOSS.

At the same time, these spills underline the importance of wastewater treatment solutions. Jacobs Engineering invited ECOSS to tour the site of the upcoming King County Georgetown Wet Weather Treatment Plant with the entire design and construction team.

Located on S. Michigan Street and 4th Avenue, the Georgetown Wet Weather Treatment Plant includes the construction of a combined sewer overflow (CSO) wet weather treatment station between the Brandon Street and South Michigan Street Regulator Stations, related pipes and a new outfall structure to release the treated water into the Duwamish River.

King County began on-site work in April 2017 and expects to finish construction in 2022. When constructed, the Georgetown station will treat up to 70 million gallons of combined rain and wastewater a day that would otherwise have discharged directly to the Duwamish without treatment during storm events. Right now, heavy rains can fill up the city’s sewer pipes, sending polluted runoff and sewage into the river, causing harm to wildlife and human health.

It was fascinating for ECOSS staff to see in-the-ground progress that shows utility investment in these types of large projects. ECOSS works with industry along the Duwamish River on innovative solutions to reduce stormwater pollution. Seeing other examples is not only inspiring, but also a great opportunity to share ideas.

Be on the lookout for news on ECOSS’ industrial-scale stormwater solutions, coming soon!

See more on how ECOSS works with industry to mitigate stormwater pollution

Combined sewer overflow: how stormwater became Puget Sound’s #1 source of pollution

June 25, 2019 / / No Comments

Stormwater runoff is the #1 source of pollution in Puget Sound, threatening human, fish and aquatic life. But how does rain result in pollution? One contributor is in how cities manage their sewage.

Seattle implemented its first centralized sewer system in the early 1900s ahead of a premier world fair. Rather than having separate pipes for sewage and stormwater, Seattle’s chosen system collected both sewage and stormwater through the same pipe. Generally, there was no issue as the combined sewage was treated at water treatment plants.

Graphic detailing the route of sewage under dry conditions.

Sewage is directed to a water treatment plant during dry weather.

However, heavy rain overloaded this system, dumping an overflow of untreated sewage and stormwater into Puget Sound, the Duwamish River and other local waters. The combined sewage included human waste, heavy metals from roads and pollutants accumulated on roofs. The polluted water is highly toxic to salmon, orcas and other aquatic wildlife. Moreover, it is detrimental to people swimming in the waters or fishing in urban rivers.

Graphic detailing the route of combined sewage during heavy storms.

During large storms, stormwater is combined with sewage in the same pipe, and the increased volume overflows straight into nearby waters.

The archaic combined sewer systems still exist today. Construction of new combined sewer systems stopped in the 1950s, but older systems have yet to be completely replaced. And with population growth and urbanization in Puget Sound, combined sewer overflow has only become more polluted.

Green Stormwater Infrastructure (GSI) such as rain gardens and cisterns reduce the amount of stormwater entering the combined sewers. More combined sewage is captured by the sewer system and treated properly, rather than going into Puget Sound waters.

Graphic detailing the route of combined sewage during heavy storms controlled by Green Stormwater Infrastructure (GSI).

Green Stormwater Infrastructure (GSI) manages stormwater so that sewer systems are less likely to overflow.

ECOSS engages multicultural communities to raise awareness about GSI opportunities for property owners so that communities of color can be included in the solutions for clean water and healthier communities. Furthermore, ECOSS recruits and guides multicultural contractors through training to install cisterns and rain gardens. These green career pathways promote small businesses of color and ensure that the benefits of GSI solutions are reaching Puget Sound’s most vulnerable communities.

Read more about stormwater solutions

Thank you King County for source material inspiration of the first two graphics.