A fight over sewage has clogged up the pipeline of development in Sammamish.
After warning the public that current sewage flows have exceeded capacity within its district, Sammamish Plateau Water (SPW), which provides water and sewer services for most of Sammamish, approved a 90-day moratorium on issuing new Certificates of Sewer Availability. This certificate is required for any new or existing home to connect to the sewage system.
The moratorium will run through May 24, with exceptions only for properties that are facing a failing septic system with verification from the King County Health Department.
At the heart of the problem is a dispute with King County over who should pay for interim infrastructure improvements to increase sewage capacity as a long-term solution gets built.
“In essence, [King County] shifted the burden entirely on the district, which is completely contrary to their written approach and what they told us,” said Jay Krauss, general manager of SPW.
The over-capacity issue has been growing for some time, according to Krauss. He said the sewage conveyance system, which carries wastewater southward to the county’s system, has exceeded capacity in the upper half of the district by 100 to 237 gallons per minute at least five times since December 2019. This tends to happen during heavy rain in the winter. The current moratorium covers only this part of the water district.
In the long term, King County is funding a wastewater diversion pipeline that will carry SPW flows northward to its Brightwater Treatment Plant in Woodinville and relieve pressure on southbound pipes. This project is expected to be completed in 2030, according to Maire Fiore, a spokesperson for King County.
To cover the gap until then, SPW issued the moratorium while King County funded an Interim Improvement Evaluation study in January to help SPW determine what measures could be taken until this northern diversion becomes operational.
On Jan. 5, SPW Board President Ryika Hooshangi wrote in an email to King County Executive Dow Constantine that the result of the study shows no simple solutions could meet the district’s regional sewage conveyance need. She said all options are costly and time-consuming to implement.
According to Bruce Kessler, King County’s deputy division director for wastewater treatment, SPW demanded the county pay for 100% of the interim fixes.
In an email response to Hooshangi on March 22, King County rejected SPW’s demand for the county to foot the entire bill. Then, on March 29, the county made a cost-sharing offer to pay for half of the interim work identified. SPW is currently reviewing the offer.
Last August, SPW proposed in an email that King County purchase part of its local sewer system to address the capacity issue, pointing to its customers being underserved due to the lack of infrastructure within the district.
“We’re just looking for a fair return for our customers on what they pay into the regional system,” Krauss said. “It’s really time for our customers to not be the victim of geographic disadvantage.”
King County denied that request as well because the county does not want to own an aged system that is not in great condition, according to Fiore.
Meanwhile, SPW declared an emergency and approved an engineering contract on March 29 to further evaluate and design interim system improvements that can temporarily alleviate the pressure on the sewer system. These improvements include the installation of larger pumps at the North Lake Lift Station and a 1,000-foot segment of 16-inch pipes from the Central Lake Lift Station to connect with existing 12-inch pipes. So far, however, the district has not decided on any particular project.
SPW’s board of commissioners has not yet established a date to consider extending the 90-day moratorium. Krauss said the district anticipates interim projects could potentially be completed within 1 to 3 years. Until then, it is unlikely for the moratorium to be lifted.