by Kirby Lindsay Laney, posted 25 September 2015
There is nothing more basic than clean water, and to keep our waterways clean takes building basic infrastructure. Right now, Seattle Public Utilities, with King County Wastewater Treatment, is hard at work on the Ship Canal Water Quality Project. They want to raise public awareness, and comment, on their plan to remove risks to the cleanliness of the water in Lake Washington Ship Canal and Lake Union – and no matter how ho-hum this all sounds, it is of fundamental importance that we listen.
No Time Like The Present
Pre-construction activity has begun on the Ballard portion of the Ship Canal Water Quality Project, and SPU has sent out representatives to local groups to explain Fremont’s part, and impacts we will feel, during the $400 million infrastructure project. At Fremont Chamber of Commerce and Fremont Neighborhood Council meetings, representatives described the vast storage system currently under design, as a way to retain and reroute storm water and sewage.
Over the next 10-years, SPU will build this much needed capture system – as agreed to with the U.S. Environmental Protection Agency (EPA.) “Many large coastal cities are being asked by the EPA to clean up their combined sewage overflows, as part of the Clean Water Act,” explained Andy Ryan, Media Relations Coordinator for SPU, “Nationally, billions and billions are being spent.”
Seattle will spend big money to fix this big problem, to clean up our canal and lakes, but the SPU engineers and planners have come up with a solution that will not only fix the problem today, but solve it for a long time into the future. After the EPA sought judgement against Seattle for the number of CSOs (Combined Sewage Overflows) around the city that allowed sewage and storm water (during storms) to spill into public waterways, the City negotiated a consent decree that “gives us more flexibility in how we spend our money to get results,” Ryan said.
Under the consent decree, the City will get our overflows down to one per year, spilling less than 50 million gallons, as opposed to the, in 2014, approximately 163 annual overflows that occurred at the 7 CSOs in Ballard and Fremont, and the approximately 275 million gallons of polluted run-off and sewage, across the City, that flowed into our waterways.
According to Ben Marré, Program Manager for the Ship Canal Water Quality Project, the City has 86 outfalls/pipes that, during storms, overflow with the water off our roofs and streets – a swirly black water containing the oils, tire dust, litter, plant matter, shingle dust, and other ick – plus some sewage, into public waterways. Of these 86, seven lay in Ballard and Fremont, with two belonging to King County, and the rest part of the City system.
Storage Instead Of Overflow
Seattle home owners, and building owners, have responsibility for sewage and drainage on their properties, which they connect to the City system. “We own and operate the connection system,” Marré explained about the complicated sewer system. “The pipes we own are 8” – 48” in diameter approximately,” Marré explained, simplifying things as much as possible, “the County’s are 48” – 120”.” King County owns the inceptor pipes that take the sewage, and run-off, collected in City pipes along to the Siphons and on to the Treatment System.
Right now, King County Wastewater has torn up an area of West Fremont as part of the replacement of the nearly 100-year-old Fremont Siphon. They will install two micro-tunnels to carry the sewage from the City connectors all over North Seattle (and well up into Shoreline) to the treatment facility at West Point.
CSOs were created as “the relief point,” Marre explained. During hard-driving rain storms our streets and homes can be deluged with water, as is the City system of sewers and sewer pipes. The City has CSOs that allow the heavy excess of water, when holding tanks fill beyond their capacity, into Salmon Bay, the Ship Canal and Lake Union.
In dry weather, all sewage flows to the Siphons, and on to the treatment plant, but during wet weather polluted runoff sharply increases the amount of the flow and exceeds these pipes capacities. The mixture of storm water (90%) and sewage (10%) exceeds the space in the long-ago built holding tanks, and some flows into nearby public waterways.
SPU has developed this plan for an elongated storage tank, 2.7 miles long and approximately 14-foot in diameter (it could be as large as 16-foot) to lay between the CSO in Ballard, beside the old Yankee Diner, to the CSO at Stone Way – and near the five other CSOs in-between. This underground container would hold more than 15-million gallons of storm water and sewage, connected to the Fremont and Ballard Siphons for reroute when the Siphons can take the increased of water, sluiced off from roofs and streets.
This storage tank, referred to as a storage tunnel, would protect the Siphons and West Point Treatment, from being bombarded with storm water. “Siphons don’t have enough capacity,” Marre observed about our storms, “West Point can’t handle the capacity.” During a storm, flow can increase by 20% – 10 to 20 times more than normal.
At the August FCC and FNC meetings, Public Relations representative Jeanne Muir spoke for SPU, and she explained that the CSOs have become particularly overwhelmed as the city has become more developed. The increase in people has contributed, but mostly it is the lack of permeable surfaces – we have less grass and soil to absorb the storm water, and more roofs and paving that drain off into the city sewer system.
‘At The Last Little Bit’
Ryan pointed out, “how dedicated Seattle has been to addressing this.” Since the 1970s, the City has been at work on cleaning up and controlling its CSOs and, “We’re at the last little bit,” Marré observed. We want clean water for the Ship Canal and Lake Union, along with Puget Sound and Lake Washington. To get clean water, we must build the infrastructure.
“We’re really thinking about neighborhood impacts,” Marré explained, and how to lessen the impacts from this much-needed, 10-year construction project. SPU and King County have identified potential locations of the elongated storage tank, between Ballard and Fremont, along with properties and places where construction can be done with the least impact on existing neighbors. In 2014, SPU conducted a series of borings along public streets (including on Evanston Avenue at N 35th, on N 35th across from the Fremont Branch Library, and on N 35th near Ashworth Ave N,) to identify what lay in the soil and where the storage tank could most safely be placed.
Design of the storage tank, the plan for placement and siting of the construction, is still in early stages. Targeted community outreach is going on now, as SPU prepare to publish an environmental impact statement (EIS) and hold design workshops in early 2016.
For questions, and comments (including what SPU may find underground in your specific area,) contact Dan Enrico, P.E., Project Manager with SPU at 206/684-7413 or SPU_ShipCanalProject@seattle.gov – or sign-up for project e-mail updates through the SPU Ship Canal Water Quality Project website.
Related Articles
- A Call For Community Feedback On Fremont Siphon
- by Kirby Lindsay, May 21, 2012
- FNC Highlight Reel: A Full FNC Agenda
- by Kirby Lindsay, May 25, 2013
- FONLU Creates Community Opportunity To Restore Our Shoreline
- by Kirby Lindsay Laney, May 8, 2015
©2015 Kirby Lindsay. This column is protected by intellectual property laws, including U.S. copyright laws. Reproduction, adaptation or distribution without permission is prohibited.