City to present stormwater solutions
By Meg Olson
solution to Blaines sewer overflow problems and a
temporary solution to the shortfalls of the citys
old sewer treatment plant are ready to be unveiled.
On July 23, city staff, consultants and members of the wastewater advisory committee will present a series of alternatives and their recommendations for overflow storage and new headworks on the east side of Drayton Harbor.
Blaine public works director Grant Stewart said, The city is a steward of water quality and we are interested in doing everything we can to return oyster harvesting to Drayton Harbor within three years. Not only that, our proposed solutions are consistent with our plans for a regional solution.
Asked to give a thumbnail view of the proposal, Stewart said The project provides a wide spot in the line to store excess water until we can pump later.
All wastewater from central and east Blaine runs downhill to lift station #1, next to Blaine Marine Park. Lift station pumps then push the sewage through a pipe under the harbor to the wastewater treatment plant at the foot of Semiahmoo spit.
Due to an aging collection system in some areas dating back to the 1920s groundwater enters the system and, in periods of heavy rain, overwhelms the pumps. The result is sewer overflows, which continue to plague the city despite several years of upgrades.
While the pumps can now handle over three times the normal wastewater flow even in winter, a once-in-five-years storm, dumping up to half an inch of rain in an hour, would swamp the system with 120,000 gallons too much flow, which would end up overflowing into the harbor.
Under an administrative order from the state department of ecology (DOE) to stop the overflows, the city put temporary bladders at the lift station #1 site as a stopgap measure, and a wastewater advisory committee made up of representatives from local stakeholders started looking at alternatives for a long-term fix.
Also under DOE orders, the group looked into replacing the wastewater treatment plants headworks, which pretreat sewage to remove grit and grease that can jam the plants equipment. Existing headworks were described in a facilities plan prepared by consultants TeteraTech/KCM as in very poor condition, which could lead to violations of the citys wastewater discharge permit.
The citys wastewater committee looked at four alternatives sites for new facilities, and cost estimates with and without new headworks. All options included facilities to remove odors.
The cheapest and easiest alternative was 400,000 gallons of extra storage in an underground tank built at the existing lift station #1 site and no new headworks, estimated at $4 million. At the high end was 700,000 of flow storage and new headworks at the site of the old Gull Station on F and Third streets, costing over $8.5 million. The site currently housing the Subway building on Peace Portal and Marine drives was also considered for both headworks and a storage tank.
The option favored by the advisory committee was new headworks at the old lift station and a long pipe for overflow storage built underneath Marine Drive.
One of the things that made that attractive was the possibility of coupling the project with road work, said assistant public works director Steve Banham. All the alternatives looked at building a public amenity as part of the sewer project, from a new visitors center at the Subway site to a new street or a skateboard park along Marine Drive.
The new headworks would be the most expensive component of the upgrade and are estimated to only extend the life of the wastewater treatment plant by three to seven years. Ideas to keep the price down include a cheaper prefabricated unit at one of the proposed sites or above ground at the existing treatment plant site, and a grease-control program for local businesses.
City manager Gary Tomsic said the proposed upgrades would be both a solution to current problems and part of a regional wastewater plan now being developed by Blaine and Birch Bay. The city is plumbed to this point, he said, referring to lift station #1. Any work that we did here would need to be done either way. Tomsic added that securing funding for a regional facility, estimated to cost $30 million, could push that project into the next decade. We could be where we are for a fairly long time, he said.
Proposed storage and headworks upgrades could allow the existing system to serve the communitys needs until then. If we cant make some interim improvements at the wastewater treatment plant, ultimately it could have an effect on growth, Tomsic said, adding the most likely impact would be that the city couldnt accommodate another large, industrial user on the system.
The public meeting is from 4 to 5:30 p.m. July 23 at city hall.