City halts storm water discharges to aquifer
October 14, 2008
By Jon Savelle
Issaquah has stopped discharging storm water to the Lower Issaquah Valley Aquifer, at least temporarily, while a dispute over possible contamination of the aquifer is resolved.
On Oct. 1, the city stopped sending Highlands runoff into the aquifer via the Lower Reid Infiltration Gallery, a series of underground injection wells just 600 feet from drinking-water wells operated by the Sammamish Plateau Water and Sewer District. The stoppage followed an agreement between the district and Issaquah to divert the storm water to the North Fork of Issaquah Creek instead.
The water district long has maintained that storm water poses a threat to the aquifer. In July, the state Department of Ecology agreed and ordered the city to begin ground water monitoring at the infiltration gallery.
Issaquah officials have appealed the order. Now, the agreement with the district stops discharges to the aquifer, at least until the appeal is resolved.
If the city must proceed with ground water monitoring, it will require the costly installation of monitoring wells and test equipment, said Keith Niven, manager of the Major Development Review Team.
City engineers have consistently maintained that injecting storm water into the aquifer via the infiltration gallery does not pose a threat to drinking water. But this is disputed by Ron Little, director of the water district, who said a two-year study found fecal coliform, metals and other pollutants in the storm water and in the aquifer between the infiltration gallery and the district’s wells.
On Oct. 1, city Public Works Operations Department workers shut a valve on the Upper Reid Pond, a storm water catchment on the bluff above the infiltration gallery, stopping its discharges to the gallery. The valve will remain closed at least until April 1.
Reach Reporter Jon Savelle at 392-6434, ext. 234, or firstname.lastname@example.org.