The Sammamish Plateau Water and Sewer District and the Issaquah City Council both voted unanimously to approve the inter-local agreement formally decommissioning the Lower Reid Infiltration Gallery. Both votes came at their respective meetings Monday, March 17.

Also known as the LRIG, it is a football-field shaped piece of land at the foot of the Issaquah Highlands. Called a vadose zone, it uses sand and gravel to naturally filtrate contaminants before they reach an underground aquifer.

Issaquah, which owns the LRIG, was seeking a permit from the Department of Ecology to inject storm water from the Issaquah Highlands into the aquifer.

The water district voiced its concerns over the practice — largely because it has three wells nearby, including one 600 feet downhill.

Issaquah City Council President, Paul Winterstein, said it was a very significant milestone.

“There’s more than one way to handle surface water correctly,” he said, adding that any alternatives would be subject to a state environmental policy act review.

The district agreed to pay the cost for the city to decommission the LRIG and to design, construct and install other storm water management projects, facilities or systems up to $1 million. The city has until the end of the year to inform the district of the estimated cost of any projects and a schedule for their completion. Then the city has five years to complete any projects related to the agreement.