In 2006, chloride sampling results from the Seabold Water Association drinking water supply well exceeded the 100 mg/L early warning level for potential seawater intrusion. In keeping with recommended management actions outlined in the City's Groundwater Monitoring Program Plan, this investigation was a two-phase project to conduct appropriate and sequential monitoring and investigative activities that, if seawater intrusion was confirmed, would lead to protective or remedial actions.
Phase I - Phase I was a preliminary desktop assessment of available water quality data for representative wells in the Sea Level Aquifer around the Seabold region encompassing the north end of the Island north of Lovgreen Road to determine if water levels or water quality were indicative of a regional issue developing in the aquifer.
Phase II - Phase II was a field investigation focused in the Seabold Water Association neighborhood encompassing the area bound by NE Ralston Road to the south, Agate Passage to the north, State Highway 305 to the east, and Port Orchard Passage to the west. Physical and chemical parameters of groundwater in the Sea Level Aquifer were measured and assessed to confirm/rule out seawater intrusion in the aquifer and, if intruded, determine extent.