Abstract
Hydrogeologic and Geochemical Analysis of Northern California Coastal Aquifers Track: Water Resources Author(s): Charlotte Hedlund The Northern Midcoast Groundwater Basin of coastal San Mateo County serves as the sole source of drinking water to roughly 6,000 residents. This aquifer system is under scrutiny, however, by local government and concerned citizens for the quantity and quality of water it produces. In 1999, the reliable capacity of the aquifer system was estimated at 310 gallons per minute (gpm) with a maximum daily demand of 471 gpm. Thus, there is an immediate need for greater source capacity. During water year 2001, hydrologic data was collected to assess seasonal fluctuations in aquifer storage and the general chemistry of the hydrostratigraphic units within the Northern Midcoast Groundwater Basin. Aquifers composed granodiorite lost approximately 82 acre-feet of storage, marine terrace deposit aquifers decreased approximately 156 acre-feet, and aquifers composed of alluvium and colluvium decreased roughly 348 acre-feet. Geochemical signatures classify these water units as enriched in sodium, potassium, sulfate, and chloride. Charlotte Hedlund San Francisco State University Geosciences 1900 Hollway Avenue San Francisco , CA 94132 US Phone: 415-596-3807 E-mail: charhedlund@yahoo.com |