Ground Water

camas San Juan Island

G R O U N D   W A T E R

Ground water is surface and storm water that infiltrates into Island aquifers where it is temporarily stored, supporting summer time flow to streams, wetlands, ponds, and lakes, and ultimately used for drinking water by Island residents. Septic system effluent also infiltrates through drainfields and becomes groundwater. Excess use of ground water can pose the risk of dry wells and salt waters intrusion. The CWU funds efforts to monitor and evaluate ground water quality and quantity in support of integrated water management. The Health Department protects public health by ensuring all drinking water and septic systems are managed properly. 


  • Water Resources Plan (2004)

  • Lopez - Salt water intrusion monitoring

  • All applicable islands - Class B water systems monitoring for water conservation and quality