The State DHS Drinking Water Program contracts with Environmental Health to administer and enforce drinking water quality standards for public water systems in Marion County that use groundwater and serve a population of 3300 or less. Marion County has close to 200 public water systems that meet this criteria. A water system survey is conducted at these systems once every 3 to 5 years.
Marion County's Drinking Water Program is a resource for water system operators and the public when dealing with water quality alerts, public notices, water monitoring & testing, and sanitary hazard analysis.
Private wells are not regulated but there is an Oregon law, ORS 448.271, which requires testing of domestic well water for a real estate transaction. Additional information on drinking water from private wells can be found at The Oregon Well Water Program-OSU or at Private Drinking Water Wells-EPA.
More information can be found on the State DHS Drinking Water Program web page.