U.S. Environmental Protection Agency: Ground Water & Drinking Water water.epa.gov/drink/index.cfm U.S. Environmental Protection Agency: Arsenic in Drinking Water www.epa.gov/safewater/arsenic/index.html Arizona Department of Environmental Quality: Water Quality Division www.azdeq.gov/environ/water/index.html Arizona Department of Health Services: Environmental Water Microbiology http://azdhs.gov/lab/microbiology/environmental/water-samples.htm Maricopa County Environmental Services Dept.: Water Quality http://www.maricopa.gov/EnvSvc/WaterWaste/DrinkingWater/DrinkingWater.aspx Centers for Disease Control: Water Quality http://www.cdc.gov/healthywater/