New Keyes plant filters out arsenic
Keyes’ problems with unacceptable high levels of arsenic arose in late 2006 when the district was issued a Notice of Non-Compliance from the California Department of Public Health. … The quality of Keyes’ drinking water had not deteriorated but the Environmental Protection Agency had lowered the maximum allowable contaminant level for arsenic from 50 parts per billion to 10 parts per billion. Three of four Keyes wells were testing at 12 to 14 parts per billion.