Tap and WellTreasure Valley water, from the public record

Arsenic in Nampa water

3 systems serving Nampa detected Arsenic in the last 36 months. 1 exceeded a federal limit. 2 are elevated. The federal MCL is 10.0ppb.

System36 mo maxLatestStatusLast sample
Valley View Water21.3ppbNDAbove limit2025-12-31
City of Caldwell7.5ppb7.5ppbElevated2025-08-20
City of Nampa5.1ppb2.5ppbElevated2024-11-13
Some people who drink water containing arsenic in excess of the MCL over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer.EPA, quoted. This site does not paraphrase health guidance.

Arsenic in Treasure Valley drinking water. Nampa water quality.

Numbers are the system's samples at its taps and wells, not yours. Lead and copper are 90th percentiles from sampled homes. Well pages are nearby-sample estimates. Health text restates EPA and DEQ. Methodology.