Tap water quality in Caldwell, Idaho
Caldwell's water systems logged 24 health-based EPA violations in 2021–2026, most recently in 2025 — most often nitrate. Health-based violations mean a federal limit or treatment standard was exceeded; check the systems below and your utility's annual report for specifics.
Averages describe states, not your faucet. A certified home water test screens for lead, nitrates, bacteria and dozens of other contaminants — the same categories EPA regulates.
Test your water at homeWe may earn a commission if you request quotes through this link. It costs you nothing and never affects the data we publish.
Caldwell tap water FAQ
Is tap water safe to drink in Caldwell?
Caldwell's systems logged 24 health-based violations in 2021–2026, most commonly nitrate. A violation is a red flag for a period of time, not a permanent condition — your utility's current Consumer Confidence Report shows today's status, and a certified home test shows what's at your tap.
Who supplies Caldwell's water?
Caldwell City Of (serving about 74,000 people); Caldwell Housing Authority (serving about 1,100 people); El Rancho Heights (serving about 300 people); Woodview Acres Property Owners (serving about 245 people). Data: EPA Safe Drinking Water Information System, July 2026.
How hard is the water in Caldwell?
City-level hardness isn't published in a single federal dataset, but Idaho averages 100 PPM — "moderately hard" on the USGS scale. Your utility's water quality report lists Caldwell's exact hardness, or a $10 test strip tells you in a minute. If it comes back over 120 PPM, see our water softener guidance in the purification calculator.
Do I need a water filter in Caldwell?
With 24 health-based violations on record in 2021–2026, a certified filter is reasonable insurance here: reverse osmosis ($150–$1,300 installed, Angi 2026) covers lead, nitrates and PFAS at the tap. Test first ($50–$200) so you buy for what's actually present.
Averages describe states, not your faucet. A certified home water test screens for lead, nitrates, bacteria and dozens of other contaminants — the same categories EPA regulates.
Test your water at homeWe may earn a commission if you request quotes through this link. It costs you nothing and never affects the data we publish.