Tap and WellTreasure Valley water, from the public record

Haloacetic Acids (HAA5) in Treasure Valley drinking water

28 of 51 systems that tested for it in the last 36 months detected it; 3 are above the limit, elevated, or an aesthetic issue. Haloacetic Acids (HAA5) is a byproduct of disinfecting water with chlorine. Certified filters are in the list.

SystemCounty36 mo maxLatestStatusLast sample
Castle Mountain Creeks Owners AssociationBoise266.0ppbNDAbove limit2026-08-14
Wilderness Ranch Owners Association Inc.Boise54.4ppb33.7ppbDetected2026-06-24
Idaho City Water DepartmentBoise53.7ppb43.2ppbDetected2026-06-23
Veolia Water IdahoAda53.2ppbNDDetected2026-08-11
Mores Creek Rim Ranch Water DistrictBoise47.4ppb47.4ppbElevated2025-09-10
Atlanta Water AssociationElmore34.2ppb26.0ppbElevated2025-09-09
City of Glenns FerryElmore31.8ppb7.1ppbDetected2026-04-09
Rivers Point Property Owners AssociationBoise23.9ppb16.3ppbDetected2026-07-14
Horseshoe Bend Water SupplyBoise16.5ppb14.0ppbDetected2026-06-18
Desert View Estates Water Corp.Ada9.0ppb7.3ppbDetected2026-07-09
City of GreenleafCanyon8.2ppbNDDetected2025-09-29
City of Mountain HomeElmore5.6ppb5.6ppbDetected2025-08-13
IDOC Mountain View Transformation CenterAda4.9ppb4.9ppbDetected2025-08-19
City of Eagle (Eastern Zone)Ada4.8ppb2.8ppbDetected2026-07-28
City of MelbaCanyon3.5ppb1.6ppbDetected2026-07-01
Mountain Home Air Force BaseElmore3.5ppb3.5ppbDetected2025-08-19
Karcher Ranchette Water Corp.Canyon3.5ppb3.5ppbDetected2024-09-26
City of KunaAda3.1ppb1.5ppbDetected2026-08-13
IDOC SBX ComplexAda2.9ppbNDDetected2025-08-13
City of NampaCanyon2.6ppb1.6ppbDetected2026-05-13
Caldwell Housing AuthorityCanyon2.2ppbNDDetected2025-08-21
New Horizons Water Inc.Elmore2.2ppb2.2ppbDetected2025-08-20
Trinity Estates Water Users AssociationElmore2.0ppb2.0ppbDetected2025-07-15
City of WilderCanyon1.6ppbNDDetected2026-08-21
Sawtooth Estates Water UsersElmore1.5ppb1.5ppbDetected2025-07-15
City of Eagle (Western Zone)Ada1.3ppbNDDetected2026-07-28
West Meadows EstatesAda1.1ppbNDDetected2026-02-12
Mellen Subdivision Water DistrictElmore1.1ppbNDDetected2026-07-08

Limits

Federal limit (MCL)
60 ug/L (60.0ppb)
Some people who drink water containing haloacetic acids in excess of the MCL over many years may have an increased risk of getting cancer.EPA, quoted.

Removal methods in the reference list: activated carbon, reverse osmosis with carbon. A method name is not a product certification.

By city: Haloacetic Acids (HAA5) in Robie Creek drinking water, Haloacetic Acids (HAA5) in Wilder drinking water, Haloacetic Acids (HAA5) in Idaho City drinking water, Haloacetic Acids (HAA5) in Boise City drinking water, Haloacetic Acids (HAA5) in Garden City drinking water, Haloacetic Acids (HAA5) in Meridian drinking water, Haloacetic Acids (HAA5) in Glenns Ferry drinking water, Haloacetic Acids (HAA5) in Horseshoe Bend drinking water, Haloacetic Acids (HAA5) in Kuna drinking water, Haloacetic Acids (HAA5) in Greenleaf drinking water, Haloacetic Acids (HAA5) in Mountain Home drinking water, Haloacetic Acids (HAA5) in Eagle drinking water, Haloacetic Acids (HAA5) in Mountain Home AFB drinking water, Haloacetic Acids (HAA5) in Nampa drinking water, Haloacetic Acids (HAA5) in Caldwell drinking water.

Not enough groundwater samples in the region to estimate Haloacetic Acids (HAA5) in private wells. A lab test is the only way to know.

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.