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Tap water quality report

Nampa, ID

EPA monitoring detected 16 contaminants across the 41 water suppliers serving Nampa. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

41
water suppliers
104,706
people served
16
contaminants found
Idaho rankings Lead in Idaho PFAS in Idaho

What was found in Nampa's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
9980 µg/L 100%
of the EPA limit 10000 µg/L
 37/41 SYR4
Nitrate-Nitrite
6400 µg/L 64%
of the EPA limit 10000 µg/L
 31/41 SYR4
Fluoride
2400 µg/L 60%
of the EPA limit 4000 µg/L
 38/41 SYR4
Barium
140 µg/L 7%
of the EPA limit 2000 µg/L
 28/41 SYR4
Total Haloacetic Acids (HAA5)
132 µg/L 220%
of the EPA limit, in the worst sample — 60 µg/L
 2/41 SYR4
Lithium
42.1 µg/L
No EPA limit set
 1/41 UCMR-5
Combined Uranium
33 µg/L 110%
of the EPA limit, in the worst sample — 30 µg/L
 36/41 SYR4
Arsenic
31 µg/L 310%
of the EPA limit, in the worst sample — 10 µg/L
 35/41 SYR4
Gross Alpha, Excl. Radon And U
18.3 pCi/L 122%
of the EPA limit, in the worst sample — 15 pCi/L
 15/41 SYR4
Nitrite
10 µg/L 1%
of the EPA limit 1000 µg/L
 1/41 SYR4
TTHM
9.89 µg/L 12%
of the EPA limit 80 µg/L
 2/41 SYR4
Chromium
8 µg/L 8%
of the EPA limit 100 µg/L
 20/41 SYR4
Combined Radium (-226 And -228)
2.87 pCi/L 57%
of the EPA limit 5 pCi/L
 18/41 SYR4
Di(2-ethylhexyl) Phthalate
1.43 µg/L 24%
of the EPA limit 6 µg/L
 2/41 SYR4
2,4-D
0.8610 µg/L 1.2%
of the EPA limit 70 µg/L
 1/41 SYR4
Lead
0.0070 mg/L 47%
of the EPA limit 0.0150 mg/L
 40/41 LCR
Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Nampa

SupplierPopulation served
NAMPA CITY OF 100,200
SHALIMAR SUBD 370
BELLE AIRE ACRES 2 350
EVERGREEN MOBILE PARK 284
ROLLING HILLS ESTATES WATER COMPANY 250
COVERT WATER USERS ASSOCIATION 250
SUNNYRIDGE 3 WATER CORP 240
INDIAN VILLAGE 225
LAKEVIEW HILLS WATER USERS ASSOCIATION 160
CAMELOT WATER ASSN INC 157
CLARK THEURER WATER ASSN 155
LEISURE HEIGHTS HOMEOWNERS ASSOCIATION 142
OK WATER ASSN 140
SHAMROCK VILLA WATER ASSN 130
APACHE HEIGHTS SUBDIVISION (2) 110
SKY RANCH ESTATES 104
M & T WATER CORP 100
NORTHSIDE ESTATES HOA INC 100
KARCHER ACRES SUBD 100
VERDE HILLS WATER USERS ASSN INC 95
WESTVIEW SHERVIK SUBD 78
MANGUM HEIGHTS SUBD 75
HORIZON RIDGE SUBDIVISION 75
SOUTHSHORE WATER 60
VALLEY VIEW WATER 57
BURNIE SUBD 55
M AND M MOUNTAIN VIEW SUBD EM2 54
SUNNYRIDGE PROPERTY OWNERS 53
DAHL SUBD 51
SKYLINE WATER ASSN 50
LAKERIDGE SECOND SUBD 50
NORTHSTAR SUBDIVISION 50
LINDENWOOD WATER ASSN 48
SILVER SPUR SUBDIVISION 44
LOCUST SUBD 42
SHIPMAN PLACE SUBD 40
COUNTRY MEADOWS SUBD 35
SUNNYRIDGE I SUBD 35
SUNNYRIDGE SUBD 2 34
AURORA SUBD 30
TWIN BRIDGES SUBD 28

Frequently asked questions about Nampa tap water

Is Nampa tap water safe to drink?

EPA testing detected 16 contaminants in the water serving Nampa. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Nampa?

41 public water suppliers report drinking-water monitoring for Nampa, Idaho to the EPA. Each is listed above with its population served.

What contaminants are in Nampa's water?

The contaminants EPA monitoring detected in Nampa include Nitrate, Nitrate-Nitrite, Fluoride, Barium, Total Haloacetic Acids (HAA5). The full list, with the highest level found and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.