City of Nampa water quality
Met every federal limit. 2 contaminants at half a limit or higher. Hard, 7.1 gpg.
ID3140080. Data through 2026-08-19. DEQ record.
What's in it
Nitrate (as N)
ElevatedEPA: infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die.
Aquasana OptimH2O Reverse Osmosis + Claryum is certified to reduce it.
Arsenic
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum is certified to reduce it.
14 other contaminants tested, not detected or well below the limit
Copper 0.12ppm Fluoride 1.34ppm Gross Alpha 22.4pCi/L Haloacetic Acids (HAA5) 2.6ppb HFPO-DA (GenX) ND Lead 2.0ppb PFBS ND PFHxS ND PFNA ND PFOA ND PFOS ND Radium 226 + 228 ND Total Trihalomethanes 11.0ppb Uranium 42.0ppb
Filters that match
Aquasana OptimH2O Reverse Osmosis + Claryum
under sink ro · diy
- Arsenicremoves it, NSF or WQA certified
- Nitrate (as N)removes it, NSF or WQA certified
To cover everything flagged
Aquasure Serene Lite 650K Salt-Free Water Conditioner with Triple Purpose Pre-Filter for 7.1 gpg hardness.
Detections ranked by share of the limitevery Tier 1 detection, highest first
Bar length is the highest result in the last 36 months as a share of the federal limit (MCL, or action level for lead and copper). The dark tick marks the limit. Gross alpha is compared after subtracting uranium, as DEQ does for compliance.
Full contaminants reporthighest, latest, limit, trend, last sample
| Contaminant | Highest, 36 mo | Federal limit | Share of limit | Status | Trend | Last sample |
|---|---|---|---|---|---|---|
| Arsenic | 5.1ppb latest 2.5ppb | 10.0ppb MCL | Elevated | 2024-11-13 | ||
| Copper 90th percentile at home taps note | 0.12ppm | 1.30ppm AL | Detected | 2026-09-14 | ||
| Fluoride | 1.34ppm | 4.00ppm MCL | Detected | 2024-03-19 | ||
| Gross Alphanote | 22.4pCi/L latest 11.1pCi/L | 15.0pCi/L MCL | Detected | 2026-05-13 | ||
| Haloacetic Acids (HAA5) | 2.6ppb latest 1.6ppb | 60.0ppb MCL | Detected | 2026-05-13 | ||
| Hardness (as CaCO3) | 7.1gpg | none | no federal limit | Meets | 2025-12-31 | |
| HFPO-DA (GenX) | ND | 10.0ppt MCL | Not detected | 2026-05-20 EPA study | ||
| Lead 90th percentile at home taps note | 2.0ppb latest 1.0ppb | 15.0ppb AL | Detected | 2026-09-14 | ||
| Nitrate (as N) | 6.30ppm latest 6.00ppm | 10.00ppm MCL | Elevated | 2026-08-19 | ||
| PFBS | ND | none | Not detected | 2025-10-28 EPA study | ||
| PFHxS | ND | 10.0ppt MCL | Not detected | 2026-05-20 EPA study | ||
| PFNA | ND | 10.0ppt MCL | Not detected | 2026-05-20 EPA study | ||
| PFOA | ND | 4.0ppt MCL | Not detected | 2025-10-28 EPA study | ||
| PFOS | ND | 4.0ppt MCL | Not detected | 2025-10-28 EPA study | ||
| Radium 226 + 228 | ND | 5.00pCi/L MCL | Not detected | 2026-05-13 | ||
| Total Trihalomethanes | 11.0ppb latest 4.6ppb | 80.0ppb MCL | Detected | 2026-05-13 | ||
| Uranium | 42.0ppb latest 20.0ppb | 30.0ppb MCL | Detected | 2026-08-19 |
- Copper: 90th percentile of samples taken at customer taps. Results depend on the home's plumbing.
- Gross Alpha: Compliance uses the running average of gross alpha minus uranium. Shown value is the highest lab result; the adjusted average is 1.02 pCi/L after subtracting 8.71 pCi/L for uranium.
- Lead: 90th percentile of samples taken at customer taps. Results depend on the home's plumbing.
ppb = parts per billion (µg/L), ppm = parts per million (mg/L), ppt = parts per trillion. ND = not detected above the lab's reporting limit. MCL = federal maximum contaminant level; AL = action level for lead and copper (90th percentile of home taps); aesthetic = secondary standard for taste, odor or staining, not health. Bars show the highest result in 36 months as a share of the limit.
8 other regulated contaminants tested
| Contaminant | 36 mo max | Limit | Status | Last sample |
|---|---|---|---|---|
| Atrazine | ND | 3.0ppb | Not detected | 2026-05-13 |
| Benzene | ND | 5.0ppb | Not detected | 2026-05-13 |
| 1,2-Dibromo-3-chloropropane | ND | 0.2ppb | Not detected | 2026-05-13 |
| Lithium | 42.1ppb | none | Detected | 2025-10-28 |
| Nitrite (as N) | ND | 1.00ppm | Not detected | 2026-08-19 |
| Tetrachloroethylene | ND | 5.0ppb | Not detected | 2026-05-13 |
| Sodium | 58.20ppm | none | Detected | 2024-11-14 |
| Trichloroethylene | ND | 5.0ppb | Not detected | 2026-05-13 |
Hardness
City of Nampa reports hardness of 7.1 grains per gallon (121.2 mg/L as CaCO3), classified as hard in its 2025 Consumer Confidence Report. At 7 grains per gallon or more, a correctly sized softener usually pays for itself in appliance life and soap. Hardness is not a federal health violation.
See also Nampa water hardness.
Track record80 violations on record, 0 health-based
✓ no violation recorded n monitoring or reporting only n includes a health-based violation ? outside the loaded record
No health-based violations (MCL, treatment technique, or disinfectant level) in the last ten years.
Monitoring and reporting violations (80)
A required sample or report was late or missing. These do not mean a contaminant was found, but a system that skips monitoring has gaps in its record.
| Year | Rule | Count | Detail |
|---|---|---|---|
| 2023 | Stage 1 Disinfectants and Disinfection Byproducts Rule | 1 | Monitoring and reporting (DBP) · Chlorine (residual) |
| 2020 | Volatile Organic Chemicals | 21 | Routine monitoring, major · Benzene, Tetrachloroethylene, Trichloroethylene |
| 2020 | Synthetic Organic Chemicals | 58 | Routine monitoring, major · 1,2-Dibromo-3-chloropropane, Atrazine |
Lead and copper at the tap90th percentile of sampled homes against the action level
90th percentile of samples taken at customer taps. Results depend on the home's plumbing. Results are from sampled homes in this system, not from your tap. Home plumbing can add lead and copper. First-draw samples run higher than flushed ones.
90th percentile of samples taken at customer taps. Results depend on the home's plumbing. Results are from sampled homes in this system, not from your tap. Home plumbing can add lead and copper. First-draw samples run higher than flushed ones.
Where the water comes from16 active wells
16 active wells, and 14 treatment points on record (SDWIS counts each chlorination or filtration point as a treatment plant).
WELL #5: Susceptibility: ioc moderate, voc moderate, soc moderate, microbial moderate.
Source water assessment susceptibility: final map[IOC:Moderate Microbials:Moderate SOC:Moderate VOC:Moderate]; hydrologic sensitivity M; pci land use map[IOC:M Microbials:M SOC:M VOC:M]; system construction M;
Source names (16)
BELMONT WELL #1 (EMERGENCY USE ONLY), BELMONT WELL #2 (EMERGENCY USE ONLY), COVENTRY WELL - #15, NEW WELL #10, NEW WELL #8 (BLENDED LOCATION), WELL #11, WELL #12, WELL #14, WELL #16, WELL #17 CARRIAGE HILLS, WELL #20, WELL #4, WELL #5, WELL #6, WELL #7, WELL #9
Every match, by categorytop three per category
We may earn a commission if you buy through these links. Rankings come from the matching engine (certification + flagged contaminants + annual cost), not from who pays more. How we earn money. As an Amazon Associate we earn from qualifying purchases. Prices are not shown; Amazon sets them on its site.
Drinking water
Under sink, pitcher, or faucet. Treats the water you drink and cook with.
Aquasana OptimH2O Reverse Osmosis + Claryum
Certified for arsenic, nitrate, and fluoride (NSF/ANSI 58, pentavalent); manufacturer-reported for uranium and gross alpha.
Plumber recommended if you are not comfortable with a drain saddle and a tank. Not a whole-house solution.
Clearly Filtered Water Pitcher
Certified for lead, total trihalomethanes, and haloacetic acids (NSF/ANSI 53); manufacturer-reported for arsenic, nitrate, and uranium.
DIY. No plumbing.
APEC ROES-50 Essence 5-Stage Reverse Osmosis
Manufacturer-reported reduction for arsenic, nitrate, and uranium. Not NSF-certified for arsenic, nitrate, and uranium.
Plumber recommended if you are not comfortable with a drain saddle and a tank. Not a whole-house solution.
Whole house
Installed where water enters the house. For fixtures, laundry and showers.
Crystal Quest Ultimate Whole House Arsenic Removal Filter (Triple Cartridge, 4-6 GPM)
Manufacturer-reported reduction for arsenic. Does not address nitrate.
Plumber recommended if you are not comfortable with this install.
Aquasana Rhino EQ-1000 Whole House Filter (1,000,000 gallons)
Manufacturer-reported reduction for total trihalomethanes. Does not address arsenic and nitrate.
Plumber recommended if you are not comfortable with this install.
Express Water WH300SCKS 3-Stage Heavy Metal Whole House Filter (Sediment, KDF, Carbon)
Manufacturer-reported reduction for lead. Does not address arsenic and nitrate.
Plumber recommended if you are not comfortable with this install.
Softener or conditioner
Worth it at 7 grains per gallon or more.
Aquasure Serene Lite 650K Salt-Free Water Conditioner with Triple Purpose Pre-Filter
Manufacturer-reported reduction for hardness. Does not address arsenic and nitrate.
Plumber recommended if you are not comfortable with this install.
Whirlpool WHES30E 30,000 Grain Water Softener
Certified for hardness (NSF/ANSI 44). Does not address arsenic and nitrate.
DIY if you are comfortable with this install.
Whirlpool WHES40E 40,000 Grain Water Softener
Certified for hardness (NSF/ANSI 44). Does not address arsenic and nitrate.
DIY if you are comfortable with this install.
Questions about City of Nampa
Is City of Nampa tap water safe to drink?
City of Nampa met every federal limit in the last 36 months, with no open health-based violation. 2 contaminants were at half the limit or higher: Arsenic and Nitrate (as N). The results table shows each value against its limit. Results reflect the system's sampling points, not the plumbing in any one home.
Is City of Nampa water hard?
City of Nampa reports hardness of 7.1 grains per gallon (121 mg/L as CaCO3), classified as hard. Hardness is not a health issue. At 7 grains or more most households see scale and soap scum; a softener is a reasonable choice.
Is City of Nampa water fluoridated?
Fluoride was measured at up to 1.34 mg/L in the last 36 months, in the range used for community fluoridation (0.7 mg/L). The federal limit (MCL) is 4 mg/L. Reverse osmosis is an optional preference if you want less fluoride.
Where does City of Nampa water come from?
City of Nampa draws from 16 active wells with 14 treatment plants on record. Source and treatment details are listed above.
What filter fits City of Nampa water?
For drinking water the matching engine ranks Aquasana OptimH2O Reverse Osmosis + Claryum first for this profile, based on certified reduction claims for the contaminants flagged above. See the filters section for the reasoning and alternatives.
Who to call
- System contact: WENDLER, SHANE P, 208-468-5860
- DEQ Boise Regional Office, 1445 N Orchard St, Boise ID 83706, (208) 373-0550
- Southwest District Health (well testing, septic, local health questions)
Sources
Sample results as of 2026-08-19; inventory and violations from EPA SDWIS; page built 2026-09-14. 599 individual results reviewed.
More: Nampa water, Canyon County, Arsenic, Nitrate (as N)
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.