Capitol Water Corp. water quality
Met every federal limit. 7 contaminants at half a limit or higher. hardness not in the latest CCR.
ID4010022. Data through 2026-07-14. DEQ record.
What's in it
PFNA
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum: manufacturer-reported, not certified.
PFOS
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum is certified to reduce it.
PFOA
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum is certified to reduce it.
Uranium
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum: manufacturer-reported, not certified.
PFHxS
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum: manufacturer-reported, not certified.
Arsenic
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum is certified to reduce it.
PFBS
ElevatedAquasana OptimH2O Reverse Osmosis + Claryum: manufacturer-reported, not certified.
5 other contaminants tested, not detected or well below the limit
Gross Alpha 37.9pCi/L HFPO-DA (GenX) ND Nitrate (as N) ND Radium 226 + 228 ND Total Trihalomethanes ND
Filters that match
Aquasana OptimH2O Reverse Osmosis + Claryum
under sink ro · diy
- Arsenicremoves it, NSF or WQA certified
- PFBSremoves it, per manufacturer testing
- PFHxSremoves it, per manufacturer testing
- PFNAremoves it, per manufacturer testing
- PFOAremoves it, NSF or WQA certified
- PFOSremoves it, NSF or WQA certified
- Uraniumremoves it, per manufacturer testing
Nothing in this water calls for whole-house treatment. A drinking-water filter covers the exposure that matters. Whole-house units here are optional, mainly for taste and chlorine.
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.
Aesthetic and unregulated
Taste, odor, staining or scale, not health limits. Bars use the EPA secondary standard where one exists.
Full contaminants reporthighest, latest, limit, trend, last sample
| Contaminant | Highest, 36 mo | Federal limit | Share of limit | Status | Trend | Last sample |
|---|---|---|---|---|---|---|
| Arsenic | 3.5ppb | 10.0ppb MCL | Elevated | 2025-08-14 | ||
| Gross Alphanote | 37.9pCi/L latest 25.0pCi/L | 15.0pCi/L MCL | Not detected | 2026-07-14 | ||
| HFPO-DA (GenX) | ND | 10.0ppt MCL | Not detected | 2024-10-08 EPA study | ||
| Nitrate (as N) | 4.10ppm latest ND | 10.00ppm MCL | Detected | 2026-07-14 | ||
| PFBS | 3.9ppt latest ND | none | no federal limit | Elevated | 2024-10-08 EPA study | |
| PFHxS | 5.1ppt latest ND | 10.0ppt MCL | Elevated | 2024-10-08 EPA study | ||
| PFNAnote | 51.0ppt latest ND | 10.0ppt MCL | Elevated | 2024-10-08 EPA study | ||
| PFOAnote | 5.7ppt latest ND | 4.0ppt MCL | Elevated | 2024-10-08 EPA study | ||
| PFOSnote | 9.8ppt latest ND | 4.0ppt MCL | Elevated | 2024-10-08 EPA study | ||
| Radium 226 + 228 | ND | 5.00pCi/L MCL | Not detected | 2025-11-13 | ||
| Total Trihalomethanes | ND | 80.0ppb MCL | Not detected | 2026-07-14 | ||
| Uranium | 32.0ppb latest 5.0ppb | 30.0ppb MCL | Elevated | 2026-07-14 |
- Gross Alpha: Compliance uses the running average of gross alpha minus uranium. Shown value is the highest lab result; the adjusted average is 0.0 pCi/L after subtracting 12.39 pCi/L for uranium.
- PFNA: Detected in EPA's UCMR 5 monitoring study at or above the 2024 MCL. Study samples are not compliance monitoring; compliance sampling under the PFAS rule begins in 2027 and is judged on a running annual average.
- PFOA: Detected in EPA's UCMR 5 monitoring study at or above the 2024 MCL. Study samples are not compliance monitoring; compliance sampling under the PFAS rule begins in 2027 and is judged on a running annual average.
- PFOS: Detected in EPA's UCMR 5 monitoring study at or above the 2024 MCL. Study samples are not compliance monitoring; compliance sampling under the PFAS rule begins in 2027 and is judged on a running annual average.
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.
7 other regulated contaminants tested
| Contaminant | 36 mo max | Limit | Status | Last sample |
|---|---|---|---|---|
| Atrazine | ND | 3.0ppb | Not detected | 2025-11-13 |
| Benzene | ND | 5.0ppb | Not detected | 2026-07-14 |
| 1,2-Dibromo-3-chloropropane | ND | 0.2ppb | Not detected | 2025-11-13 |
| Lithium | 19.0ppb | none | Detected | 2023-12-06 |
| Tetrachloroethylene | ND | 5.0ppb | Not detected | 2026-07-14 |
| Sodium | 52.60ppm | none | Detected | 2025-11-13 |
| Trichloroethylene | 2.1ppb | 5.0ppb | Detected | 2026-07-14 |
Hardness
Hardness is not reported in the latest CCR. Hardness not reported for this system; softener sizing uses a regional default of 11.7 gpg until a CCR value is reviewed.
See also Boise City water hardness.
Track record126 violations on record, 3 health-based
✓ no violation recorded n monitoring or reporting only n includes a health-based violation ? outside the loaded record
Health-based violations
| Period | What happened | Contaminant | Rule | Status |
|---|---|---|---|---|
| 2025-04-01 to 2025-06-30 | Maximum contaminant level exceeded (Single sample MCL exceeded) | Uranium | Radionuclides | resolved |
| 2025-01-01 to 2025-03-31 | Maximum contaminant level exceeded (Single sample MCL exceeded) | Uranium | Radionuclides | resolved |
| 2024-10-17 | Treatment technique not met (Level 2 assessment, treatment technique (RTCR)) | n/a | Lead and Copper Rule Revisions | resolved 2024-11-15 |
Monitoring and reporting violations (123)
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 |
|---|---|---|---|
| 2025 | Public Notification Rule | 2 (1 open) | Public notice rule linked to violation |
| 2025 | Nitrates | 1 | Routine monitoring, major · Nitrate (as N) |
| 2024 | Lead and Copper Rule Revisions | 1 | |
| 2023 | Synthetic Organic Chemicals | 115 | Routine monitoring, major · 1,2-Dibromo-3-chloropropane, Atrazine |
| 2022 | Radionuclides | 2 | Routine monitoring, major · Uranium |
| 2019 | Revised Total Coliform Rule | 1 | Monitoring, routine (RTCR) |
| 2017 | Lead and Copper Rule | 1 | Lead service line replacement (LCR) |
Lead and copper at the tap90th percentile of sampled homes against the action level
No lead and copper tap sampling summary in the window we reviewed.
Where the water comes from5 active wells
5 active wells, and 4 treatment points on record (SDWIS counts each chlorination or filtration point as a treatment plant).
WELL #4: Susceptibility: ioc high (auto), voc high (auto), soc high (auto), microbial high (auto).
Source water assessment susceptibility: final map[IOC:Auto High Microbials:Auto High SOC:Auto High VOC:Auto High]; hydrologic sensitivity M; pci land use map[IOC:M Microbials:M SOC:M VOC:M]; system construction M;
Source names (5)
WELL #3, WELL #4, WELL #5 (NEW), WELL #6 BACK UP WELL, WELL #7
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, PFOA, and PFOS (NSF/ANSI 58, pentavalent); manufacturer-reported for uranium, PFHxS, and PFNA.
Plumber recommended if you are not comfortable with a drain saddle and a tank. Not a whole-house solution.
PUR Basic Vertical Faucet Mount Filter System
Certified for PFOA, PFOS, and PFHxS (NSF/ANSI 53). Does not address arsenic and uranium.
DIY. No plumbing.
Waterdrop G3P800 Tankless Reverse Osmosis with UV
Certified for PFOA and PFOS (NSF/ANSI 58); manufacturer-reported for arsenic, uranium, and PFHxS.
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.
Nothing in this water calls for whole-house treatment. A drinking-water filter covers the exposure that matters. Whole-house units here are optional, mainly for taste and chlorine.
Crystal Quest Ultimate Whole House Arsenic Removal Filter (Triple Cartridge, 4-6 GPM)
Manufacturer-reported reduction for arsenic. Does not address uranium, PFOA, and PFOS and 3 more.
Plumber recommended if you are not comfortable with this install.
Sprite High Output 2 Universal Shower Filter with 3-Setting Shower Head (HO2-WH-M)
Does not address arsenic, uranium, and PFOA and 4 more.
DIY. No plumbing.
Culligan WSH-C125 Wall-Mount Shower Filter
Does not address arsenic, uranium, and PFOA and 4 more.
DIY. No plumbing.
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
Does not address arsenic, uranium, and PFOA and 4 more.
Plumber recommended if you are not comfortable with this install.
Whirlpool WHES30E 30,000 Grain Water Softener
Does not address arsenic, uranium, and PFOA and 4 more.
DIY if you are comfortable with this install.
Whirlpool WHES40E 40,000 Grain Water Softener
Does not address arsenic, uranium, and PFOA and 4 more.
DIY if you are comfortable with this install.
Questions about Capitol Water Corp.
Is Capitol Water Corp. tap water safe to drink?
Capitol Water Corp. met every federal limit in the last 36 months, with no open health-based violation. 7 contaminants were at half the limit or higher: Arsenic, PFBS, PFHxS, PFNA, PFOA, PFOS and Uranium. The results table shows each value against its limit. Results reflect the system's sampling points, not the plumbing in any one home.
Is Capitol Water Corp. water hard?
Hardness has not been reported for Capitol Water Corp. in a reviewed Consumer Confidence Report yet. The softener sizing widget uses a labelled county default until a report is reviewed.
Is Capitol Water Corp. water fluoridated?
No fluoride result in the last 36 months.
Where does Capitol Water Corp. water come from?
Capitol Water Corp. draws from 5 active wells with 4 treatment plants on record. Source and treatment details are listed above.
What filter fits Capitol Water Corp. 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: PRICE, ROBERT H, 208-375-0931
- DEQ Boise Regional Office, 1445 N Orchard St, Boise ID 83706, (208) 373-0550
- Central District Health (well testing, septic, local health questions)
Sources
Sample results as of 2026-07-14; inventory and violations from EPA SDWIS; page built 2026-09-14. 198 individual results reviewed.
More: Boise City water, Ada County, Arsenic, Uranium, PFOA, PFOS, PFHxS, PFNA, PFBS
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.