Is Boise, ID Tap Water Safe to Drink?
Yes, Boise tap water is safe to drink. Hardness is low at 110 PPM, and no contaminants exceed health guidelines. Most homes here don't need treatment.
Hardness Scale: Where Boise Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Boise Compares
Boise's water is close to the national average of 138 PPM, ranking #544 out of 1000 cities tracked. Within Idaho, Boise has the 2nd hardest water out of 11 cities - 51% above the state average of 73 PPM. Among large cities (200k-500k), Boise ranks #88 of 165 for hardness.
What Boise's Water Means for Your Home
Hardness: 110 PPM - Low Concern
Boise's water is firmly in the moderate range at 110 PPM. You'll see some spotting on glassware and a film on shower doors over time, but it's not the kind of hardness that demands a full softener. A salt-free conditioner is worth considering if you have a tankless water heater or high-end fixtures.
Contaminants & Safety
Disinfection byproducts are the notable finding here. Boise's water has TTHMs at 32.1 ppb and HAA5 at 27.6 ppb — both within legal limits, but the EWG health guidelines are far stricter. These byproducts form when chlorine reacts with organic matter during treatment. A whole-house activated carbon filter reduces both chlorine and its byproducts. Want the full picture? Request your utility's annual Consumer Confidence Report.
What's in the Treatment Process
Boise's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 32.1 ppb (40% of the legal limit, but 214x the EWG guideline) and HAA5 at 27.6 ppb (46% of the legal limit, but 276x the EWG guideline). These are within legal limits, but the EWG sets much tighter thresholds based on cancer-risk research. A whole-house activated carbon filter reduces both chlorine and byproducts.
Chromium-6 was detected at 0.429 ppb, which is 21x the EWG health guideline. There's no separate federal limit for chromium-6, only total chromium. A reverse osmosis system is the most effective removal method. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 110 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 170 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 0 ppt | — | No total limit | ✓ ND |
| ↳ PFOA | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 2 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 0.4 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 1.14 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Recommendations for Boise Homes
How to Test Your Water in Boise
City-wide data is a solid starting point, but your specific tap might differ based on plumbing age, distance from the treatment plant, or seasonal changes.
Free option: Request Suez Water Idaho's annual Consumer Confidence Report for official city-level data.
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About Boise's Water Supply
Water Utility: Suez Water Idaho
Water Source: Boise River + groundwater (Surface Water)
Population Served: 264,978
Hardness: 110 PPM (6.4 grains per gallon)
Boise's drinking water comes from surface sources — Boise River + groundwater. Surface water requires more extensive treatment than groundwater, including coagulation, filtration, and disinfection. This heavier chlorination is why disinfection byproducts tend to be higher in surface-supplied systems. On the upside, surface sources often deliver softer water than deep aquifers. The system serves 265,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request Suez Water Idaho's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by Suez Water Idaho in Boise, ID, including ZIP codes:
83624, 83701, 83702, 83703, 83704, 83705, 83706, 83707, 83708, 83709, 83711, 83712, 83713, 83715, 83716, 83717, 83719, 83720, 83722, 83724, 83725, 83726, 83728, 83729, 83731, 83732, 83735, 83756, 83799
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Boise to Other Idaho Cities
Frequently Asked Questions About Boise Water
Is Boise tap water safe to drink?
Where does Boise's water come from?
Do I need a water softener in Boise?
What is the hardness of Boise water in grains per gallon?
What are disinfection byproducts in Boise's water?
Is chromium-6 in Boise's water?
Can I drink Boise tap water straight from the faucet?
How does Boise compare to the Idaho average?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.