Is Coolin, ID Tap Water Safe to Drink?
Graded B+ — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
84.3/100
waterverge.com Coolin, ID — Water Quality Report
Coolin's drinking water received a grade of B+ (84.3 out of 100), indicating good water quality. The city's 2 water systems serve approximately 632 residents using groundwater.
Lead levels were measured at 5.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 50 violations on record, including 2 health-based violations. 3 remain unresolved.
What to know about Coolin's water
Coolin ranks #46 out of 139 cities in Idaho for water quality, placing it mid-range in the state.
Coolin relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Coolin may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Coolin, ID water safe to drink?
Coolin's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (84.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 632 residents using groundwater (wells).
Recent water quality updates for Coolin
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Coolin's water quality assessment. Grade: B+ (84.3/100).
Contaminants: Nitrate.
Contaminants: Revised Total Coliform Rule.
Contaminants: E. COLI, Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-4313). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1987). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Coolin's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Coolin's water system has 50 total violations on record, including 2 health-based violations. 3 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Bonner County has experienced 4 federally declared disasters since 1974. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Priest Lake, Priest R Outflow Nr Coolin.
Where does Coolin's water come from?
Coolin's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 632 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Priest Lake (lake), Priest R Outflow Nr Coolin (river).
What Coolin residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Coolin's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Coolin's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Drought conditions
D2 — severe droughtBonner County is currently in D2 (severe drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Bonner County has experienced 4 federally declared disasters since 1974. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Coolin's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 5.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.87 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Coolin compares by contaminant
Explore where Coolin ranks among all Idaho cities for specific contaminants.
Water source & infrastructure
Where Coolin's water comes from
Coolin's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by private ownership and serves approximately 632 people through 2 water systems.
Water bodies near Coolin
Coolin is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Coolin
| System Name | PWSID | Population | Source |
|---|---|---|---|
| HUCKLEBERRY BAY WATER SYSTEM | ID1090209 | 362 | GW |
| COUGAR CREEK WATER ASSN | ID1090030 | 270 | GW |
How Coolin compares
Full Idaho rankings →Coolin's score of 84.3/100 is above the average of 43/100 among major Idaho cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Idaho rankings →Learn more about your water
Guides and resources related to Coolin's water quality findings.
Explore water quality across Bonner
Frequently asked questions
Is Coolin, ID tap water safe to drink?
Coolin's water quality earned a grade of B+ (84.3/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #46 out of 139 cities tested in Idaho.
What contaminants are in Coolin's water?
Lead was measured at 5.0 ppb (90th percentile). 50 violations are on record.
How is Coolin's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Coolin?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Coolin's water come from?
Coolin's water is sourced from Groundwater. The city has 2 water systems serving approximately 632 residents.
What health violations has Coolin's water system had?
Coolin has 2 health-based violations on record. The most recent violation was recorded in January 2022. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
Is Coolin's groundwater at risk of contamination?
Coolin uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 50 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Coolin's water compare to other cities?
Coolin ranks #46 out of 139 cities in Idaho (better than 67% of state cities) and #6000 out of 15744 cities nationally (62th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.