Is Harlem, MT Tap Water Safe to Drink?
Graded D — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
47/100
waterverge.com Harlem, MT — Water Quality Report
Harlem's drinking water received a grade of D (47 out of 100), indicating poor water quality. The city's 6 water systems serve approximately 4,102 residents using surface water.
Lead levels were measured at 1.0 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 811 violations on record, including 237 health-based violations. 40 remain unresolved.
What to know about Harlem's water
Harlem ranks #90 out of 115 cities in Montana for water quality, placing it among the lowest-rated in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
The system has seen 90 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Harlem, MT water safe to drink?
Harlem's drinking water has significant quality concerns based on EPA testing data. With a grade of D (47/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 6 water systems serve approximately 4,102 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Harlem
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Harlem's water quality assessment. Grade: D (47/100).
2 health-based. Contaminants: TTHM, Consumer Confidence Rule.
1 health-based. Contaminants: Revised Total Coliform Rule.
2 health-based. Contaminants: TTHM.
Federal disaster declaration (FEMA DR-4726). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4388). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Harlem'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
Harlem's water system has 811 total violations on record, including 237 health-based violations. 40 remain unresolved. 90 violations were issued in the last 5 years.
Flood & environmental risk
Blaine County has experienced 5 federally declared disasters since 1986. 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 Milk River At Merrill Rd, Nr Harlem, Milk River Near Harlem.
Where does Harlem's water come from?
Harlem's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 6 water systems serving approximately 4,102 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Milk River At Merrill Rd, Nr Harlem (river), Milk River Near Harlem (river).
What Harlem residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Harlem'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.
Harlem'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 droughtBlaine 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
Blaine County has experienced 5 federally declared disasters since 1986. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Harlem'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. | 1.0 | 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. | 2.18 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 2.180 mg/L (2009)
EPA action level: 1.3 mg/L
See how Harlem compares by contaminant
Explore where Harlem ranks among all Montana cities for specific contaminants.
Water source & infrastructure
Where Harlem's water comes from
Harlem's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by native american ownership and serves approximately 4,102 people through 6 water systems.
Water bodies near Harlem
Harlem is located near 2 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Harlem
| System Name | PWSID | Population | Source |
|---|---|---|---|
| FORT BELKNAP AGENCY WATER SYSTEM | 083090041 | 2,100 | SW |
| HAYS/WHITE COW CANYON WS | 083090044 | 840 | GW |
| HARLEM CITY OF | MT0000239 | 820 | SW |
| MNIHNAPA WATER SYSTEM | 083090047 | 220 | GW |
| OLD HAYS | 083090045 | 80 | GW |
| NORTH HARLEM COLONY | MT0001771 | 42 | GW |
How Harlem compares
Full Montana rankings →Harlem's score of 47/100 is on par with the average of 45/100 among major Montana cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Montana rankings →ZIP codes served by Harlem
The water systems serving Harlem cover 1 ZIP code. Select any ZIP to see which water systems serve that area.
About Harlem, MT
Learn more about your water
Guides and resources related to Harlem's water quality findings.
Explore water quality across Blaine
Frequently asked questions
Is Harlem, MT tap water safe to drink?
Harlem's water quality earned a grade of D (47/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #90 out of 115 cities tested in Montana.
What contaminants are in Harlem's water?
Lead was measured at 1.0 ppb (90th percentile). 811 violations are on record.
How is Harlem'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 Harlem?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Harlem's water come from?
Harlem's water is sourced from Surface water. The city has 6 water systems serving approximately 4,102 residents.
What health violations has Harlem's water system had?
Harlem has 237 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 40 violations remain unresolved.
How does Harlem's water compare to other cities?
Harlem ranks #90 out of 115 cities in Montana (better than 22% of state cities) and #13712 out of 15744 cities nationally (13th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.