Is Harlowton, MT Tap Water Safe to Drink?
Graded C+, with 38 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
68.5/100
waterverge.com Harlowton, MT — Water Quality Report
Harlowton's drinking water received a grade of C+ (68.5 out of 100), indicating fair water quality. The city's 4 water systems serve approximately 2,346 residents using groundwater.
Lead levels were measured at 2.0 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 144 violations on record, including 9 health-based violations. 38 remain unresolved.
What to know about Harlowton's water
Harlowton ranks #56 out of 115 cities in Montana for water quality, placing it mid-range in the state.
Harlowton 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, Harlowton may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 12 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Harlowton, MT water safe to drink?
Harlowton's drinking water has significant quality concerns based on EPA testing data. With a grade of C+ (68.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 2,346 residents using groundwater (wells).
Recent water quality updates for Harlowton
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Harlowton's water quality assessment. Grade: C+ (68.5/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Lead and Copper Rule.
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-4745). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4405). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Harlowton's water supply.
Well within EPA limits.
Violation history
Harlowton's water system has 144 total violations on record, including 9 health-based violations. 38 remain unresolved. 12 violations were issued in the last 5 years.
Flood & environmental risk
Musselshell County has experienced 5 federally declared disasters since 2005. 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 Musselshell River Near Roundup.
Where does Harlowton's water come from?
Harlowton's drinking water comes from groundwater (wells), supplied by 4 water systems serving approximately 2,346 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Musselshell River Near Roundup (river).
What Harlowton residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Harlowton'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.
Harlowton'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 droughtWheatland 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
Musselshell County has experienced 5 federally declared disasters since 2005. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
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. | 2.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Harlowton compares by contaminant
Explore where Harlowton ranks among all Montana cities for specific contaminants.
Water source & infrastructure
Where Harlowton's water comes from
Harlowton'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 2,346 people through 4 water systems.
Water bodies near Harlowton
Harlowton is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Harlowton
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CMRWA MUSSELSHELL JUDITH RURAL WATER SYS | MT0005109 | 1,100 | GW |
| HARLOWTON CITY OF | MT0000240 | 1,050 | GWP |
| SPRINGWATER COLONY | MT0000719 | 100 | GW |
| DUNCAN RANCH COLONY | MT0000418 | 96 | GW |
How Harlowton compares
Full Montana rankings →Harlowton's score of 68.5/100 is above the average of 45/100 among major Montana cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Montana rankings →About Harlowton, MT
Wikipedia →Roundup is a city in and the county seat of Musselshell County, Montana, United States. The population was 1,742 as of the 2020 census.
Learn more about your water
Guides and resources related to Harlowton's water quality findings.
Explore water quality across Wheatland
Frequently asked questions
Is Harlowton, MT tap water safe to drink?
Harlowton's water quality earned a grade of C+ (68.5/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #56 out of 115 cities tested in Montana.
What contaminants are in Harlowton's water?
Lead was measured at 2.0 ppb (90th percentile). 144 violations are on record.
How is Harlowton'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 Harlowton?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Harlowton's water come from?
Harlowton's water is sourced from Groundwater. The city has 4 water systems serving approximately 2,346 residents.
What health violations has Harlowton's water system had?
Harlowton has 9 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 38 violations remain unresolved.
Is Harlowton's groundwater at risk of contamination?
Harlowton 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 144 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 Harlowton's water compare to other cities?
Harlowton ranks #56 out of 115 cities in Montana (better than 51% of state cities) and #11066 out of 15744 cities nationally (30th percentile). The grade of C+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.