Is Cassville, WI Tap Water Safe to Drink?
Graded B-, with 11 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
73.9/100
waterverge.com Cassville, WI — Water Quality Report
Cassville's drinking water received a grade of B- (73.9 out of 100), indicating fair water quality. The city's 2 water systems serve approximately 817 residents using groundwater.
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 17 violations on record, including 7 health-based violations. 11 remain unresolved.
What to know about Cassville's water
Cassville ranks #331 out of 446 cities in Wisconsin for water quality, placing it below average in the state.
Cassville 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, Cassville may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 6 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Cassville, WI water safe to drink?
Cassville's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (73.9/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 817 residents using groundwater (wells).
Recent water quality updates for Cassville
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Cassville's water quality assessment. Grade: B- (73.9/100).
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS, Public Notice.
Contaminants: Lead and Copper Rule.
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-3249). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1369). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Cassville's water supply.
Well within EPA limits.
Violation history
Cassville's water system has 17 total violations on record, including 7 health-based violations. 11 remain unresolved. 6 violations were issued in the last 5 years.
Flood & environmental risk
Grant County has experienced 5 federally declared disasters since 1969. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Cassville's water come from?
Cassville's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 817 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Cassville residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Cassville'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.
Cassville'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
Flood & disaster history
Grant County has experienced 5 federally declared disasters since 1969. 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. | 1.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Cassville compares by contaminant
Explore where Cassville ranks among all Wisconsin cities for specific contaminants.
Water source & infrastructure
Where Cassville's water comes from
Cassville'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 local government ownership and serves approximately 817 people through 2 water systems.
Water systems serving Cassville
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CASSVILLE WATERWORKS | WI1220091 | 777 | GW |
| BLUFFSIDE COURT | WI1220090 | 40 | GW |
How Cassville compares
Full Wisconsin rankings →Cassville's score of 73.9/100 is above the average of 65/100 among major Wisconsin cities. It outscores 6 of 10 nearby cities.
Nearby cities
View Wisconsin rankings →About Cassville, WI
Learn more about your water
Guides and resources related to Cassville's water quality findings.
Explore water quality across Grant
Frequently asked questions
Is Cassville, WI tap water safe to drink?
Cassville's water quality earned a grade of B- (73.9/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #331 out of 446 cities tested in Wisconsin.
What contaminants are in Cassville's water?
Lead was measured at 1.0 ppb (90th percentile). 17 violations are on record.
How is Cassville'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 Cassville?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Cassville's water come from?
Cassville's water is sourced from Groundwater. The city has 2 water systems serving approximately 817 residents.
What health violations has Cassville's water system had?
Cassville has 7 health-based violations on record. The most recent violation was recorded in October 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 11 violations remain unresolved.
Is Cassville's groundwater at risk of contamination?
Cassville 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 17 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 Cassville's water compare to other cities?
Cassville ranks #331 out of 446 cities in Wisconsin (better than 26% of state cities) and #9994 out of 15744 cities nationally (37th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.