Is Rockwell City, IA 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 ↓
82.4/100
waterverge.com Rockwell City, IA — Water Quality Report
Rockwell City's drinking water received a grade of B+ (82.4 out of 100), indicating good water quality. The city's 2 water systems serve approximately 2,550 residents using groundwater.
Lead levels were measured at 0.0 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 22 violations on record, including 6 health-based violations. 5 remain unresolved.
What to know about Rockwell City's water
Rockwell City ranks #379 out of 436 cities in Iowa for water quality, placing it among the lowest-rated in the state.
Rockwell City 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, Rockwell City may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Rockwell City, IA water safe to drink?
Rockwell City's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (82.4/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 2,550 residents using groundwater (wells).
Recent water quality updates for Rockwell City
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Rockwell City's water quality assessment. Grade: B+ (82.4/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Lead and Copper Rule.
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-4421). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3239). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Rockwell City'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
Rockwell City's water system has 22 total violations on record, including 6 health-based violations. 5 remain unresolved. 3 violations were issued in the last 5 years.
Flood & environmental risk
Calhoun County has experienced 5 federally declared disasters since 1990. 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 Rockwell City's water come from?
Rockwell City's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 2,550 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Rockwell City residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Rockwell City'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.
Rockwell City'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
Calhoun County has experienced 5 federally declared disasters since 1990. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Rockwell City'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. | 0.0 | 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. | 2.30 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Rockwell City compares by contaminant
Explore where Rockwell City ranks among all Iowa cities for specific contaminants.
Water source & infrastructure
Where Rockwell City's water comes from
Rockwell City'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 2,550 people through 2 water systems.
Water systems serving Rockwell City
| System Name | PWSID | Population | Source |
|---|---|---|---|
| ROCKWELL CITY WATER SUPPLY | IA1376098 | 2,250 | GW |
| TWIN LAKES UTILITIES | IA1300101 | 300 | GWP |
How Rockwell City compares
Full Iowa rankings →Rockwell City's score of 82.4/100 is above the average of 72/100 among major Iowa cities. It outscores 7 of 10 nearby cities.
Nearby cities
View Iowa rankings →About Rockwell City, IA
Wikipedia →Rockwell City is a city and the county seat of Calhoun County, Iowa, United States. The population was 2,240 in 2020.
Learn more about your water
Guides and resources related to Rockwell City's water quality findings.
Explore water quality across Calhoun
Frequently asked questions
Is Rockwell City, IA tap water safe to drink?
Rockwell City's water quality earned a grade of B+ (82.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #379 out of 436 cities tested in Iowa.
What contaminants are in Rockwell City's water?
Lead was measured at 0.0 ppb (90th percentile). 22 violations are on record.
How is Rockwell City'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 Rockwell City?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Rockwell City's water come from?
Rockwell City's water is sourced from Groundwater. The city has 2 water systems serving approximately 2,550 residents.
What health violations has Rockwell City's water system had?
Rockwell City has 6 health-based violations on record. The most recent violation was recorded in July 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
Is Rockwell City's groundwater at risk of contamination?
Rockwell City 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 22 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 Rockwell City's water compare to other cities?
Rockwell City ranks #379 out of 436 cities in Iowa (better than 13% of state cities) and #6987 out of 15744 cities nationally (56th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.