Is Keystone, IA Tap Water Safe to Drink?
Graded A-, with 4 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
87.3/100
waterverge.com Keystone, IA — Water Quality Report
Keystone's drinking water received a grade of A- (87.3 out of 100), indicating good water quality. The city's 1 water system serves approximately 599 residents using groundwater.
Lead levels were measured at 5.9 ppb (90th percentile), which is within EPA limits but above recommended levels. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 33 violations on record, including 7 health-based violations. 4 remain unresolved.
What to know about Keystone's water
Keystone ranks #300 out of 436 cities in Iowa for water quality, placing it below average in the state.
Keystone 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.
While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection.
As a small community water system, Keystone may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Keystone, IA water safe to drink?
Keystone's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (87.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 599 residents using groundwater (wells).
Recent water quality updates for Keystone
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Keystone's water quality assessment. Grade: A- (87.3/100).
1 health-based. Contaminants: Groundwater Rule.
1 health-based. Contaminants: Nitrite.
1 health-based. Contaminants: Nitrite.
Federal disaster declaration (FEMA DR-4289). 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 Keystone's water supply.
Within EPA limits but above the American Academy of Pediatrics recommended level of 1 ppb. An NSF 53-certified filter provides additional protection.
Violation history
Keystone's water system has 33 total violations on record, including 7 health-based violations. 4 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Benton County has experienced 9 federally declared disasters since 1965. 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 Stein Creek Near Clutier, Salt Creek Near Elberon, Iowa River Near Belle Plaine.
Where does Keystone's water come from?
Keystone's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 599 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Stein Creek Near Clutier (river), Salt Creek Near Elberon (river), Iowa River Near Belle Plaine (river).
What Keystone residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Keystone'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.
Keystone'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
Benton County has experienced 9 federally declared disasters since 1965. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Keystone'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. | 5.9 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Keystone compares by contaminant
Explore where Keystone ranks among all Iowa cities for specific contaminants.
Water source & infrastructure
Where Keystone's water comes from
Keystone'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 599 people through 1 water system.
Water bodies near Keystone
Keystone is located near 3 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Keystone
| System Name | PWSID | Population | Source |
|---|---|---|---|
| KEYSTONE WATER SUPPLY | IA0640030 | 599 | GW |
How Keystone compares
Full Iowa rankings →Keystone's score of 87.3/100 is above the average of 72/100 among major Iowa cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Iowa rankings →About Keystone, IA
Wikipedia →Keystone is a city in Benton County, Iowa, United States. The population was 599 at the time of the 2020 census. It is part of the Cedar Rapids Metropolitan Statistical Area.
Learn more about your water
Guides and resources related to Keystone's water quality findings.
Explore water quality across Benton
Frequently asked questions
Is Keystone, IA tap water safe to drink?
Keystone's water quality earned a grade of A- (87.3/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #300 out of 436 cities tested in Iowa.
What contaminants are in Keystone's water?
Lead was measured at 5.9 ppb (90th percentile). 33 violations are on record.
How is Keystone'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 Keystone?
While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Keystone's water come from?
Keystone's water is sourced from Groundwater. The city has 1 water system serving approximately 599 residents.
What health violations has Keystone's water system had?
Keystone has 7 health-based violations on record. The most recent violation was recorded in May 2021. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 4 violations remain unresolved.
Is Keystone's groundwater at risk of contamination?
Keystone 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 33 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 Keystone's water compare to other cities?
Keystone ranks #300 out of 436 cities in Iowa (better than 31% of state cities) and #4164 out of 15744 cities nationally (74th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Keystone's small water system affect quality?
Keystone's system serves approximately 599 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 33 violations on record.