Is Coggon, IA Tap Water Safe to Drink?
Graded A-, with 2 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
89/100
waterverge.com Coggon, IA — Water Quality Report
Coggon's drinking water received a grade of A- (89 out of 100), indicating good water quality. The city's 1 water system serves approximately 701 residents using groundwater.
Lead levels were measured at 5.8 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 41 violations on record, including 0 health-based violations. 2 remain unresolved.
What to know about Coggon's water
Coggon ranks #247 out of 436 cities in Iowa for water quality, placing it below average in the state.
Coggon 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, Coggon may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Coggon, IA water safe to drink?
Coggon's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (89/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 701 residents using groundwater (wells).
Recent water quality updates for Coggon
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Coggon's water quality assessment. Grade: A- (89/100).
Contaminants: Revised Total Coliform Rule.
Contaminants: Nitrate.
Contaminants: Lead and Copper Rule.
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 Coggon'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
Coggon's water system has 41 total violations on record, including 0 health-based violations. 2 remain unresolved. 4 violations were issued in the last 5 years.
Flood & environmental risk
Linn County has experienced 10 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 Coggon's water come from?
Coggon's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 701 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Coggon residents can do
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.
Coggon'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
Linn County has experienced 10 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Coggon'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. | 5.8 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Coggon compares by contaminant
Explore where Coggon ranks among all Iowa cities for specific contaminants.
Water source & infrastructure
Where Coggon's water comes from
Coggon'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 701 people through 1 water system.
Water systems serving Coggon
| System Name | PWSID | Population | Source |
|---|---|---|---|
| COGGON WATER DEPARTMENT | IA5722053 | 701 | GW |
How Coggon compares
Full Iowa rankings →Coggon's score of 89/100 is above the average of 72/100 among major Iowa cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Iowa rankings →About Coggon, IA
Learn more about your water
Guides and resources related to Coggon's water quality findings.
Explore water quality across Linn
Frequently asked questions
Is Coggon, IA tap water safe to drink?
Coggon's water quality earned a grade of A- (89/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #247 out of 436 cities tested in Iowa.
What contaminants are in Coggon's water?
Lead was measured at 5.8 ppb (90th percentile). 41 violations are on record.
How is Coggon'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 Coggon?
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 Coggon's water come from?
Coggon's water is sourced from Groundwater. The city has 1 water system serving approximately 701 residents.
Is Coggon's groundwater at risk of contamination?
Coggon 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 41 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 Coggon's water compare to other cities?
Coggon ranks #247 out of 436 cities in Iowa (better than 43% of state cities) and #3136 out of 15744 cities nationally (80th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Coggon's small water system affect quality?
Coggon's system serves approximately 701 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 41 violations on record.