01The verdict: is Postville water safe?
Postville's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (86.6/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 2,513 residents using groundwater (wells).
1 unresolved violation on record
EPA records show an open compliance item for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓3K people, 1 system
All figures on this page come from federal EPA compliance and testing data for the systems serving this city.
See the systems ↓1 violation in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Postville's drinking water received a grade of A- (86.6 out of 100), indicating good water quality. The city's 1 water system serves approximately 2,513 residents using groundwater.
Lead levels were measured at 9.9 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 8 violations on record, including 0 health-based violations. 1 remains unresolved.
Postville ranks #317 out of 430 cities in Iowa for water quality, placing it below average in the state. Postville 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, Postville may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Postville's water
Every contaminant flagged in Postville, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
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. | 9.9 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in Iowa
Cities ranked by compounds detected Cu Copper in Iowa
Cities ranked by 90th-percentile copper
03Postville's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 8 violations on record, including 0 health-based violations. 1 remains unresolved.
8 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▲ Up 2.9 ppb since 1993. Latest reading: 9.9 ppb (2023) — 66% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Postville's water comes from
Postville's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
1 system
1 water system, operated under local government ownership.
2,513 people
Residents served across Postville's service area.
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 2,513 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| POSTVILLE WATER DEPARTMENT | IA0375053 | 2,513 | Groundwater |
05Pressure on Postville's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
3 facilities within 10 miles reported 822k lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
10 federal disaster declarations on record for Allamakee County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Postville compares
Scores for nearby Iowa cities on one line, with the average marked.
dashed line = Iowa average (72/100)
Postville scores 86.6/100 — above the Iowa average of 72/100. It outscores 9 of 10 nearby cities. Full Iowa rankings →
85 / 100CDavenport, IA
55 / 100DCedar Rapids, IA
45.5 / 100FIowa City, IA
42 / 100BAmes, IA
81.5 / 100BSioux City, IA
77.3 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Postville's water — not generic advice.
Filter drinking & cooking water
Basic carbon filter for extra protection. Lead detected at 9.9 ppb
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Postville alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Postville, IA tap water safe to drink?
Postville's water quality earned a grade of A- (86.6/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #317 out of 430 cities tested in Iowa.
What contaminants are in Postville's water?
Lead was measured at 9.9 ppb (90th percentile). 8 violations are on record.
How is Postville'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 Postville?
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 Postville's water come from?
Postville's water is sourced from Groundwater. The city has 1 water system serving approximately 2,513 residents.
Is Postville's groundwater at risk of contamination?
Postville 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 8 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 Postville's water compare to other cities?
Postville ranks #317 out of 430 cities in Iowa (better than 26% of state cities) and #4565 out of 15382 cities nationally (70th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Postville's small water system affect quality?
Postville's system serves approximately 2,513 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 8 violations on record.