01The verdict: is Colfax water safe?
Colfax's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (87.9/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 2,305 residents using groundwater (wells).
Copper is over its legal limit
Measured at 2.19 mg/L against the EPA Action Level of 1.3 mg/L. The ledger below shows how far over — and which filter removes it.
See the measurement ↓2K 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 ↓A flood-prone service area
7 federal disaster declarations on record. After severe weather, watch for boil-water advisories.
See the risk factors ↓Colfax's drinking water received a grade of A- (87.9 out of 100), indicating good water quality. The city's 1 water system serves approximately 2,305 residents using groundwater.
Lead levels were measured at 5.1 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 12 violations on record, including 2 health-based violations. 2 remain unresolved.
Colfax ranks #273 out of 430 cities in Iowa for water quality, placing it below average in the state. Colfax 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, Colfax may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Colfax's water
Every contaminant flagged in Colfax, 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.
Over Limit — EPA Action Level: 1.3 mg/L
Exceeds the EPA action level. Copper leaches from household plumbing — flush taps for 30 seconds before drinking, and consider a certified filter.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. | 5.1 | 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. | 2.19 | 1.3 | mg/L | Inorganic | Over Limit |
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
03Colfax'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 12 violations on record, including 2 health-based violations. 2 remain unresolved.
All ten of the last ten years were clean — no EPA violations recorded for Colfax.
▲ Up 5.1 ppb since 1993. Latest reading: 5.1 ppb (2024) — 34% of the action level. Sampled at higher-risk homes (90th percentile).
▲ Up 0.53 mg/L since 1993. The latest reading (2.2 mg/L, 2005) is over the action level. Sampled at higher-risk homes (90th percentile).
04Where Colfax's water comes from
Colfax'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.
2,305 people
Residents served across Colfax'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 2,305 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| COLFAX WATER SUPPLY | IA5009056 | 2,305 | Groundwater |
Water bodies near Colfax
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Colfax'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
1 facility within 10 miles reported 0 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
7 federal disaster declarations on record for Jasper County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Colfax compares
Scores for nearby Iowa cities on one line, with the average marked.
dashed line = Iowa average (72/100)
Colfax scores 87.9/100 — above the Iowa average of 72/100. It outscores 10 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 Colfax's water — not generic advice.
Filter drinking & cooking water
Basic carbon filter for extra protection. Lead detected at 5.1 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 Colfax 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 Colfax, IA tap water safe to drink?
Colfax's water quality earned a grade of A- (87.9/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #273 out of 430 cities tested in Iowa.
What contaminants are in Colfax's water?
Lead was measured at 5.1 ppb (90th percentile). 12 violations are on record.
How is Colfax'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 Colfax?
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 Colfax's water come from?
Colfax's water is sourced from Groundwater. The city has 1 water system serving approximately 2,305 residents.
What health violations has Colfax's water system had?
Colfax has 2 health-based violations on record. The most recent violation was recorded in July 2011. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.
Is Colfax's groundwater at risk of contamination?
Colfax 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 12 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 Colfax's water compare to other cities?
Colfax ranks #273 out of 430 cities in Iowa (better than 37% of state cities) and #3743 out of 15382 cities nationally (76th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Colfax's small water system affect quality?
Colfax's system serves approximately 2,305 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 12 violations on record.