Is St John, KS Tap Water Safe to Drink?
Graded B+, with 10 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
81.6/100
waterverge.com St John, KS — Water Quality Report
St John's drinking water received a grade of B+ (81.6 out of 100), indicating good water quality. The city's 1 water system serves approximately 1,176 residents using groundwater.
Lead levels were measured at 1.9 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 24 violations on record, including 8 health-based violations. 10 remain unresolved.
What to know about St John's water
St John ranks #143 out of 323 cities in Kansas for water quality, placing it mid-range in the state.
St John 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, St John may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 6 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is St John, KS water safe to drink?
St John's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (81.6/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 1,176 residents using groundwater (wells).
Recent water quality updates for St John
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into St John's water quality assessment. Grade: B+ (81.6/100).
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Contaminants: Lead and Copper Rule.
Contaminants: Public Notice.
Federal disaster declaration (FEMA DR-3236). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1000). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for St John's water supply.
Well within EPA limits.
Violation history
St John's water system has 24 total violations on record, including 8 health-based violations. 10 remain unresolved. 6 violations were issued in the last 5 years.
Flood & environmental risk
Stafford County has experienced 4 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 Rattlesnake C Nr Macksville.
Where does St John's water come from?
St John's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,176 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Rattlesnake C Nr Macksville (river).
What St John residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in St John'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.
St John'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
Drought conditions
D3 — extreme droughtStafford County is currently in D3 (extreme drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Stafford County has experienced 4 federally declared disasters since 1965. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
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. | 1.9 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how St John compares by contaminant
Explore where St John ranks among all Kansas cities for specific contaminants.
Water source & infrastructure
Where St John's water comes from
St John'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 1,176 people through 1 water system.
Water bodies near St John
St John is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving St John
| System Name | PWSID | Population | Source |
|---|---|---|---|
| ST JOHN, CITY OF | KS2018502 | 1,176 | GW |
How St John compares
Full Kansas rankings →St John's score of 81.6/100 is above the average of 62/100 among major Kansas cities. It outscores 8 of 10 nearby cities.
Nearby cities
View Kansas rankings →Learn more about your water
Guides and resources related to St John's water quality findings.
Explore water quality across Stafford
Frequently asked questions
Is St John, KS tap water safe to drink?
St John's water quality earned a grade of B+ (81.6/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #143 out of 323 cities tested in Kansas.
What contaminants are in St John's water?
Lead was measured at 1.9 ppb (90th percentile). 24 violations are on record.
How is St John'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 St John?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does St John's water come from?
St John's water is sourced from Groundwater. The city has 1 water system serving approximately 1,176 residents.
What health violations has St John's water system had?
St John has 8 health-based violations on record. The most recent violation was recorded in January 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 10 violations remain unresolved.
Is St John's groundwater at risk of contamination?
St John 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 24 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 St John's water compare to other cities?
St John ranks #143 out of 323 cities in Kansas (better than 56% of state cities) and #7405 out of 15744 cities nationally (53th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does St John's small water system affect quality?
St John's system serves approximately 1,176 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 24 violations on record.