Is Walnut Grove, MO Tap Water Safe to Drink?
Graded B-, with 11 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
72.2/100
waterverge.com Walnut Grove, MO — Water Quality Report
Walnut Grove's drinking water received a grade of B- (72.2 out of 100), indicating fair water quality. The city's 1 water system serves approximately 665 residents using groundwater.
Lead levels were measured at 0.0 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 56 violations on record, including 7 health-based violations. 11 remain unresolved.
What to know about Walnut Grove's water
Walnut Grove ranks #382 out of 509 cities in Missouri for water quality, placing it below average in the state.
Walnut Grove 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, Walnut Grove may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 7 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Walnut Grove, MO water safe to drink?
Walnut Grove's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (72.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 665 residents using groundwater (wells).
Recent water quality updates for Walnut Grove
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Walnut Grove's water quality assessment. Grade: B- (72.2/100).
1 health-based. Contaminants: Revised Total Coliform Rule.
Contaminants: E. COLI.
Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-4317). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4250). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Walnut Grove's water supply.
Well within EPA limits.
Violation history
Walnut Grove's water system has 56 total violations on record, including 7 health-based violations. 11 remain unresolved. 7 violations were issued in the last 5 years.
Flood & environmental risk
Greene County has experienced 7 federally declared disasters since 1974. 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 Sac River Near Dadeville, Little Sac River Near Morrisville.
Where does Walnut Grove's water come from?
Walnut Grove's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 665 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Sac River Near Dadeville (river), Little Sac River Near Morrisville (river).
What Walnut Grove residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Walnut Grove'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.
Walnut Grove'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
Greene County has experienced 7 federally declared disasters since 1974. 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. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Walnut Grove compares by contaminant
Explore where Walnut Grove ranks among all Missouri cities for specific contaminants.
Water source & infrastructure
Where Walnut Grove's water comes from
Walnut Grove'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 665 people through 1 water system.
Water bodies near Walnut Grove
Walnut Grove is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Walnut Grove
| System Name | PWSID | Population | Source |
|---|---|---|---|
| WALNUT GROVE PWS | MO5010829 | 665 | GW |
How Walnut Grove compares
Full Missouri rankings →Walnut Grove's score of 72.2/100 is above the average of 62/100 among major Missouri cities. It outscores 5 of 10 nearby cities.
Nearby cities
View Missouri rankings →About Walnut Grove, MO
Learn more about your water
Guides and resources related to Walnut Grove's water quality findings.
Explore water quality across Greene
Frequently asked questions
Is Walnut Grove, MO tap water safe to drink?
Walnut Grove's water quality earned a grade of B- (72.2/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #382 out of 509 cities tested in Missouri.
What contaminants are in Walnut Grove's water?
Lead was measured at 0.0 ppb (90th percentile). 56 violations are on record.
How is Walnut Grove'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 Walnut Grove?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Walnut Grove's water come from?
Walnut Grove's water is sourced from Groundwater. The city has 1 water system serving approximately 665 residents.
What health violations has Walnut Grove's water system had?
Walnut Grove has 7 health-based violations on record. The most recent violation was recorded in December 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 11 violations remain unresolved.
Is Walnut Grove's groundwater at risk of contamination?
Walnut Grove 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 56 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 Walnut Grove's water compare to other cities?
Walnut Grove ranks #382 out of 509 cities in Missouri (better than 25% of state cities) and #10426 out of 15744 cities nationally (34th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Walnut Grove's small water system affect quality?
Walnut Grove's system serves approximately 665 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 56 violations on record.