Is Southwest City, MO Tap Water Safe to Drink?
Graded B-, with 13 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
72.1/100
waterverge.com Southwest City, MO — Water Quality Report
Southwest City's drinking water received a grade of B- (72.1 out of 100), indicating fair water quality. The city's 2 water systems serve approximately 1,576 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 84 violations on record, including 58 health-based violations. 13 remain unresolved.
What to know about Southwest City's water
Southwest City ranks #383 out of 509 cities in Missouri for water quality, placing it among the lowest-rated in the state.
Southwest City 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, Southwest City may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Southwest City, MO water safe to drink?
Southwest City's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (72.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,576 residents using groundwater (wells).
Recent water quality updates for Southwest City
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Southwest City's water quality assessment. Grade: B- (72.1/100).
Contaminants: Public Notice.
1 health-based. Contaminants: Groundwater Rule.
Contaminants: Consumer Confidence 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 Southwest City's water supply.
Well within EPA limits.
Violation history
Southwest City's water system has 84 total violations on record, including 58 health-based violations. 13 remain unresolved. 5 violations were issued in the last 5 years.
Flood & environmental risk
McDonald County has experienced 6 federally declared disasters since 1986. 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 Elk River Near Tiff City, Mo, Cave Springs Branch Near South West City, Honey Creek Near South West City, Spavinaw Creek Near Maysville.
Where does Southwest City's water come from?
Southwest City's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 1,576 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Elk River Near Tiff City, Mo (river), Cave Springs Branch Near South West City (river), Honey Creek Near South West City (river), Spavinaw Creek Near Maysville (river).
What Southwest City residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Southwest City'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.
Southwest City'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
Top industrial polluters within 10 miles of Southwest City
Industrial polluters nearby
Reported releases to surface water by facilities near Southwest City, ranked by pounds discharged annually.
Total reported releases to surface water: 24,646 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
SIMMONS FOODS SOUTH WEST CITY, MO64863 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 24,646 | 1.8 mi |
TYSON CHICKEN INC. - NOEL COMPLEX NOEL, MO64854 | — | — | 7.1 mi |
PRIDE PLATING INC GROVE, OK74344 | — | — | 8.8 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
McDonald County has experienced 6 federally declared disasters since 1986. 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 Southwest City compares by contaminant
Explore where Southwest City ranks among all Missouri cities for specific contaminants.
Water source & infrastructure
Where Southwest City's water comes from
Southwest City'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 1,576 people through 2 water systems.
Water bodies near Southwest City
Southwest City is located near 4 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Southwest City
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SOUTHWEST CITY PWS | MO5010751 | 976 | GW |
| MC DONALD COUNTY PWSD 3 | MO5021168 | 600 | GW |
How Southwest City compares
Full Missouri rankings →Southwest City's score of 72.1/100 is above the average of 62/100 among major Missouri cities. It outscores 5 of 10 nearby cities.
Nearby cities
View Missouri rankings →About Southwest City, MO
Learn more about your water
Guides and resources related to Southwest City's water quality findings.
Explore water quality across Mcdonald
Frequently asked questions
Is Southwest City, MO tap water safe to drink?
Southwest City's water quality earned a grade of B- (72.1/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #383 out of 509 cities tested in Missouri.
What contaminants are in Southwest City's water?
Lead was measured at 0.0 ppb (90th percentile). 84 violations are on record.
How is Southwest City'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 Southwest City?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Southwest City's water come from?
Southwest City's water is sourced from Groundwater. The city has 2 water systems serving approximately 1,576 residents.
What health violations has Southwest City's water system had?
Southwest City has 58 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. 13 violations remain unresolved.
Is Southwest City's groundwater at risk of contamination?
Southwest City 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 84 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 Southwest City's water compare to other cities?
Southwest City ranks #383 out of 509 cities in Missouri (better than 25% of state cities) and #10441 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.