Is Marshall, OK Tap Water Safe to Drink?
Graded B- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
72.4/100
waterverge.com Marshall, OK — Water Quality Report
Marshall's drinking water received a grade of B- (72.4 out of 100), indicating fair water quality. The city's 2 water systems serve approximately 1,876 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 42 violations on record, including 10 health-based violations. 13 remain unresolved.
What to know about Marshall's water
Marshall ranks #117 out of 358 cities in Oklahoma for water quality, placing it mid-range in the state.
Marshall 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, Marshall 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 Marshall, OK water safe to drink?
Marshall's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (72.4/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,876 residents using groundwater (wells).
Recent water quality updates for Marshall
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Marshall's water quality assessment. Grade: B- (72.4/100).
Contaminants: Consumer Confidence Rule.
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-1754). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3219). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Marshall's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Marshall's water system has 42 total violations on record, including 10 health-based violations. 13 remain unresolved. 7 violations were issued in the last 5 years.
Flood & environmental risk
Logan County has experienced 8 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 Skeleton Creek Near Lovell.
Where does Marshall's water come from?
Marshall's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 1,876 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Skeleton Creek Near Lovell (river).
What Marshall residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Marshall'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.
Marshall'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 droughtLogan 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
Logan County has experienced 8 federally declared disasters since 1974. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Marshall's water supply, we recommend the following filter types.
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 |
| 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. | 1.40 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Marshall compares by contaminant
Explore where Marshall ranks among all Oklahoma cities for specific contaminants.
Water source & infrastructure
Where Marshall's water comes from
Marshall'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 1,876 people through 2 water systems.
Water bodies near Marshall
Marshall is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Marshall
| System Name | PWSID | Population | Source |
|---|---|---|---|
| LOGAN CO RWS & SWMD #3 | OK2004230 | 1,618 | GW |
| MARSHALL | OK3004201 | 258 | GWP |
How Marshall compares
Full Oklahoma rankings →Marshall's score of 72.4/100 is above the average of 45/100 among major Oklahoma cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Oklahoma rankings →About Marshall, OK
Wikipedia →Marshall is a rural town in Logan County, Oklahoma, United States, and is an outer suburb/exurb on the northern edge of the Oklahoma City Metropolitan Statistical Area. The population was 210 as of the 2020 United States census.
Learn more about your water
Guides and resources related to Marshall's water quality findings.
Explore water quality across Logan
Frequently asked questions
Is Marshall, OK tap water safe to drink?
Marshall's water quality earned a grade of B- (72.4/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #117 out of 358 cities tested in Oklahoma.
What contaminants are in Marshall's water?
Lead was measured at 0.0 ppb (90th percentile). 42 violations are on record.
How is Marshall'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 Marshall?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Marshall's water come from?
Marshall's water is sourced from Groundwater. The city has 2 water systems serving approximately 1,876 residents.
What health violations has Marshall's water system had?
Marshall has 10 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 13 violations remain unresolved.
Is Marshall's groundwater at risk of contamination?
Marshall 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 42 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 Marshall's water compare to other cities?
Marshall ranks #117 out of 358 cities in Oklahoma (better than 67% of state cities) and #10323 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.