Is London, OH 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 ↓
79.5/100
waterverge.com London, OH — Water Quality Report
London's drinking water received a grade of B (79.5 out of 100), indicating good water quality. The city's 2 water systems serve approximately 2,930 residents using groundwater.
Lead levels were measured at 0.9 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 37 violations on record, including 10 health-based violations. 13 remain unresolved.
What to know about London's water
London ranks #281 out of 511 cities in Ohio for water quality, placing it below average in the state.
London 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, London may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is London, OH water safe to drink?
London's drinking water has significant quality concerns based on EPA testing data. With a grade of B (79.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 2,930 residents using groundwater (wells).
Recent water quality updates for London
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into London's water quality assessment. Grade: B (79.5/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Lead and Copper Rule.
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-3250). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for London'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
London's water system has 37 total violations on record, including 10 health-based violations. 13 remain unresolved. 4 violations were issued in the last 5 years.
Flood & environmental risk
Madison County has experienced 1 federally declared disaster since 2005. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does London's water come from?
London's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 2,930 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What London residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in London'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.
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 London
Industrial polluters nearby
Reported releases to surface water by facilities near London, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
STANLEY ELECTRIC U.S. CO INC. LONDON, OH43140 | — | — | 1.2 mi |
ARMALY BRANDS LONDON PLANT LONDON, OH43140 | — | — | 0.9 mi |
INTELLIGRATED PRODUCTS LLC LONDON, OH43140 | — | — | 1.6 mi |
JEFFERSON INDUSTRIES CORP WEST JEFFERSON, OH43162 | — | — | 7.7 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Madison County has experienced 1 federally declared disaster since 2005. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in London'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. | 0.9 | 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. | 1.83 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how London compares by contaminant
Explore where London ranks among all Ohio cities for specific contaminants.
Water source & infrastructure
Where London's water comes from
London'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 private ownership and serves approximately 2,930 people through 2 water systems.
Water systems serving London
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CHOCTAW UTILITIES, INC. | OH4900212 | 2,200 | GW |
| GREEN MEADOWS MOBILE HOME PARK | OH4901812 | 730 | GW |
How London compares
Full Ohio rankings →London's score of 79.5/100 is above the average of 58/100 among major Ohio cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Ohio rankings →About London, OH
Wikipedia →London is a city in and the county seat of Madison County, Ohio, United States. Located about 25 miles (40 km) southwest of the Ohio capital of Columbus, London was established in 1811 to serve as the county seat. The population was 10,279 at the 2020 census. It is part of the Columbus metropolitan area.
Learn more about your water
Guides and resources related to London's water quality findings.
Explore water quality across Madison
Frequently asked questions
Is London, OH tap water safe to drink?
London's water quality earned a grade of B (79.5/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #281 out of 511 cities tested in Ohio.
What contaminants are in London's water?
Lead was measured at 0.9 ppb (90th percentile). 37 violations are on record.
How is London'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 London?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does London's water come from?
London's water is sourced from Groundwater. The city has 2 water systems serving approximately 2,930 residents.
What health violations has London's water system had?
London has 10 health-based violations on record. The most recent violation was recorded in December 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 13 violations remain unresolved.
Is London's groundwater at risk of contamination?
London 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 37 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 London's water compare to other cities?
London ranks #281 out of 511 cities in Ohio (better than 45% of state cities) and #8240 out of 15744 cities nationally (48th percentile). The grade of B reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.