Water system
Mansfield City
EPA ID OH7002914 · Richland County · 51,000 people served · owned by a local government
Mansfield City treats its own water from Clear Fork Reservoir (Clear Fork of the Mohican River), plus 9 city wells.
The system's record
- Water bodies
- Clear Fork Reservoir, Clear Fork Mohican River
- Raw intakes
- Clear Fork River
- Active wells
- 9
- Serves
- 51,000 people · Richland County
- EPA ID
- OH7002914
About this area's water
Did you know
- Despite the reservoir's prominence, only about 22% of Mansfield's tap water is lake water - roughly 78% comes from municipal wells, and the blend shifts with algae blooms and taste-and-odor episodes.
- Potassium permanganate is dosed right at the reservoir intake for one specific job: keeping zebra mussels from colonizing the intake line.
- About 5.5 million cubic yards of silt have settled into Clear Fork Reservoir since 1949 - roughly a quarter of its capacity - and it has never once been dredged.
- Mansfield voters rejected a quarter-percent water-main income tax in November 2023, then passed the very same tax four months later by 97 votes.
History5
- 1949Clear Fork Reservoir built, impounding the Clear Fork of the Mohican River to serve Mansfield as its surface water source.
- 1960Present wastewater treatment plant went into service as a 4 MGD facility; capacity was expanded between 1984 and 1987.
- 2023-2024Voters rejected a quarter-percent water-main income tax in Nov. 2023 (5,865-5,251), then approved it in March 2024 by 97 votes (2,701-2,604).
- 2025City launched a $3.6 million water main program and recorded three treatment technique violations at the water plant, including a nine-hour turbidity violation on Jan. 2.
- 2026Stantec sediment survey found roughly 5.5 million cubic yards of silt and ~26% capacity loss, but concluded the reservoir remains dependable for at least 50 more years.
Treatment & pressure
How it is treated
Blend of surface and ground water - about 22% from the 4.4-billion-gallon Clear Fork Reservoir (24-inch line) and about 78% from municipal wells (two 18-inch lines), with the ratio set by lake clarity, algal blooms and taste/odor. Potassium permanganate at the intake controls zebra mussels; then…
Water pressure
not published; no system-wide psi figure appears in the city's plant pages or the 2025 CCR
What it costs
No per-1,000-gallon figure is published online. Utility Collections directs residents to city ordinances 937.11 (water) and 941.08 (sewer) for yearly rates and fees; the ordinance…
Water quality & impurities8
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Total trihalomethanes (TTHM) Running average at 94% of the MCL; single samples ranged to 108.6 ppb | 75.0 ppb | MCL 80 | 2025 |
| Haloacetic acids (HAA5) Range 18.2-78.5; TTHM and HAA5 exceeded operational evaluation levels at 4 of 8 sites in Q3 | 52.5 ppb | MCL 60 | 2025 |
| Turbidity Exceeded the limit - treatment technique violation; 98.3% of samples met the standard | 2.60 NTU | TT: 1.0 NTU max | 2025 |
| Lead (90th percentile) 90th percentile well under the action level, but 1 of 31 samples exceeded 15 ppb | 1.8 ppb | AL 15 | 2025 |
| Copper (90th percentile) 0 of 31 samples over the action level | 0.2 ppm | AL 1.3 | 2025 |
| Nitrate Range 0.13-0.58; low for an agricultural watershed | 0.58 ppm | MCL 10 | 2025 |
| Combined radium From the well sources; gross alpha was 3.02 pCi/L against a 15 limit | 2.35 pCi/L | MCL 5 | 2022 |
| PFOA About 1 ppt, a quarter of the new federal limit; PFOS 0.000921 ppb, other four PFAS non-detect | 0.00102 ppb | MCL 0.004 | 2025 |
EPA compliance record
Lead at the tap: 90th-percentile result 2 ppb in 2025 (action level 15 ppb).
EPA health-based violations since 2015:
- 2025Interim Enhanced Surface Water Treatment Rule · turbidity above the limit in a single reading · returned to compliance
- 2025Long Term 2 Enhanced Surface Water Treatment Rule · required treatment not met · returned to compliance
- 2024Lead and Copper Rule Revisions · lead service line inventory missing or incomplete (a records requirement, not a lead test result) · returned to compliance
- 2023Lead and Copper Rule · water quality limits for corrosion control not met · returned to compliance
- 2019Interim Enhanced Surface Water Treatment Rule · turbidity above the limit in a single reading · returned to compliance
- 2018Lead and Copper Rule · water quality limits for corrosion control not met · returned to compliance
EPA's count of 7 includes 1 repeat quarterly violation of the problems listed.
8 violations of any kind logged since 2020: 3 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records); 5 health-based.
Projects & plans3
Recent and current work
- Water main replacement program (4-inch to 8-inch mains) · $3.6 million · 2025 · under construction
About 14,000 feet of main, 37 hydrants and 246 reconnected homes in six areas; first phase of a 53-mile replacement need. - Clear Fork Reservoir sediment survey · $149,799 · 2026 · completed
Stantec study found ~5.5 million cubic yards of sediment and ~26% capacity loss, yet a dependable supply for 50+ years.
Planned or needed
- Continued small-diameter water main replacement (53 miles total) · 2025-2029 · planned
About three miles per year over roughly four funding cycles, paid from the 0.25% income tax generating ~$4.8 million annually.
Supply stress
Silt has claimed roughly 26% of Clear Fork Reservoir's capacity since 1949 and it has never been dredged, though a 2026 Stantec survey found 50+ years of dependable supply. Nearer-term pressures are on the treatment side: three treatment technique violations in 2025 and disinfection byproducts running close to their limits.
Sewers
Sanitary
City-operated wastewater treatment plant (not a regional district): 12 MGD average design flow, 25 MGD peak. Treatment runs equalization, bar screening, aerated grit removal, primary clarification, extended aeration in eight tanks, four final clarifiers, then chlorination and dechlorination, with anaerobic digestion and centrifuge…
Storm
Largely separate storm system - about 400 miles of storm lines, 7,200-plus catch basins and roughly 1,200 outfalls draining to 10 major waterways. No stormwater utility fee is published.
Sourcesverified
Compiled from the utility's own reports and public records, then independently re-checked against primary sources.
Main supplier in 4 ZIP codes
Serves
Main water supplier in 6 ZIP codes
- 44901 · Mansfield100% of residents
- 44902 · Mansfield100% of residents
- 44907 · Mansfield86% of residents
- 44906 · Mansfield46% of residents
- 44903 · Mansfield37% of residents
- 44905 · Madison Township and Mansfield10% of residents
Also present in 1 more ZIP code
- 44904 · Lexington and Mansfield22% of residents
Population-weighted resident shares; a ZIP code can have more than one system on record. Recomputed from each ZIP's own system list, not from the map's cached footprint.
Buys from · Sells to
Mansfield City does not buy water from another system on record; it treats its own source water.
No other system is on record buying water from Mansfield City.
What the records show about Mansfield City
Who runs it
EPA's record describes Mansfield City as owned by a local government. It has 17,862 service connections and serves 51,000 people.
EPA classes it as a community water system, one that serves the same residents all year.
EPA's record says it has substantially implemented source water protection under Ohio's program, dating the program from 2023. Its office telephone on EPA's record is 419-755-9628.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
EPA's treatment table registers these steps for Mansfield City: aeration, corrosion control, coagulation and settling, chlorine disinfection, iron and manganese removal, powdered activated carbon, and sand or media filtration.
The list is what each system registered with EPA for treatment plants EPA still shows as active, and it can lag a plant upgrade.
Source: EPA Safe Drinking Water Information System (SDWIS) treatment table (EPA Envirofacts, pulled September 2026).
Violations
EPA counts 7 health-based violations for Mansfield City since 2015. Health-based means a contaminant above its legal limit or a required treatment step not carried out. They fall into 6 separate problems (one contaminant or rule in one year); the table lists them all.
EPA logs a violation for each compliance period a problem lasts, so the count of 7 includes 1 repeat entry of the problems listed.
EPA logs 8 violations of any kind since 2020: 3 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records); 5 health-based.
| Year | Contaminant or rule | Kind | Measured | Limit | Status in EPA's record |
|---|---|---|---|---|---|
| 2025 | Interim Enhanced Surface Water Treatment Rule | turbidity above the limit in a single reading | not on file | not on file | returned to compliance |
| 2025 | Long Term 2 Enhanced Surface Water Treatment Rule | required treatment not met | not on file | not on file | returned to compliance |
| 2024 | Lead and Copper Rule Revisions | lead service line inventory missing or incomplete (a records requirement, not a lead test result) | not on file | not on file | returned to compliance |
| 2023 | Lead and Copper Rule | water quality limits for corrosion control not met | not on file | not on file | returned to compliance |
| 2019 | Interim Enhanced Surface Water Treatment Rule | turbidity above the limit in a single reading | not on file | not on file | returned to compliance |
| 2018 | Lead and Copper Rule | water quality limits for corrosion control not met | not on file | not on file | returned to compliance |
Source: EPA Safe Drinking Water Information System (SDWIS) violation records: health-based violations with compliance periods beginning in 2015 or later, all violations from 2020 or later (EPA Envirofacts, pulled September 2026).
Lead and copper at the tap
In the sampling period ending December 2025, the 90th-percentile lead result at Mansfield City was 2 ppb, under both the current 15 ppb action level and the 10 ppb level that applies from 2027.
The highest result on file is 3.8 ppb, in the period ending December 2016.
EPA has 9 sampling periods on file for Mansfield City since 2016, the first ending in 2016; no period was above 10 ppb.
Every water system has to inventory its service lines, the pipes from the main to each building. In the inventory Mansfield City sent EPA, 22,949 lines are counted.
| Material | Lines |
|---|---|
| Lead | 0 |
| Galvanized, needing replacement | 43 |
| Unknown material | 21,334 |
| Not lead | 1,572 |
| All lines | 22,949 |
Systems sample taps in the homes most likely to have lead pipes or solder. The 90th-percentile result is the level nine in ten of the sampled homes were at or below. Lead comes mostly from service lines and house plumbing, not the source water, so a low result for the system does not clear an old house.
EPA's dashboard status for this inventory: reported all required service line types.
Source: EPA Safe Drinking Water Information System (SDWIS) lead and copper 90th-percentile results (EPA Envirofacts), sampling periods ending 2016 or later; EPA's service line inventory dashboard, Ohio's 2026 Q2 submission.
PFAS
EPA's fifth national round of testing (UCMR 5) took 5 samples of the water entering the pipes of Mansfield City in 2023 to 2024 and measured 29 PFAS. No PFAS was detected, PFOA and PFOS (federal limit 4 ng/L each) among them.
The system reported potential PFAS sources near its supply.
Ohio EPA's own statewide sampling tested 1 plant of Mansfield City (latest sample June 2020). Not one of the six PFAS tested (PFOA, PFOS, PFHxS, PFNA, GenX and PFBS) was detected.
Ohio EPA's current sampling status map lists 1 plant of Mansfield City as sampled, most recently August 2026.
PFAS are the 'forever chemicals' from firefighting foam, plating shops and non-stick coatings. Results are for water leaving the plant, not your tap.
Source: EPA UCMR 5 occurrence data (final release, August 2026); Ohio EPA statewide PFAS sampling, 2019 to 2021, and its sampling status map.
Disinfection byproducts
Chlorine that disinfects water also reacts with organic matter to form byproducts. Two groups have federal limits: total trihalomethanes (TTHM, 80 µg/L) and five haloacetic acids (HAA5, 60 µg/L), judged on running yearly averages at each sampling site.
For TTHM, the average of Mansfield City's samples in 2019, the last year it was sampled, was 57.3 µg/L. The worst yearly average was 65.3 µg/L and the highest single sample was 97.8 µg/L, from 256 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 38.7 µg/L. The worst yearly average was 47.9 µg/L and the highest single sample was 76.8 µg/L, from 257 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 57.3 µg/L (2019) | 65.3 µg/L | 97.8 µg/L | 256 |
| HAA5 | 60 µg/L | 38.7 µg/L | 47.9 µg/L | 76.8 µg/L | 257 |
A yearly average of 0 means nothing was detected in that year's samples. EPA's file stops at 2019; Ohio EPA's Drinking Water Watch has newer results.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, distribution-system samples (non-detects counted as zero).
Nitrate, arsenic and radioactivity
Nitrate: the highest of 96 samples was 0.9 mg/L (as nitrogen), in 2019, the last year sampled. No sample was over the limit of 10 mg/L. Nitrate above 10 is unsafe for infants.
Arsenic was not detected in 8 samples (limit 10 µg/L).
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 96 | 0.9 mg/L | 10 mg/L | 0 |
| Arsenic | 8 | not detected | 10 µg/L | 0 |
| Combined radium | 1 | not detected | 5 pCi/L | 0 |
Measured in finished water: at the plant's entry points and in the distribution system; raw well and intake samples are left out. Non-detects count as zero.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.
Solvents and fuels
EPA's file holds results for all six solvent and fuel compounds it checked. Benzene, carbon tetrachloride, 1,2-dichloroethane, trichloroethylene, tetrachloroethylene, and vinyl chloride were not detected in 8 samples each.
| Compound | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|
| Benzene | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Carbon tetrachloride | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| 1,2-dichloroethane | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Trichloroethylene (TCE) | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Tetrachloroethylene (PCE) | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Vinyl chloride | 2 µg/L | 8 | 0 of 8 | not detected | 0 |
"Not detected" means the lab's result was below what its method can measure, not that the compound is absent. Non-detects count as zero in the highest-result column.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.
Farm chemicals and metals
EPA's file holds results for 8 of the nine herbicides and metals it checked. Detected: atrazine in 1 of 8 samples, highest 0.11 µg/L (limit 3); barium in 8 of 8 samples, highest 100 µg/L (limit 2,000). Not detected: alachlor, chromium, cadmium, mercury, selenium, and thallium, in 8 samples each.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 8 | 1 of 8 | 0.11 µg/L | 0 |
| Alachlor | Farm chemical | 2 µg/L | 8 | 0 of 8 | not detected | 0 |
| Chromium | Metal | 100 µg/L | 8 | 0 of 8 | not detected | 0 |
| Cadmium | Metal | 5 µg/L | 8 | 0 of 8 | not detected | 0 |
| Barium | Metal | 2,000 µg/L | 8 | 8 of 8 | 100 µg/L | 0 |
| Mercury | Metal | 2 µg/L | 8 | 0 of 8 | not detected | 0 |
| Selenium | Metal | 50 µg/L | 8 | 0 of 8 | not detected | 0 |
| Thallium | Metal | 2 µg/L | 8 | 0 of 8 | not detected | 0 |
Non-detects count as zero in the highest-result column.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.
Bacteria in the pipes
From 2012 to 2019, 5 of 6,654 routine total coliform samples taken in the distribution system at Mansfield City tested positive (0.08%); in 2019, the last year on file, 0 of 730 did. E. coli was never found in the 5 samples tested for it.
A positive coliform test is a warning sign, not a violation by itself. E. coli is a sign that human or animal waste may have reached the water. Coliform counts are routine samples only; E. coli counts include repeat samples.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, distribution-system presence/absence tests for total coliform and E. coli.
Fluoride
The Ohio Department of Health's report to the CDC (My Water's Fluoride) says Mansfield City has fluoride from natural sources, but at a level below what is recommended for preventing tooth decay, and does not adjust it. The level it reports is 0.15 mg/L.
EPA's treatment table lists no fluoridation step at Mansfield City.
Measured fluoride: 0.13 mg/L on average at the plant's entry points in 2019 (too little to protect teeth); samples ran from 0.13 to 0.18 mg/L across 8 samples in 2012 to 2019.
The recommended level for preventing tooth decay is 0.7 mg/L; the federal limit is 4 mg/L. The treatment list is what each system registered with EPA and can lag a plant upgrade.
Source: CDC My Water's Fluoride (fluoridation status as reported by the Ohio Department of Health, fetched September 2026); EPA Safe Drinking Water Information System (SDWIS) treatment table; EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, entry-point fluoride samples.
Lithium
Lithium was not detected in 4 UCMR 5 samples at Mansfield City, last sampled in 2024 (the method reports from 9 µg/L).
Lithium is not regulated. EPA's draft health reference level is 10 µg/L, and it occurs naturally in deep groundwater, so well systems in the northwest run highest.
Source: EPA UCMR 5 occurrence data (final release, August 2026), samples from 2023 to 2025.
Algal toxins
Ohio EPA tests for microcystin, a toxin that harmful algal blooms can release, in raw water at the intake and in treated water.
At the intake, microcystin was detected 27 times in 353 raw-water samples, across 5 bloom seasons (2016 to 2024); the highest raw-water result was 5.6 µg/L on October 24, 2016. The highest raw-water result since 2024 was 0.536 µg/L.
Microcystin was never detected in treated water (344 samples).
In all, 697 samples from 2016 to 2026, the latest on August 24, 2026.
| Water | Samples | Detections | Highest result |
|---|---|---|---|
| Raw water, at the intake | 353 | 27 | 5.6 µg/L |
| Treated water | 344 | 0 | not detected |
The ten-day advisory levels for treated water are 0.3 µg/L for children under six and 1.6 µg/L for everyone else. Any detection at the intake triggers more frequent testing until two clean weeks.
Source: Ohio EPA public water system harmful algal bloom monitoring, 2016 to present (HAB data, fetched September 2026).
Water and sewer bills
Ohio EPA's 2023 rate survey puts the water bill at Mansfield City for a household using 5,000 gallons a month at $412 a year, about $34 a month.
The sewer bill in the same survey is $580 a year at 5,000 gallons a month.
| Use | Water, per year | Sewer, per year |
|---|---|---|
| 2,500 gallons a month | $248 | $319 |
| 5,000 gallons a month | $412 | $580 |
| 8,000 gallons a month | $632 | $894 |
The survey lists it as “Mansfield”. These are inside-city rates and annual bills at the use shown.
Source: Ohio EPA 2023 Sewer and Water Rate Survey (Ohio State University, May 2025).
How well the service area is mapped
The service area drawn on the map for Mansfield City comes from the utility's own map.
Counting the people who live in the ZIP codes it overlaps, this atlas estimates 39,771 residents are inside the boundary, 78% of the 51,000 people Mansfield City reports serving.
The resident count is an estimate from 2020 Census ZIP-code populations, not a count of customers.
Source: EPA Service Area Boundaries; resident estimate by this atlas from ZIP-code overlap.
Photograph
On the map
Show this system's territory on the map — 7 ZIP codes in all.
Sources
U.S. EPA SDWIS and Community Water System Service Area Boundaries (v3, 2026), Ohio EPA primacy data, 2020 census blocks: the system serving most residents, traced through purchases to the treating utility; Ohio EPA 2023 Sewer and Water Rate Survey (Ohio State, May 2025) for household bills; Ohio EPA DEFA loan awards since 2016 for the loans paragraph · EPA SDWIS · EPA service area boundaries · Ohio EPA drinking water · Ohio EPA rate survey
EPA's own record for this system: Enforcement and Compliance History report for OH7002914 (EPA ECHO).
Mansfield City's own pages: ci.mansfield.oh.us, en.wikipedia.org