Water system
Mount Vernon City
EPA ID OH4200812 · Knox County · 16,990 people served · owned by a local government
Mount Vernon City treats its own water from Buried Valley Aquifer (Kokosing River valley wells).
The system's record
- Aquifer
- Buried Valley Aquifer along the Kokosing River
- Water bodies
- Kokosing River
- Active wells
- 2
- Serves
- 16,990 people · Knox County
- EPA ID
- OH4200812
About this area's water
Did you know
- One of the city's supply wells sits on the far side of the Kokosing River, behind the water plant's own sludge lagoons.
- The aquifer under Mount Vernon's well field is so shallow — under 15 feet to water, with as little as zero feet of protective clay — that state assessors rate it highly susceptible to surface contamination.
- Mount Vernon disinfects with chlorine dioxide, unusual for a small groundwater system; the giveaway is chlorite showing up in its annual report as a by-product.
- The city's stormwater fee is measured in 'Equivalent Residential Units' of 2,900 square feet — before the utility existed, stormwater work was quietly eating about 40% of the Street Department's budget.
- The city's own rate FAQ benchmarks its sewer bill against Danville, Fredericktown and Centerburg — and Mount Vernon came out cheapest by a wide margin, $19.60 a month against Centerburg's $83.19 for the same 3,000…
History6
- 2020City created a Stormwater Utility in July 2020 at $4.00/month per Equivalent Residential Unit, rising to $5.00 in January 2021 and $6.00 in January 2022.
- 2021Council passed a wastewater rate increase of 15% per year effective March 1, 2021, January 1, 2022 and January 1, 2023, to fund digester rehabilitation and Ohio EPA-mandated phosphorus removal.
- 2023Water rates rose about 5% effective March 1, taking the in-city minimum from $23.76 to $24.95 for the first 400 cubic feet.
- 2024City completed its federally required initial lead service line inventory under the Lead and Copper Rule and posted it publicly.
- 2024Mount Vernon participated in the fifth round of EPA's Unregulated Contaminant Monitoring Rule (UCMR5) testing, and held an unconditioned license to operate its water system.
- 2026Water rates rose 7% and wastewater 11% effective April 2026, with identical increases scheduled for the second quarters of 2027 and 2028.
Treatment & pressure
How it is treated
Groundwater is drawn from wells in the City of Mount Vernon well field at Riverside Park, plus an additional well on the west side of the Kokosing River behind the sludge lagoons. The source is the Buried Valley Aquifer coincident with part of the Kokosing River. The plant disinfects with chlorine…
Source: mtvernonoh.gov
Water pressure
Not published. No system pressure figure appears in the CCR, the rate documents or the city utilities pages.
What it costs
$6.68 per 1,000 gallons
Typical household bill about $27 a month for water.
Mount Vernon bills in hundreds of cubic feet (100 cu ft = 748 gallons); the city's own wastewater FAQ states its 400 cu ft minimum equals 2,992.2 gallons, confirming the…
Water quality & impurities8
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Chlorine Disinfectant residual; range 1.09-1.37. No violation. | 1.23 ppm | 4 (MRDL) | 2024 |
| Chlorite By-product of chlorine dioxide disinfection; range 0.44-0.48. No violation. | 0.46 ppm | 1.0 | 2024 |
| Chlorine Dioxide Disinfectant; range 0.23-0.47. No violation. | 0.47 ppm | 0.8 (MRDL) | 2024 |
| Fluoride Naturally occurring plus additive for dental health. No violation. | 0.274 ppm | 4 | 2024 |
| Barium Erosion of natural deposits; discharge of drilling wastes. No violation. | 0.023 ppm | 2 | 2024 |
| Total Coliform Monitored in 2024; no violation. | Not detected presence/a… | TT | 2024 |
| Copper (90th pct) 0 of 30 sites above the action level. | 0.025 ppm | 1.3 (AL) | 2022 |
| Lead (90th pct) 0 of 30 sites above the action level. | 0.000 ppb | 15 (AL) | 2022 |
Source: mtvernonoh.gov
EPA compliance record
Lead at the tap: 90th-percentile result 0 ppb in 2025 (action level 15 ppb).
EPA record: no health-based violations since 2015.
2 violations of any kind logged since 2020: 2 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records).
Projects & plans8
Recent and current work
- Initial Lead Service Line Inventory · 2024 · completed
Published per the federal Lead and Copper Rule and linked from the 2024 CCR. - Stormwater Utility establishment · 2020 · completed
Created July 2020 at $4.00/ERU/month, stepped to $6.00/ERU by January 2022. Before the utility existed, stormwater work consumed roughly 40% of the Street… - Clinton Road sanitary sewer replacement and pump station upgrades · 2021 · completed
Ohio EPA-mandated sanitary sewer overflow elimination project, funded by the wastewater rate increase. No standalone cost published. - Wastewater treatment plant digester rehabilitation · 2021 · under construction
The city describes two digesters 'on the verge of permanent breakdown' after operating 24/7 since the 1980s. No standalone cost published. - Waterline extensions and improvements (Newark Road, Dixie Drive, Venture Drive, Northwest neighborhood, North… · 2022 · completed
Funded from water fees; the North Sandusky Street replacement kicked off 2022. No individual costs published.
Source: mtvernonoh.govmtvernonoh.govmtvernonoh.gov
Planned or needed
- Wastewater treatment plant upgrades (Ohio EPA-mandated phosphorus removal) · planned
Ohio EPA has mandated phosphorus removal during treatment; the city says this will raise operating costs through additional chemicals and extra waste sludge… - Water treatment plant improvements · 2026 · planned
The safety-service director cited future water plant improvements as a reason for the 7%/year water increases beginning April 2026. Scope and cost not yet… - Collections system repairs (lift stations, manholes, main lines) · needed
Identified by the city as an ongoing need alongside the plant work. No cost published.
Source: mtvernonoh.govyourohionews.com
Supply stress
The city's own source water assessment, quoted in the 2024 CCR, rates the Buried Valley Aquifer as having a high susceptibility to contamination: depth to water is less than 15 feet from the ground surface, and zero to 25 feet of clay is present in the vicinity of the wellfield, providing limited protection from contaminants infiltrating…
Source: mtvernonoh.gov
Sewers
Sanitary
The city runs its own wastewater treatment plant, operating continuously since the 1980s and described by the city in 2021 as deteriorating rapidly. Treatment runs preliminary (trash, sticks, debris), primary (grease, oils, fats, floatable and settleable solids), secondary (biological), and final chlorination and dechlorination before…
Storm
Mount Vernon has a separate Stormwater Utility, created July 2020 at $4.00/month per Equivalent Residential Unit, raised to $5.00/ERU in January 2021 and $6.00/ERU in January 2022, where it remains. Residential landowners pay 1 ERU; commercial properties pay…
Sourcesverified
Compiled from the utility's own reports and public records, then independently re-checked against primary sources.
Main supplier in 1 ZIP code
Serves
Main water supplier in 1 ZIP code
- 43050 · Mount Vernon62% 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
Mount Vernon City does not buy water from another system on record; it treats its own source water.
2 systems on record buy water from Mount Vernon City: Gambier Village, Westgate Mobile Home Community.
What the records show about Mount Vernon City
Who runs it
EPA's record describes Mount Vernon City as owned by a local government. It has 7,348 service connections and serves 16,990 people.
EPA classes it as a community water system, one that serves the same residents all year.
Its office telephone on EPA's record is 740-393-9504.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
EPA's treatment table registers these steps for Mount Vernon City: chlorine dioxide, coagulation and settling, lime softening, 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's record shows no health-based violations for Mount Vernon City since 2015.
EPA logs 2 violations of any kind since 2020: 2 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records).
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 Mount Vernon City was 0 ppb, under both the current 15 ppb action level and the 10 ppb level that applies from 2027. A result of 0 means at least nine in ten of the homes sampled had no lead detected.
EPA has 4 sampling periods on file for Mount Vernon City since 2016, the first ending in 2018; 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 Mount Vernon City sent EPA, 6,728 lines are counted.
| Material | Lines |
|---|---|
| Lead | 0 |
| Galvanized, needing replacement | 242 |
| Unknown material | 4,267 |
| Not lead | 2,219 |
| All lines | 6,728 |
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 2 samples of the water entering the pipes of Mount Vernon City in 2024 and measured 29 PFAS. No PFAS was detected, PFOA and PFOS (federal limit 4 ng/L each) among them.
Ohio EPA's own statewide sampling tested 1 plant of Mount Vernon City (latest sample October 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 Mount Vernon City as sampled, most recently April 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 Mount Vernon City's samples in 2019, the last year it was sampled, was 0 µg/L. The worst yearly average was 0 µg/L and the highest single sample was 0 µg/L, from 39 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 0 µg/L. The worst yearly average was 0 µg/L and the highest single sample was 0 µg/L, from 39 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 0 µg/L (2019) | 0 µg/L | 0 µg/L | 39 |
| HAA5 | 60 µg/L | 0 µg/L | 0 µg/L | 0 µg/L | 39 |
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 was not detected in 8 samples through 2019 (limit 10 mg/L as nitrogen; above 10 is unsafe for infants).
Arsenic was not detected in 4 samples (limit 10 µg/L).
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 8 | not detected | 10 mg/L | 0 |
| Arsenic | 4 | not detected | 10 µg/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 4 samples each.
| Compound | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|
| Benzene | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Carbon tetrachloride | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| 1,2-dichloroethane | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Trichloroethylene (TCE) | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Tetrachloroethylene (PCE) | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Vinyl chloride | 2 µg/L | 4 | 0 of 4 | 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: barium in 2 of 3 samples, highest 21 µg/L (limit 2,000). Not detected: atrazine, alachlor, chromium, cadmium, mercury, selenium, and thallium, in 3 samples each.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 3 | 0 of 3 | not detected | 0 |
| Alachlor | Farm chemical | 2 µg/L | 3 | 0 of 3 | not detected | 0 |
| Chromium | Metal | 100 µg/L | 3 | 0 of 3 | not detected | 0 |
| Cadmium | Metal | 5 µg/L | 3 | 0 of 3 | not detected | 0 |
| Barium | Metal | 2,000 µg/L | 3 | 2 of 3 | 21 µg/L | 0 |
| Mercury | Metal | 2 µg/L | 3 | 0 of 3 | not detected | 0 |
| Selenium | Metal | 50 µg/L | 3 | 0 of 3 | not detected | 0 |
| Thallium | Metal | 2 µg/L | 3 | 0 of 3 | 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, 4 of 1,921 routine total coliform samples taken in the distribution system at Mount Vernon City tested positive (0.21%); in 2019, the last year on file, 0 of 241 did. E. coli was never found in the 4 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 Mount Vernon 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 0.27 mg/L.
EPA's treatment table lists no fluoridation step at Mount Vernon City.
Measured fluoride: 0.34 mg/L on average at the plant's entry points in 2018 (below the 0.7 mg/L target); samples ran from 0.24 to 0.34 mg/L across 3 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 2 UCMR 5 samples at Mount Vernon 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.
How well the service area is mapped
EPA estimated the service area of Mount Vernon City with a computer model rather than drawing it from the utility's map, so its edges are approximate.
Counting the people who live in the ZIP codes it overlaps, this atlas estimates 18,283 residents are inside the boundary, 108% of the 16,990 people Mount Vernon 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 — 1 ZIP code 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 OH4200812 (EPA ECHO).
Mount Vernon City's own pages: mtvernonoh.gov
Notable facts: mtvernonoh.gov, mtvernonoh.gov, mtvernonoh.gov
History: mtvernonoh.gov, mtvernonoh.gov, mountvernonnews.com, yourohionews.com
Water quality: mtvernonoh.gov
Planned work: mtvernonoh.gov, yourohionews.com
Capital projects: mtvernonoh.gov, mtvernonoh.gov, mtvernonoh.gov
Rates: mtvernonoh.gov, mtvernonoh.gov, mtvernonoh.gov, yourohionews.com
Sewers: mtvernonoh.gov, mtvernonoh.gov, yourohionews.com
Treatment: mtvernonoh.gov
Supply stress: mtvernonoh.gov
