Water system
Mid-ohio WSD - Chrisman Avenue WTP
EPA ID OH4900712 · Madison County · 10,256 people served · owned by a local government
Mid-ohio WSD - Chrisman Avenue WTP treats its own water from Local glacial sand-and-gravel wells (Madison County).
The system's record
- Active wells
- 6
- Serves
- 10,256 people · Madison County
- EPA ID
- OH4900712
About this area's water
Did you know
- London softens its water with lime — the 2025 CCR runs a photo of the plant's lime softening contact tanks.
- Cyanide is on London's list of detected contaminants, at 7 ppb against a 200 ppb limit — about a 29th of the MCL.
- Arsenic in London's water runs at 5 ppb, exactly half the federal limit, in a state where most groundwater systems report a fraction of that.
- The district's proposed new regional water plant is budgeted at $60-90 million for construction-management services alone, before design, land or permits.
- Board meetings for a London water system are held in Plain City, at the village's municipal building on the first and third Tuesday of each month.
History6
- 2023-2024The City of London's water and sewer systems transferred to the Mid-Ohio Water and Sewer District, which has issued London City PWS consumer confidence reports since the 2023 report. Trustees have…
- 2022-07London City PWS had an E. coli MCL violation; a public notice was issued at the time, but the district failed to include it in the 2022 CCR as required — one of four CCR content deficiencies (2017…
- 2023-07London failed to collect well water samples for E. coli after a routine total coliform positive in the distribution system; a public notice was issued. One Level 1 assessment and three corrective…
- 2024-01The Village of Plain City formally transferred control of its water and sewer services, including billing, to Mid-Ohio WSD.
- 2025-07-01London City PWS missed the federal deadline for annual Service Line Materials Notifications, sending inadequate and incorrect notices — a reporting violation under 40 CFR 141.85 and 141.90.
- 2025-09-18Mid-Ohio corrected the Service Line Inventory and distributed proper notifications to the right residents, resolving the violation.
Treatment & pressure
How it is treated
Groundwater from a wellfield in a shallow glacial sand-and-gravel (buried valley) aquifer, treated by lime softening — the 2025 CCR carries a photograph captioned 'London's lime softening contact tanks' — followed by chlorination (total chlorine 1.08 mg/L in 2025) and fluoridation (0.96 ppm).…
Source: midohiowsd.gov
Water pressure
Not published — no psi figure appears in the London City CCR, the district's fee schedule, its capital projects page, or the board minutes reviewed.
Source: midohiowsd.govmidohiowsd.gov
What it costs
$9.96 per 1,000 gallons
Typical household bill about $48 a month for water.
From the Mid-Ohio WSD 'Water and Sanitary Sewer Fee Schedule - 2024,' the current schedule linked from the district's Fee Schedule page (which notes only that tap fees changed in…
Water quality & impurities10
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Arsenic Range 2.0-5.0 ppb — half the MCL, and notably higher than most Ohio groundwater systems. MCLG is zero. | 5 ppb | 10 | 2025 |
| Total Trihalomethanes (TTHM) Range 0.7-39.9 ppb. | 24.8 ppb | 80 | 2025 |
| Haloacetic Acids (HAA5) Range 0.0-9.3 ppb. | 5.3 ppb | 60 | 2025 |
| Total chlorine Range 0.6-1.6 mg/L. | 1.08 mg/L | 4 (MRDL) | 2025 |
| Fluoride Range 0.94-1.10 ppm; includes added fluoride. | 0.96 ppm | 4 | 2024 |
| Cyanide Range 7.0-7.0 ppb; CCR attributes it to discharge from plastic, fertilizer and steel/metal factories. | 7 ppb | 200 | 2024 |
| Barium Range 0.0059-0.0059 ppm. | 0.0059 ppm | 2 | 2024 |
| Chromium Range 0.9-0.9 ppb. | 0.9 ppb | 100 | 2024 |
| Lead (90th percentile) Zero of 20 samples exceeded the action level. The printed unit and value are internally inconsistent in the CCR table… | 0.002 ppm (the… | 15 ppb (action… | 2025 |
| Copper (90th percentile) Zero of 20 samples exceeded the action level. The CCR's copper row is garbled in the published PDF (the 90th-percentile… | 0.086 ppm | 1.3 (action… | 2025 |
Source: midohiowsd.gov
EPA compliance record
Lead at the tap: 90th-percentile result 2.1 ppb in 2025 (action level 15 ppb).
EPA health-based violations since 2015:
- 2022Revised Total Coliform Rule · E. coli limit exceeded · returned to compliance
7 violations of any kind logged since 2020: 1 for required testing that was missed or reported late; 5 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records); 1 health-based.
Projects & plans10
Recent and current work
- New regional water treatment plant (5 MGD, CMAR delivery) · 2026 · proposed
RFQ issued 2026-05-03; CMAR to be contracted by June 30, 2026. Nominal capacity 5 MGD, technology still in alternatives analysis (lime softening or membranes… - Plain City water plant renovation and additional well · 2026 · planned
District capital plan (updated June 3, 2025): renovation operational by September 2026, new well operational February 2026. Serves the Plain City PWS, not…
Source: midohiowsd.govmidohiowsd.govmidohiowsd.gov
Planned or needed
- SR 161 water transmission line and water tower · 2026 · planned
Transmission line May 2026-May 2027; tower April 2026-April 2027. Cost not published. - Water District water treatment plant expansion · 2027 · planned
Operational November 2027. Serves the district's Water District 1 system. Cost not published. - Northeastern new water treatment facility · 2027 · planned
Construction January 2027-January 2029. Cost not published. - Central new water treatment facility · 2027 · planned
Construction July 2027-July 2029. Cost not published. - Regional Water Reclamation Facility · 2028 · planned
Sewer project; target online and operational June 2028. Cost not published. - London Gateway sanitary sewer, Phase 1 · 2026 · planned
Construction April-October 2026, on the London side of the system. Cost not published. - US 42 force main sewer to the regional WRF · 2026 · planned
Construction August 2026-February 2028. Cost not published. - US 40 sanitary sewer (SR 56 to US 42) · 2026 · planned
Construction August 2026-February 2028. Cost not published.
Source: midohiowsd.govmidohiowsd.gov
Supply stress
The documented risk is aquifer vulnerability, not shortage. Ohio EPA's source water study rates the aquifer supplying London as HIGHLY SUSCEPTIBLE to contamination, on three grounds: a relatively thin protective clay layer over the uppermost sand and gravel aquifer, a shallow aquifer depth of less than 75 feet below ground surface, and…
Sewers
Sanitary
Mid-Ohio WSD provides sanitary sewer as well as water across its Madison County service area, and operates the London wastewater treatment plant (used as a board meeting location). Sewer is metered off the drinking water meter reading. London Service Area residential sewer: $13.48 monthly minimum plus $5.82 per 1,000 gallons. Outside the…
Storm
Not documented — no stormwater utility, fee, or program appears in the district's fee schedule, capital projects page, or board minutes reviewed. The district's predecessor entity in Madison County was the Madison County Sanitary and Stormwater District, but…
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
- 43140 · London50% 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
Mid-ohio WSD - Chrisman Avenue WTP does not buy water from another system on record; it treats its own source water.
No other system is on record buying water from Mid-ohio WSD - Chrisman Avenue WTP.
What the records show about Mid-ohio WSD - Chrisman Avenue WTP
Who runs it
EPA's record describes Mid-ohio WSD - Chrisman Avenue WTP as owned by a local government. It has 4,302 service connections and serves 10,256 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 740-412-2479.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
EPA's treatment table registers these steps for Mid-ohio WSD - Chrisman Avenue WTP: coagulation and settling, chlorine disinfection, fluoridation, 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 counts 1 health-based violation for Mid-ohio WSD - Chrisman Avenue WTP since 2015. Health-based means a contaminant above its legal limit or a required treatment step not carried out. It falls into 1 separate problem (one contaminant or rule in one year); the table lists it.
EPA logs 7 violations of any kind since 2020: 1 for required testing that was missed or reported late; 5 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records); 1 health-based.
| Year | Contaminant or rule | Kind | Measured | Limit | Status in EPA's record |
|---|---|---|---|---|---|
| 2022 | Revised Total Coliform Rule | E. coli limit exceeded | 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 Mid-ohio WSD - Chrisman Avenue WTP was 2.1 ppb, under both the current 15 ppb action level and the 10 ppb level that applies from 2027.
EPA has 4 sampling periods on file for Mid-ohio WSD - Chrisman Avenue WTP 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 Mid-ohio WSD - Chrisman Avenue WTP sent EPA, 4,133 lines are counted.
| Material | Lines |
|---|---|
| Lead | 0 |
| Galvanized, needing replacement | 39 |
| Unknown material | 1,128 |
| Not lead | 2,966 |
| All lines | 4,133 |
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 Mid-ohio WSD - Chrisman Avenue WTP in 2023 to 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 Mid-ohio WSD - Chrisman Avenue WTP (latest sample August 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 Mid-ohio WSD - Chrisman Avenue WTP as sampled, most recently July 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 Mid-ohio WSD - Chrisman Avenue WTP's samples in 2019, the last year it was sampled, was 22.1 µg/L. The worst yearly average was 31.1 µg/L and the highest single sample was 32.8 µg/L, from 15 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 0 µg/L. The worst yearly average was 38.5 µg/L and the highest single sample was 40.8 µg/L, from 15 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 22.1 µg/L (2019) | 31.1 µg/L | 32.8 µg/L | 15 |
| HAA5 | 60 µg/L | 0 µg/L | 38.5 µg/L | 40.8 µg/L | 15 |
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 8 samples was 0.47 mg/L (as nitrogen) in 2012; in 2019, the last year sampled, nitrate was not detected. No sample was over the limit of 10 mg/L. Nitrate above 10 is unsafe for infants.
Arsenic: the highest of 18 samples was 11.5 µg/L (limit 10); detections averaged 6.8; 1 over the limit.
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 8 | 0.47 mg/L | 10 mg/L | 0 |
| Arsenic | 18 | 11.5 µg/L | 10 µg/L | 1 |
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 3 samples each.
| Compound | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|
| Benzene | 5 µg/L | 3 | 0 of 3 | not detected | 0 |
| Carbon tetrachloride | 5 µg/L | 3 | 0 of 3 | not detected | 0 |
| 1,2-dichloroethane | 5 µg/L | 3 | 0 of 3 | not detected | 0 |
| Trichloroethylene (TCE) | 5 µg/L | 3 | 0 of 3 | not detected | 0 |
| Tetrachloroethylene (PCE) | 5 µg/L | 3 | 0 of 3 | not detected | 0 |
| Vinyl chloride | 2 µg/L | 3 | 0 of 3 | 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. Not detected: atrazine in 2 samples, alachlor in 2 samples, chromium in 3 samples, cadmium in 3 samples, barium in 3 samples, mercury in 3 samples, selenium in 3 samples, thallium in 3 samples.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 2 | 0 of 2 | not detected | 0 |
| Alachlor | Farm chemical | 2 µg/L | 2 | 0 of 2 | 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 | 0 of 3 | not detected | 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, 10 of 963 routine total coliform samples taken in the distribution system at Mid-ohio WSD - Chrisman Avenue WTP tested positive (1.04%); in 2019, the last year on file, 0 of 121 did. E. coli was found in 1 of 15 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 Mid-ohio WSD - Chrisman Avenue WTP adjusts the fluoride level to the recommended level for preventing tooth decay.
EPA's treatment table lists fluoridation among the steps at Mid-ohio WSD - Chrisman Avenue WTP.
Measured fluoride: 0.8 mg/L on average at the plant's entry points in 2018 (in the range dentists aim for); samples ran from 0.8 to 1.15 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 found in 2 of 2 UCMR 5 samples at Mid-ohio WSD - Chrisman Avenue WTP, highest 12 µg/L; detections averaged 10.8, last sampled in 2024.
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 Mid-ohio WSD - Chrisman Avenue WTP 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 12,123 residents are inside the boundary, 118% of the 10,256 people Mid-ohio WSD - Chrisman Avenue WTP 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 OH4900712 (EPA ECHO).
Mid-ohio WSD - Chrisman Avenue WTP's own pages: dam.assets.ohio.gov, midohiowsd.gov
Notable facts: midohiowsd.gov, midohiowsd.gov, midohiowsd.gov
History: midohiowsd.gov, midohiowsd.gov, plaincityohio.gov, midohiowsd.gov
Water quality: midohiowsd.gov
Planned work: midohiowsd.gov, midohiowsd.gov
Water pressure: midohiowsd.gov, midohiowsd.gov
Capital projects: midohiowsd.gov, midohiowsd.gov, midohiowsd.gov
Rates: midohiowsd.gov, midohiowsd.gov, midohiowsd.gov
Sewers: midohiowsd.gov, midohiowsd.gov, midohiowsd.gov
Treatment: midohiowsd.gov
Supply stress: midohiowsd.gov, midohiowsd.gov, midohiowsd.gov
