Water system
Ada Village
EPA ID OH3300012 · Hardin County · 5,334 people served · owned by a local government
Ada Village treats its own water from Groundwater wells (3 wells).
The system's record
- Active wells
- 3
- Serves
- 5,334 people · Hardin County
- EPA ID
- OH3300012
About this area's water
Did you know
- Ada's sewage plant flow drops by more than 40% when Ohio Northern University lets out for the summer — roughly 1.0 million gallons a day with students in session against 0.59 million without — so the plant was designed…
- Probably more than a hundred abandoned wells puncture the confining layer above Ada's aquifer, each one a direct pathway from the ground surface down to the village's drinking water.
- Among the 33 potential contaminant sources Ada has mapped inside its wellhead protection area is a football factory: Ada is home to the only plant in the United States that makes leather footballs.
- Meter-pit inspections and excavations confirmed Ada's distribution system has no lead, no galvanized pipe requiring replacement, and no unknown-material service lines at all.
- Ada was platted as 'Johnstown' in 1853 and took its present name from its post office, which was named after the postmaster's daughter.
History6
- 1853Village platted as 'Johnstown' by S. M. Johnson.
- 1850sA post office was established as the Ada Post Office, named after the postmaster's daughter Ada, and the village took that name.
- 1871Ohio Normal School, now Ohio Northern University, founded by Henry Solomon Lehr — eighteen years after Ada was first settled — driving the village's growth.
- 1910President William Howard Taft delivered Ohio Northern's fall commencement address in Ada; he remains the only sitting U.S. president to visit the village.
- 1955Ada's first activated-sludge wastewater treatment plant built, designed for an annual average flow of 860,000 gallons per day.
- 1996Village adopted its 'Wellhead Protection Education and Management Plan,' prepared in April by S.A. Smith Consulting Services and endorsed by Ohio EPA that year.
Treatment & pressure
How it is treated
Three wells at the water treatment plant draw from the carbonate aquifer beneath Ada; water in that aquifer generally stands 20 to 40 feet below the ground surface. The well water is aerated, softened, stabilized, filtered, chlorinated and fluoridated before being pumped into the distribution…
Source: adaoh.gov
Water pressure
Not published — no psi figures, pressure zones, storage volumes, or main mileage appear in the 2025 CCR or anywhere on the village website.
What it costs
Ada publishes no water or sewer rate schedule. The village's ordinance and resolution indices covering 2020 through 2026 contain no water or sewer rate ordinance — the only…
Water quality & impurities10
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Total Chlorine Range 2.0-2.2 ppm; disinfectant residual. | 2.1 ppm | 4 (MRDL) | 2025 |
| Total Trihalomethanes (TTHM) Range 30.1-47.0 ppb — the closest any Ada result comes to its limit, at about 59% of the MCL. | 47 ppb | 80 | 2025 |
| Haloacetic Acids (HAA5) Range 4.7-5.6 ppb; disinfection byproduct. | 5.6 ppb | 60 | 2025 |
| Fluoride Range 0.9-1.1 ppm; naturally occurring plus water additive. | 0.99 ppm | 4 | 2025 |
| Nitrate About 3% of the limit — very low for an agricultural county. | 0.297 ppm | 10 | 2025 |
| Barium Monitored less than annually because levels change slowly; well below the limit. | 0.0089 ppm | 2 | 2021 |
| Cyanide Discharge from plastic, fertilizer and steel/metal factories; 0.5% of the limit. | 1 ppb | 200 | 2024 |
| Lead Zero individual results over the action level; 0 of 20 samples exceeded it. The village reports no lead… | 0.2 (90th… ppb | 15 (Action… | 2025 |
| Copper Zero individual results over the action level; 0 of 20 samples exceeded it. | 0.006 (90th… ppm | 1.3 (Action… | 2025 |
| Lithium Range 45.7-45.8 ppb; detected under EPA's unregulated contaminant monitoring, which exists to help decide whether… | 45.8 ppb | unregulated (no… | 2023 |
Source: adaoh.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 & plans3
Recent and current work
- Wastewater treatment plant liquid-stream replacement · $14 million · 2015 · completed
Funded by a 20-year Water Pollution Control Loan Fund loan of $14,200,000, with design fees on a separate loan. Jones & Henry Engineers replaced the 1955… - Service line material verification · 2025 · completed
Village staff used historical records and water line installation dates to narrow the undocumented service lines, then field-verified the remainder through… - Drinking Water Source Protection Plan revision · 2024 · completed
The April 1996 'Wellhead Protection Education and Management Plan' by S.A. Smith Consulting Services, endorsed by Ohio EPA in 1996, was revised into a Drinking…
Supply stress
Ada's wellfield draws from a carbonate aquifer that Ohio EPA and the village's own assessment rate as highly susceptible to contamination, for three stated reasons: water in the aquifer stands only 20 to 40 feet below the ground surface; probably more than 100 unused wells within the protection area breach the confining layer and provide…
Source: adaoh.gov
Sewers
Sanitary
The Ada WWTP (Ohio NPDES permit 2PB00050*ND) sits on about five acres bordered by a railroad, Grass Run Creek and County Road 44, and discharges to Grass Run Creek. A 1955 activated-sludge plant designed for 860,000 gpd was replaced under a $14.2 million WPCLF-funded project; the new liquid stream — designed for 2.0 mgd average flow, 6.0…
Storm
Not documented — the village publishes no stormwater utility, fee, or drainage plan. Its Ohio EPA reporting is for sanitary sewer overflows rather than combined sewer overflows, which indicates a separate sanitary system.
Main supplier in 1 ZIP code
Serves
Main water supplier in 1 ZIP code
- 45810 · Ada66% 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
Ada Village does not buy water from another system on record; it treats its own source water.
No other system is on record buying water from Ada Village.
What the records show about Ada Village
Who runs it
EPA's record describes Ada Village as owned by a local government. It has 1,848 service connections and serves 5,334 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 2025. Its office telephone on EPA's record is 419-634-4045.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
EPA's treatment table registers these steps for Ada Village: aeration, corrosion control, 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's record shows no health-based violations for Ada Village 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 Ada Village 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.
The highest result on file is 0.6 ppb, in the period ending December 2022.
EPA has 4 sampling periods on file for Ada Village 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 Ada Village sent EPA, 1,845 lines are counted.
| Material | Lines |
|---|---|
| Lead | 0 |
| Galvanized, needing replacement | 0 |
| Unknown material | 0 |
| Not lead | 1,845 |
| All lines | 1,845 |
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 Ada Village in 2023 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 Ada Village (latest sample September 2020). Not one of the six PFAS tested (PFOA, PFOS, PFHxS, PFNA, GenX and PFBS) was detected.
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 Ada Village's samples in 2019, the last year it was sampled, was 38 µg/L. The worst yearly average was 45.8 µg/L and the highest single sample was 53.6 µg/L, from 13 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 14.2 µg/L. The worst yearly average was 14.2 µg/L and the highest single sample was 28.5 µg/L, from 13 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 38 µg/L (2019) | 45.8 µg/L | 53.6 µg/L | 13 |
| HAA5 | 60 µg/L | 14.2 µg/L | 14.2 µg/L | 28.5 µg/L | 13 |
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 0.25 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 was not detected in 3 samples (limit 10 µg/L).
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 8 | 0.25 mg/L | 10 mg/L | 0 |
| Arsenic | 3 | 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 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, alachlor, chromium, cadmium, barium, 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 | 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, 1 of 685 routine total coliform samples taken in the distribution system at Ada Village tested positive (0.15%); in 2019, the last year on file, 0 of 90 did. E. coli was never found in the 1 sample 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 Ada Village adjusts the fluoride level to the recommended level for preventing tooth decay.
EPA's treatment table lists fluoridation among the steps at Ada Village.
Measured fluoride: 0.88 mg/L on average at the plant's entry points in 2018 (in the range dentists aim for); samples ran from 0.87 to 1 mg/L across 4 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 Ada Village, highest 45.8 µg/L; detections averaged 45.8, last sampled in 2023.
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.
Water and sewer bills
Ohio EPA's 2023 rate survey puts the water bill at Ada Village for a household using 5,000 gallons a month at $475 a year, about $40 a month.
The sewer bill in the same survey is $692 a year at 5,000 gallons a month.
| Use | Water, per year | Sewer, per year |
|---|---|---|
| 2,500 gallons a month | $256 | $536 |
| 5,000 gallons a month | $475 | $692 |
| 8,000 gallons a month | $738 | $880 |
The survey lists it as “Ada”. 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
EPA estimated the service area of Ada Village 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 5,208 residents are inside the boundary, 98% of the 5,334 people Ada Village 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 OH3300012 (EPA ECHO).
Notable facts: adaoh.gov, adaoh.gov, en.wikipedia.org
History: en.wikipedia.org, adaoh.gov, adaoh.gov
Water quality: adaoh.gov
Water pressure: adaoh.gov, adaoh.gov
Capital projects: adaoh.gov, adaoh.gov, adaoh.gov
Sewers: adaoh.gov, adaoh.gov, adaoh.gov
Treatment: adaoh.gov
Supply stress: adaoh.gov
