Water system
Dayton Public Water System
EPA ID OH5703512 · Montgomery County · 141,407 people served · owned by a local government
Dayton Public Water System treats its own water from Great Miami Buried Valley Aquifer wells (recharged by Great Miami & Mad Rivers).
The system's record
- Aquifer
- Great Miami Buried Valley Aquifer
- Water bodies
- Great Miami River, Mad River
- Raw intakes
- Dayton Miami
Dayton Mad River - Active wells
- 105
- Serves
- 141,407 people · Montgomery County
- EPA ID
- OH5703512
About this area's water
Did you know
- The Great Miami Buried Valley Aquifer holds more than a trillion gallons and is the principal water source for an estimated 1.5 million people in southwest Ohio.
- Dayton recycles its own softening waste: a Lime Recovery Facility recalcines lime sludge from both plants back into usable lime, 36,533 tons of it in 2021.
- Each of Dayton's two plants is rated at 96 million gallons a day, yet the city pumped about 24.35 billion gallons in all of 2025, roughly a third of that capacity.
- Dayton's 1870 waterworks used a Holly system, an early direct-pumping fire-and-water design; it started up March 31, 1870, after voters approved it in 1869.
History5
- 1869-1870Dayton voters approved a municipal waterworks in 1869; a Holly direct-pumping system began operating March 31, 1870.
- 1929Dayton's Division of Water Reclamation began continuous operation, treating sewage before discharge to the Great Miami River.
- 1988U.S. EPA designated the Great Miami Buried Valley Aquifer, Dayton's sole water source, a Sole Source Aquifer in May 1988.
- 2016In April 2016 Dayton took production wells near Tait's Hill out of service over PFAS suspected from the city's own Fire Training Center.
- 2021The city sued Wright-Patterson Air Force Base and the Pentagon over PFAS contamination of its groundwater.
Treatment & pressure
How it is treated
Conventional lime (calcium oxide) softening, then pH adjustment with carbon dioxide, fluoridation, chlorine disinfection, and rapid sand filtration as the final step. A Lime Recovery Facility recalcines softening sludge from both plants back into usable lime.
Water pressure
Not published. Dayton runs 2 main and 11 booster pump stations and 16 storage facilities holding 88 million gallons, implying several zones, but no psi figure.
What it costs
$5.97 per 1,000 gallons
Effective Jan 1, 2026: $44.67 per 1,000 cubic feet on the first block, which is $5.97/1,000 gal, plus an $18.60 monthly minimum for a 5/8-inch meter.
Water quality & impurities7
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| PFOS (finished water, Ottawa plant) Average of monthly finished-water samples; range 5.45-13.67 ppt, above the 4 ppt MCL. | 8.81 ppt | 4 | 2025 |
| PFHxS (finished water, Ottawa plant) Range 6.70-23.32 ppt at Ottawa, above the 10 ppt MCL; Miami plant was below 2 ppt. | 13.53 ppt | 10 | 2025 |
| PFOA (finished water, Ottawa plant) Range under 2.0 to 4.5 ppt; average below the MCL. Miami plant non-detect. | 2.97 ppt | 4 | 2025 |
| Lead (90th percentile) 0 of 54 samples above the action level; lead was not detected in most samples. | <3.0 ppb | 15 | 2023 |
| Copper (90th percentile) 0 of 54 samples above the 1.3 ppm action level. | 0.044 ppm | 1.3 | 2023 |
| Total trihalomethanes (TTHM) Highest running annual average in the distribution system; range 17.9-41.5 ppb. | 28.83 ppb | 80 | 2025 |
| Nitrate Highest at the Miami plant; Ottawa reached 1.44 ppm. Well under the limit. | 1.71 ppm | 10 | 2025 |
EPA compliance record
Lead at the tap: 90th-percentile result 0 ppb in 2023 (action level 15 ppb).
EPA record: no health-based violations since 2015.
Projects & plans6
Recent and current work
- Lime Recovery Facility recalcination · 2021 · completed
Reclaims lime from softening residuals at both plants; produced 36,533 tons of recovered lime in 2021. - Tait's Hill production well removal · 2016 · completed
City proactively took wells near its Fire Training Center out of service over suspected PFAS contamination. - Renewable natural gas from digester biogas · 2024 · completed
Since November 2024 biogas from the Water Reclamation Plant's anaerobic digesters is cleaned and injected into gas pipelines.
Planned or needed
- PFAS removal facility and treatment plant retrofit · 2024 · planned
City estimates $300M-$500M for PFAS remediation and management; a Shook contract is reportedly about $350M. - PFAS treatment pilot and plant upgrades · planned
EPA pilot treatment project underway; part-funded by 0% Ohio EPA loans with principal forgiveness the city says will not raise water rates. - Wright-Patterson AFB remediation request · 2024 · proposed
An October 2024 letter asked the base to remediate PFAS; the city had already sued the base and the Pentagon in 2021.
Supply stress
PFAS from firefighting foam is the binding constraint: Ottawa plant finished water averaged 8.81 ppt PFOS and 13.53 ppt PFHxS in 2025, over the 4 and 10 ppt MCLs. Quantity is not a concern - the aquifer holds over a trillion gallons and is river-recharged - but treatment will cost hundreds of millions.
Sewers
Sanitary
Dayton's Division of Water Reclamation has run continuously since 1929; the plant is rated 72 MGD and discharges to the Great Miami River at river mile 76.1, serving about 340,000 people including parts of Greene County and Wright-Patterson AFB. About 765 miles of sanitary sewer.
Storm
A separate MS4 storm system of over 400 miles of storm sewers, run by the city's Sewer Maintenance Bureau alongside 28 pumping stations. No stormwater utility fee was found published.
Sourcesverified
Compiled from the utility's own reports and public records, then independently re-checked against primary sources.
Main supplier in 12 ZIP codes
Serves
Main water supplier in 12 ZIP codes
- 45402 · Dayton100% of residents
- 45403 · Dayton100% of residents
- 45410 · Dayton100% of residents
- 45423 · Dayton100% of residents
- 45428 · Dayton100% of residents
- 45469 · Dayton100% of residents
- 45406 · Dayton86% of residents
- 45405 · Dayton67% of residents
- 45404 · Dayton67% of residents
- 45417 · Dayton61% of residents
- 45420 · Dayton59% of residents
- 45409 · Dayton53% of residents
Also present in 9 more ZIP codes
- 45432 · Beavercreek and Dayton25% of residents
- 45419 · Oakwood and Dayton20% of residents
- 45315 · Clayton14% of residents
- 45424 · Huber Heights and Dayton14% of residents
- 45414 · Harrison Township and Dayton13% of residents
- 45431 · Beavercreek and Dayton9% of residents
- 45416 · Trotwood and Dayton0% of residents
- 45439 · Moraine and Dayton0% of residents
- 45322 · Englewood0% 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
Dayton Public Water System does not buy water from another system on record; it treats its own source water.
7 systems on record buy water from Dayton Public Water System: Brookville Municipality, Dayton Va Bldg 320 Pod A, Dayton Va Bldg 410, Greene County - Kitridge, Montgomery County Water Services 1, Montgomery County Water Services 2, Trotwood City.
What the records show about Dayton Public Water System
Who runs it
EPA's record describes Dayton Public Water System as owned by a local government. It has 50,351 service connections and serves 141,407 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 937-333-6099.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
EPA's treatment table registers these steps for Dayton Public Water System: 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 Dayton Public Water System since 2015.
EPA logs no violations of any kind for Dayton Public Water System since 2020.
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 2023, the 90th-percentile lead result at Dayton Public Water System 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 4 ppb, in the period ending December 2020.
EPA has 3 sampling periods on file for Dayton Public Water System since 2016, the first ending in 2017; 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 Dayton Public Water System sent EPA, 64,726 lines are counted.
| Material | Lines |
|---|---|
| Lead | 9,393 |
| Galvanized, needing replacement | 527 |
| Unknown material | 4 |
| Not lead | 54,802 |
| All lines | 64,726 |
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 9 samples of the water entering the pipes of Dayton Public Water System in 2023 and measured 29 PFAS.
The highest PFOA or PFOS result, 10 ng/L, is at or above the federal limit of 4 ng/L that EPA set in 2024. Systems have until 2029 to comply, and in May 2026 EPA proposed letting systems apply for two more years. One sample over the limit is not a violation: compliance is judged on a running annual average.
The highest PFAS results were PFOS 10 ng/L, PFHxS 9.8 ng/L, and PFPeA 4.6 ng/L.
The highest PFOA or PFOS result was measured at Ottawa TP.
The system reported potential PFAS sources near its supply.
Ohio EPA's own statewide sampling tested 2 plants of Dayton Public Water System (latest sample February 2021). The highest result was PFHxS at 7.7 ppt (ppt is the same unit as ng/L), against Ohio's action level of 140 ppt. Those action levels are the ones Ohio EPA used for the survey; the 2024 federal limit for PFOA and PFOS is 4 ng/L.
Ohio EPA's current sampling status map lists 2 plants of Dayton Public Water System as sampled, most recently April 2026.
| Compound | Highest result | Federal limit |
|---|---|---|
| PFOA | not detected | 4 ng/L |
| PFOS | 10 ng/L | 4 ng/L |
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 Dayton Public Water System's samples in 2019, the last year it was sampled, was 23.4 µg/L. The worst yearly average was 25.2 µg/L and the highest single sample was 46.9 µg/L, from 197 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 1.2 µg/L. The worst yearly average was 6 µg/L and the highest single sample was 21.3 µg/L, from 168 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 23.4 µg/L (2019) | 25.2 µg/L | 46.9 µg/L | 197 |
| HAA5 | 60 µg/L | 1.2 µg/L | 6 µg/L | 21.3 µg/L | 168 |
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 260 samples was 1.9 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 31 samples (limit 10 µg/L).
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 260 | 1.9 mg/L | 10 mg/L | 0 |
| Arsenic | 31 | 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.
EPA's file lumps the entry-point samples of all 2 plants of Dayton Public Water System together, so a result over a limit may come from a plant that serves a different part of town.
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. trichloroethylene (TCE) was detected in 1 of 98 samples, highest 1.06 µg/L (limit 5). Benzene, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethylene, and vinyl chloride were not detected in 98 samples each.
| Compound | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|
| Benzene | 5 µg/L | 98 | 0 of 98 | not detected | 0 |
| Carbon tetrachloride | 5 µg/L | 98 | 0 of 98 | not detected | 0 |
| 1,2-dichloroethane | 5 µg/L | 98 | 0 of 98 | not detected | 0 |
| Trichloroethylene (TCE) | 5 µg/L | 98 | 1 of 98 | 1.06 µg/L | 0 |
| Tetrachloroethylene (PCE) | 5 µg/L | 98 | 0 of 98 | not detected | 0 |
| Vinyl chloride | 2 µg/L | 98 | 0 of 98 | 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 31 of 33 samples, highest 94.2 µg/L (limit 2,000). Not detected: atrazine in 18 samples, alachlor in 18 samples, chromium in 31 samples, cadmium in 31 samples, mercury in 22 samples, selenium in 28 samples, thallium in 22 samples.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 18 | 0 of 18 | not detected | 0 |
| Alachlor | Farm chemical | 2 µg/L | 18 | 0 of 18 | not detected | 0 |
| Chromium | Metal | 100 µg/L | 31 | 0 of 31 | not detected | 0 |
| Cadmium | Metal | 5 µg/L | 31 | 0 of 31 | not detected | 0 |
| Barium | Metal | 2,000 µg/L | 33 | 31 of 33 | 94.2 µg/L | 0 |
| Mercury | Metal | 2 µg/L | 22 | 0 of 22 | not detected | 0 |
| Selenium | Metal | 50 µg/L | 28 | 0 of 28 | not detected | 0 |
| Thallium | Metal | 2 µg/L | 22 | 0 of 22 | not detected | 0 |
Non-detects count as zero in the highest-result column.
EPA's file lumps the entry-point samples of all 2 plants of Dayton Public Water System together, so a result over a limit may come from a plant that serves a different part of town.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.
Bacteria in the pipes
From 2012 to 2019, 37 of 12,062 routine total coliform samples taken in the distribution system at Dayton Public Water System tested positive (0.31%); in 2019, the last year on file, 1 of 1,502 did. E. coli was found in 1 of 38 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 Dayton Public Water System adjusts the fluoride level to the recommended level for preventing tooth decay.
EPA's treatment table lists fluoridation among the steps at Dayton Public Water System.
Measured fluoride: 0.88 mg/L on average at the plant's entry points in 2019 (in the range dentists aim for); samples ran from 0.84 to 1 mg/L across 16 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 8 UCMR 5 samples at Dayton Public Water System, last sampled in 2023 (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.
No microcystin was detected in the 164 raw-water samples.
Microcystin was never detected in treated water (199 samples).
In all, 363 samples from 2016 to 2026, the latest on May 19, 2026.
| Water | Samples | Detections | Highest result |
|---|---|---|---|
| Raw water, at the intake | 164 | 0 | not detected |
| Treated water | 199 | 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 Dayton Public Water System for a household using 5,000 gallons a month at $212 a year, about $18 a month.
The sewer bill in the same survey is $301 a year at 5,000 gallons a month.
| Use | Water, per year | Sewer, per year |
|---|---|---|
| 2,500 gallons a month | $212 | $196 |
| 5,000 gallons a month | $212 | $301 |
| 8,000 gallons a month | $212 | $427 |
The survey lists it as “Dayton”. 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 Dayton Public Water System comes from the utility's own map.
Counting the people who live in the ZIP codes it overlaps, this atlas estimates 137,948 residents are inside the boundary, 98% of the 141,407 people Dayton Public Water System 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 — 21 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 OH5703512 (EPA ECHO).
Dayton Public Water System's own pages: daytonohio.gov, daytonohio.gov, daytonohio.gov
