Water system
Fairfield City
EPA ID OH0900715 · Butler County · 44,907 people served · owned by a local government
Fairfield City treats its own water from Great Miami Buried Valley Aquifer (wells).
The system's record
- Aquifer
- Great Miami Buried Valley Aquifer
- Active wells
- 6
- Serves
- 44,907 people · Butler County
- EPA ID
- OH0900715
6 deep wells draw from the Great Miami Buried Valley Aquifer; Fairfield participates in the Hamilton-to-New Baltimore Groundwater Consortium protecting this shared aquifer.
About this area's water
Did you know
- The plant pumped and treated over 2 billion gallons in 2025 from just six deep wells tapping sand and gravel that glaciers laid down more than 10,000 years ago.
- Lead is barely an issue here: the city reports no known lead water service lines or mains, and the 2025 90th-percentile result was 2.4 ppb against a 15 ppb action level.
- Fairfield keeps emergency interconnections with Butler County, Cincinnati and Hamilton, and used the Butler County one in 2025 for 1,518,554 gallons.
- The plant's original 1956 ion-exchange softening was retired as two-stage lime softening phased in between 1983 and 2000, lifting lime capacity to 9.1 MGD.
History5
- 1956Original water treatment plant built on Groh Lane with 750,000 gallons-per-day capacity.
- 1963Plant doubled in size, raising production to 1.5 MGD.
- 1983First lime-softening phase added: two solid-contact clarifiers of 2.5 MGD each.
- 1998-2000Second lime-softening phase adds two more 2.5 MGD clarifiers, lime-plant capacity reaches 9.1 MGD, and the ion-exchange train is dismantled.
- 2025City activates an emergency interconnection with Butler County, flowing 1,518,554 gallons into the Fairfield system.
Treatment & pressure
How it is treated
Six deep wells draw the Great Miami Buried Valley Aquifer; water is aerated to strip CO2, lime-softened in solid-contact clarifiers, pH-adjusted by recarbonation, disinfected with sodium hypochlorite, filtered, fluoridated, and held in a clear well.
Water pressure
Not published. No psi figure or zone map found; the city describes about 200 miles of main with storage towers, pump stations and pressure regulators.
What it costs
$5.41 per 1,000 gallons
3/4-inch meter: $17.70/month minimum covers 3,000 gal, then $5.41/1,000 gal. Sewer is $20.67 plus $6.89/1,000 gal; trash $16.13/month.
Water quality & impurities8
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| TTHM (total trihalomethanes) Range 25.0-27.9 ppb, about a third of the limit. | 27.9 ppb | 80 | 2025 |
| HAA5 (haloacetic acids) Range 2.4-3.8 ppb; very low for a chlorinated supply. | 3.8 ppb | 60 | 2025 |
| Lead (90th percentile) 60 homes sampled; 2 individual results over the AL, 90th percentile well under it. | 2.4 ppb | 15 (action… | 2025 |
| Copper (90th percentile) Zero of 60 samples over the action level. | 0.024 ppm | 1.3 (action… | 2025 |
| Nitrate Well under the MCL; background nitrate is one marker of aquifer vulnerability. | 1.28 ppm | 10 | 2025 |
| Fluoride Added to promote strong teeth; range 0.65-1.14 ppm. | 1.14 ppm | 4 | 2025 |
| HFPO-DA (GenX) UCMR5 detection; PFOA and PFOS both under 4 ppt, below the reporting limit. | 5.7 ppt | 10 (EPA MCL) | 2023-202… |
| Nickel Unregulated, no MCL; sits just under EPA's lifetime health advisory level. | 0.091 ppm | 0.1 (lifetime… | 2023 |
EPA compliance record
Lead at the tap: 90th-percentile result 0 ppb in 2026 (action level 15 ppb).
EPA record: no health-based violations since 2015.
Supply stress
Sole source is the Great Miami Buried Valley Aquifer, which Ohio EPA calls highly susceptible: no protective clay cap, shallow water, nearby contaminant sources, low background nitrate. Fairfield activated an emergency Butler County interconnection in 2025, importing 1.5 million gallons.
Sewers
Sanitary
The City of Fairfield provides wastewater service as well as water; sewer is billed at a $20.67 monthly minimum for 3,000 gal plus $6.89/1,000 gal. Plant name, capacity, receiving stream, CSO status and any consent decree were not confirmed.
Storm
Not confirmed. No separate stormwater utility fee appears on the city's utility rate schedule, which lists only water, sewer and trash charges.
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
- 45014 · Fairfield88% of residents
Also present in 1 more ZIP code
- 45011 · Liberty Township and Hamilton1% 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
Fairfield 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 Fairfield City.
On the map
Show this system's territory on the map — 2 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
Fairfield City's own pages: fairfield-city.org, data.epa.gov, hamilton-oh.gov