Water system
Wilmington City
EPA ID OH1401211 · Clinton County · 12,401 people served · owned by a local government
Wilmington City treats its own water from Caesar Creek Lake (with Burtonville reservoirs/Cowan Creek as backup).
The system's record
- Water bodies
- Caesar Creek Lake, Burtonville Reservoirs (Cowan Creek)
- Raw intakes
- Wilmington Caesar Lake Inta
Wilmington Reservoir
Wilmington Cowan Creek Inta - Serves
- 12,401 people · Clinton County
- EPA ID
- OH1401211
Since 1994 Caesar Creek Lake (Army Corps flood-control lake) has been the principal source; the two Burtonville reservoirs fed by Cowan Creek serve as backup, used e.g. during 2017 and 2022 algal bloom events on the lake.
About this area's water
Did you know
- Wilmington's backup reservoirs became the contaminated ones: the Burtonville pair, built in 1945 and 1962 as the city's safety net, hold PFOS and PFHxS from firefighting foam the military required at the adjacent…
- The city sued 3M, maker of the PFAS-containing firefighting foam, in federal court to recover contamination costs.
- Caesar Creek Lake, the primary source, is a 2,830-acre Army Corps flood-control reservoir with 40 miles of shoreline draining a 237-square-mile watershed.
- Wilmington's water was privately owned for roughly half a century: Dayton Power and Light ran the water and electric utility from 1914 until the city took the water system back around 1970.
- The city keeps an auxiliary interconnection with the Western Water Company purely to keep outlying customers in water during main-break repairs.
History6
- 1899-1906After a mixed 1899 vote and a successful 1901 vote, Wilmington's first municipal water system was completed in 1906.
- 1914Dayton Power and Light took over the local water and electric utility.
- 1945First Burtonville reservoir (100 million gallons) built, along with a water plant on Wall Street that operated until 2000.
- 1962Second Burtonville reservoir added (350 million gallons), giving 450 million gallons of combined backup storage.
- 1970The City took over the water system from Dayton Power and Light (city states 'around 1970').
- 1990Current water treatment plant built.
Treatment & pressure
How it is treated
Surface-water lime softening plant. Multi-stage: powdered activated carbon adsorption, coagulation/flocculation with aluminum sulfate and lime, softening, sedimentation, re-carbonation, filtration through eight coal-and-sand filters, stabilization, and chlorine disinfection. The plant produces…
Source: wilmingtonohio.govgemgrp.com
Water pressure
Not published. Neither the city's water pages nor the 2025 CCR give service pressures or pressure zones; the only distribution figures published are four water towers plus two…
Source: wilmingtonohio.govgemgrp.com
What it costs
$10.03 per 1,000 gallons
Typical household bill about $47 a month for water.
Codified in Wilmington Code of Ordinances Sec. 929.01 (Ord. O-25-61, sec. 1, adopted 11-6-25; code version June 12, 2026). Inside-city usage fee is tiered per 1,000 gallons…
Water quality & impurities10
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Total trihalomethanes (TTHM) Range of individual detections 23.5-83.9 ppb; the high end exceeds the 80 ppb MCL although compliance is judged on the… | 63.3 ppb | 80 (LRAA) | 2025 |
| Haloacetic acids (HAA5) Range 13.8-23.0 ppb. By-product of chlorinating organic-rich reservoir water. | 22.1 ppb | 60 (LRAA) | 2025 |
| Total organic carbon (TOC) Range 2.76-4.33 ppm; TOC is the disinfection-byproduct precursor and explains the high TTHM. | 3.61 ppm | treatment… | 2025 |
| Chlorine Range 1.32-2.66 ppm. | 2.18 ppm | 4 (MRDL) | 2025 |
| Nitrate Range 0.46-3.24 ppm; agricultural watershed. | 3.24 ppm | 10 | 2025 |
| Fluoride Range 0.80-1.07 ppm; added at the plant. | 0.93 ppm | 4 | 2025 |
| Barium Far below the MCL. | 0.0085 ppm | 2 | 2025 |
| Cyanide Far below the MCL. | 1.56 ppb | 200 | 2025 |
| Turbidity 100% of monthly samples met the limit. | 0.14 NTU | treatment… | 2025 |
| Lead Range ND-4.8 ppb; 0 of 30 samples over the action level. | 0.8 (90th… ppb | 15 (action… | 2025 |
Source: gemgrp.comwilmingtonohio.gov
EPA compliance record
Lead at the tap: 90th-percentile result 0.8 ppb in 2025 (action level 15 ppb).
EPA record: no health-based violations since 2015.
1 violation of any kind logged since 2020, 1 of them paperwork (monitoring, reporting, public notice or consumer report).
Projects & plans3
Recent and current work
- New Wilmington wastewater treatment plant · $5 million · 2023-2026 · under construction
Being built on S. Nelson Avenue across from the existing plant at 475 S. Nelson Ave. Average daily capacity will be 50% higher than the existing plant and it… - Water tower upgrades · 2015 · completed
City states its water has met every state and federal standard since upgrades were installed in two water towers in 2015. No cost published.
Source: wilmingtonohio.govwilmingtonohio.govwnewsj.com
Planned or needed
- PFAS removal feasibility study for the Burtonville reservoirs · planned
City states it secured federal funding for a study to determine how PFAS could be removed so the reservoirs can be used in the future. No cost, scope or…
Source: wilmingtonohio.gov
Supply stress
Wilmington's stress is quality, not quantity. Its backup reservoirs at Burtonville carry PFOS and PFHxS at roughly 10-20 ppt from firefighting foam the military mandated at the adjacent Wilmington Air Park; the city sued 3M and is pursuing a PFAS-removal study. The reservoirs have not been abandoned - the 2025 CCR says they are 'often…
Sewers
Sanitary
City-operated. The existing Wilmington Wastewater Treatment Plant is at 475 S. Nelson Ave.; treated effluent discharges to Lytle Creek and biosolids are land-applied to agricultural fields for their fertilizer value. A replacement plant has been under construction since 2023 on the opposite side of S. Nelson Ave., with 50% more average…
Storm
Wilmington runs a genuine stormwater utility (Code Ch. 924, with illicit-discharge and comprehensive stormwater management under Ch. 938 and 939). The residential charge is $0.0271 per square foot of impervious surface per year, billed monthly.
Source: wilmingtonohio.govwilmingtonohio.govwilmingtonohio.gov
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
- 45177 · Wilmington61% 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
Wilmington 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 Wilmington City.
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
Wilmington City's own pages: wnewsj.com, wnewsj.com
Notable facts: wilmingtonohio.gov, wilmingtonohio.gov, gemgrp.com, library.municode.com
History: wilmingtonohio.gov, gemgrp.com, wilmingtonohio.gov, wnewsj.com
Water quality: gemgrp.com, wilmingtonohio.gov
Planned work: wilmingtonohio.gov
Water pressure: wilmingtonohio.gov, gemgrp.com
Capital projects: wilmingtonohio.gov, wilmingtonohio.gov, wnewsj.com, wilmingtonohio.gov
Rates: library.municode.com, wilmingtonohio.gov
Sewers: wilmingtonohio.gov, wilmingtonohio.gov, wilmingtonohio.gov, library.municode.com
Treatment: wilmingtonohio.gov, gemgrp.com
Supply stress: gemgrp.com, wilmingtonohio.gov, wnewsj.com