Water system
Butler Co. Water District 2
EPA ID OH0900303 · Butler County · 116,572 people served · owned by a local government
Butler Co. Water District 2 buys its water from Hamilton Public Water System.
The system's record
Also connected to Cincinnati Public Water System (Ohio River (Miller Plant, ~88%) plus Great Miami Buried Valley Aquifer wells (~12%)), used as a secondary or emergency supply.
- Aquifer
- Great Miami Buried Valley Aquifer
- Active wells
- 21
- Serves
- 62,447 people · Butler County
- EPA ID
- OH0904012
About this area's water
Did you know
- Hamilton's tap water took the gold medal for Best Municipal Water at the Berkeley Springs International Water Tasting's 25th running — the origin of the city's 'world's best water' billing.
- BCWS reported no lead, galvanized-requiring-replacement, or unknown-material service lines at all across 41,354 connections — unusual for a system this size.
- Hamilton disinfects with chlorine dioxide rather than plain chlorine; its 2025 residual of 660 ppb ran at 83% of the 800 ppb federal maximum.
- Some Butler County taps blend aquifer water from Hamilton's wells with Ohio River water from Cincinnati, so what you drink depends on which intertie feeds your street.
History4
- 1884The City of Hamilton began owning and operating its own water utility; it remains Butler County Water & Sewer's principal supplier today.
- 1913The March 1913 Great Miami River flood devastated Hamilton and led to the Miami Conservancy District's regional flood-control system.
- 2015Hamilton's tap water took the gold medal for Best Municipal Water at the 25th Berkeley Springs International Water Tasting.
- 2025BCWS reported its lead service line inventory complete: no lead, galvanized-requiring-replacement or unknown-material lines among 41,354 connections.
Treatment & pressure
How it is treated
Buys all water finished. Hamilton pulls the Great Miami Buried Valley Aquifer via 21 deep wells, disinfecting with chlorine dioxide; GCWW adds Ohio River water treated by settling, filtration, a very large GAC plant and UV. BCWS re-chlorinates and adds soda ash.
Water pressure
not published — BCWS says pump stations and storage tanks hold pressure through peak demand, but no system psi figure appears in its published reports.
What it costs
The $3.36/1,000 gal + $4.53 figure (eff. Jan 1, 2023) is tiered by lift station, i.e. sewer service; we found no BCWS water rate schedule.
Water quality & impurities8
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| TTHM (total trihalomethanes) Measured in BCWS distribution; range 8.9-44.8. No violation. | 37.125 ppb | 80 | 2025 |
| HAA5 (haloacetic acids) Measured in BCWS distribution; range 0-9.5, well under the MCL. | 9.425 ppb | 60 | 2025 |
| Lead (90th percentile) 1 of 50 samples exceeded the action level; 90th percentile reported as 0. No violation. | 0 ppb | 15 (action… | 2025 |
| Chlorine dioxide Hamilton's disinfectant; range 100-660, running at 83% of the federal maximum. | 660 ppb | 800 (MRDL) | 2025 |
| Chlorite Chlorine dioxide byproduct in Hamilton water; range 0.41-0.70, 68% of the MCL. | 0.68 ppm | 1.0 | 2025 |
| Nitrate Highest of the two suppliers (GCWW); Hamilton 0.64 ppm. Well under the MCL. | 1.25 ppm | 10 | 2025 |
| Fluoride GCWW 0.88, Hamilton 0.87; added to promote strong teeth. | 0.88 ppm | 4 | 2025 |
| PFHxS UCMR5, Hamilton intertie; range ND-4.7. Cincinnati intertie was ND. PFBS also 3.3 ppt. | 2.4 ppt | 10 | 2023 |
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.
4 violations of any kind logged since 2020: 2 for required testing that was missed or reported late; 2 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records).
EPA compliance record · Hamilton Public Water System (treats the water)
Lead at the tap: 90th-percentile result 2 ppb in 2024 (action level 15 ppb).
EPA record: no health-based violations since 2015.
2 violations of any kind logged since 2020: 1 for required testing that was missed or reported late; 1 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records).
Projects & plans5
Recent and current work
- Lead service line inventory and field verification · 2025 · completed
Records review plus 395 field verifications across 41,354 connections found no lead or galvanized service lines on either the utility or private side.
Planned or needed
- Upper Mill Creek WRF equalization system and sludge drying facility · $21 million · planned
Roughly $21M of upgrades at one of BCWS's two regional wastewater reclamation plants. - Pheasant Hills water main replacement · $1.4 million · planned
About 3,886 ft of 6-inch and 3,895 ft of 10-inch water main. - West Chester Township sewer cleaning and inspection · planned
Systemwide cleaning and inspection of sewers in the district's largest township. - Water service line replacement contracts · 2026-2030 · planned
Multiple service line replacement contracts programmed through 2030 in the county capital plan.
Supply stress
Ohio EPA rates both sources highly susceptible: the Great Miami Buried Valley Aquifer has no protective clay cap, a shallow water table and nearby contaminant sources, while the Ohio River leg is open to spills — GCWW found Cryptosporidium in 1 of 4 raw samples in 2025, none in treated water.
Sewers
Sanitary
BCWS runs the sanitary sewers, serving about 100,000 people through five plants — regional LeSourdsville and Upper Mill Creek plus satellites Wade Mill, New Miami and Queen Acres — treating about 20 MGD against 33 MGD of combined permitted discharge. The City of Hamilton runs its own system.
Sourcesverified
Compiled from the utility's own reports and public records, then independently re-checked against primary sources.
Main supplier in 2 ZIP codes
Serves
Main water supplier in 2 ZIP codes
- 45069 · West Chester Township and West Chester96% of residents
- 45011 · Liberty Township and Hamilton60% of residents
Also present in 6 more ZIP codes
- 45044 · Middletown34% of residents
- 45241 · Sharonville and Cincinnati29% of residents
- 45040 · Mason3% of residents
- 45015 · Hamilton1% of residents
- 45246 · Springdale and Cincinnati0% of residents
- 45014 · Fairfield0% 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
Butler Co. Water District 2 buys its water from Hamilton Public Water System.
1 system on record buys water from Butler Co. Water District 2: Monroe City.
What the records show about Butler Co. Water District 2
Who runs it
EPA's record describes Butler Co. Water District 2 as owned by a local government. It has 43,457 service connections and serves 116,572 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 513-887-3929.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
Butler Co. Water District 2 buys water that Hamilton Public Water System treats first, so the steps that count are the seller's. EPA's treatment table registers these steps for Hamilton Public Water System: aeration, chlorine dioxide, coagulation and settling, fluoridation, lime softening, and sand or media filtration.
Butler Co. Water District 2 itself also registers: chlorine disinfection.
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 Butler Co. Water District 2 since 2015.
EPA logs 4 violations of any kind since 2020: 2 for required testing that was missed or reported late; 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 Butler Co. Water District 2 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 3.9 ppb, in the period ending December 2024.
EPA has 5 sampling periods on file for Butler Co. Water District 2 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 Butler Co. Water District 2 sent EPA, 42,124 lines are counted.
| Material | Lines |
|---|---|
| Lead | 0 |
| Galvanized, needing replacement | 0 |
| Unknown material | 0 |
| Not lead | 42,124 |
| All lines | 42,124 |
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 15 samples of the water entering the pipes of Butler Co. Water District 2 in 2023 to 2025 and measured 29 PFAS.
PFOA and PFOS were not detected, against a federal limit of 4 ng/L each.
The highest PFAS results were PFHxS 4.7 ng/L and PFBS 3.5 ng/L.
The system reported potential PFAS sources near its supply.
Ohio EPA's own statewide sampling tested 2 plants of Hamilton Public Water System (latest sample July 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 2 plants of Hamilton Public Water System as sampled, most recently February 2026.
| Compound | Highest result | Federal limit |
|---|---|---|
| PFOA | not detected | 4 ng/L |
| PFOS | not detected | 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 Butler Co. Water District 2's samples in 2019, the last year it was sampled, was 25.4 µg/L. The worst yearly average was 32 µg/L and the highest single sample was 53.3 µg/L, from 171 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 5.1 µg/L. The worst yearly average was 8 µg/L and the highest single sample was 14.4 µg/L, from 168 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 25.4 µg/L (2019) | 32 µg/L | 53.3 µg/L | 171 |
| HAA5 | 60 µg/L | 5.1 µg/L | 8 µg/L | 14.4 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
The water Butler Co. Water District 2 buys is treated by Hamilton Public Water System, so the results below are Hamilton Public Water System's.
Nitrate: the highest of 15 samples was 1.5 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 4 samples (limit 10 µg/L).
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 15 | 1.5 mg/L | 10 mg/L | 0 |
| Arsenic | 4 | 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 Hamilton 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 of Hamilton Public Water System.
Solvents and fuels
The water Butler Co. Water District 2 buys is treated by Hamilton Public Water System, so the results below are Hamilton Public Water System's.
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 4 samples each.
| Compound | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|
| Benzene | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Carbon tetrachloride | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| 1,2-dichloroethane | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Trichloroethylene (TCE) | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Tetrachloroethylene (PCE) | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Vinyl chloride | 2 µg/L | 4 | 0 of 4 | 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 of Hamilton Public Water System.
Farm chemicals and metals
The water Butler Co. Water District 2 buys is treated by Hamilton Public Water System, so the results below are Hamilton Public Water System's.
EPA's file holds results for 8 of the nine herbicides and metals it checked. Detected: barium in 2 of 4 samples, highest 57.2 µg/L (limit 2,000). Not detected: atrazine, alachlor, chromium, cadmium, mercury, selenium, and thallium, in 4 samples each.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 4 | 0 of 4 | not detected | 0 |
| Alachlor | Farm chemical | 2 µg/L | 4 | 0 of 4 | not detected | 0 |
| Chromium | Metal | 100 µg/L | 4 | 0 of 4 | not detected | 0 |
| Cadmium | Metal | 5 µg/L | 4 | 0 of 4 | not detected | 0 |
| Barium | Metal | 2,000 µg/L | 4 | 2 of 4 | 57.2 µg/L | 0 |
| Mercury | Metal | 2 µg/L | 4 | 0 of 4 | not detected | 0 |
| Selenium | Metal | 50 µg/L | 4 | 0 of 4 | not detected | 0 |
| Thallium | Metal | 2 µg/L | 4 | 0 of 4 | 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 Hamilton 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 of Hamilton Public Water System.
Bacteria in the pipes
From 2012 to 2019, 8 of 9,944 routine total coliform samples taken in the distribution system at Butler Co. Water District 2 tested positive (0.08%); in 2019, the last year on file, 1 of 1,224 did. E. coli was never found in the 35 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 Butler Co. Water District 2 buys its water from Hamilton Public Water System, a system that adjusts the fluoride level to the recommended level for preventing tooth decay.
EPA's treatment table lists fluoridation among the steps at Hamilton Public Water System, which treats the water Butler Co. Water District 2 buys.
Measured fluoride: 0.8 mg/L on average leaving the plants of Hamilton Public Water System, which supplies Butler Co. Water District 2, in 2018 (in the range dentists aim for); samples ran from 0.78 to 1.8 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 not detected in 6 UCMR 5 samples at Butler Co. Water District 2, 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.
How well the service area is mapped
The service area drawn on the map for Butler Co. Water District 2 comes from the utility's own map.
Counting the people who live in the ZIP codes it overlaps, this atlas estimates 124,080 residents are inside the boundary, 106% of the 116,572 people Butler Co. Water District 2 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 — 8 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 OH0900303 (EPA ECHO).
Butler Co. Water District 2's own pages: cms5.revize.com, bcohio.gov, journal-news.com
