Water system
Greene County - northwest Reg Water
EPA ID OH2903512 · Greene County · 41,895 people served · owned by a local government
Greene County - northwest Reg Water treats its own water from Little Miami River Buried Valley Aquifer (2 wellfields, Beavercreek area).
The system's record
- Aquifer
- Little Miami River Buried Valley Aquifer
- Active wells
- 17
- Serves
- 41,895 people · Greene County
- EPA ID
- OH2903512
About this area's water
Did you know
- The plant does not only serve its own system - it also treats water for Greene County's Eastern Regional Water System.
- Ohio EPA found a documented contaminant plume in the uppermost aquifer, and the aquifer runs as shallow as 21 feet at the North Well Field.
- The county's 2026 report had to reprint its own 2024 contaminant table, which it acknowledged was inaccurate.
- Emergency connections to Bellbrook and Fairborn stand ready but delivered zero water in 2025.
History4
- 2020Ohio EPA sampled the Northwest Regional North (Beaver Valley Rd) and South (Shakertown Rd) plants for PFAS on July 27; all six GCSED samples came back non-detect.
- 2020sGCSED launched Greene Forward, its infrastructure-updating program, and rolled out Advanced Metering Infrastructure with the WaterSmart customer portal.
- 2025System operated on a current, unconditional license with no monitoring, reporting, or enforcement violations.
- 2026The 2026 CCR republished a corrected 2024 contaminant table after the prior year's report was found to be inaccurate.
Treatment & pressure
How it is treated
The 2026 CCR says the system draws from two well fields, Beaver Valley Road and Valley Springs Road, in the Little Miami River Buried Valley Aquifer, treated at the Northwest Regional plant (North WTP-1, South WTP-2) with chlorination and fluoridation.
Water pressure
Not published; no psi figure appears in the 2026 CCR or the county's schedule of charges.
What it costs
$5.12 per 1,000 gallons
Effective Jan 1, 2026: $14.99/mo minimum (5/8-in meter) covers the first 1,000 gal, then $5.12 per 1,000 gal. Fire and irrigation base rate $9.51/mo.
Water quality & impurities8
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Total trihalomethanes (TTHM) Range 12.9-79.7; one site came within 0.3 ppb of the MCL. No violation. | 57.1 ppb | 80 | 2025 |
| Haloacetic acids (HAA5) Range 0-12.7 ppb; well under the MCL. | 9.7 ppb | 60 | 2025 |
| Lead (90th percentile) 2 of 120 samples exceeded the 15 ppb action level; 90th percentile compliant. | 2.2 ppb | 15 | 2025 |
| Copper (90th percentile) 0 of 120 samples exceeded the 1.3 ppm action level. | 0.123 ppm | 1.3 | 2025 |
| Nitrate Range 0 to <1.0 ppm; essentially non-detect. | <0.10 ppm | 10 | 2025 |
| Fluoride Range 0.78-1.68; natural deposits plus water additive. | 0.96916 ppm | 4 | 2025 |
| Arsenic North 5.8, South 6.3. The CCR prints the limit as 8; federal MCL is 10 ppb. | 5.8-6.3 ppb | 10 | 2024 |
| Total hardness GCSED's published figure for Beavercreek; no aesthetic standard applies. | 8 grains… | n/a | 2026 |
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.
1 violation of any kind logged since 2020: 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 & plans2
Recent and current work
- Greene Forward infrastructure program · under construction
County water and sewer modernization including the Advanced Metering Infrastructure rollout and WaterSmart customer portal. No cost published.
Planned or needed
- Membrane softening / reverse osmosis facility
Reported by Dayton Daily News as driving a rate increase. GCSED now lists Beavercreek hardness at 8 grains per gallon.
Supply stress
Ohio EPA rates the Little Miami River Buried Valley Aquifer highly susceptible: a variable clay layer thinnest at the North Well Field, aquifer as shallow as 21 feet, a documented contaminant plume in the uppermost aquifer, and nearby contaminant sources. TTHM averaged 57.1 ppb in 2025 against an 80 ppb MCL.
Sewers
Sanitary
Greene County Sanitary Engineering runs sewer in the Greater Greene-Little Miami Sewer District. Metered rates effective Jan 1, 2026: $23.28/mo minimum (5/8-in meter) covers the first 3,000 gal, then $7.29 per 1,000 gal; unmetered single-family flat rate is $60.24/mo.
Storm
Not detailed in the CCR or the county's 2026 schedule of charges; no stormwater utility fee appears in that fee schedule.
Sourcesverified
Compiled from the utility's own reports and public records, then independently re-checked against primary sources.
Main supplier in 5 ZIP codes
Serves
Main water supplier in 5 ZIP codes
- 45301 · Beavercreek and Alpha100% of residents
- 45430 · Beavercreek and Dayton100% of residents
- 45434 · Beavercreek and Dayton100% of residents
- 45431 · Beavercreek and Dayton51% of residents
- 45432 · Beavercreek and Dayton49% of residents
Also present in 5 more ZIP codes
- 45440 · Kettering and Dayton31% of residents
- 45305 · Bellbrook14% of residents
- 45385 · Xenia12% of residents
- 45324 · Fairborn3% of residents
- 45387 · Yellow Springs0% 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
Greene County - northwest Reg Water does not buy water from another system on record; it treats its own source water.
1 system on record buys water from Greene County - northwest Reg Water: Greene County Eastern Regional.
What the records show about Greene County - northwest Reg Water
Who runs it
EPA's record describes Greene County - northwest Reg Water as owned by a local government. It has 16,597 service connections and serves 41,895 people.
EPA classes it as a community water system, one that serves the same residents all year.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
EPA's treatment table registers these steps for Greene County - northwest Reg Water: aeration, corrosion control, chlorine disinfection, dechlorination, fluoridation, reverse osmosis, 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 Greene County - northwest Reg Water since 2015.
EPA logs 1 violation of any kind since 2020: 1 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 June 2026, the 90th-percentile lead result at Greene County - northwest Reg Water 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 6.1 ppb, in the period ending December 2019.
EPA has 11 sampling periods on file for Greene County - northwest Reg Water 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 Greene County - northwest Reg Water sent EPA, 19,700 lines are counted.
| Material | Lines |
|---|---|
| Lead | 1 |
| Galvanized, needing replacement | 0 |
| Unknown material | 23 |
| Not lead | 19,676 |
| All lines | 19,700 |
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 4 samples of the water entering the pipes of Greene County - northwest Reg Water in 2023 to 2024 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 2 plants of Greene County - northwest Reg Water (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 Greene County - northwest Reg Water as sampled, most recently May 2026.
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 Greene County - northwest Reg Water's samples in 2019, the last year it was sampled, was 50.4 µg/L. The worst yearly average was 50.4 µg/L and the highest single sample was 81.4 µg/L, from 114 samples taken from 2012 to 2019.
For HAA5, the average in the last year sampled was 11.2 µg/L. The worst yearly average was 12.9 µg/L and the highest single sample was 25.6 µg/L, from 114 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 50.4 µg/L (2019) | 50.4 µg/L | 81.4 µg/L | 114 |
| HAA5 | 60 µg/L | 11.2 µg/L | 12.9 µg/L | 25.6 µg/L | 114 |
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 15 samples was 1.39 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: the highest of 36 samples was 7.3 µg/L (limit 10); detections averaged 5.8; none over the limit.
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 15 | 1.39 mg/L | 10 mg/L | 0 |
| Arsenic | 36 | 7.3 µg/L | 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.
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 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.
Farm chemicals and metals
EPA's file holds results for 8 of the nine herbicides and metals it checked. Detected: barium in 4 of 4 samples, highest 204 µg/L (limit 2,000). Not detected: atrazine in 6 samples, alachlor in 6 samples, chromium in 4 samples, cadmium in 4 samples, mercury in 4 samples, selenium in 4 samples, thallium in 4 samples.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 6 | 0 of 6 | not detected | 0 |
| Alachlor | Farm chemical | 2 µg/L | 6 | 0 of 6 | 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 | 4 of 4 | 204 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.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water.
Bacteria in the pipes
From 2012 to 2019, 0 of 3,845 routine total coliform samples taken in the distribution system at Greene County - northwest Reg Water tested positive (0%); in 2019, the last year on file, 0 of 480 did.
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 Greene County - northwest Reg Water adjusts the fluoride level to the recommended level for preventing tooth decay.
EPA's treatment table lists fluoridation among the steps at Greene County - northwest Reg Water.
Measured fluoride: 0.91 mg/L on average at the plant's entry points in 2017 (in the range dentists aim for); samples ran from 0.81 to 0.94 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 4 UCMR 5 samples at Greene County - northwest Reg Water, last sampled in 2024 (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 Greene County - northwest Reg Water comes from the utility's own map.
Counting the people who live in the ZIP codes it overlaps, this atlas estimates 55,715 residents are inside the boundary, 133% of the 41,895 people Greene County - northwest Reg Water 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 — 10 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 OH2903512 (EPA ECHO).
Greene County - northwest Reg Water's own pages: greenecountyohio.gov, greenecountyohio.gov, greenecountyohio.gov
