Water system
Rio Grande
EPA ID OH2700316 · Gallia County · 830 people served
Rio Grande buys its water from Gallia Co. Rural Water Association.
The system's record
- Aquifer
- Ohio River Valley Aquifer
- Active wells
- 10
- Serves
- 20,995 people · Gallia County
- EPA ID
- OH2700012
About this area's water
Did you know
- Despite its name, Rio Grande commemorates the Mexican-American War rather than sitting near the actual Rio Grande river.
- The village flag is a variant of the Flag of Wales, reflecting heavy 1830s-40s Welsh immigrant settlement.
- The first Bob Evans restaurant operated as a truck-stop diner in Rio Grande before the chain expanded nationally, per Wikipedia.
- EPA records show Rio Grande's own Indian Creek Reservoir intake -- once a supplemental surface-water source with its own 'Rio Grande WTP' -- was taken offline in 2004; today the village's water arrives entirely through…
Source: en.wikipedia.orgdata.epa.gov
History5
- 1818-1840sWelsh immigrants began settling the area from 1818, with over 3,000 arriving from Welsh parishes during the 1830s-40s, giving the village its lasting Welsh heritage (per Wikipedia).
- 1874Village of Rio Grande formally established (July 6), named to commemorate the Mexican-American War (per Wikipedia).
- 2004The village's own surface-water intake on Indian Creek Reservoir was deactivated, per EPA SDWIS facility records.
- 2016-2023EPA's record shows a string of violations: routine coliform testing missed in 2016 and 2020 (both resolved), lead and copper tap testing missed or late in 2023, public notices not given in 2021 and 2023 (resolved), and inadequate yearly water quality reports in 2018, 2020 and 2023 (still open).
- 2020Census population 724 (per Wikipedia).
Source: en.wikipedia.orgdata.epa.gov
Treatment & pressure
How it is treated
SDWIS facility records show two source facilities: an active purchased interconnect from Gallia County Rural Water Association (arrives pre-treated; GCRWA's own supply comes from roughly 10 wells in the Ohio River Valley Aquifer near Gallipolis/Addison Twp.), and a former…
Source: data.epa.govdata.epa.gov
What it costs
We found no current rate schedule for Rio Grande or for Gallia County Rural Water Association.
Water quality & impurities3
| Contaminant | Level | Limit | Year |
|---|---|---|---|
| Coliform testing missed Routine coliform samples missed in Dec. 2016 and June 2020, per EPA; both resolved (2017-01-10 and 2020-07-15). | N/A violation | N/A | 2016… |
| Yearly water quality report (inadequate) Opened Nov. 14, 2018 and Oct. 3, 2023; both remain open in EPA SDWIS with no return-to-compliance date recorded as of… | N/A violation | N/A | 2018… |
| Monitoring/Reporting violation Opened Jan. 1, 2023; resolved Jan. 1, 2024 per SDWIS return-to-compliance date. | N/A violation | N/A | 2023 |
Source: data.epa.gov
EPA compliance record
Lead at the tap: 90th-percentile result 3.3 ppb in 2025 (action level 15 ppb).
EPA record: no health-based violations since 2015.
6 violations of any kind logged since 2020: 2 for required testing that was missed or reported late; 4 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 · Gallia Co. Rural Water Association (treats the water)
Lead at the tap: 90th-percentile result 1.8 ppb in 2025 (action level 15 ppb).
EPA record: no health-based violations since 2015.
1 violation of any kind logged since 2020: 1 for a report, record or notice that was missing, late or incomplete (the yearly water quality report, a public notice, lead line records).
Supply stress
System currently relies on a single active source -- the Gallia County Rural Water Association interconnect -- for its water; the village's own Indian Creek Reservoir intake, which could otherwise serve as backup, has been inactive since 2004 per SDWIS. EPA's record shows missed coliform and lead testing, public notices not given and inadequate yearly water quality reports from 2016 to 2023; three of the report violations (2018, 2020, 2023) remain open.
Source: data.epa.govdata.epa.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
- 45674 · Rio Grande98% of residents
Also present in 1 more ZIP code
- 45614 · Springfield Township and Bidwell1% 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
Rio Grande buys its water from Gallia Co. Rural Water Association.
No other system is on record buying water from Rio Grande.
What the records show about Rio Grande
Who runs it
EPA's record says Rio Grande has 265 service connections and serves 830 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 740-245-5089.
Source: EPA Safe Drinking Water Information System (SDWIS), water system record.
How the water is treated
Rio Grande buys water that Gallia Co. Rural Water Association treats first, so the steps that count are the seller's. EPA's treatment table registers these steps for Gallia Co. Rural Water Association: corrosion control, chlorine disinfection, iron and manganese removal, and fluoridation.
Rio Grande adds nothing of its own on that table.
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 Rio Grande since 2015.
EPA logs 6 violations of any kind since 2020: 2 for required testing that was missed or reported late; 4 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 Rio Grande was 3.3 ppb, under both the current 15 ppb action level and the 10 ppb level that applies from 2027.
The highest result on file is 12 ppb, in the period ending June 2023.
EPA has 9 sampling periods on file for Rio Grande since 2016, the first ending in 2018; 1 of the 9 periods went above 10 ppb.
Every water system has to inventory its service lines, the pipes from the main to each building. In the inventory Rio Grande sent EPA, 281 lines are counted.
| Material | Lines |
|---|---|
| Lead | 0 |
| Galvanized, needing replacement | 0 |
| Unknown material | 0 |
| Not lead | 281 |
| All lines | 281 |
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
The water Rio Grande buys is treated by Gallia Co. Rural Water Association, so the results below are Gallia Co. Rural Water Association's.
EPA's fifth national round of testing (UCMR 5) took 3 samples of the water entering the pipes of Gallia Co. Rural Water Association in 2024 to 2025 and measured 29 PFAS.
The highest PFOA or PFOS result, 7.5 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 result was PFOA 7.5 ng/L.
The system reported potential PFAS sources near its supply.
Ohio EPA's own statewide sampling tested 1 plant of Gallia Co. Rural Water Association (latest sample April 2021). The highest result was PFOA at 10.6 ppt (ppt is the same unit as ng/L), against Ohio's action level of 70 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 1 plant of Gallia Co. Rural Water Association as sampled, most recently March 2026.
| Compound | Highest result | Federal limit |
|---|---|---|
| PFOA | 7.5 ng/L | 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 Rio Grande's samples in 2019, the last year it was sampled, was 12.1 µg/L. The worst yearly average was 32.1 µg/L and the highest single sample was 33.9 µg/L, from 14 samples taken from 2013 to 2019.
For HAA5, the average in the last year sampled was 0 µg/L. The worst yearly average was 3.7 µg/L and the highest single sample was 4.7 µg/L, from 14 samples.
| Byproduct | Limit | Latest yearly average | Worst yearly average | Highest sample | Samples |
|---|---|---|---|---|---|
| TTHM | 80 µg/L | 12.1 µg/L (2019) | 32.1 µg/L | 33.9 µg/L | 14 |
| HAA5 | 60 µg/L | 0 µg/L | 3.7 µg/L | 4.7 µg/L | 14 |
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 Rio Grande buys is treated by Gallia Co. Rural Water Association, so the results below are Gallia Co. Rural Water Association's.
Nitrate: the highest of 8 samples was 0.52 mg/L (as nitrogen) in 2013; in 2019, the last year sampled, nitrate was not detected. No sample was over the limit of 10 mg/L. Nitrate above 10 is unsafe for infants.
Arsenic was not detected in 2 samples (limit 10 µg/L).
| Contaminant | Samples | Highest result | Limit | Samples over limit |
|---|---|---|---|---|
| Nitrate (as nitrogen) | 8 | 0.52 mg/L | 10 mg/L | 0 |
| Arsenic | 2 | 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.
Source: EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, finished water of Gallia Co. Rural Water Association.
Solvents and fuels
The water Rio Grande buys is treated by Gallia Co. Rural Water Association, so the results below are Gallia Co. Rural Water Association'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 2 samples each.
| Compound | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|
| Benzene | 5 µg/L | 2 | 0 of 2 | not detected | 0 |
| Carbon tetrachloride | 5 µg/L | 2 | 0 of 2 | not detected | 0 |
| 1,2-dichloroethane | 5 µg/L | 2 | 0 of 2 | not detected | 0 |
| Trichloroethylene (TCE) | 5 µg/L | 2 | 0 of 2 | not detected | 0 |
| Tetrachloroethylene (PCE) | 5 µg/L | 2 | 0 of 2 | not detected | 0 |
| Vinyl chloride | 2 µg/L | 2 | 0 of 2 | 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 Gallia Co. Rural Water Association.
Farm chemicals and metals
The water Rio Grande buys is treated by Gallia Co. Rural Water Association, so the results below are Gallia Co. Rural Water Association's.
EPA's file holds results for 8 of the nine herbicides and metals it checked. Detected: barium in 2 of 2 samples, highest 65.7 µg/L (limit 2,000). Not detected: atrazine in 3 samples, alachlor in 3 samples, chromium in 3 samples, cadmium in 3 samples, mercury in 2 samples, selenium in 2 samples, thallium in 2 samples.
| Substance | Kind | Limit | Samples | Detected in | Highest result | Samples over limit |
|---|---|---|---|---|---|---|
| Atrazine | Farm chemical | 3 µg/L | 3 | 0 of 3 | not detected | 0 |
| Alachlor | Farm chemical | 2 µg/L | 3 | 0 of 3 | not detected | 0 |
| Chromium | Metal | 100 µg/L | 3 | 0 of 3 | not detected | 0 |
| Cadmium | Metal | 5 µg/L | 3 | 0 of 3 | not detected | 0 |
| Barium | Metal | 2,000 µg/L | 2 | 2 of 2 | 65.7 µg/L | 0 |
| Mercury | Metal | 2 µg/L | 2 | 0 of 2 | not detected | 0 |
| Selenium | Metal | 50 µg/L | 2 | 0 of 2 | not detected | 0 |
| Thallium | Metal | 2 µg/L | 2 | 0 of 2 | 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 of Gallia Co. Rural Water Association.
Bacteria in the pipes
From 2012 to 2019, 0 of 107 routine total coliform samples taken in the distribution system at Rio Grande tested positive (0%); in 2019, the last year on file, 0 of 12 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 Rio Grande buys its water from Gallia Co. Rural Water Association, 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 Gallia Co. Rural Water Association, which treats the water Rio Grande buys.
Measured fluoride: 1.03 mg/L on average leaving the plants of Gallia Co. Rural Water Association, which supplies Rio Grande, in 2017 (in the range dentists aim for); samples ran from 1.03 to 1.08 mg/L across 2 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 found in 1 of 2 UCMR 5 samples at Gallia Co. Rural Water Association, which supplies Rio Grande, highest 9.7 µg/L, last sampled in 2025.
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
EPA estimated the service area of Rio Grande with a computer model rather than drawing it from the utility's map, so its edges are approximate.
Source: EPA Service Area Boundaries; resident estimate by this atlas from ZIP-code overlap.
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
EPA's own record for this system: Enforcement and Compliance History report for OH2700316 (EPA ECHO).
Notable facts: en.wikipedia.org, data.epa.gov
History: en.wikipedia.org, data.epa.gov
Water quality: data.epa.gov
Treatment: data.epa.gov, data.epa.gov
Supply stress: data.epa.gov, data.epa.gov
