Guernsey County Water Dept. water quality
Old Washington, OH · serves 8,891 people (3,660 connections) · Purchased surface water · Local government · EPA ID OH3000603
Data: U.S. EPA · How we read the data · How we check it
Buys water from City of Cambridge. Treated water bought from another system can carry that system's contaminants.
Summary
PFAS above the 2024 federal limits. Systems have until 2029 to meet the PFAS limits.
Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility ever issues a boil-water or do-not-drink notice, follow it.
- PFAS
- Above limitPFOA above the federal limit in EPA's 2023–2025 testing (PFOA 7.8 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lithium
- Above screening levelHighest result 17 ppb. EPA uses 10 ppb to decide what to study further. It is not a health limit, and there is no federal limit for lithium. About 1 in 4 systems tested were above it.
- Lead
- Below action level0 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period Jan 2024 – now, still in progress (results reported so far). Your home's pipes can make yours higher.
- Violations
- Resolved4 health-based violations since 2016, most recently Apr 2024.
- Pregnant, or mixing baby formula with tap water? Babies drink more water for their size, so PFAS exposure matters more for them. Consider bottled water or a filter certified for PFAS for formula, and ask your doctor. Health effects.
- To lower your PFAS exposure now, a home filter certified for PFAS reduction works (reverse osmosis, or activated carbon certified to NSF/ANSI 53 or 58). Filters for these results.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Guernsey County Water Dept.'s annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill, and you can also request it at (740) 432-9200. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 1 entry point tested Feb 2025 to Nov 2025. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Above limit Limit 4 ppt | 7.8 ppt 1.95× the limit |
| PFOS Not detected Limit 4 ppt | – |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Not detected Limit 1 | – |
| PFBS Not detected Guideline 2,000 ppt | – |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Not detected Guideline 3,000 ppt | – |
For context: the PFOA average is higher than at 98% of the Ohio systems EPA tested.
29 PFAS tested, 1 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Detected in 2 of 4 samples. Highest result 17 ppb. EPA's non-enforceable screening level is 10 ppb. Above screening level The screening level is how EPA decides what to study further, not a health limit. There is no federal limit for lithium and no filter is certified to remove it. About lithium.
Lead and copper
Latest 90th percentile: 0 ppb lead (Jan 2024 – now (in progress)). Below action level
1 reported result in EPA's records is far above anything physically plausible (likely a unit or data-entry error) and is not used in the summary.
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2024 – now (in progress) | 0 ppb |
| Jan 2021 – Dec 2023 | 0 ppb |
| Jan 2018 – Dec 2020 | 0 ppb |
Earlier results (9)
| Jan 2015 – Dec 2017 | 0 ppb |
| Jan 2012 – Dec 2014 | 0 ppb |
| Jan 2009 – Dec 2011 | 0 ppb |
| Jan 2008 – Dec 2010 | 0 ppb |
| Jan 2005 – Dec 2007 | 0 ppb |
| Jun 2005 – Sep 2005 | Reported value looks erroneous |
| Jan 2002 – Dec 2004 | 0 ppb |
| Jan 2000 – Dec 2002 | 5 ppb |
| Jan 1999 – Dec 2001 | 0 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
| When | What happened |
|---|---|
| Apr 2024 | The running annual average for Total Haloacetic Acids (HAA5) was above the legal limit. EPA record: Total Haloacetic Acids (HAA5) · Maximum Contaminant Level Violation, Average · measured 0.063 mg/l (limit 0.060 mg/L) Resolved |
| Apr 2017 – Oct 2017 3 times | The running annual average for TTHM was above the legal limit. EPA record: TTHM · Maximum Contaminant Level Violation, Average · measured 0.081 mg/l (limit 0.080 mg/L) Resolved |
1 unresolved monitoring or reporting violation: Consumer Confidence Rule.
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Where it serves
Old Washington, Buffalo
ZIP codes the system reported serving: 43722, 43723, 43725, 43733, 43749, 43755, 43768, 43772, 43773, 43778, 43780, 43973
Nearby utilities
- City of Cambridge Cambridge · 8 mi · PFAS above limit
- Barnesville Water System Barnesville · 15 mi · PFAS above limit
- Caldwell Village Public Water System Caldwell · 20 mi · PFAS above limit
- St. Clairsville, City of Public Water System St. Clairsville · 29 mi · PFAS above limit
- Martins Ferry Public Water System Martins Ferry · 38 mi · PFAS above limit
- Marietta City Public Water System Marietta · 42 mi · PFAS above limit
Questions
Is Guernsey County Water Dept. water safe to drink?
Guernsey County Water Dept. had 4 health-based violations since 2016, all since resolved. EPA testing found PFAS above the 2024 federal limits, which systems must meet by 2029. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Guernsey County Water Dept. water have PFAS?
Yes. EPA's 2023–2025 testing of Guernsey County Water Dept. found 1 PFAS at least once. The highest entry-point averages were above the federal limit for PFOA: PFOA 7.8 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Guernsey County Water Dept. water?
The most recent 90th-percentile lead result for Guernsey County Water Dept. is 0 ppb, for the monitoring period that began Jan 2024 (still in progress). The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for OH3000603: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID OH3000603).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Guernsey County Water Dept. at (740) 432-9200, or see EPA's guide to finding it.
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.