Is Guernsey, WY Tap Water Safe to Drink?
Graded A-, with 2 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
88.8/100
waterverge.com Guernsey, WY — Water Quality Report
Guernsey's drinking water received a grade of A- (88.8 out of 100), indicating good water quality. The city's 1 water system serves approximately 1,157 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 80 violations on record, including 9 health-based violations. 2 remain unresolved.
What to know about Guernsey's water
Guernsey ranks #11 out of 65 cities in Wyoming for water quality, placing it above average in the state.
Guernsey relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Guernsey may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Guernsey, WY water safe to drink?
Guernsey's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (88.8/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 1,157 residents using groundwater (wells).
Recent water quality updates for Guernsey
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Guernsey's water quality assessment. Grade: A- (88.8/100).
Contaminants: Revised Total Coliform Rule.
Contaminants: Lead and Copper Rule.
Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-4227). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1923). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Guernsey's water supply.
Well within EPA limits.
Violation history
Guernsey's water system has 80 total violations on record, including 9 health-based violations. 2 remain unresolved. 3 violations were issued in the last 5 years.
Flood & environmental risk
Platte County has experienced 2 federally declared disasters since 2010. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include North Platte River Below Whalen Diversion Dam.
Where does Guernsey's water come from?
Guernsey's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,157 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include North Platte River Below Whalen Diversion Dam (river).
What Guernsey residents can do
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Guernsey
Industrial polluters nearby
Reported releases to surface water by facilities near Guernsey, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
US ARMY CAMP GUERNSEY TRAINING AREAS GUERNSEY, WY82214 | — | — | 0.3 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D4 — exceptional droughtPlatte County is currently in D4 (exceptional drought) per the U.S. Drought Monitor (week of May 5, 2026). 16.5% of the county is in D4 (exceptional) drought. Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Platte County has experienced 2 federally declared disasters since 2010. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Guernsey compares by contaminant
Explore where Guernsey ranks among all Wyoming cities for specific contaminants.
Water source & infrastructure
Where Guernsey's water comes from
Guernsey's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by local government ownership and serves approximately 1,157 people through 1 water system.
Water bodies near Guernsey
Guernsey is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Guernsey
| System Name | PWSID | Population | Source |
|---|---|---|---|
| GUERNSEY, TOWN OF | WY5600023 | 1,157 | GW |
How Guernsey compares
Full Wyoming rankings →Guernsey's score of 88.8/100 is above the average of 55/100 among major Wyoming cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Wyoming rankings →About Guernsey, WY
Wikipedia →Guernsey is a town in Platte County, Wyoming, United States. As of the 2020 census, Guernsey had a population of 1,130.
Learn more about your water
Guides and resources related to Guernsey's water quality findings.
Explore water quality across Platte
Frequently asked questions
Is Guernsey, WY tap water safe to drink?
Guernsey's water quality earned a grade of A- (88.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #11 out of 65 cities tested in Wyoming.
What contaminants are in Guernsey's water?
Lead was measured at 0.0 ppb (90th percentile). 80 violations are on record.
How is Guernsey's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Guernsey?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Guernsey's water come from?
Guernsey's water is sourced from Groundwater. The city has 1 water system serving approximately 1,157 residents.
What health violations has Guernsey's water system had?
Guernsey has 9 health-based violations on record. The most recent violation was recorded in March 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.
Is Guernsey's groundwater at risk of contamination?
Guernsey uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 80 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Guernsey's water compare to other cities?
Guernsey ranks #11 out of 65 cities in Wyoming (better than 83% of state cities) and #3250 out of 15744 cities nationally (79th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Guernsey's small water system affect quality?
Guernsey's system serves approximately 1,157 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 80 violations on record.