Is Dayton, WY Tap Water Safe to Drink?
Graded A-, with 1 unresolved violation on record. See what was cited — and what it means for your tap. What to do next ↓
88.9/100
waterverge.com Dayton, WY — Water Quality Report
Dayton's drinking water received a grade of A- (88.9 out of 100), indicating good water quality. The city's 1 water system serves approximately 824 residents using surface water.
Lead levels were measured at 4.0 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 52 violations on record, including 3 health-based violations. 1 remains unresolved.
What to know about Dayton's water
Dayton ranks #9 out of 65 cities in Wyoming for water quality, placing it above average in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
As a small community water system, Dayton may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Dayton, WY water safe to drink?
Dayton's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (88.9/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 824 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Dayton
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Dayton's water quality assessment. Grade: A- (88.9/100).
Contaminants: Interim Enhanced Surface Water Treatment Rule.
Contaminants: Interim Enhanced Surface Water Treatment Rule.
Contaminants: Interim Enhanced Surface Water Treatment Rule.
Federal disaster declaration (FEMA DR-557). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Dayton's water supply.
Well within EPA limits.
Violation history
Dayton's water system has 52 total violations on record, including 3 health-based violations. 1 remain unresolved. 3 violations were issued in the last 5 years.
Flood & environmental risk
Sheridan County has experienced 1 federally declared disaster since 1978. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Dayton's water come from?
Dayton's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 824 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.
What Dayton 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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Drought conditions
D2 — severe droughtSheridan County is currently in D2 (severe drought) per the U.S. Drought Monitor (week of May 5, 2026). 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
Sheridan County has experienced 1 federally declared disaster since 1978. 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. | 4.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Dayton compares by contaminant
Explore where Dayton ranks among all Wyoming cities for specific contaminants.
Water source & infrastructure
Where Dayton's water comes from
Dayton's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 824 people through 1 water system.
Water systems serving Dayton
| System Name | PWSID | Population | Source |
|---|---|---|---|
| DAYTON, TOWN OF | WY5600202 | 824 | SW |
How Dayton compares
Full Wyoming rankings →Dayton's score of 88.9/100 is above the average of 55/100 among major Wyoming cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Wyoming rankings →About Dayton, WY
Wikipedia →Dayton is a town in Sheridan County, Wyoming, United States. The population was 822 at the 2020 census.
Learn more about your water
Guides and resources related to Dayton's water quality findings.
Explore water quality across Sheridan
Frequently asked questions
Is Dayton, WY tap water safe to drink?
Dayton's water quality earned a grade of A- (88.9/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #9 out of 65 cities tested in Wyoming.
What contaminants are in Dayton's water?
Lead was measured at 4.0 ppb (90th percentile). 52 violations are on record.
How is Dayton'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 Dayton?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Dayton's water come from?
Dayton's water is sourced from Surface water. The city has 1 water system serving approximately 824 residents.
What health violations has Dayton's water system had?
Dayton has 3 health-based violations on record. The most recent violation was recorded in July 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
How does Dayton's water compare to other cities?
Dayton ranks #9 out of 65 cities in Wyoming (better than 86% of state cities) and #3188 out of 15744 cities nationally (80th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Dayton's small water system affect quality?
Dayton's system serves approximately 824 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 52 violations on record.