01The verdict: is Riddle water safe?
Riddle's drinking water has significant quality concerns based on EPA testing data. With a grade of F (42/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 5 water systems serve approximately 2,014 residents using surface water (rivers, lakes, or reservoirs).
74 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓2K people, 5 systems
All figures on this page come from federal EPA compliance and testing data for the systems serving this city.
See the systems ↓58 violations in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Riddle's drinking water received a grade of F (42 out of 100), indicating failing water quality. The city's 5 water systems serve approximately 2,014 residents using surface water.
Lead levels were measured at 10.0 ppb (90th percentile), which is within EPA limits but above recommended levels. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 785 violations on record, including 55 health-based violations. 74 remain unresolved.
Riddle ranks #191 out of 213 cities in Oregon for water quality, placing it among the lowest-rated 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. While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection. As a small community water system, Riddle may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 58 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Riddle's water
Every contaminant flagged in Riddle, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
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. | 10.0 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in Oregon
Cities ranked by compounds detected Cu Copper in Oregon
Cities ranked by 90th-percentile copper
03Riddle's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 785 violations on record, including 55 health-based violations. 74 remain unresolved.
1 of the last ten years was clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▲ Up 5 ppb since 1993. Latest reading: 5 ppb (2025) — 33% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Riddle's water comes from
Riddle's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface Water
Rivers, lakes, or reservoirs — more exposed to runoff, agriculture, and seasonal swings than groundwater.
Local treatment
Multi-barrier treatment: coagulation, sedimentation, filtration, and disinfection to meet EPA standards.
5 systems
5 water systems, operated under local government ownership.
2,014 people
Residents served across Riddle's service area.
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 2,014 people through 5 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| RIDDLE, CITY OF | OR4100706 | 1,224 | Surface Water |
| SOUTH UMPQUA WATER ASSOCIATION | OR4100705 | 575 | Purchased Surface Water |
| DIAMOND LAKE LODGE/RESORT | OR4192104 | 90 | Groundwater |
| LAWSON ACRES WATER ASSOCIATION | OR4100707 | 75 | Purchased Surface Water |
| WINCHESTER RIDGE | OR4101565 | 50 | Groundwater |
Water bodies near Riddle
As a surface-water system, these water bodies may directly influence Riddle's drinking water supply.
05Pressure on Riddle's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
2 facilities within 10 miles reported 0 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
8 federal disaster declarations on record for Douglas County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Superfund proximity
1 National Priorities List site within 10 miles. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
Drought
Douglas County is in D3 (extreme drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Riddle compares
Scores for nearby Oregon cities on one line, with the average marked.
dashed line = Oregon average (42/100)
Riddle scores 42/100 — on par with the Oregon average of 42/100. It outscores 6 of 10 nearby cities. Full Oregon rankings →
39.4 / 100FBeaverton, OR
40.7 / 100FSalem, OR
43.6 / 100FEugene, OR
28 / 100FBend, OR
41 / 100FMedford, OR
29.4 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Riddle's water — not generic advice.
Filter drinking & cooking water
NSF-certified water filter. Lead detected at 10.0 ppb
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Riddle alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Riddle, OR tap water safe to drink?
Riddle's water quality earned a grade of F (42/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #191 out of 213 cities tested in Oregon.
What contaminants are in Riddle's water?
Lead was measured at 10.0 ppb (90th percentile). 785 violations are on record.
How is Riddle'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 Riddle?
While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Riddle's water come from?
Riddle's water is sourced from Surface water. The city has 5 water systems serving approximately 2,014 residents.
What health violations has Riddle's water system had?
Riddle has 55 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 74 violations remain unresolved.
How does Riddle's water compare to other cities?
Riddle ranks #191 out of 213 cities in Oregon (better than 10% of state cities) and #14576 out of 15382 cities nationally (5th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.