Community Water System · PWSID WY5680085

Ynp-Old Faithful

Serves 7,675 peopleSurface WaterOwner: FederalYellowstone, Wyoming
Nothing open right now.

On record since 2016: 28 violations. 5 over the limit · 6 treatment lapses · 17 missed or late tests. Most recent began 2024-07-01.

For this year's test results, ask the utility for its annual Consumer Confidence Report. Every community system must publish one.

5Over the limit
6Treatment lapse
17Missed or late test
0Notice or report

More violations on record than 91% of active water systems in Wyoming. Small systems with no staff chemist often rack up missed-test violations; big utilities rarely do.

The record, year by year

2005201020152016 · Over the limit: 12020 · Over the limit: 120202022 · Treatment lapse: 22022 · Missed or late test: 22023 · Over the limit: 32023 · Over the limit: 32023 · Treatment lapse: 12023 · Missed or late test: 142023 · Missed or late test: 142023 · Missed or late test: 142023 · Missed or late test: 142023 · Missed or late test: 142023 · Missed or late test: 142023 · Missed or late test: 142024 · Treatment lapse: 32024 · Treatment lapse: 32024 · Missed or late test: 12025
One square ≈ 2 violations (rounded up), by the year they began. Empty columns are years with nothing on EPA's record.
18% over the limit · 521% treatment lapse · 661% missed or late test · 17

Across Wyoming, 85% of violations are missed or late tests and 4% are water over a limit.

How far over the limit

at the limit2×5×10×100×+Arsenic2023-04-01 · Arsenic: measured 0.0110 MG/L vs limit 0.0100 MG/L (1.1×)2020-01-01 · Arsenic: measured 0.0110 MG/L vs limit 0.0100 MG/L (1.1×)2016-01-01 · Arsenic: measured 0.0110 MG/L vs limit 0.0100 MG/L (1.1×)
Each dot is one over-the-limit violation: the measured value divided by the limit it broke, on a log scale. Most legal limits for chemicals are running averages set for a lifetime of drinking, so “just over” and “ten times over” are very different news. Hover a dot for the numbers.

Lead & copper at the tap

Utilities sample taps in homes most likely to have lead pipes, and report the 90th-percentile result: 9 in 10 homes sampled came in at or below this number. Above the red line (the action level) the utility must act. The action level is not a safe level; EPA's health goal for lead is zero. EPA's file does not date these results, so they are shown highest first.

Lead, 90th percentile 7 results on file · action level 15 ppb

125 ppb
6 ppb
4 ppb
4 ppb
4 ppb
3 ppb
1 ppb

Every violation on record

  1. 2024-07-01Lead and Copper RuleOCCT/SOWT Study/RecommendationBack in compliance
  2. 2024-07-01Lead and Copper RuleInitial, Follow-up, or Routine Source Water M/RBack in compliance
  3. 2024-06-01Lead and Copper RulePublic EducationBack in compliance
  4. 2024-03-01Lead and Copper RulePublic EducationBack in compliance
  5. 2023-12-30Lead and Copper RuleLead Consumer NoticeBack in compliance
  6. 2023-11-30Lead and Copper RulePublic EducationBack in compliance
  7. 2023-10-01ArsenicMCL, Averagemeasured 0.0120 MG/LPeriod ended · no return to compliance on file
  8. 2023-10-01Lead and Copper RuleFollow-up Or Routine LCR Tap M/RBack in compliance
  9. 2023-07-01Total Haloacetic Acids (HAA5)Monitoring and Reporting (DBP)Back in compliance
  10. 2023-07-01Trihalomethanes (TTHM)Monitoring and Reporting (DBP)Back in compliance
  11. 2023-07-01ArsenicMCL, Averagemeasured 0.0120 MG/LPeriod ended · no return to compliance on file
  12. 2023-04-01ArsenicMCL, Averagemeasured 0.0110 MG/L · limit 0.0100 MG/LPeriod ended · no return to compliance on file
  13. 2023-01-01Calcium ×2Water Quality Parameter M/RBack in compliance
  14. 2023-01-01Temperature (Centigrade) ×2Water Quality Parameter M/RBack in compliance
  15. 2023-01-01Tds ×2Water Quality Parameter M/RBack in compliance
  16. 2023-01-01Alkalinity, Total ×2Water Quality Parameter M/RBack in compliance
  17. 2023-01-01pH ×2Water Quality Parameter M/RBack in compliance
  18. 2022-09-17Surface water treatment (LT2)Failure To Address DeficiencyBack in compliance
  19. 2022-06-01Surface water filtration (IESWTR)Monthly Turbidity Exceed (Enhanced SWTR)Back in compliance
  20. 2022-04-01Revised Total Coliform RuleMONBack in compliance
  21. 2022-04-01Surface water treatment (SWTR)Monitoring of Treatment (SWTR-Filter)Back in compliance
  22. 2020-01-01ArsenicMCL, Averagemeasured 0.0110 MG/L · limit 0.0100 MG/LBack in compliance
  23. 2016-01-01ArsenicMCL, Averagemeasured 0.0110 MG/L · limit 0.0100 MG/LBack in compliance

System details

Population served7,675
Service connections153
Water sourceSurface Water
System typeCommunity Water System
OwnerFederal
StatusActive
CityYellowstone
EPA ZIP on file82190

Areas served

  • Yellowstone Np, Teton County

Reading this record

Ynp-Old Faithful is a community water system that draws from surface water and serves about 7,675 people in Yellowstone, Wyoming. Everything above comes from the EPA's Safe Drinking Water Information System (SDWIS), where states report every violation by every public water system.

Four kinds of violation. Only one is a measurement of the water: over the limit means a test came back above a legal maximum (an MCL). A treatment lapse means a required protective step was not done, such as disinfection, filtration, fixing a defect an inspector found, or filing a lead-pipe inventory. A missed or late test means a required test was skipped or never reported. That is the most common kind, and the most misread: it does not mean the water was bad, and it does not mean the water was fine. Notices and reports covers public notices and the annual Consumer Confidence Report.

Status. “Back in compliance” means the state recorded a return to compliance. “Period ended” means the violation's compliance period is over but no return to compliance was ever filed, which is common in older records. EPA's federal copy lags state records by months, so call the utility for anything current.