Community Water System · PWSID CT0419221

31 Grist Mill Rd

Serves 30 peopleGroundwaterOwner: PrivateOld Lyme, Connecticut
1 open treatment violation.

Open for: Lead service line inventory. EPA counts treatment-technique violations as health-based: a required protective step was not done. It is not a measurement of contamination.

On record since 2015: 202 violations. 5 over the limit · 4 treatment lapses · 172 missed or late tests · 21 notices or reports. Most recent began 2025-07-01.

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

5Over the limit
4Treatment lapse1 open
172Missed or late test
21Notice or report1 open

More violations on record than 99% of active water systems in Connecticut. Small systems with no staff chemist often rack up missed-test violations; big utilities rarely do.

The record, year by year

200520102015 · Over the limit: 32015 · Missed or late test: 12015 · Notice or report: 120152016 · Missed or late test: 162016 · Missed or late test: 162016 · Notice or report: 12017 · Treatment lapse: 22017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Missed or late test: 1302017 · Notice or report: 42018 · Over the limit: 12018 · Missed or late test: 52018 · Notice or report: 62019 · Over the limit: 12019 · Missed or late test: 32019 · Notice or report: 22020 · Treatment lapse: 12020 · Missed or late test: 22020 · Notice or report: 520202021 · Missed or late test: 122022 · Missed or late test: 12023 · Missed or late test: 12024 · Treatment lapse: 12024 · Notice or report: 12025 · Missed or late test: 12025 · Notice or report: 12025
One square ≈ 12 violations (rounded up), by the year they began. Empty columns are years with nothing on EPA's record.
2% over the limit · 52% treatment lapse · 485% missed or late test · 17210% notice or report · 21

Across Connecticut, 76% of violations are missed or late tests and 1% are water over a limit.

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 19 results on file · action level 15 ppb

14 ppb
6.5 ppb
2.8 ppb
1.3 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb
0 ppb

Open now (2)

  1. 2024-10-17Lead service line inventoryRPTOpen
  2. 2024-10-17Lead service line inventoryTTOpen

Every violation on record

  1. 2025-07-01Consumer Confidence RuleCCR Complete Failure to ReportBack in compliance
  2. 2025-01-01DieldrinMonitoring, RegularPeriod ended · no return to compliance on file
  3. 2024-10-17Lead service line inventoryRPTOpen
  4. 2024-10-17Lead service line inventoryTTOpen
  5. 2023-04-01Lead and Copper RuleLead Consumer NoticeBack in compliance
  6. 2022-01-01DieldrinMonitoring, RegularBack in compliance
  7. 2021-10-01Combined Radium (-226 and -228)Monitoring, RegularBack in compliance
  8. 2021-05-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  9. 2021-04-01Lead and Copper RuleLead Consumer NoticeBack in compliance
  10. 2021-04-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  11. 2021-04-01Revised Total Coliform RuleMONBack in compliance
  12. 2021-03-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  13. 2021-03-01Revised Total Coliform RuleMONBack in compliance
  14. 2021-02-01Revised Total Coliform RuleMONBack in compliance
  15. 2021-02-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  16. 2021-01-01DieldrinMonitoring, RegularBack in compliance
  17. 2021-01-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  18. 2021-01-01Revised Total Coliform RuleMONBack in compliance
  19. 2020-12-10Public NoticePN Violation for NPDWR ViolationBack in compliance
  20. 2020-09-29Lead and Copper RuleLead Consumer NoticeBack in compliance
  21. 2020-03-31Lead and Copper RuleLead Consumer NoticeBack in compliance
  22. 2020-03-15Public Notice ×4PN Violation for NPDWR ViolationBack in compliance
  23. 2020-02-08Groundwater RuleFailure To Address ContaminationSystem inactive
  24. 2019-09-29Lead and Copper RuleLead Consumer NoticeBack in compliance
  25. 2019-07-01DieldrinMonitoring, RegularBack in compliance
Show the other 108 entries
  1. 2019-04-01Lead and Copper RuleLead Consumer NoticeBack in compliance
  2. 2019-01-17Public NoticePN Violation for NPDWR ViolationBack in compliance
  3. 2019-01-17Public NoticePN Violation for NPDWR ViolationSystem inactive
  4. 2019-01-01Revised Total Coliform RuleMCLBack in compliance
  5. 2018-12-01Revised Total Coliform RuleMONBack in compliance
  6. 2018-10-12Public NoticePN Violation for NPDWR ViolationBack in compliance
  7. 2018-10-01Revised Total Coliform RuleMCLBack in compliance
  8. 2018-09-29Lead and Copper RuleLead Consumer NoticeBack in compliance
  9. 2018-09-05E. ColiMonitoring, Source Water (GWR)Back in compliance
  10. 2018-08-10Consumer Confidence RuleCCR Inadequate ReportingBack in compliance
  11. 2018-08-02E. Coli ×2Monitoring, Source Water (GWR)Back in compliance
  12. 2018-05-07Public NoticePN Violation for NPDWR ViolationSystem inactive
  13. 2018-04-13Public NoticePN Violation for NPDWR ViolationBack in compliance
  14. 2018-02-17Public Notice ×2PN Violation for NPDWR ViolationBack in compliance
  15. 2017-11-30Public NoticePN Violation for NPDWR ViolationBack in compliance
  16. 2017-11-24Revised Total Coliform RuleRPTBack in compliance
  17. 2017-11-24Revised Total Coliform RuleTTBack in compliance
  18. 2017-09-29Lead and Copper RuleLead Consumer NoticeBack in compliance
  19. 2017-08-13Public NoticePN Violation for NPDWR ViolationBack in compliance
  20. 2017-08-01Revised Total Coliform RuleMONBack in compliance
  21. 2017-07-01Consumer Confidence RuleCCR Complete Failure to ReportBack in compliance
  22. 2017-07-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  23. 2017-05-28Revised Total Coliform RuleTTSystem inactive
  24. 2017-04-01DieldrinMonitoring, RegularBack in compliance
  25. 2017-01-01Gross Beta Particle Activity ×2Monitoring, RegularBack in compliance
  26. 2017-01-01Tritium ×2Monitoring, RegularBack in compliance
  27. 2017-01-0138-Strontium-90 ×2Monitoring, RegularBack in compliance
  28. 2017-01-01ManMade Beta Particle and Photon Emitter ×2Monitoring, RegularBack in compliance
  29. 2017-01-01Bhc-Gamma ×2Monitoring, RegularBack in compliance
  30. 2017-01-01Methoxychlor ×2Monitoring, RegularBack in compliance
  31. 2017-01-01Toxaphene ×2Monitoring, RegularBack in compliance
  32. 2017-01-01Carbaryl ×2Monitoring, RegularBack in compliance
  33. 2017-01-01Methomyl ×2Monitoring, RegularBack in compliance
  34. 2017-01-01Dalapon ×2Monitoring, RegularBack in compliance
  35. 2017-01-01Diquat ×2Monitoring, RegularBack in compliance
  36. 2017-01-01Glyphosate ×2Monitoring, RegularBack in compliance
  37. 2017-01-01Di(2-ethylhexyl) adipate ×2Monitoring, RegularBack in compliance
  38. 2017-01-01Oxamyl ×2Monitoring, RegularBack in compliance
  39. 2017-01-01Simazine ×2Monitoring, RegularBack in compliance
  40. 2017-01-01Di(2-ethylhexyl) phthalate ×2Monitoring, RegularBack in compliance
  41. 2017-01-01Picloram ×2Monitoring, RegularBack in compliance
  42. 2017-01-01Dinoseb ×2Monitoring, RegularBack in compliance
  43. 2017-01-01Hexachlorocyclopentadiene ×2Monitoring, RegularBack in compliance
  44. 2017-01-01Aldicarb sulfoxide ×2Monitoring, RegularBack in compliance
  45. 2017-01-01Aldicarb sulfone ×2Monitoring, RegularBack in compliance
  46. 2017-01-01Metolachlor ×2Monitoring, RegularBack in compliance
  47. 2017-01-01Carbofuran ×2Monitoring, RegularBack in compliance
  48. 2017-01-01Aldicarb ×2Monitoring, RegularBack in compliance
  49. 2017-01-01Atrazine ×2Monitoring, RegularBack in compliance
  50. 2017-01-01Lasso ×2Monitoring, RegularBack in compliance
  51. 2017-01-01Heptachlor ×2Monitoring, RegularBack in compliance
  52. 2017-01-013-Hydroxycarbofuran ×2Monitoring, RegularBack in compliance
  53. 2017-01-01Heptachlor epoxide ×2Monitoring, RegularBack in compliance
  54. 2017-01-01Butachlor ×2Monitoring, RegularBack in compliance
  55. 2017-01-01Propachlor ×2Monitoring, RegularBack in compliance
  56. 2017-01-012, 4-D ×2Monitoring, RegularBack in compliance
  57. 2017-01-012, 4, 5-Tp ×2Monitoring, RegularBack in compliance
  58. 2017-01-01Hexachlorobenzene ×2Monitoring, RegularBack in compliance
  59. 2017-01-01Benzo(a)pyrene ×2Monitoring, RegularBack in compliance
  60. 2017-01-01Pentachlorophenol ×2Monitoring, RegularBack in compliance
  61. 2017-01-01Aldrin ×2Monitoring, RegularBack in compliance
  62. 2017-01-01Total Polychlorinated Biphenyls (PCB) ×2Monitoring, RegularBack in compliance
  63. 2017-01-01Dicamba ×2Monitoring, RegularBack in compliance
  64. 2017-01-01Metribuzin ×2Monitoring, RegularBack in compliance
  65. 2017-01-011, 2-Dibromo-3-Chloropropane ×2Monitoring, RegularBack in compliance
  66. 2017-01-01Ethylene Dibromide ×2Monitoring, RegularBack in compliance
  67. 2017-01-01Chlordane ×2Monitoring, RegularBack in compliance
  68. 2017-01-01DieldrinMonitoring, RegularBack in compliance
  69. 2017-01-01EndrinMonitoring, RegularBack in compliance
  70. 2017-01-01Selenium ×2Monitoring, RegularBack in compliance
  71. 2017-01-01Thallium, Total ×2Monitoring, RegularBack in compliance
  72. 2017-01-01Beryllium, Total ×2Monitoring, RegularBack in compliance
  73. 2017-01-01Antimony, Total ×2Monitoring, RegularBack in compliance
  74. 2017-01-01Sulfate ×2Monitoring, RegularBack in compliance
  75. 2017-01-01Sodium ×2Monitoring, RegularBack in compliance
  76. 2017-01-01Silver ×2Monitoring, RegularBack in compliance
  77. 2017-01-01Nickel ×2Monitoring, RegularBack in compliance
  78. 2017-01-01Mercury ×2Monitoring, RegularBack in compliance
  79. 2017-01-01Fluoride ×2Monitoring, RegularBack in compliance
  80. 2017-01-01Cyanide ×2Monitoring, RegularBack in compliance
  81. 2017-01-01Chromium ×2Monitoring, RegularBack in compliance
  82. 2017-01-01Chloride ×2Monitoring, RegularBack in compliance
  83. 2017-01-01Cadmium ×2Monitoring, RegularBack in compliance
  84. 2017-01-01Barium ×2Monitoring, RegularBack in compliance
  85. 2017-01-01Arsenic ×2Monitoring, RegularBack in compliance
  86. 2017-01-01Combined Radium (-226 and -228) ×2Monitoring, RegularBack in compliance
  87. 2017-01-01Combined Uranium ×2Monitoring, RegularBack in compliance
  88. 2017-01-01Gross Alpha, Excl. Radon and U ×2Monitoring, RegularBack in compliance
  89. 2016-11-04E. Coli ×2Monitoring, Source Water (GWR)Back in compliance
  90. 2016-09-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  91. 2016-08-04E. ColiMonitoring, Source Water (GWR)Back in compliance
  92. 2016-08-04E. ColiMonitoring, Source Water (GWR)System inactive
  93. 2016-08-01Revised Total Coliform RuleMONBack in compliance
  94. 2016-07-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  95. 2016-06-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  96. 2016-05-07Public NoticePN Violation for NPDWR ViolationBack in compliance
  97. 2016-05-01Revised Total Coliform RuleMONBack in compliance
  98. 2016-05-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  99. 2016-04-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  100. 2016-03-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  101. 2016-02-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  102. 2016-01-01Lead and Copper RuleInitial Tap Sampling for Pb and CuBack in compliance
  103. 2016-01-01Tritium ×2Monitoring, RegularBack in compliance
  104. 2015-12-01Coliform (TCR)Monitoring, Routine Major (TCR)Back in compliance
  105. 2015-11-01Coliform (TCR)MCL, Monthly (TCR)Back in compliance
  106. 2015-10-12Public NoticePN Violation for NPDWR ViolationBack in compliance
  107. 2015-08-01Coliform (TCR)MCL, Monthly (TCR)Back in compliance
  108. 2015-07-01Coliform (TCR)MCL, Monthly (TCR)Back in compliance

System details

Population served30
Service connections14
Water sourceGroundwater
System typeCommunity Water System
OwnerPrivate
StatusActive
CityOld Lyme
EPA ZIP on file06371

Areas served

  • East Haddam, Middlesex County

Reading this record

31 Grist Mill Rd is a community water system that draws from groundwater and serves about 30 people in Old Lyme, Connecticut. 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.