Community Water System · PWSID MO2024382

Mercer County Pwsd 1

Serves 3,200 peopleSurface Water PurchasedOwner: Local GovernmentMercer, Missouri
Nothing open right now.

On record since 2014: 8 violations. 1 over the limit · 4 missed or late tests · 3 notices or reports. Most recent began 2025-03-27.

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

1Over the limit
0Treatment lapse
4Missed or late test
3Notice or report

More violations on record than 66% of active water systems in Missouri. Small systems with no staff chemist often rack up missed-test violations; big utilities rarely do.

The record, year by year

200520102014 · Notice or report: 12015 · Over the limit: 1201520202023 · Missed or late test: 12024 · Missed or late test: 32024 · Missed or late test: 32024 · Missed or late test: 32025 · Notice or report: 22025 · Notice or report: 22025
One square = one violation, by the year it began. Empty columns are years with nothing on EPA's record.
13% over the limit · 150% missed or late test · 438% notice or report · 3

Across Missouri, 54% of violations are missed or late tests and 8% are water over a limit.

How far over the limit

at the limit2×5×10×100×+Trihalomethanes (TTHM)2015-07-01 · Trihalomethanes (TTHM): measured 83.00 UG/L vs limit 80.00 UG/L (1.0×)
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 6 results on file · action level 15 ppb

1.8 ppb
1.8 ppb
1.3 ppb
1.3 ppb
1.2 ppb
0 ppb

Every violation on record

  1. 2025-03-27Public NoticePN Violation for NPDWR ViolationBack in compliance
  2. 2025-03-05Public NoticePN Violation for NPDWR ViolationBack in compliance
  3. 2024-06-01Revised Total Coliform RuleMONBack in compliance
  4. 2024-02-01Revised Total Coliform RuleMONBack in compliance
  5. 2024-01-01Revised Total Coliform RuleMONBack in compliance
  6. 2023-11-01Revised Total Coliform RuleMONBack in compliance
  7. 2015-07-01Trihalomethanes (TTHM)MCL, Averagemeasured 83.00 UG/L · limit 80.00 UG/LBack in compliance
  8. 2014-07-01Consumer Confidence RuleCCR Complete Failure to ReportBack in compliance

System details

Population served3,200
Service connections1,525
Water sourceSurface Water Purchased
System typeCommunity Water System
OwnerLocal Government
StatusActive
CityMercer
EPA ZIP on file64661-0000

Areas served

  • Mercer

Reading this record

Mercer County Pwsd 1 is a community water system that draws from surface water purchased and serves about 3,200 people in Mercer, Missouri. 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.