Skip to content
TapBuff
ZIP

Green Castle PWS

What EPA’s and CDC’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
212 people
Connections
121
Water source
Surface water bought from another system
Based in
Green Castle, MO
County
Sullivan
Owner
Local government
The ZIP code it serves

63544

The short answer

1 result is above the health goal. The worst: Lead, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2016 to 2024.

Total trihalomethanes (TTHM) and haloacetic acids (HAA5): Missouri’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

9.9ppb

90th percentile, 2022 to 2024

In the latest period, 9 in 10 homes sampled were at or below 9.9 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits2

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

64.6ppb

Highest yearly average, 2020 to 2023

2023 average: 37 ppb

Averaged by year, the highest was 64.6 ppb, in 2022, below EPA’s legal limit of 80 ppb. In 2023, the latest year on file, it averaged 37 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 78.6 ppb, in 2019.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

48ppb

Highest yearly average, 2020 to 2023

2023 average: 24.9 ppb

Averaged by year, the highest was 48 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2023, the latest year on file, it averaged 24.9 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 45.8 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best water filters for lead, ranked

Violations since 2016

No health-based violations on file with EPA since 2016. There are 6 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM) and haloacetic acids (HAA5) results here are Missouri’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Green Castle PWS’s own annual report, which it must send you every year, has the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; CDC’s yearly averages for Missouri cover 2020 to 2023.

Testing your own tap

Green Castle PWS’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Missouri certifies.

The 3 labs Missouri certifies closest to the area Green Castle PWS serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • North Central Missouri Regional Water Commission

    Milan, MO · about 16 miles

    Certified for bacteria

    (660) 256-3807

  • Microbac Laboratories Inc.-Centerville

    Centerville, IA · about 32 miles

    Certified for bacteria

    (641) 792-8451

  • Rathbun Regional Water Association

    Centerville, IA · about 32 miles

    Certified for bacteria

    (641) 647-2416

Missouri State Public Health Laboratory: Coliform and E. coli testing for private wells and other private drinking water sources, in kits from your local public health agency. A free state courier can carry the sample to the lab overnight. The handling fee is $10, by check or money order. Private Drinking Water Bacteriological Testing, Missouri Department of Health and Senior Services.

All 64 certified labs for Missouri

Sources

PWSID MO2010328. Rebuilt from EPA data on Oct. 18, 2026.

Nearby

All Missouri utilities

What to do next