Adelaar WD

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

Serves: 1,000 people
Connections: 15
Water source: Surface water bought from another system
Based in: Thompson (T), NY
County: Sullivan
Owner: Local government

The short answer

Nothing in EPA’s and New York’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, not everything. No health-based violations on file since 2016.

What was found

Total trihalomethanes (TTHM) and haloacetic acids (HAA5): New York’s yearly summaries per water system, 2020 to 2024, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits2

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

54.2ppb

Highest yearly average, 2020 to 2024

2024 average: 27.5 ppb

Averaged by year, the highest was 54.2 ppb, in 2022, below EPA’s legal limit of 80 ppb. Its highest single sample was 69 ppb. In 2024, the latest year on file, it averaged 27.5 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 42.5 ppb, in 2017.

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

32.8ppb

Highest yearly average, 2020 to 2024

2024 average: 22.3 ppb

Averaged by year, the highest was 32.8 ppb, in 2022, below EPA’s legal limit of 60 ppb. Its highest single sample was 36 ppb. In 2024, the latest year on file, it averaged 22.3 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 21 ppb, in 2018.

What handles it

No certification claim covers this compound yet.

Violations since 2016

No health-based violations on file with EPA since 2016.

What this report can’t tell you

Everything else. Total trihalomethanes (TTHM) and haloacetic acids (HAA5) results here are New York’s own yearly summaries from 2020 on, with EPA’s national file for 2012 to 2019. Adelaar WD’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; New York’s yearly summaries cover 2020 to 2024.

Testing your own tap

Adelaar WD’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 New York certifies.

No lab New York certifies is within 75 miles of the area Adelaar WD serves on the state’s list. Some take samples by mail; the state’s page lists them all.

All 161 certified labs for New York