Aquarion - Lakeside
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
- 455 people
- Connections
- 201
- Water source
- Groundwater
- Based in
- Southbury, CT
- County
- New Haven
- Owner
- Private
The ZIP code it serves
The short answer
Nothing in EPA’s and CDC’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.
What was found
Total trihalomethanes (TTHM), haloacetic acids (HAA5), nitrate and arsenic: Connecticut’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.
Fluoride, chromium (total) and uranium: EPA’s compliance monitoring file, samples taken from May 16, 2012 to May 9, 2018. Newer results are in the utility’s annual water quality report.
Below EPA’s limits4
Total trihalomethanes (TTHM)
Forms or is added in treatment
10.5ppb
Highest yearly average, 2020 to 2023
2023 average: 5.0 ppb
Averaged by year, the highest was 10.5 ppb, in 2022, below EPA’s legal limit of 80 ppb. In 2023, the latest year on file, it averaged 5.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 10 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
4.5ppb
Highest yearly average, 2020 to 2023
2023 average: 1.5 ppb
Averaged by year, the highest was 4.5 ppb, in 2022, below EPA’s legal limit of 60 ppb. In 2023, the latest year on file, it averaged 1.5 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.0 ppb, in 2019.
What handles it
No certification claim covers this compound yet.
Nitrate
Comes from the source
0.41ppm
Highest yearly average, 2020 to 2023
2023 average: 0.25 ppm
Averaged by year, the highest was 0.41 ppm, in 2021, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 0.25 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.47 ppm, in 2017.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
Fluoride
Forms or is added in treatment
0.06ppm
Highest yearly average, 2012 to 2018
2018, one sample: 0.03 ppm
Averaged by year, the highest was 0.06 ppm, in 2015, below EPA’s legal limit of 4.0 ppm. In 2018, the latest year on file, its one sample was 0.03 ppm.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Lead
- Uranium
Violations since 2016
No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.
What this report can’t tell you
Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5), nitrate and arsenic results here are Connecticut’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride, chromium (total) and uranium come from EPA’s file alone, which ends in 2019. Aquarion - Lakeside’s own annual report, which it must send you every year, has newer results for those and 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 Connecticut cover 2020 to 2023; EPA’s compliance samples are from May 16, 2012 to May 9, 2018.
Testing your own tap
The 3 labs Connecticut certifies closest to the area Aquarion - Lakeside serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
ALS Environmental - Newtown
Newtown, CT · about 7 miles
Certified for bacteria, nitrate, metals, minerals and other inorganics, organic chemicals, radioactivity
Aquarion Water Trap Falls Water Quality Lab
Shelton, CT · about 13 miles
Certified for bacteria
Northwest Environmental Water Labs
Waterbury, CT · about 13 miles
Certified for bacteria, nitrate, metals, minerals and other inorganics
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- CDC Environmental Public Health Tracking Network, yearly averages Connecticut supplied to CDC, 2020 to 2023, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or Connecticut’s.
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Connecticut DPH, approved commercial laboratories certified to test drinking water, read Oct. 10, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID CT1300031. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and CDC’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportAquarion - Lakeside must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded