Downing, LLC
What EPA’s and Florida’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
- 67 people
- Connections
- 18
- Water source
- Groundwater
- Based in
- Dover, FL
- County
- Hillsborough
- Owner
- Private
The ZIP code it serves
The short answer
Nothing in EPA’s and Florida’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), fluoride, nitrate, arsenic and chromium (total): Florida’s own results, samples taken from Sept. 10, 2020 to Aug. 11, 2024, with EPA’s 2012 to 2019 file for earlier years.
Uranium: EPA’s compliance monitoring file, samples taken from Dec. 4, 2012 to Dec. 4, 2012. Newer results are in the utility’s annual water quality report.
Below EPA’s limits4
Total trihalomethanes (TTHM)
Forms or is added in treatment
34.7ppb
Highest yearly average, 2021 to 2024
2024, one sample: 21.2 ppb
Averaged by year, the highest was 34.7 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2024, the latest year on file, its one sample was 21.2 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 26 ppb, in 2015.
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
19.8ppb
Highest yearly average, 2021 to 2024
Averaged by year, the highest was 19.8 ppb, in 2024, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 16.1 ppb, in 2018.
What handles it
No certification claim covers this compound yet.
Fluoride
Forms or is added in treatment
0.46ppm
Highest yearly average, 2021 to 2024
2024 average: 0.42 ppm
Averaged by year, the highest was 0.46 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.5 ppm. In 2024, the latest year on file, its three samples averaged 0.42 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.5 ppm, in 2015.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Nitrate
Comes from the source
0.36ppm
Highest sample; found in 1 of 4
2024: not found
The highest sample, in 2020, was 0.36 ppm, below EPA’s legal limit of 10 ppm. In 2024, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 5.0 ppm, in 2019.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
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.
What this report can’t tell you
Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, nitrate, arsenic and chromium (total) results here are Florida’s own from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. Downing, LLC’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; Florida’s results run from Sept. 10, 2020 to Aug. 11, 2024; EPA’s compliance samples are from Dec. 4, 2012 to Dec. 4, 2012.
Testing your own tap
The 3 labs Florida certifies closest to the area Downing, LLC serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Advanced Environmental Laboratories, Inc. - Tampa
Tampa, FL · about 10 miles
Certified for bacteria, lead and copper, minerals and other inorganics, organic chemicals, disinfection byproducts
Hillsborough County Environmental Laboratory
Tampa, FL · about 10 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics
KNL Environmental Testing
Tampa, FL · about 15 miles
Certified for bacteria, radioactivity
Florida Department of Health Bureau of Public Health Laboratories: Coliform and E. coli testing for private wells at the Jacksonville and Miami labs. Collection kits come from your county health department, and the sample has to reach the lab on ice the same day it is collected. $40 for private testing through the state lab. Well Water Testing, Florida Department of Health.
All 212 certified labs for FloridaSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Florida Department of Environmental Protection, Drinking Water Program, results from Jan. 2, 2020 to Dec. 31, 2024, read Oct. 8, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Florida Department of Health Environmental Laboratory Certification Program, drinking water labs, as listed in TNI LAMS, read Oct. 11, 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 FL6295151. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and Florida’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 reportDowning, LLC 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