Aquarion-Stamford water quality
Stamford, CT · serves 119,214 people (21,259 connections) · Surface water · Private · EPA ID CT1350011
Data: U.S. EPA · How we read the data · How we check it
Buys water from Aquarion-Eastern Fairfield County, Aquarion-Greenwich. Treated water bought from another system can carry that system's contaminants.
Summary
No federal limits exceeded in EPA data.
- PFAS
- Detected, below limit3 of 29 PFAS found at least once. All averages below the federal limits.
- Lead
- Below action level0 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period Jan 2026 – now, still in progress (results reported so far). Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Want to reduce what was found? Filters for these results.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Aquarion-Stamford's annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill, and you can also request it at (203) 926-4320. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 2 entry points tested Mar 2025 to Dec 2025. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA One sample above limit Limit 4 ppt | 2.13 ppt 53% of the limit |
| PFOS Not detected Limit 4 ppt | – |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Not detected Limit 1 | – |
| PFBS Not detected Guideline 2,000 ppt | – |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Detected, below limit Guideline 3,000 ppt | 0.75 ppt |
| PFPeA Detected, no limit | 0.78 ppt |
29 PFAS tested, 3 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Not detected in 8 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 0 ppb lead (Jan 2026 – now (in progress)). Below action level
Highest since 2016: 2 ppb (Dec 2021).
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2026 – now (in progress) | 0 ppb |
| Jan 2025 – Dec 2025 | 0 ppb |
| Jan 2024 – Dec 2024 | 0 ppb |
Earlier results (9)
| Jan 2023 – Dec 2023 | 0 ppb |
| Jan 2022 – Dec 2022 | 0 ppb |
| Jan 2021 – Dec 2021 | 2 ppb |
| Jul 2020 – Dec 2020 | 2 ppb |
| Jan 2020 – Dec 2020 | 0 ppb |
| Jan 2020 – Jun 2020 | 0 ppb |
| Jul 2019 – Dec 2019 | 1 ppb |
| Jan 2019 – Dec 2019 | 0 ppb |
| Jan 2019 – Jun 2019 | 0 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 4.37 ppb | 300 ppb |
| Chromium-6 | 0.16 ppb | – |
| Strontium | 0.091 ppm | 1.5 ppm |
| Chlorate | 220 ppb | 210 ppb |
| Vanadium | 0.71 ppb | 21 ppb |
Where it serves
Stamford, Greenwich, Darien
ZIP codes the system reported serving: 06831, 06901, 06902, 06903, 06904, 06905, 06906, 06907, 06908, 06909, 06910
Nearby utilities
- Aquarion-Greenwich Greenwich · 5 mi · PFAS above limit
- Norwalk First Taxing District Norwalk · 7 mi · PFAS above limit
- Aquarion-Eastern Fairfield County Fairfield · 16 mi
- Aquarion-Ridgefield Ridgefield · 17 mi · PFAS above limit
- Bethel Water Dept Bethel · 22 mi · PFAS above limit
- Danbury Water Department Danbury · 22 mi · PFAS above limit
Questions
Is Aquarion-Stamford water safe to drink?
Aquarion-Stamford has no health-based violations since 2016. EPA testing found no PFAS above the federal limits. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Aquarion-Stamford water have PFAS?
Yes. EPA's 2023–2025 testing of Aquarion-Stamford found 3 PFAS at least once. None of the averages were above the federal limits.
What is the lead level in Aquarion-Stamford water?
The most recent 90th-percentile lead result for Aquarion-Stamford is 0 ppb, for the monitoring period that began Jan 2026 (still in progress). The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for CT1350011: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID CT1350011).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Aquarion-Stamford at (203) 926-4320, or see EPA's guide to finding it.
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.