Water Quality in Stamford, CT

Stamford's water quality is good overall. Hardness is low at 22 PPM, and no contaminants exceed health guidelines. Most homes here do not need a water softener.

Aquarion Water · Source: Reservoirs · Serves 135,470 residents

22
Hardness (PPM)
49
TDS (PPM)
1.1
Chlorine (mg/L)
4
PFAS (ppt)
7
Lead (ppb)
22 PPM 0 400 Slightly Hard
CONTAMINANT LEVELS Hardness 22 PPM TDS 49 PPM PFAS 4 ppt Lead 7 ppb Chlorine 1.1 mg/L Nitrate 1 mg/L

Hardness Scale: Where Stamford Falls

Soft 060120180250400+
Elevated lead

Stamford's protected reservoir system in Fairfield County produces soft water typical of New England granite geology.

What Stamford's Water Means for Your Home

Stamford's water is slightly hard at 22 PPM. At this level, hard water is not a significant concern for most households. Scale buildup is minimal, and a water softener would provide little measurable benefit. If you are considering water treatment in Stamford, focus on contaminant filtration rather than softening.

Lead is the primary water quality concern for Stamford homes, especially those built before 1986 when lead solder was still legal in plumbing. At 7 ppb, Stamford's average lead level is above the health guideline of zero. Lead enters water from service lines and interior plumbing, not from the water source itself. Running cold water for 30 seconds before use reduces exposure, and a certified lead-reduction filter at the kitchen faucet provides ongoing protection.

ContaminantDetectedHealth GuidelineLegal LimitStatus
Hardness (as CaCO₃)22 PPM< 60 PPMNo federal limit✓ OK
Total Dissolved Solids49 PPM< 300 PPM500 PPM✓ OK
PFAS (total)4 ppt4 ppt (EPA)4 ppt (2024)✓ OK
Lead7 ppb0 ppb (no safe level)15 ppb (action level)⚠ Elevated
Chlorine / Chloramine1.1 mg/LTaste threshold ~1.04.0 mg/L✓ Normal
Nitrate1 mg/L5 mg/L10 mg/L✓ OK

Recommendations for Stamford Homes

⚠️ Lead-Reduction Filter
Lead detected at 7 ppb. There is no safe level of lead in drinking water, and children are especially vulnerable. Lead typically enters water from old plumbing, not the source water. A point-of-use filter certified to NSF/ANSI Standard 53 for lead is the most practical solution. If your home was built before 1986, testing is strongly recommended.
Learn more about this solution →

About Stamford's Water Supply

Water Utility: Aquarion Water

Water Source: Reservoirs

Population Served: 135,470

Hardness: 22 PPM (1.3 grains per gallon)

Water quality can vary by neighborhood and season. The values above represent typical averages reported by Aquarion Water. To get exact numbers for your address, request a copy of the most recent Consumer Confidence Report (CCR) from your utility, or have your water independently tested.

Compare Stamford to Other Connecticut Cities

Bridgeport

41 PPM · Slightly Hard

Hartford

48 PPM · Slightly Hard

New Haven

34 PPM · Slightly Hard

Waterbury

55 PPM · Slightly Hard

Danbury

50 PPM · Slightly Hard

Frequently Asked Questions About Stamford Water

Is Stamford tap water safe to drink?
Stamford's water meets EPA legal standards for drinking water safety. However, legal limits and health-optimal levels are different things. Lead levels are elevated. This is especially concerning in older buildings with lead service lines or lead solder. Review the contaminant table above for specific numbers and how they compare to both legal limits and health guidelines.
Do I need a water softener in Stamford?
No. At 22 PPM, Stamford's water is very soft. A water softener would provide no benefit here. Focus on filtration if you have specific contaminant concerns.
What water filter is best for Stamford?
The best filter depends on which contaminants you want to address. For lead, look for NSF/ANSI Standard 53 certification specifically for lead reduction. Point-of-use filters at the kitchen faucet are the most practical approach. See our softener vs. filter guide to understand the difference between these categories.
Where does Stamford's water come from?
Stamford's drinking water is sourced from Reservoirs and treated by Aquarion Water. Stamford's protected reservoir system in Fairfield County produces soft water typical of New England granite geology..
What is the hardness of Stamford water in grains per gallon?
Stamford's water hardness is 1.3 grains per gallon (GPG), which equals 22 parts per million (PPM). This is classified as slightly hard. To convert: 1 GPG = 17.1 PPM.
Does Stamford water damage tankless water heaters?
At 1.3 GPG, Stamford's water is unlikely to cause significant issues for tankless water heaters. However, if you notice reduced flow or efficiency over time, scale buildup could be a factor. Annual flushing with vinegar is good maintenance regardless of hardness.
Is Stamford water safe for babies and infants?
Lead is the primary concern for infants and young children. Stamford's lead level of 7 ppb is elevated. Run the cold water tap for 30 seconds before using it for formula or cooking, and consider a certified lead-reduction filter for the kitchen faucet.

Data sources. Water quality data compiled from EPA SDWIS, EWG Tap Water Database, USGS water hardness studies, and the Aquarion Water Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.