Water Quality in Lewiston, ME

Lewiston's water quality is good overall. Hardness is low at 37 PPM, and no contaminants exceed health guidelines. Most homes here do not need a water softener.

Lewiston-Auburn Water District · Source: Lake Auburn · Serves 37,121 residents

37
Hardness (PPM)
39
TDS (PPM)
1.2
Chlorine (mg/L)
3
PFAS (ppt)
4
Lead (ppb)
37 PPM 0 400 Slightly Hard
CONTAMINANT LEVELS Hardness 37 PPM TDS 39 PPM PFAS 3 ppt Lead 4 ppb Chlorine 1.2 mg/L Nitrate 2 mg/L

Hardness Scale: Where Lewiston Falls

Soft 060120180250400+
Generally good quality

Lewiston-Auburn share one of only 50 unfiltered surface water systems in the US. Lake Auburn's water is exceptionally soft and clean.

What Lewiston's Water Means for Your Home

Lewiston's water is slightly hard at 37 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 Lewiston, focus on contaminant filtration rather than softening.

Beyond hardness, Lewiston's water quality is generally within EPA guidelines for regulated contaminants. Chlorine is present at 1.2 mg/L as a disinfectant residual, which is normal for municipal water systems. If you notice a pool-like taste or experience dry skin, a whole-house carbon filter is the most common and affordable solution. For homeowners who want to understand the full picture, requesting your utility's annual Consumer Confidence Report provides neighborhood-level data.

ContaminantDetectedHealth GuidelineLegal LimitStatus
Hardness (as CaCO₃)37 PPM< 60 PPMNo federal limit✓ OK
Total Dissolved Solids39 PPM< 300 PPM500 PPM✓ OK
PFAS (total)3 ppt4 ppt (EPA)4 ppt (2024)✓ OK
Lead4 ppb0 ppb (no safe level)15 ppb (action level)✓ Low
Chlorine / Chloramine1.2 mg/LTaste threshold ~1.04.0 mg/L✓ Normal
Nitrate2 mg/L5 mg/L10 mg/L✓ OK

Good news for ${esc(c.city)} residents. Your water quality is generally good. Most homes in this area do not need a water softener. If you have concerns about lead (especially in buildings constructed before 1986) or chlorine taste, a point-of-use filter is the most practical and cost-effective solution.

About Lewiston's Water Supply

Water Utility: Lewiston-Auburn Water District

Water Source: Lake Auburn

Population Served: 37,121

Hardness: 37 PPM (2.2 grains per gallon)

Water quality can vary by neighborhood and season. The values above represent typical averages reported by Lewiston-Auburn Water District. 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 Lewiston to Other Maine Cities

Portland

10 PPM · Soft

Bangor

44 PPM · Slightly Hard

Frequently Asked Questions About Lewiston Water

Is Lewiston tap water safe to drink?
Lewiston's water meets EPA legal standards for drinking water safety. However, legal limits and health-optimal levels are different things. 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 Lewiston?
Probably not. At 37 PPM, Lewiston's water is on the softer end. Most homes will not experience noticeable scale buildup. That said, if you have high-end fixtures, a glass shower enclosure, or a tankless water heater, even mild hardness can leave mineral deposits over time. A salt-free conditioner is a low-cost insurance policy in that case.
What water filter is best for Lewiston?
The best filter depends on which contaminants you want to address. See our softener vs. filter guide to understand the difference between these categories.
Where does Lewiston's water come from?
Lewiston's drinking water is sourced from Lake Auburn and treated by Lewiston-Auburn Water District. Lewiston-Auburn share one of only 50 unfiltered surface water systems in the US. Lake Auburn's water is exceptionally soft and clean.
What is the hardness of Lewiston water in grains per gallon?
Lewiston's water hardness is 2.2 grains per gallon (GPG), which equals 37 parts per million (PPM). This is classified as slightly hard. To convert: 1 GPG = 17.1 PPM.
Does Lewiston water damage tankless water heaters?
At 2.2 GPG, Lewiston'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 Lewiston water safe for babies and infants?
Lewiston's water meets all EPA safety standards and is generally considered safe for preparing infant formula. The hardness minerals (calcium and magnesium) are not harmful. If your home has older plumbing, running cold water for 30 seconds before use is a good precaution to flush any lead from pipes.

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