Water Quality in Daly City, CA

Daly City's water quality is good overall. Hardness is low at 34 PPM, and no contaminants exceed health guidelines. Most homes here do not need a water softener.

City of Daly City · Source: SFPUC Hetch Hetchy · Serves 104,901 residents

34
Hardness (PPM)
55
TDS (PPM)
0.7
Chlorine (mg/L)
4
PFAS (ppt)
2
Lead (ppb)
34 PPM 0 400 Slightly Hard
CONTAMINANT LEVELS Hardness 34 PPM TDS 55 PPM PFAS 4 ppt Lead 2 ppb Chlorine 0.7 mg/L Nitrate 2 mg/L

Hardness Scale: Where Daly City Falls

Soft 060120180250400+
Generally good quality

Daly City receives nearly pure Hetch Hetchy water from Yosemite, among the softest municipal water supplies in California.

What Daly City's Water Means for Your Home

Daly City's water is slightly hard at 34 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 Daly City, focus on contaminant filtration rather than softening.

Beyond hardness, Daly City's water quality is generally within EPA guidelines for regulated contaminants. Chlorine is present at 0.7 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)34 PPM< 60 PPMNo federal limit✓ OK
Total Dissolved Solids55 PPM< 300 PPM500 PPM✓ OK
PFAS (total)4 ppt4 ppt (EPA)4 ppt (2024)✓ OK
Lead2 ppb0 ppb (no safe level)15 ppb (action level)✓ Low
Chlorine / Chloramine0.7 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 Daly City's Water Supply

Water Utility: City of Daly City

Water Source: SFPUC Hetch Hetchy

Population Served: 104,901

Hardness: 34 PPM (2 grains per gallon)

Water quality can vary by neighborhood and season. The values above represent typical averages reported by City of Daly City. 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 Daly City to Other California Cities

Los Angeles

180 PPM · Hard

San Diego

200 PPM · Very Hard

San Jose

183 PPM · Very Hard

San Francisco

21 PPM · Slightly Hard

Fresno

126 PPM · Hard

Sacramento

18 PPM · Slightly Hard

Frequently Asked Questions About Daly City Water

Is Daly City tap water safe to drink?
Daly City'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 Daly City?
Probably not. At 34 PPM, Daly City'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 Daly City?
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 Daly City's water come from?
Daly City's drinking water is sourced from SFPUC Hetch Hetchy and treated by City of Daly City. Daly City receives nearly pure Hetch Hetchy water from Yosemite, among the softest municipal water supplies in California..
What is the hardness of Daly City water in grains per gallon?
Daly City's water hardness is 2 grains per gallon (GPG), which equals 34 parts per million (PPM). This is classified as slightly hard. To convert: 1 GPG = 17.1 PPM.
Does Daly City water damage tankless water heaters?
At 2 GPG, Daly City'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 Daly City water safe for babies and infants?
Daly City'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 City of Daly City Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.