Water Quality in San Francisco, CA
San Francisco's water quality is good overall. Hardness is low at 21 PPM, and no contaminants exceed health guidelines. Most homes here do not need a water softener.
Hardness Scale: Where San Francisco Falls
Among the nation's best tap water from Hetch Hetchy. Lead in building plumbing is the only real concern.
What San Francisco's Water Means for Your Home
San Francisco's water is slightly hard at 21 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 San Francisco, focus on contaminant filtration rather than softening.
Beyond hardness, San Francisco'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.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 21 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 34 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 3 ppt | 4 ppt (EPA) | 4 ppt (2024) | ✓ OK |
| Lead | 2 ppb | 0 ppb (no safe level) | 15 ppb (action level) | ✓ Low |
| Chlorine / Chloramine | 0.7 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 1 mg/L | 5 mg/L | 10 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 San Francisco's Water Supply
Water Utility: SFPUC
Water Source: Hetch Hetchy (Yosemite)
Population Served: 873,965
Hardness: 21 PPM (1.2 grains per gallon)
Water quality can vary by neighborhood and season. The values above represent typical averages reported by SFPUC. 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 San Francisco to Other California Cities
Frequently Asked Questions About San Francisco Water
Is San Francisco tap water safe to drink?
Do I need a water softener in San Francisco?
What water filter is best for San Francisco?
Where does San Francisco's water come from?
What is the hardness of San Francisco water in grains per gallon?
Does San Francisco water damage tankless water heaters?
Is San Francisco water safe for babies and infants?
Data sources. Water quality data compiled from EPA SDWIS, EWG Tap Water Database, USGS water hardness studies, and the SFPUC Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.