Is San Francisco, California Shower Water Safe? What's In Your Water (2026)
Khat Cruz
Is San Francisco, California Shower Water Safe?
Population: 808,988 · Water Source: Hetch Hetchy Reservoir (Yosemite National Park), Local Groundwater
Understanding what's in your shower water is crucial for your health and well-being in San Francisco. While the city's tap water meets federal standards for drinking, certain contaminants can impact your skin, hair, and respiratory health, especially during a hot shower. Don't let unknown elements compromise your daily routine; empower yourself with knowledge about San Francisco's water quality.
💧 Where Does San Francisco's Water Come From?
Primary Source: Hetch Hetchy Reservoir (Yosemite National Park), Local Groundwater
San Francisco's primary water supply comes from the pristine Hetch Hetchy watershed in Yosemite National Park, a protected mountain source that requires minimal treatment. This high-quality water is supplemented by local groundwater sources, particularly during dry periods or to meet peak demands. The SFPUC manages an extensive system of reservoirs, pipelines, and treatment facilities to deliver water to residents.
Treatment: Filtration, Disinfection (Chloramination), pH Adjustment, Fluoridation
🔬 What's In San Francisco's Shower Water?
Here are the key contaminants detected in San Francisco's water supply based on real testing data from the EWG Tap Water Database:
| Contaminant | Level Found | EPA Limit | EWG Guideline | Status |
|---|---|---|---|---|
| Haloacetic acids (HAA9) | 39.48 ppb | No federal limit | 0.060 ppb | ⚠️ Exceeds EWG Health Guideline (658x above) |
| Haloacetic acids (HAA5) | 34.40 ppb | 60.0 ppb | 0.100 ppb | ⚠️ Exceeds EWG Health Guideline (344x above) |
| Total trihalomethanes (TTHMs) | 33.25 ppb | 80.0 ppb | 0.150 ppb | ⚠️ Exceeds EWG Health Guideline (222x above) |
| Trichloroacetic acid | 9.57 ppb | No federal limit | 0.100 ppb | ⚠️ Exceeds EWG Health Guideline (96x above) |
| Dichloroacetic acid | 17.13 ppb | No federal limit | 0.200 ppb | ⚠️ Exceeds EWG Health Guideline (86x above) |
| Chloroform | 30.37 ppb | No federal limit | 0.400 ppb | ⚠️ Exceeds EWG Health Guideline (76x above) |
| Bromodichloromethane | 2.33 ppb | No federal limit | 0.060 ppb | ⚠️ Exceeds EWG Health Guideline (39x above) |
| Nitrate | 3.28 ppm | 10.0 ppm | 0.140 ppm | ⚠️ Exceeds EWG Health Guideline (23x above) |
| Nitrate and nitrite | 2.95 ppm | 10.0 ppm | 0.140 ppm | ⚠️ Exceeds EWG Health Guideline (21x above) |
| Arsenic | 0.079 ppb | 10.0 ppb | 0.0040 ppb | ⚠️ Exceeds EWG Health Guideline (20x above) |
Contaminant Details
Haloacetic acids (HAA9)
The health guideline of 0.06 ppb for haloacetic acids (HAA9) was defined by EWG . This health guideline protects against cancer.
Comparison: State average: 15.50 ppb. National average: 23.70 ppb.
Shower Impact: These disinfection byproducts become airborne in hot shower steam. You can inhale and absorb them through your skin, potentially increasing your exposure beyond just drinking water.
Haloacetic acids (HAA5)
The health guideline of 0.1 ppb for haloacetic acids (HAA5) was defined by as . This health guideline protects against cancer.
Comparison: State average: 35.45 ppb. National average: 19.82 ppb.
Shower Impact: These disinfection byproducts become airborne in hot shower steam. You can inhale and absorb them through your skin, potentially increasing your exposure beyond just drinking water.
Total trihalomethanes (TTHMs)
The health guideline of 0.15 ppb for trihalomethanes was defined by in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level. as a draft public health goal, the level of drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.
Comparison: State average: 27.09 ppb. National average: 29.06 ppb.
Shower Impact: These disinfection byproducts become airborne in hot shower steam. You can inhale and absorb them through your skin, potentially increasing your exposure beyond just drinking water.
Trichloroacetic acid
The health guideline of 0.1 ppb for trichloroacetic acid was defined by the Environmental Protection Agency as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Comparison: State average: 3.71 ppb. National average: 6.57 ppb.
Shower Impact: These disinfection byproducts become airborne in hot shower steam. You can inhale and absorb them through your skin, potentially increasing your exposure beyond just drinking water.
Dichloroacetic acid
The health guideline of 0.2 ppb for dichloroacetic acid was defined by the Environmental Protection Agency as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Comparison: State average: 4.69 ppb. National average: 8.00 ppb.
Shower Impact: These disinfection byproducts become airborne in hot shower steam. You can inhale and absorb them through your skin, potentially increasing your exposure beyond just drinking water.
Chloroform
The health guideline of 0.4 ppb for chloroform was defined by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Comparison: State average: 10.45 ppb. National average: 16.20 ppb.
Shower Impact: These disinfection byproducts become airborne in hot shower steam. You can inhale and absorb them through your skin, potentially increasing your exposure beyond just drinking water.
Bromodichloromethane
The health guideline of 0.06 ppb for bromodichloromethane was defined by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Comparison: State average: 5.64 ppb. National average: 5.89 ppb.
Shower Impact: These disinfection byproducts become airborne in hot shower steam. You can inhale and absorb them through your skin, potentially increasing your exposure beyond just drinking water.
Nitrate
The health guideline of 0.14 ppm for nitrate was defined in a peer-reviewed scientific study by EWG and corresponds to one-in-one-million annual cancer risk level.
Comparison: State average: 1.21 ppm. National average: 0.824 ppm.
Shower Impact: While primarily a drinking water concern, nitrates can contribute to skin irritation during extended shower exposure.
Nitrate and nitrite
The health guideline of 0.14 ppm for nitrate and nitrite was defined by based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. . This health guideline protects against one-in-one-million annual cancer risk level.
Comparison: State average: 0.972 ppm. National average: 0.780 ppm.
Shower Impact: While primarily a drinking water concern, nitrates can contribute to skin irritation during extended shower exposure.
Arsenic
The health guideline of 0.004 ppb for arsenic was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.
Comparison: State average: 0.899 ppb. National average: 0.624 ppb.
Shower Impact: Arsenic in shower water can be absorbed through the skin. Long hot showers increase exposure time and absorption.
🧴 How San Francisco's Water Affects Your Skin, Hair & Health
When you shower, contaminants in the water don't just wash off — they're absorbed through your skin and inhaled as steam. Here's how San Francisco's water quality may be affecting you:
🧖 Skin Effects
- Dry, itchy skin due to chloramine stripping natural oils.
- Exacerbation of eczema and other skin sensitivities.
- Potential for allergic reactions or rashes from chemical contaminants.
- Premature aging or dullness from oxidative stress.
💇 Hair Effects
- Dry, brittle, and damaged hair from chloramine exposure.
- Fading of hair color and reduced vibrancy.
- Scalp irritation and flakiness.
- Lack of lather from soaps and shampoos (less common with SF's soft water, but can occur).
🫁 Respiratory Effects
- Inhalation of chloramine and disinfection byproducts (TTHMs, HAA5) in steam.
- Irritation of nasal passages and lungs.
- Worsening of asthma or other respiratory conditions.
- Potential long-term health risks from chronic inhalation of volatile organic compounds.
✅ What You Can Do About It
Test Your Shower Water
Get a home water test kit or professional analysis to know the exact levels of contaminants in your specific San Francisco home's shower water. This provides personalized data beyond city averages.
Install a Quality Shower Filter
A high-quality shower filter can significantly reduce chloramines, chlorine, heavy metals, and disinfection byproducts, improving water quality for skin, hair, and respiratory health.
Ventilate Your Bathroom
Ensure good ventilation during and after showering by using an exhaust fan or opening a window. This helps to reduce the concentration of chemical vapors in the air.
Limit Shower Time and Temperature
Shorter, cooler showers can reduce exposure to volatile contaminants and prevent excessive stripping of natural skin and hair oils, especially for sensitive individuals.
Moisturize Immediately After Showering
Apply a good moisturizer to damp skin immediately after showering to lock in hydration and counteract the drying effects of treated water.
Protect Your Skin & Hair From San Francisco's Water
The easiest way to remove chlorine, heavy metals, and other contaminants from your shower water.
Shop Afina Filtered Showerheads →🛒 Recommended Products for San Francisco Residents
Afina Filtered Showerhead
15-stage filtered showerhead that removes chlorine, heavy metals, and other contaminants while providing great water pressure.
✨ All-in-one solution — filters water and gives you a premium shower experience
Shop Now →Afina Shower Filter
Universal shower filter that attaches to any existing showerhead. Removes chlorine, chloramine, and sediment.
✨ Keep your current showerhead and add powerful filtration
Shop Now →Afina Replacement Filter
Replacement filter cartridge for Afina shower filters. Lasts up to 6 months or 10,000 gallons.
✨ Easy replacement every 2-3 months to maintain peak filtration
Shop Now →❓ Frequently Asked Questions
Related Reading
- why your skin feels dry after showering
- nitrate contamination in water
- arsenic in your water supply
- shower water quality in Anaheim, California
- shower water quality in Bakersfield, California
Is San Francisco tap water safe to shower in?
While San Francisco's tap water meets federal drinking water standards, showering introduces unique exposure routes like skin absorption and inhalation of steam. Contaminants like chloramines and disinfection byproducts can still impact sensitive individuals or those with specific health concerns, making it important to understand your personal risk.
Does San Francisco's water cause dry skin or hair damage?
Yes, the chloramines used for disinfection in San Francisco's water can strip natural oils from your skin and hair, leading to dryness, irritation, and damage over time. This effect can be more pronounced for individuals with sensitive skin, eczema, or color-treated hair.
What are disinfection byproducts and why are they in my shower water?
Disinfection byproducts (DBPs) like TTHMs and HAA5 form when disinfectants like chloramine react with natural organic matter in the water. These compounds are volatile and can vaporize into the air during hot showers, leading to inhalation and skin absorption, posing potential long-term health risks.
How effective are shower filters for San Francisco water?
High-quality shower filters can be very effective at reducing a range of contaminants found in San Francisco's water, including chloramines, heavy metals, and DBPs. Look for filters specifically designed to address these compounds to protect your skin, hair, and respiratory health.
Is San Francisco's water hard or soft?
San Francisco's primary Hetch Hetchy water source is generally considered very soft. However, local groundwater sources can vary in hardness. Soft water is typically better for skin and hair, reducing mineral buildup, but it doesn't eliminate concerns about chemical disinfectants or other contaminants.
