San Francisco Water Quality Analysis

Who Regulates San Francisco’s Water Supply?

That tap water isn’t going to regulate itself!

In order to ensure safe drinking water, several local and national organizations are hard at work, including:

• The Environmental Protection Agency (EPA) and the California State Water Resources Control Board (SWRCB) set national contaminant limits for public water systems. 
• The Food and Drug Administration (FDA) regulates contaminants in bottled water.  
• The San Francisco Public Utilities Commission (SFPUC) conducts daily treating and testing of local water supplies. 

Here’s what the SFPUC found in their latest water quality report:

San Francisco Public Utilities Commission Water Quality Report

In the SFPUC’s latest water quality report, San Francisco’s water was below the legal limit of all 120+ contaminants regulated by the EPA. 

That means that according to the government, your water is healthy and safe to drink. 

With that said, they did find a few unregulated contaminants above levels they’d normally like to see, including boron and PFAs...

Boron is a naturally occurring element that enters the water from rocks and soil. 

In San Francisco’s Alameda Watershed, boron was detected at a level of 1.06 parts per million (ppm). Although this is higher than previous reports, it’s still considered safe to drink. 

The report also found trace amounts of PFAS in the city’s distribution system. 

PFAS, or per- and polyfluoroalkyl substances, are a group of man-made chemicals used in a variety of consumer products, like Teflon and water-proof materials. 

On the brightside, no PFAS were detected in watersheds or other surface water sources. 

Considering how common PFAS are throughout the country, this is a big win!

Environmental Working Group Water Quality Report 

The Environmental Working Group (EWG) is a non-profit organization that compiles data from a variety of water quality reports, including the EPA and the California State Water Resources Control Board. 

Overall, the EWG has much stricter health standards than the EPA. 

They believe that the EPA’s standards are outdated, considering that the list of regulated contaminants hasn’t been updated for more than 20 years. 

In the EWG’s latest report, they found only three contaminants at alarming levels, including:

• Chromium: 4.5x EWG HEALTH GUIDELINES
• Haloacetic acids: 315x EWG HEALTH GUIDELINES
• Total trihalomethanes: 259x EWG HEALTH GUIDELINES

Compared to most other major US cities, these numbers are still quite good.

Where Does San Francisco Get Its Water?

San Francisco gets its drinking water from a large network of surface water supplies and underground aquifers that span across several counties. 

Most of the surface water comes from reservoirs in the Sierra Nevadas, Alameda County and San Mateo County. 

Groundwater sources come from aquifers in San Francisco County and San Mateo County.

This diverse mix ensures that water supplies stay consistent during natural disasters and droughts.

Treating San Francisco’s Drinking Water

San Francisco’s surface water undergoes extensive treatment before it reaches your tap, including:

• Ultraviolet (UV) light disinfection: Kills harmful microorganisms by blasting them with ultraviolet spectrum light.
• Chlorine disinfection: A chemical disinfectant that’s added to distribution pipes to destroy bacteria and viruses on contact.
• Chloramine disinfection: A chemical disinfectant similar to chlorine but that produces fewer unhealthy byproducts. 
• pH adjustment: Controlling the water’s pH (acidity level) helps prevent corrosion in distribution pipes. 
• Filtration: Removes sediment, rust, dirt, debris and other large contaminants.
• Fluoridation: A nationally mandated treatment for dental health and cavity prevention.

Although the EPA considers chlorine, chloramine and fluoridation to be safe, not all health experts agree…

Chlorine and chloramine produce disinfection byproducts (DBPs) when mixed with organic matter in water. Some research shows that DBPs may cause side effects like spontaneous abortions, stillbirth and birth defects.

Although fluoridation’s side effects are less serious, long-term exposure may cause children to develop tiny white lines or streaks in their teeth. 

Luckily, in-home water filters can remove up to 99.9% of DBPs and fluoride from your tap water, but more on that in a sec…

For now, let’s take a closer look at how San Francisco tests and monitors their tap water:

Testing and Monitoring Water Quality

The SFPUC tests water samples at hundreds of different points throughout the supply chain.

In 2020 alone, they conducted more than 95,400 hands-on drinking water tests at watersheds, reservoirs and distribution pipes. 

At the same time, they use online instruments to monitor water quality 24/7. 

And when it comes to their watersheds, San Francisco takes things extra seriously…

They partner with several agencies, including the National Park Service and US Forest Service, to conduct in-depth sanitation surveys at least once a year. 

These surveys closely monitor the effects of wildfire, wildlife, livestock and other human activities on the area’s water supply.

Contaminants Threatening San Francisco’s Water Supply

San Francisco’s drinking water takes quite the journey before it reaches your tap, flowing through rivers, lakes, streams, ponds, reservoirs and wells. 

Along the way, it has plenty of time to pick up pollutants, including:

• Inorganic contaminants, like salts and metals from mining, farming, oil and gas production, wastewater discharges, stormwater runoff, and naturally occuring salts and metals. 
• Organic chemical contaminants, like volatile organic compounds (VOCs), which come from gas stations, urban stormwater runoff, septic systems, agriculture, industrial processes and oil production.
• Radioactive contaminants, either naturally occurring or from mining activities and oil production.  
• Pesticides and herbicides from agricultural sources, residential uses and urban stormwater runoff.
• Microbial contaminants, like viruses and bacteria from septic tanks, wildlife, livestock and sewage treatment plants.

When it comes to microbial contaminants in surface water, a parasitic microbe called Cryptosporidium is notorious for polluting drinking water. 

Ingesting Cryptosporidium can cause symptoms like diarrhea, abdominal cramps, nausea and headaches.

In 2020, the SFPUC found very low levels in both source water and treated water. Fortunately, it’s nothing that regular disinfection can’t handle. 

Lead in drinking water is another common health concern.

Next, let’s see what San Francisco is doing to protect you from lead exposure:

Steps to Reduce Lead Exposure

Lead is a heavy metal that’s found in old distribution pipes and home plumbing. 

NOTE: Homes built before 1986 are the most at risk. 

Lead enters the water supply when aging pipes start to corrode. 

Long-term exposure can cause serious health effects in all people, but pregnant women and young children are the most at risk. 

When pregnant women drink lead-tainted water, it can cause birth defects. 

Young children who consume lead in drinking water can experience learning and behavioral problems, like low IQ and shortened attention spans. 

At the same time, adults have an increased risk of high blood pressure, heart disease and liver, kidney and nervous system problems.

Fortunately, the SFPUC is taking a number of steps to minimize lead in drinking water, including:

• Replacing old lead-containing water meters with lead-free automated water meters.
• Annual monitoring for lead in the city’s distribution systems (they didn’t detect any lead in 2020).
• Offering low-cost lead water tests for only $25 to all residents. 
• Partnering with the San Francisco Department of Public Health to offer free lead testing vouchers to qualified residents. 
• Conducting free lead testing at over 190 public and private schools. 
• Installing hundreds of lead-free water fountains and bottle refill stations throughout the city. 

Want to take matters into your own hands?

There’s plenty you can do to further reduce your family’s risk of lead exposure. 

Whenever your water hasn’t run for a couple hours, turn on the faucet and flush your pipes for a few minutes. This should greatly reduce any lead that might be lurking in your tap. 

The best safety step, though, is to install a water filter in your home...

Should San Franciscans Use In-Home Water Filters?

Even though San Francisco’s water is head-and-shoulders above other big cities, they still can’t guarantee toxin-free drinking water in every home. 

Ultimately, the only way to protect your family from harmful pollutants is to install an in-home water filtration system. 

Believe it or not, not all water filters are created equal...

Some inexpensive options, like activated carbon filters, only protect against chlorine and a few other contaminants. 

Reverse osmosis (RO) filters, on the other hand, remove up to 99.9% of dangerous pollutants. 

RO membranes work by forcing highly pressurized water through a semipermeable membrane to trap hard-to-remove contaminants like lead, PFAs and bacteria. 

Plus, RO systems combine sediment filters, activated carbon filters, ion exchange resins and polishing filters to make your water as pure as possible. 

Some high-end RO systems even use remineralization to add healthy minerals and balance pH. 

Cloud Water Filters also include built-in software that syncs to an app on your phone so you can monitor your water quality 24/7. It turns your tap into an oasis of safe, high-quality drinking water!

Click here to learn more.