Drinking Water

The source of San Francisco's drinking water is from the Hetch Hetchy Reservoir that collects water from snowmelt running down the Tuolumne River.

According to the City & County of San SF Annual Water Quality Report for 2017, the water from the Hetch Hetchy Reservoir is treated with "ultraviolet light and chlorine disinfection, pH adjustment for optimum corrosion control, fluoridation for dental health protection, and chloramination for maintaining disinfectant residual and minimizing the formation of disinfection byproducts." The two watersheds in the Bay Area are the Alameda Watershed and the Peninsula Watershed. Looking at the chart provided in the Water Quality Report, I did not notice any chemicals in SF water that was higher than expected. Although the range is <1-10.3, I was surprised that lead (4.8 parts per billion) was found in the water due to "internal corrosion of household plumbing systems."

Here are the associated health risks with the chemicals found in SF's water extracted from the EPA website:

Chemical	Health Risks	Source of Contaminant
Carbon tetrachloride	Liver problems; increased risk of cancer	Discharge from chemical plants and other industrial activities
Chloramines	Eye/nose irritation; stomach discomfort; anemia	Water additive used to control microbes
Copper	Short-term exposure: Gastrointestinal distress. Long- term exposure: Liver or kidney damage. People with Wilson’s Disease should consult their personal doctor if the amount of copper in their water exceeds the action level	Corrosion of household plumbing systems; erosion of natural deposits
Ethylene dibromide	Problems with liver, stomach, reproductive system, or kidneys; increased risk of cancer	Discharge from petroleum refineries
Fecal coliform and E. coli	Fecal coliforms and E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes may cause short term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a special health risk for infants, young children, and people with severely compromised immune systems.	Human and animal fecal waste
Fluoride	Bone disease (pain and tenderness of the bones); children may get mottled teeth	Water additive which promotes strong teeth; erosion of natural deposits; discharge from fertilizer and aluminum factories
Giardia lamblia	Short-term exposure: Gastrointestinal illness (e.g., diarrhea, vomiting, cramps)	Human and animal fecal waste
Haloacetic acids (HAA5)	Increased risk of cancer	Byproduct of drinking water disinfection
Lead	Infants and children: Delays in physical or mental development; children could show slight deficits in attention span and learning abilities; Adults: Kidney problems; high blood pressure	Corrosion of household plumbing systems; erosion of natural deposits
Total Trihalomethanes	Liver, kidney, or central nervous system problems; increased risk of cancer	Byproduct of drinking water disinfection

Despite how clean the water may be in SF, I still use a water filter to give myself the peace of mind that I have the cleanest water possible (even if I am using a Brita filter that is flashing red, signaling the sign that it needs changing). I always try to carry my Hydroflask with me to store my drinking water. However, I do buy bottled water for emergencies, disaster preparation kits, or even long road trips. 

It is understood that climate change is predicted to cause droughts and extreme weather conditions that may create overwhelming floods. These events can impact the quality and quantity of safe drinking water, such as increasing runoff into rivers and lakes in flooding incidences leading pollutants into water supplies. In contrast, droughts can increase salinity in water and disturb aquatic life. 

If I were to develop a nationwide campaign to get people to drink tap water instead of bottled water, my campaign slogan would be: "Drip! Drip! Hooray!  Tap water, any time of day!"

In this article from The New York Times, military families in Fountain Colorado face health issues, such as cancer, thyroid conditions, and fatigue after being exposed to military toxic chemicals that leached into the water supply. Apparently, it has been known for years that the town's water supply is contaminated; however, it was not till recently that EPA announced regulatory action, infuriating the people of Fountain.