Is San Diego Tap Water Safe to Drink?
Quick Summary: San Diego tap water meets federal and state safety standards, but it still contains contaminants like HAA5, TTHMs, arsenic, and uranium that may pose health risks over time. These substances often exceed the stricter health guidelines set by the Environmental Working Group (EWG), even though they’re legally allowed. Aging infrastructure, pollution, and natural disasters like wildfires and earthquakes can further impact water quality. To ensure safer drinking water, residents are encouraged to use certified filtration systems like reverse osmosis or activated carbon filters.
San Diego has many water sources from a combination of local fresh water basins and imported supplies from the Colorado River and Northern California. Despite rigorous treatment processes to protect public health these sources introduce contaminants into the water supply, including HAA5, TTHM, arsenic, and uranium. Continue below to see a list of potential contaminants in your San Diego tap water.
1. HAA5 (Haloacetic Acids)
HAA5 are disinfection byproducts formed when chlorine reacts with natural organic matter in the water.
- Health Effects: Long-term exposure can increase cancer risk and may damage the liver, kidneys, and nervous system.
- Levels in San Diego: According to EWG, HAA5 levels in San Diego utilities exceed the group’s health guideline of 0.1 ppb. Some samples tested as high as 34.5 ppb.
- Mitigation: Use granular activated carbon or reverse osmosis filters.
2. TTHM (Total Trihalomethanes)
TTHMs are another group of disinfection byproducts formed through chlorination.
- Health Effects: Long-term exposure is linked to bladder cancer and may harm the liver and nervous system.
- Levels in San Diego: EWG reports TTHM levels that exceed their health guideline of 0.15 ppb, with some samples measuring over 60 ppb.
- Mitigation: Use activated carbon or reverse osmosis filter water systems.
3. Chlorine
Chlorine is widely used for water disinfection.
- Health Effects: Chlorine itself is safe at low levels, but its byproducts (like TTHM and HAA5) can be harmful. High levels may cause skin irritation and exacerbate respiratory conditions like asthma.
- Levels in San Diego: Chlorine is used across San Diego, with utilities maintaining levels within legal limits for disinfection.
- Mitigation: Use carbon filters certified to remove chlorine.
4. Arsenic
Arsenic is naturally present in bedrock and can seep into groundwater.
- Health Effects: Long-term exposure may lead to various cancers, cardiovascular issues, and developmental problems.
- Levels in San Diego: Arsenic has been detected above EWG’s health guideline of 0.004 ppb, with maximum levels recorded up to 2.5 ppb.
- Mitigation: Use reverse osmosis, distillation, or specialty absorptive filters.
5. Uranium
Uranium is a radioactive element that can contaminate groundwater in mineral-rich areas.
- Health Effects: Long-term ingestion can cause kidney damage and increase cancer risk.
- Levels in San Diego: Detected in parts of inland San Diego, but generally within legal limits.
- Mitigation: Reverse osmosis and ion exchange systems are effective.
6. Hard Water
Hard water is common in San Diego due to high mineral content, especially calcium and magnesium.
- Health Effects: Not harmful but can cause dry skin and soap scum, and reduce appliance efficiency.
- Levels in San Diego: The San Diego County Water Authority confirms moderate to high hardness across most cities.
- Mitigation: Use a water softener that exchanges calcium and magnesium for sodium or potassium.
For a more in-depth look at the levels of these contaminants in your area, check your utility’s EWG Tap Water Database.
Ensuring Safe Tap Water: A Guide for San Diego Residents
One common concern for San Diego residents is the accessibility of water that is safe to drink. With recent wildfires and seismic activity in California, concerns about water quality levels are growing. This guide provides practical steps to ensure you have clean drinking water.
Legal Standards vs. Actual Safety
Although San Diego utilities comply with federal and state standards, the EWG highlights that legal thresholds often lag behind modern science. Contaminants like PFAS, lead, and arsenic may still pose risks despite being “within legal limits.” This is why it’s important to work with a water provider who can help treat clean your home’s drinking water.
How Can I Make My Water Safer to Drink?
1. Water Filtration Systems: Culligan offers under-sink, whole-home, and countertop systems that remove impurities to provide safe water and improve taste. Learn more about whole house water filter systems here.
2. Reverse Osmosis Systems: Culligan’s multi-stage RO systems eliminate contaminants like arsenic, lead, bacteria, and PFAS.
3. Water Softeners: San Diego’s hard water can be treated with Culligan water softeners, helping extend the life of plumbing and appliances.
4. Bottle-Free Water Coolers: Culligan’s bottle-free water coolers provide a convenient and sustainable solution for clean drinking water. These coolers are connected directly to your water supply and use advanced filtration technology to deliver refreshing water on demand.
Natural Disasters’ Effects on Water Quality in California
Wildfires
Previous wildfires like the 2020 Bond Fire in Southern California damaged reservoirs and pumping stations, leading to water pressure drops and potential contamination in water systems. Ash and burned materials can also infiltrate the water supply. Local agencies have recommended to not have camp fires during droughts or dry seasons.
Another crucial strategy involves maintaining and restoring the natural landscapes that surround key water sources. By supporting reforestation and soil stabilization projects, the city reduces the risk of erosion and sediment runoff into reservoirs and waterways. These efforts not only protect water quality but also help preserve the region’s ecological balance and reduce the likelihood of future fires.
Advisories, such as not using clothes dryers, washing dishes, or a washing machine, are also common during wildfires. They also advised to not use flush systems and provide bottled water during these events. When there is a loss of pressure in pipes during wildfires, there may be a boil water advisory, which can help you create clean water.
Earthquakes
San Diego is seismically active. Earthquakes can rupture pipes, introduce sediments, or mobilize contaminants in groundwater which may cause water advisories and damage drinking water quality. Local agencies conduct regular infrastructure assessments and have emergency preparedness protocols in place.
Aging Infrastructure & San Diego Water Quality
Old pipes and treatment systems are an ongoing concern:
- Lead Pipes: Older buildings in parts of San Diego may still have lead plumbing.
- Corrosion: Aging mains can leach metals or allow bacterial intrusion.
- PFAS: Older treatment methods may not remove “forever chemicals.”
Pollution & Runoff Contaminating San Diego’s Water Supply
Urban Runoff
Impermeable surfaces in dense cities like San Diego carry oil, trash, and heavy metals into storm drains that empty into local aquifers or the Pacific Ocean.
Agricultural and Industrial Runoff
San Diego County’s agricultural regions contribute pesticides and fertilizers to local watersheds. Industrial facilities may release heavy metals if not properly regulated.
Mitigation Efforts
San Diego is investing in green infrastructure like rain gardens and permeable pavement. Public education campaigns encourage proper disposal of chemicals and yard waste to reduce runoff.
By staying informed and proactive, San Diego residents can take control of their water quality and health.
