Types of Contaminants
Possible Contaminants in Source Water
All source water contains contaminants, nearly all of which are removed during the treatment process. Here are some potential contaminants:
- Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations and wildlife.
- Inorganic contaminants, such as salts and metals, which can be naturally-occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining and farming.
- Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban storm water runoff and residential uses.
- Organic chemical contaminants, including synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production, and can, also come from gas stations, urban storm water runoff and septic systems.
Radioactive contaminants, which can be naturally occurring or be the result of oil and gas production and mining activities.
For people with sensitive immune systems ...
Cryptosporidium is a microbial pathogen found in surface water throughout the U.S. When ingested, the organism may cause nausea, diarrhea and other gastrointestinal symptoms. The organism comes from animal wastes and may be found in surface watersheds. Water purchased from Metropolitan Water District of Southern California via Foothill Municipal Water District was tested for Cryptosporidium in 2007 and it was not detected in the water. If detected, Cryptosporidium is eliminated by an effective treatment combination including sedimentation, filtration and disinfection.
Some people may be more vulnerable to constituents in the water than the general population. Immunocompromised people, such as those with cancer undergoing chemotherapy, persons with HIV/AIDS or other immune system disorders, some elderly persons and infants can be particularly at risk of infections. These people should seek advice from their healthcare provider about their drinking water.
The USEPA and the Centers for Disease Control have guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants, which are available through the USEPA’s Safe Drinking Water Hotline at (800) 426-4791.
Laboratory Analyses
During the past year, the water delivered to your home or business complied with, or did better than, all State and Federal drinking water requirements. Last year, RCLWA conducted thousands of water quality tests for more than 81 contaminants. Only 23 of the 81 contaminants were found in detectable quantities.
It is important that you know what was detected and how much of the substance was present in the water. The State allows RCLWA to monitor some contaminants less than once per year because the concentrations of these contaminants do not change frequently. Some data, though representative, are more than one year old.