Water Source & Components
1. What are the sources of the water Santa Ana delivers?
The City of Santa Ana depends on two sources for the 12.5 billion gallons of water we supply each year—68 percentage is groundwater and 32 percentage is imported water, purchased from the Metropolitan Water District of Southern California (MWD).
The groundwater accumulates and is stored beneath the surface of the earth and then pumped to the surface by 20 City-owned wells. MWD brings Colorado River water from Lake Havasu and runoff from the snow pack in the Sierra Nevada Range in Northern California. The water is then treated at either the Diemer Filtration Plant in Yorba Linda or the Weymouth Filtration Plant in LaVerne before it is delivered to Santa Ana.
There are seven MWD connections located in the city. Most of our customers receive a blending of the two sources, groundwater and imported water. For more details, see the Water Quality Standards for each of these sources in the data that follow. We have listed groundwater and imported water in separate columns.
2. What’s in my drinking water?
Your tap water may contain different types of chemicals (organic and inorganic), microscopic organisms (e.g., bacteria, algae, viruses) and radioactive materials (radionuclides), many of which are naturally occurring. Health agencies require monitoring for these constituents, because at certain levels they could make a person sick. The column marked “Parameter” lists the constituents found in the water used by Santa Ana.
3. What are the maximum allowed levels for constituents in drinking water?
Health agencies have maximum contaminant levels for constituents so that drinking water is safe and looks, tastes and smells good. A few constituents have the letters “TT” in the MCL column because they do not have a numerical MCL. Instead, they have certain treatment requirements that have to be met. One of the constituents, total chlorine residual, has an MRDL (maximum residual disinfection level) instead of an MCL.
The MRDL is the maximum level of a disinfectant added for water treatment that is allowed in water. While disinfectants are necessary to kill harmful microbes, drinking water regulations protect against too much disinfectant being added. Another constituent, turbidity, has a requirement that 95 percent of the measurements taken must be below a certain number. Turbidity is a measure of the cloudiness of the water. We monitor it because it is a good indicator of the efﬁciency of the ﬁltration system.
4. Why are some of the constituents listed in the section labeled “Primary Standards” and others in the “Secondary Standards”?
Constituents that are grouped in the primary standards section may be unhealthy at certain levels. Constituents that are grouped under the secondary standards section can affect the appearance, taste and smell of water, but do not affect the safety of the water unless they also have a primary standard. Some constituents (e.g., aluminum) have two different MCLs (Maximum Contaminent Level), one for health-related impacts, and another for non-health-related impacts not related to health.
5. How do I know how much of a constituent is in my water and if it is at a safe level?
With a few exceptions, if the average amount of a constituent found in tap water over the course of a year is no greater than the MCL, then the regulatory requirements are considered to be satisfied. The highest and lowest levels measured over a year are shown in the range. Requirements for safety, appearance, taste and smell are based on the average levels recorded and not the range.
6. How do constituents get into our water?
Drinking water (tap water and bottled water) comes from rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or human activity. The most likely source for each constituent is listed in the last column of the table.
7. Are there any potential sources of contamination in our system?
An assessment of the drinking water wells for the City of Santa Ana was completed in December 2013. The City wells are considered most vulnerable to the following activities associated with contaminants detected in the water supply: historic agricultural activities, golf courses, and application of fertilizers.
The City’s wells are considered most vulnerable to the following activities not associated with detected contaminates: chemical/petroleum pipelines, chemical/petroleum processing/stores, dry cleaners, gas stations, junk/scrap/salvage yards, metal plating/ﬁnishing/fabrication, plastics/synthetics producers, and sewer collection systems.