Castaic Lake Water Agency is committed to keeping the residents of the Santa Clarita Valley informed about their water quality.
The pages (links) below explain information about chemicals you may have heard about on the news or read about in the newspapers. The information is technical in nature and we have tried to make it as easy as possible to understand.
ARSENIC
Arsenic is a naturally occurring substance that is sometimes found at very low levels in drinking water, primarily groundwater.
Studies from Taiwan suggest that exposure to drinking water containing more than 100 micrograms per Liter (mg/L) of arsenic – more than twice the amount allowed by U.S. law – may be linked to greater incidence of some forms of cancer. While there has been research indicating that low levels of arsenic in drinking water poses a risk to human health, scientists agreed that there are significant gaps in the data and that additional research is needed to formulate an appropriate level for a primary drinking water standard.
The U.S. Environmental Protection Agency (EPA) is required by the Safe Drinking Water Act Amendments of 1996, to finalize a new drinking water standard for arsenic by January 2001 based on good scientific information and data. The current maximum contaminant level (MCL) is 50 mg/L. In May 2000, the EPA proposed an arsenic standard of 5 ug/L but is considering standards of 3 mg/L and 10 mg/L as well.
The problem with the expected rule is that most of the research will not be available in time to affect the proposal, and the EPA has indicated that it will not be able to consider any of the research findings prior to finalizing the rule in January 2001. Some of the research will not be completed until a year or two after the rule is now scheduled to be finalized.
A recent memo from the Office of Congressional and Intergovernmental Relations to the EPA’s Arsenic Work Group published by the national " Inside EPA" newsletter raises further doubts about the rule. In it, EPA’s governmental affairs office warned that it "would not support a proposal of 5 ug/L, indeed, we have substantial concerns about a proposal of 10 ug/L as well."
In preparation for the proposed rule, EPA asked the National Academy of Sciences (NAS) to conduct a risk assessment for arsenic based on currently available science. The NAS report was released in late March 1999, and doesn’t recommend an arsenic standard. It does state that the arsenic regulation must be strengthened, but calls for more research to support an appropriate standard.
The EPA was supposed to publish a proposed rule to lower the Maximum Contaminant Level (MCL) of arsenic in January 2000. When they did not, the National Resources Defense Council (NRDC) sued the EPA. The NRDC also released a report on its estimate of the risks of arsenic in drinking water and contended that the MCL should be no greater than 3 mg/L.
In this report, the arsenic concentrations of many drinking water utilities were published, including those serving the Santa Clarita Valley. The NRDC took data from the EPA database and calculated different estimates of the average amount of arsenic in each water system. They calculated a "low" and "best" average based on the most current results. For the water systems in the Santa Clarita Valley, the results were between five and ten years old. The NRDC estimated that none of water served in the Santa Clarita Valley exceeded the current MCL of 50 mg/L, the expected proposed MCL of 5 mg/L, or the NRDC’s proposed MCL of 3 mg/L. Despite this, the NRDC’s estimates are still much higher than the actual levels in the drinking water of the Santa Clarita Valley. There have been no levels reported above 3 mg/L, and the majority of tests show no detectable arsenic at all.
For additional information on arsenic you can contact the USEPA at www.epa.gov, the United States Geological Survey at water.wr.usgs.gov or wwwsd.cr.usgs.gov, the California Department of Health Services at www.dhs.cahwnet.gov, the California Environmental Protection Agency (Cal/EPA) at www.calepa.ca.gov. Much of the information presented here was provided by the Association of California Water Agencies at www.acwanet.com.
MTBE
Over the last several years, Methyl Tertiary Butyl Ether (MTBE) has been making headlines in California. Back in the 1980’s, it was hailed as major break-through in air pollution prevention. By adding it to gasoline, the amount of carbon monoxide released by automobiles could be greatly reduced. The California Air Resources Board (CARB) credits MTBE with removing 3 million pounds of carbon monoxide from our air per year. Both CARB and the United States Environmental Protection Agency (USEPA) required that MTBE be added to gasoline.
In 1995 however, it was discovered that MTBE had contaminated the groundwater in the City of Santa Monica. It had leaked from underground fuel tanks and migrated into the City’s aquifer. Since then, many wells throughout California have been found to have similar contamination problems. MTBE has also been found in a number of lakes in California. In this case, the MTBE is not present because of leaking fuel tanks but rather it came from motorboats that burn gasoline containing MTBE. MTBE is foul tasting at even very low concentrations and there are many concerns about long term consumption of drinking water contaminated with MTBE. In response to these problems, California has banned the use of MTBE as a fuel additive. However, the USEPA continues to require its use so it is still found in California gasolines. California has requested a waiver from the USEPA, but it has yet to be granted.
Recently MTBE has been thrust into the national limelight with a special two-part story on the CBS news show "60 Minutes". Following this program, several residents have asked about the presence of MTBE in our local drinking water. All drinking water in the Santa Clarita Valley comes from the approximately 40 local wells and Castaic Lake. The Regional Water Quality Control Board requires that owners of underground storage tanks test the ground for contamination. A few leaking tanks have been found in the Santa Clarita Valley. However, the local wells have been tested every year since 1997 for MBTE at the Castaic Lake Water Agency’s Water Quality Laboratory. No MTBE has ever been found in any of the local drinking water wells.
The water in Castaic Lake has been tested by the Department of Water Resources (DWR) for possible MTBE contamination. MTBE and other gasoline components have been found on the surface of the lake, particularly near the boat launches. However, DWR has not found MTBE in the water leaving the lake. The Castaic Lake Water Agency checks the water entering its two water treatment plants from Castaic Lake as well as the water leaving the plants at least 6 times per year. No MTBE has ever been found in Castaic Lake water delivered to the consumers of the Santa Clarita Valley.
For additional information on MTBE you can contact the USEPA at www.epa.gov, the United States Geological Survey at water.wr.usgs.gov/mtbe or wwwsd.cr.usgs.gov, the California Department of Health Services at www.dhs.cahwnet.gov, the California Environmental Protection Agency (Cal/EPA) at www.calepa.ca.gov/programs/mtbe, the State Water Resources Control Board and the Los Angeles Regional Water Quality Control Board at www.swrcb.ca.gov.
PERCHLORATE
The
City of Santa Clarita's Perchlorate and Bermite Site Cleanup
Process (Requires
Adobe Acrobat Reader)
PERCHLORATE CONTAMINATION OF GROUNDWATER AND THE SAUGUS FORMATION
What is perchlorate?
Ammonium perchlorate is an inorganic chemical that is used in solid rocket propellants, fireworks and explosives.
It interferes with the ability of the thyroid gland to utilize iodine to produce thyroid hormones. Thyroid hormones are needed for normal prenatal and postnatal growth and development in children, and for normal metabolic function in adults.
Since 1997, perchlorate has been found to be a drinking water contaminant in about 284 water sources throughout California (in Los Angeles County, 23 wells have been found to exceed allowable levels of perchlorate and have been taken out of service). Most of this contamination appears to be the result of historic activities in the aerospace and defense industries.
What is the Saugus Formation?
The Saugus Formation is a large, deep body of sediments under the Santa Clarita Valley. Extending over 85 square miles, and containing about 1.4 million acre feet of water, it is one of two major sources of groundwater in the area, the other being the shallow Alluvial Aquifer that overlies it.
Is there a water quality problem in the Saugus?
Yes. In 1997, ammonium perchlorate was discovered in four Saugus wells. The State Department of Health Services had established a limit on the amount of this substance allowed in drinking water. As a consequence, these four Saugus wells were shut down; the other eight wells are all safe and operable.
Can perchlorate be removed from water?
Yes. There are several proven and emerging removal technologies. An ion exchange system installed in the San Gabriel Valley has been permitted for use, and is capable of treating over 3.5 million gallons per day to drinking water standards. An ion exchange system is under development in Redlands. A promising biological treatment process is being used in the Sacramento area, and other treatment processes called are under development. All are being evaluated for use in the Santa Clarita Valley.
Can additional wells be safely drilled in the Saugus if needed?
Yes. The Saugus is divided by the San Gabriel Fault. All current Saugus wells are located south of the fault, many near the location of the former Whittaker-Bermite site where the perchlorate contamination originated. Other large areas north of the fault are considered viable for future wells.
Is the Saugus an important water resource to the Santa Clarita Valley?
Yes, but as only one of the multiple water resources available to the area. It is very important in that it serves as a back-up dry year supply to the Valley.
In addition to the Alluvium, which is the major current source of groundwater, there is a large supply from the State Water Project, a master plan for recycled water now being implemented, and reliability-enhancement projects and programs which include groundwater banking, water transfers, water conservation, and desalination. A cooperative water sharing and exchange program among the purveyors adds flexibility. The Santa Clarita Valley has never suffered a water shortage, even during the most recent drought, and the water community continues to plan for future water supplies.
Are area water purveyors limiting their use of the Saugus?
Yes, but mostly for reasons unrelated to contamination. Purveyors are pumping water from the shallow alluvial aquifer because it costs less to pump than the deeper Saugus. Also, State Water Project transmission pipelines are connected to all purveyors, making the imported supply more available than in the past. Finally, the local water community has decided to reserve the Saugus as a fallback resource for drought protection should other supplies be temporarily reduced in the future due to dry conditions.
Can we tell if the perchlorate is spreading?
Yes. Each purveyor regularly collects groundwater samples from the many wells in the alluvial aquifer. In November 2002 perchlorate was detected in a single Alluvial well near the Saugus Speedway, and that well has been closed. These wells actually serve as an early warning device. Similarly, the wells in the Saugus are pumped and monitored for perchlorate. If found, changes in pumping locations and patterns help minimize its movement.
How long will it take to clean up the perchlorate?
Full cleanup of the basin is a long-term and costly process. It is estimated that the treatment process required to clean up the contamination will cost $35 million. However, containment and clean-up should begin a soon as possible, both on and off the contamination site. The result will be usable water and a reduction in the area of contamination. CLWA, the local water purveyors and the U.S. Army Corps of Engineers are working with the state Department of Toxic Substances Control to determine a total clean up strategy.
A lawsuit was filed by CLWA and the water purveyors in November 2000 to compel the former site owner, Whittaker Corporation, to pay for the costs of the groundwater contamination cleanup.
NDMA
Another chemical making news lately is N-nitrosodimethylamine (NDMA). This chemical has been found on many of the same sites as perchlorate. Some NDMA has been found locally on the same Bermite site where perchlorate has been detected. However, NDMA has been found in very small quantities and has not been detected in any well water, in sharp contrast to perchlorate.
The United States Environmental Protection Agency (EPA) has classified NDMA as a probable carcinogen. However, EPA has not yet established a regulation, or "Maximum Contaminant Level (MCL)" for NDMA. This is because NDMA is just now being detected and understood, and only a very small amount of information on NDMA exists - there is not enough information yet for EPA to set an appropriate MCL.
The California Department of Health Services (DHS) has established an interim "Action Level" level of 20 ng/L (nanograms per liter or parts per trillion). This is an extremely low level. In fact, if you were to fill the Rose Bowl in Pasadena all the way to the top row of seats with water, two drops of that water would be about the same as 20 ng/L. DHS put this very low level in place to provide public health protection while we wait for doctors and scientists to determine what a safe level of NDMA might be.
It may be possible that NDMA is formed as a by-product produced during disinfection of water or treated wastewater with chlorine. Such disinfection is critical to the safety of drinking water, as it kills the bacteria, viruses, and other microorganisms that cause such waterborne diseases as typhoid, polio, and dysentery - diseases that kill more than 10,000 children each day around the world.
At the present time, there are very few laboratories that can detect NDMA at these low levels, and there is no laboratory method that has been approved by EPA or DHS. The Castaic Lake Water Agency and several other water agencies are working with DHS to try out new NDMA testing methods, and to determine if NDMA is present in local drinking water supplies.
In December 1999, the DHS laboratory detected 7 ng/L in the Rio Vista Treatment Plant effluent. However, at the same time Montgomery Laboratories in Pasadena did not detect any NDMA in the same sample. Montgomery Laboratories did detect 2 ng/L of NDMA in the effluent of the Earl Schmidt Filtration Plant. DHS did not analyze that sample. DHS and Montgomery Laboratories tested five more samples from various sites in the Santa Clarita Valley. No NDMA was detected in any of the other samples.
Additional information on NDMA can be found at the EPA and DHS web sites,www.epa.gov, and www.dhs.cahwnet.gov. Check our web site in the future for any new information we receive regarding the health studies on NDMA and the results of NDMA testing in your drinking water.
CHROMIUM
Testing Results for Chromium
Neither Castaic Lake nor any of the Santa Clarita Valley’s Wells have had any chromium detected in concentrations greater than 0.01 mg/L.
Chromium Fact Sheet
(Courtesy of ACWA)
Chromium is an inorganic chemical that is used in electroplating, leather tanning, wood treatment, pigments manufacture and cooling tower treatment for corrosion control. Chromium can enter drinking water sources through discharges from industries, leaching from hazardous waste sites, and erosion of natural deposits.
There are two forms of chromium species that may be present in drinking water: chromium III and chromium VI. There are uncertainties in the balance of occurrence of the two species in drinking water sources. Chromium III is an essential nutrient at trace concentrations. Chromium VI is the primary species of health concern and its toxicity is the basis for setting the chromium drinking water standard. There is evidence that chromium VI may be reduced to chromium III in the human body, particularly in the reducing environment of saliva and gastric juices.
The U.S. Environmental Protection Agency (USEPA) has classified chromium VI as a human carcinogen by inhalation. In 1991, USEPA reviewed the existing chromium standard, and raised the Maximum Contaminant Level (MCL) from 0.05 mg/L (1975 Interim Drinking Water Standard) to 0.1 mg/L as total chromium, based on its decision that chromium VI was not carcinogenic by ingestion.
The California Department of Health Services (CDHS) reviewed the chromium risk assessment data in 1994, and maintained the State chromium MCL of 0.05 mg/L. In its 1999 risk assessment, the California EPA, Office of Environmental Health Hazard Assessment (OEHHA) disagreed with USEPA's conclusion on the carcinogenicity of chromium VI. OEHHA determined that a health protective level against carcinogenicity for chromium VI was 0.2 ug/L(ppb), and set the Public Health Goal (PHG) for total chromium at 2.5 ug/L. The PHG was calculated assuming that total chromium in water is made up of no more than 7.1 percent chromium VI. (Note: More recent analyses suggest the proportion of hexavalent chromium to total chromium may be much higher.)
The California chromium MCL is currently under review. CDHS has indicated that it must have more occurrence data before considering revising the total chromium MCL, or adopting an MCL for chromium VI. CDHS plans to add chromium VI to the list of unregulated chemicals for which monitoring is required when the Department amends the existing unregulated chemical monitoring regulation to be effective in 2001.
Because chromium VI is not a regulated contaminant, there are no officially approved analytical methods for compliance purposes. The USEPA Method 7199 (and other equivalent methods) uses Ion Chromatography followed by post-column derivatization. The Method Detection Limits are typically between 0.2 to 0.3 ug/L. One commercial laboratory in southern California has so far been identified as capable of measuring chromium VI at concentrations below 0.2 ug/L.
More information on chromium can be obtained from OEHHA and DHS.
What is Chromium?
- Chromium is a naturally occurring element, the 11th most common in the earth's crust.
- Chromium is also an inorganic chemical that is used
in many industrial processes including electroplating, wood treatment,
pigments manufacture and cooling tower treatment for corrosion control.
Where is Chromium found?
- Chromium is found in air, soil, water, and food.
- According to the World Health Organization, food contributes about 93-98% of total chromium intake in humans while water contributes 1.9-7%.
- Foods with the highest concentrations of chromium include meat, fish, fruit, and vegetables. Chrome-plated utensils used in the preparation of food may contribute to chromium levels.
- According to the U.S. Environmental
Protection Agency (EPA), chromium may also enter water from plumbing
fixtures in the home such as pipes or faucets.
What is Chromium VI?
- The two most common species of chromium are chromium III, an essential dietary nutrient, and chromium VI, which can be toxic. Chromium VI can constitute anywhere from 7% to 80% of the total chromium found in drinking water supplies. According to the World Health Organization, there is evidence that when chromium VI enters the stomach, gastric acids reduce it to chromium III, the dietary nutrient.
- Conversely,
according to drinking water experts, it is possible that when chromium
III, the dietary nutrient, enters a disinfecting treatment plant,
it could be oxidized to chromium VI, the potential toxin. However,
recent sampling at a Southern California water system found no change
in chromium species following disinfection.
How much Chromium is typically found in water?
- According to the U.S. Environmental Protection Agency (EPA), background levels of chromium in U.S. waters average 1 part per billion (ppb) and drinking water averages 0.1-35 ppb.
- The average amount of chromium in seawater is 0.3 ppb, most of which is chromium VI.
- An EPA survey of over 3,800 U.S. tap waters found average chromium levels of 0.4 ppb to 8 ppb, with varying amounts of chromium VI present.
How much Chromium is in California water?
- California water utilities have been monitoring for total chromium since the 1970's. Since 1984, about 1% of water systems have detected total chromium, according to the California Department of Health Services (DHS). Of these 1%, about 95% are groundwater sources and 5% are surface water sources.
- There is limited information about the presence of chromium VI in drinking water.
- Sampling performed between 1997 and 2000 has found chromium VI in drinking water at locations in southern, central, and northern California. The levels of chromium VI found ranged from non-detectable to 34 ppb.
- Unless an industrial activity is known
to have existed in the area, it is nearly impossible to determine
whether chromium detected in water is naturally-occurring or the result
of industrial contamination.
What is the drinking water standard for Chromium VI?
- There is currently no proposed or existing drinking water standard for chromium VI. There are, however, federal and state standards for total chromium in drinking water.
- The U.S. EPA has established a national drinking water standard for total chromium of 100 ppb.
- The World Health Organization has adopted a guideline for total chromium of 50 ppb.
- The California standard for total chromium is 50 parts per billion (ppb).
- DHS is currently considering setting a standard specific
to chromium VI. Beginning in late 1999, many water systems began
sampling for chromium VI and DHS is now in the process of requiring
this sampling for all vulnerable systems.
What are the health effects of Chromium VI?
- There is much debate about the effects of chromium VI when it is ingested.
It is a known fact that when some forms of chromium VI are inhaled, they
can cause cancer. However, because of the possible changes to chromium
VI in the stomach when it is ingested, there is currently no agreement
among experts about its toxicity in drinking water.
In fact, U.S. EPA firmly believes there is no evidence that chromium VI causes cancer when ingested and, in 1991, raised its chromium drinking water standard from 50 ppb to 100 ppb, the first and only time EPA has done this for a drinking water standard. - The World Health Organization
has also found there is not enough evidence to prove chromium VI
in drinking water causes cancer.
What is a Public Health Goal and is there one for chromium VI?
- A Public Health Goal (PHG) is a health risk assessment, not a proposed drinking water standard. The PHG is the level below which a contaminant will cause no adverse health effects over a lifetime of exposure.
- The PHG is just one factor considered in the setting of a drinking water standard. The California Department of Health Services (DHS) is the agency charged with setting drinking water standards and it also considers analytical capabilities, treatment feasibility, and cost.
- The California Office of Environmental Health Hazard Assessment has
published a Public Health Goal (PHG) for total chromium at 2.5 ppb,
which translates to a goal of 0.2 ppb for chromium VI.
What treatment is used to remove Chromium VI from drinking water?
- Since only total chromium, not specifically chromium VI, has been regulated in drinking water, there is currently little knowledge about chromium VI treatment options.
- The federal and state approved technologies for removing total chromium from drinking water include coagulation/filtration, anion exchange, reverse osmosis, and lime softening.
- A recent study
commissioned by ACWA and performed by Kennedy-Jenks Consultants found
coagulation-microfiltration and ion exchange to be the two most likely
treatment options for chromium VI. Although reverse osmosis is also
an effective treatment option, the study found that the 15% water
loss commonly associated with this mode of treatment would make it
unattractive to most water suppliers.
How much does it cost to remove Chromium VI from drinking water? / Cost Update:
- Because of a lack of treatment data, ACWA commissioned a basic treatment cost study by Kennedy-Jenks Consultants. As stated above, the study analyzed costs for two treatment options: coagulation-microfiltration and anion exchange.
- The study analyzed well flow rates of 70, 400, 1,000, and 2,000 gallons per minute (gpm). The study calculated the costs to treat to four different goals: 20, 10, 2 and 0.2 parts per billion (ppb).
- The study found that costs will range from $1.50 to $5.40 per 1,000 gallons ($480 to $1,700 per acre-foot) using coagulation-microfiltration. The cost to treat water using anion exchange range from $1.60 to $16.00 per 1,000 gallons ($510 to $5,300 per acre-foot).
- It must be noted that these costs are rough estimates and were calculated assuming wastes generated would be non-hazardous and that no land acquisition is needed. If treatment wastes are determined to be hazardous, the wastes would require hauling to a hazardous waste landfill, thereby inflating the costs significantly. Since the majority of wells needing treatment do not currently have treatment facilities in place, additional land will frequently need to be purchased at costs ranging from $5,000 to $1 million per well.
What actions are being taken to address Chromium VI in drinking water?
- The Department of Health Services is actively collecting data on chromium VI in drinking water from water suppliers to determine the true occurrence of chromium VI throughout the state. This sampling is now mandatory for most systems since DHS placed chromium VI on the Unregulated Contaminant list in January 2001.
- DHS is also actively trying to certify laboratories for chromium VI drinking water analysis. Currently, there are only 12 labs in California certified to perform this complex analysis.
- If DHS determines that a drinking water standard
for chromium VI is needed, the Office of Environmental Health Hazard
Assessment will first develop a public health goal specifically for
chromium VI. DHS will then consider the PHG, available treatment
technologies, and treatment costs in setting the chromium VI standard.
What is the water community doing to address Chromium VI in drinking water?
- Since last summer, water utilities throughout the state have begun sampling for the presence of chromium VI in drinking water and reporting results to local and state officials. Since the Department of Health Services placed chromium VI on the
- Unregulated Contaminant list, all vulnerable water systems are required to begin this sampling.
- The water community plans to work cooperatively with the Department of Health Services in determining if a drinking water standard for chromium VI is needed, and at what level the standard should be set.
Contacts
- Krista Clark, ACWA Regulatory Affairs Specialist, (946) 441-4545
- Steve Book, California Department of Health Services, (916) 322-1553
- Alexis Milea, California Department of Health Services (510) 540-2177
