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HEALTH CONSULTATION

Total and Hexavalent Chromium, Lead, Mercury, Nitrate, and Thallium Levels in Water from Private Domestic Wells Near the Pacific Gas and Electric Facility in Hinkley, California

PACIFIC GAS AND ELECTRIC FACILITY
HINKLEY, SAN BERNARDINO, CALIFORNIA


SUMMARY

In August 2001, the Environmental Health Investigations Branch (EHIB) of the CaliforniaDepartment of Health Services (CDHS) was asked by the Lahontan Regional Water QualityControl Board (Lahontan RWQCB) to review and provide a public health interpretation ofsampling results for 25 private domestic wells in Hinkley, California. These wells are locatedaround the area of groundwater that has been contaminated with chromium by the Pacific Gas &Electric (PG&E) gas compressor station. The content of the letters that EHIB sent to theresidences and property owners is the basis of this health consultation (see Appendices A-D).EHIB has a cooperative agreement with the Agency for Toxic Substances and Disease Registry(ATSDR) and this health consultation is being forwarded to ATSDR for their concurrence.


BACKGROUND AND STATEMENT OF ISSUES

In December 2000, EHIB completed a public health assessment of exposures from the PG&E gascompressor station, in which EHIB recommended that the Lahontan RWQCB sample privatedomestic wells located around the chromium-contaminated groundwater for total chromium andhexavalent chromium. In August 2001, the Lahontan RWQCB sampled 25 private domesticwells and had the water analyzed for total and hexavalent chromium. In order to improve theirunderstanding of the quality of the groundwater, the Lahontan RWQCB also had the wateranalyzed for other metals and minerals that are regulated in public drinking water systems. Theprivate wells were not tested for coliform. EHIB reviewed the results of these tests and comparedthe levels of contaminants to drinking water standards. The levels of total and hexavalentchromium did not exceed the drinking water standard for total chromium in any of the 25 wells.The levels of lead, nitrate, mercury, and thallium were higher than the primary MaximumContaminant Level (MCL, or drinking water standard) in ten residential wells (see Appendices A-D).


DISCUSSION

The following is a summary of the total and hexavalent chromium, lead, nitrate, mercury andthallium findings, as well as the pertinent information that was included in the letters to the 17residences and five property owners (for more detail refer to Appendices A-D). Copies of thelaboratory reports for the chromium, other metals and minerals tests were included with each letter.

Total and Hexavalent Chromium
None of the private domestic wells sampled by Lahontan RWQCB had levels of total chromium above California's drinking water standard (50 micrograms per liter (g/L); US Environmental Protection Agency's MCL is 100 ug/L). There is no drinking water standard for hexavalent chromium. The letters provided the results of the total and hexavalent chromium analyses and explained that no health effects were expected to result from the levels measured in their water. EHIB included a copy of a the laboratory results for the chromium tests as well as a fact sheet on "Chromium in Drinking Water" that was developed jointly by the CDHS Division of Drinking Water and Environmental Management and the California Environmental Protection Agency Office of Environmental Health Hazard Assessment (see Appendix E).

Lead
Seven wells had lead levels above the drinking water standard (0.015 milligrams per liter (mg/L)). The levels of lead in these wells ranged from 0.05 mg/L to 0.10 mg/L. In the letters to the nine residences served by these wells, EHIB described the susceptibility of children to lead poisoning, provided contact information for childhood blood lead tests, and included two information brochures on childhood lead poisoning (see Appendices F and G). Though the source of the lead contamination is currently unknown, community members were informed of possible sources of lead contamination.

Mercury
The level of mercury in one well was 0.0029 milligrams per liter (mg/L), which is higher than the drinking water standard (0.002 mg/L). In the letter to the property owner, EHIB described the health effects of mercury as well as possible sources of mercury contamination. A definite source of the mercury contamination is currently unknown.

Nitrate
Eight wells had nitrate levels above the drinking water standard (10 milligrams mg/L). The levels of nitrate in these wells ranged from 12 mg/L to 62 mg/L. In the letters to the residences, EHIB described the susceptibility of pregnant women and formula-fed infants to nitrate, and provided an EHIB fact sheet on "Health Concerns Related to Nitrate and Nitrite in Private Well Water" (see Appendix H). Though the source of the nitrate contamination is currently unknown, community members were informed of typical sources of nitrate contamination, namely agricultural and dairy farms.

Thallium
Two wells had thallium levels above the drinking water standard (0.002 mg/L). The levels of thallium in these wells were 0.11 mg/L and 0.19 mg/L. In the letters to the two residences, EHIB described the health effects of thallium, and discussed possible sources of thallium contamination. A definite source of the thallium contamination is currently unknown.

Follow-Up Testing
During the week of September 24, 2001, the Lahontan RWQCB sampled the wells with elevated levels of lead, nitrate, mercury, and thallium for confirmation testing. The Lahontan RWQCB provided the residents and property owners with the results of these tests.


CONCLUSIONS

The levels of total chromium measured in the 25 private domestic wells are below the drinkingwater standard for total chromium and do not pose a health risk. The levels of lead, mercury,nitrate, and thallium were above the drinking water standards and, therefore, may pose a health hazard.


PUBLIC HEALTH ACTION PLAN

The Public Health Action Plan (PHAP) for this site contains a description of actions taken, to betaken, or under consideration by ATSDR and EHIB at and near the site. The purpose of thePHAP is to ensure that this health consultation not only identifies public health hazards, but alsoprovides a plan of action designed to mitigate and prevent adverse human health effects resultingfrom exposure to hazardous substances in the environment. EHIB and ATSDR will follow-up onthis plan to ensure that actions are carried out.

Actions Completed:

  1. EHIB informed Hinkley residents of the results and health implications of the private domestic well testing performed by Lahontan RWQCB.


  2. EHIB informed the residents and property owners that their water was not tested for coliform, one of the more common water contaminants.


  3. EHIB recommended that the residences with elevated levels of lead in their well water use a different water supply (bottled or municipal) for drinking and cooking.


  4. EHIB recommended that children who had consumed water from the lead contaminated wells get a blood lead test.


  5. EHIB recommended that pregnant women and formula-fed infants who consume waterfrom the wells with elevated levels of nitrate use a different water supply (bottled ormunicipal) for drinking, cooking, and making infant formula.


  6. EHIB recommended that the residents served by the well with elevated mercury use adifferent water supply (bottled or municipal) for drinking and cooking.


  7. EHIB recommended that the residents and property owner of the well with elevatedmercury continue to test their well for mercury and try to identify the source of thecontamination.


  8. EHIB informed the residents and property owners that store-bought water filters are not certified to meet drinking water standards.


  9. EHIB informed the residents and property owners that private wells are not regulated or tested by the state and that the owners of private wells are responsible for making sure that the water is safe to consume.

Recommendation:

  1. EHIB recommends that private well owners test their wells on a regular basis forchemicals, metals, minerals and bacteria that may be present in underground water atlevels injurious to health.

PREPARERS OF REPORT

Environmental and Health Effects Assessors

Jackie Schwartz, MPH
Environmental Health Scientist
Environmental Health Investigations Branch
California Department of Health Services

Tracy Barreau, REHS
Environmental Health Scientist
Environmental Health Investigations Branch
California Department of Health Services


ATSDR Regional Representatives

William Nelson
Gwendolyn Eng
Libby Levy
Regional Representatives, Region IX
Agency for Toxic Substances and Disease Registry


ATSDR Technical Project Officer

Tammie McRae, M.S.
Environmental Health Scientist
Division of Health Assessment and Consultation
Superfund Site Assessment Branch, State Programs Section


CERTIFICATION

This Total and Hexavalent Chromium, Lead, Mercury, Nitrate, and Thallium Levels in water from Private Domestic Wells Near the Pacific Gas & Electric Facility in Hinkley, California, Health Consultation was prepared by the California Department of Health Services under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with the approved methodology and procedures existing at the time the health consultation was begun.

Tammie McRae, M.S.
Technical Project Officer
Superfund Site Assessment Branch (SSAB)
Division of Health Assessment and Consultation (DHAC)
ATSDR


The Division of Health Assessment and Consultation, ATSDR, has reviewed this healthconsultation, and concurs with its findings.

Roberta Erlwein.
Chief, SPS, SSAB, DHAC, ATSDR


APPENDIX A-D: LETTERS

To: Hinkley Residents and Property Owner
Re: Results of Private Well Testing
From: The California Department of Health Services
Date: September 14, 2001

DEPARTMENT OF   HEALTH SERVICESDEPARTMENT OF HEALTH SERVICES
1515 CLAY STREET, SUITE 1700
OAKLAND, CA 94612
(510) 622-4500


September 14, 2001

Resident/Property Owner
Hinkley, CA


Dear Resident/Property Owner:

We are writing to provide you with the results of the tests that the Lahontan Regional Water Quality Control Board recently performed on water from your private well (located at ADDRESS). Your private well water was tested because it is located near the area of the groundwater that has been contaminated with chromium 6 (hexavalent chromium) by the Pacific Gas and Electric Company. We (the California Department of Health Services Environmental Health Investigations Branch) recommended that the Lahontan Regional Water Quality Control Board measure the levels of total chromium and chromium 6 in private wells located near the chromium 6 groundwater contamination.

The Lahontan Regional Water Quality Control Board had E.S. Babcock & Sonslaboratory measure the levels of total chromium and chromium 6 in your private drinkingwell water. In order to learn more about the characteristics and quality of thegroundwater, they also had NEL laboratories analyze your water for metals, mineralsand other inorganic compounds. At high levels, these compounds can make watereither unsafe or unpleasant (bad taste, odor or appearance) to drink. Copies of thelaboratory reports are included with this letter.

We reviewed the results of the tests that were performed on water from your privatewell. We also compared the levels of compounds in your water to the levels that areallowed in public drinking water systems. (The state of California regulates publicdrinking water systems in order to ensure the safety and the quality of public watersupplies.)

As we will explain in more detail in the remainder of this letter, the levels of totalchromium and chromium 6 in your drinking water do not pose a risk to yourhealth. However, the levels of lead, chloride, specific conductance, sulfate, andtotal dissolved solids in your water do exceed public drinking water standardsand therefore may affect the safety or the quality (taste, odor, appearance) of yourwell water.

Results for Total Chromium and Chromium 6

The California drinking water standard for total chromium was created in order to ensure that public water supplies are safe to drink. The drinking water standard for total chromium is 50 micrograms per liter (g/L). There is no specific drinking water standard for chromium 6.

Total chromium is made up of chromium 3 (trivalent chromium) and chromium 6. The Lahontan Regional Water Quality Control Board measured the levels of total chromium and chromium 6 in your water. The test results show that your private well water contains 6 g/L ppb total chromium and 0.63 g/L chromium 6.

The amount of total chromium in your private well water is below the drinking waterstandard for total chromium and therefore does not pose a risk to your health.

We have included a fact sheet that provides more information on chromium in drinkingwater and on the chromium drinking water standard.

Results for Lead

The California drinking water standard for lead was created to ensure that public watersupplies are safe to drink. The drinking water standard for lead is 0.015 milligrams perliter (mg/L).

The test results show that the concentration of lead in your private well water is 0.079mg/L. This amount is higher than the California drinking water standard of 0.015 mg/L.

Children under six years old are at the highest risk for lead poisoning. Lead poisoningcan harm the brain, nerves and kidneys of a young child and make it very hard for achild to learn, pay attention, and behave. Most children with lead poisoning do not lookor act sick.

There are many ways that children may be exposed to lead, including air, water, dust,soil and older paints that contain lead. We have included two brochures that providemore information on childhood lead poisoning and the ways that children may beexposed to lead.

A child who drinks water from your well and who is also exposed to lead from other common sources may be exposed to greater amounts of lead than is recommended. If you have a young child who drinks water from your well, or if you have other sources of lead exposure in your home (for example, paint manufactured before 1978), we recommend that you use different water (municipal or bottled). We also recommend that the child have a blood lead test. The blood lead test is the only way to know if your child has lead poisoning. Your doctor or clinic can give your child a blood lead test. You may also call the San Bernardino County Childhood Lead Poisoning Prevention Program at (909) 387-6305 for further information on lead poisoning and the blood lead test.

The source of the lead contamination is currently unknown. Because water was takenfrom your well and not from inside your house, we do know that the source of the leadcontamination is not your plumbing. The lead in your water could be coming from amaterial that was used to construct your well or from an outside source that hascontaminated the groundwater in your area. We recommend that you ask your wellconstructor if lead solder was used to construct your well. This information should berecorded in the drill records for your well.

Results for Chloride, Specific Conductance, Sulfate, and Total Dissolved Solids

The drinking water standards for chloride, specific conductance, sulfate, and total dissolved solids were created in order to protect the quality (taste, odor, appearance) of public water supplies. The standard for chloride is 250 mg/L, for specific conductance is 900 micromhos (S/cm), for sulfate is 250 mg/L and for total dissolved solids is 500 mg/L.

The test results show that your private well water has 660 mg/L chloride, 3600 S/cm specific conductance, 580 mg/L sulfate, and 2340 mg/L total dissolved solids. These levels are higher than the California drinking water standards. High levels of chloride, specific conductance, sulfate, and total dissolved solids may affect the taste, odor or appearance of your well water. These compounds do not put your health at risk.

Follow-up Testing

One water test does not provide enough information to fully understand the safety andquality of your water. For this reason, the Lahontan Regional Water Quality ControlBoard would like to take another sample of your well water in the near future. They willretest the water for lead, thallium, chloride, specific conductance, sulfate, and totaldissolved solids. Lahontan Regional Water Quality Control Board will provide you withthe results of these tests.

Recommendations for Private Well Owners

Many chemicals, metals, minerals and bacteria may be present in private wells andmay threaten the safety and quality of your drinking water. These compounds can comefrom both natural sources and human activity. Private drinking water wells are notregulated or tested by the state, so people with private wells are responsible for makingsure that their own drinking water is safe.

We encourage you to have your well water tested routinely to ensure the safety ofyour drinking water. Since bacteria are the most common problem in private wells, wewould suggest that you have your well tested for coliform on a periodic basis. TheLahontan Regional Water Quality Control Board did not perform a bacteria test onyour well water.

Lastly, California-certified water filters and treatment systems that you can purchase in stores are not intended to treat water with levels of contaminants that are above the health-based drinking water standard. Therefore, we do not recommend that you rely upon these filters and treatment systems to reduce the levels of nitrate, lead, and mercury measured in your well water.

If you have any questions about the information we have provided, please do nothesitate to call Tracy Barreau at (510) 622-4489 or Jackie Schwartz at (510) 622-4487.

Sincerely,

Jackie Schwartz, MPH
Environmental Health Scientist
Environmental Health Investigations Branch

Marilyn Underwood, Ph.D.
Staff Toxicologist
Environmental Health Investigations Branch


Enclosures

cc:

Harold Singer, Executive Officer
Lahontan Regional Water Quality Control Board
2501 Lake Tahoe Boulevard
South Lake Tahoe, CA 96150

Mike Plaziak, Acting Mojave Unit Chief
Lahontan Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

Joe Koutsky, AWRCE
Lahontan Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

William Vance, Assistant Secretary of Air and Water Programs
California Environmental Protection Agency
1001 "I" Street, 25th Floor
Sacramento, CA 95814

Lynn Baker, Staff Air Pollution Specialist
California Air Resources Board
1001 "I" Street, 6th Floor
Sacramento, CA 95814

Property Owner



DEPARTMENT OF   HEALTH SERVICESDEPARTMENT OF HEALTH SERVICES
1515 CLAY STREET, SUITE 1700
OAKLAND, CA 94612
(510) 622-4500


September 13, 2001

Resident/Property Owner
Hinkley, CA


Dear Resident/Property Owner:

We are writing to provide you with the results of the tests that the Lahontan RegionalWater Quality Control Board recently performed on water from your private well (locatedat ADDRESS). Your private well water was tested because it is located near the area ofthe groundwater that has been contaminated with chromium 6 (hexavalent chromium)by the Pacific Gas and Electric Company. We (the California Department of HealthServices Environmental Health Investigations Branch) recommended that the LahontanRegional Water Quality Control Board measure the levels of total chromium andchromium 6 in private wells located near the chromium 6 groundwater contamination.

The Lahontan Regional Water Quality Control Board had E.S. Babcock & Sonslaboratory measure the levels of total chromium and chromium 6 in your private drinkingwell water. In order to learn more about the characteristics and quality of thegroundwater, they also had NEL laboratories analyze your water for metals, mineralsand other inorganic compounds. At high levels, these compounds can make watereither unsafe or unpleasant (bad taste, odor or appearance) to drink. Copies of thelaboratory reports are included with this letter.

We reviewed the results of the tests that were performed on water from your privatewell. We also compared the levels of compounds in your water to the levels that areallowed in public drinking water systems. (The state of California regulates publicdrinking water systems in order to ensure the safety and the quality of public watersupplies.)

As we will explain in more detail in the remainder of this letter, the levels of totalchromium and chromium 6 in your drinking water do not pose a risk to yourhealth. However, the levels of nitrate, thallium, specific conductance, sulfate, andtotal dissolved solids in your water do exceed public drinking water standardsand therefore may affect the safety or the quality (taste, odor, appearance) of yourwell water.

Results for Total Chromium and Chromium 6

The California drinking water standard for total chromium was created in order to ensure that public water supplies are safe to drink. The drinking water standard for total chromium is 50 micrograms per liter (g/L). There is no specific drinking water standard for chromium 6.

Total chromium is made up of chromium 3 (trivalent chromium) and chromium 6. The Lahontan Regional Water Quality Control Board measured the levels of total chromium and chromium 6 in your water. The test results show that your private well water contains 24 g/L ppb total chromium and 24 g/L chromium 6.

The amount of total chromium in your private well water is below the drinking waterstandard for total chromium and therefore does not pose a risk to your health.

We have included a fact sheet that provides more information on chromium in drinkingwater and on the chromium drinking water standard.

Results for Nitrate

The California drinking water standard for nitrate was created to ensure that publicwater supplies are safe to drink. The drinking water standard for nitrate is 10 milligramsper liter as nitrogen (mg/L-N).

The test results show that the concentration of nitrate in your private well water is 20mg/L-N. This level is greater than the California drinking water standard of 10 mg/L-N.The source of the nitrate contamination of your well water is unknown; however, nitrateis commonly found in water supplies, especially in agricultural areas.

Pregnant women and young infants who drink water contaminated with high levels ofnitrate are the most at risk of developing serious health problems. However, thesehealth problems will stop once you are no longer exposed to nitrate. If you arepregnant or have a young infant (under six months old), we recommend that youuse different water (for example, municipal or bottled water) for drinking,cooking, and making infant formula.

We have included a brochure that provides more information on nitrate. The brochure istitled "Health Concerns Related to Nitrate and Nitrite in Private Well Water."

Results for Thallium

The California drinking water standard for thallium was created to ensure that publicwater supplies are safe to drink. The drinking water standard for thallium is 0.002milligrams per liter (mg/L).

The test results show that the amount of thallium in your private well water is 0.11 mg/L.This level is greater than the California drinking water standard of 0.002 mg/L. Thesource of the thallium contamination in your well water is currently unknown. Thallium isa metal that is found in natural deposits in soil and rock. Leaching from ore processingoperations is the major source of thallium contamination in water.

People who consume high amounts of thallium for a short period of time canexperience problems with their digestion and nervous system. Exposure to high levelsof thallium over a lifetime can cause hair loss, changes in blood chemistry, or damageto the liver, kidney, and digestive tract.

Because the level of thallium in your well water is above the drinking waterstandard, we recommend that you use water from a different source (bottled ormunicipal) for drinking, cooking, and watering your vegetable, fruit garden. It mayalso be advisable to not give your well water to your animals. We also recommend thatyou test your well water for thallium again in order to confirm and better understand theamount of thallium in your water.

Results for Specific Conductance, Sulfate, and Total Dissolved Solids

The drinking water standards for specific conductance, sulfate, and total dissolved solids were created in order to protect the quality (taste, odor, appearance) of public water supplies. The standard for specific conductance is 900 micromhos (S/cm), for sulfate is 250 mg/L and for total dissolved solids is 500 mg/L.

The test results show that your private well water has 1680 S/cm specific conductance, 280 mg/L sulfate, and 1050 mg/L total dissolved solids. These levels are higher than the California drinking water standards. High levels of specific conductance, sulfate, and total dissolved solids may affect the taste, odor or appearance of your well water. However, these compounds do not put your health at risk.

Follow-up Testing

One water test does not provide enough information to fully understand the safety and quality of your water. For this reason, the Lahontan Regional Water Quality Control Board would like to take another sample of your well water in the near future. They will retest the water for nitrate, thallium, specific conductance, sulfate, and total dissolved solids. Lahontan Regional Water Quality Control Board will provide you with the results of these tests.

Recommendations for Private Well Owners

Many chemicals, metals, minerals and bacteria may be present in private wells andmay threaten the safety and quality of your drinking water. These compounds can comefrom both natural sources and human activity. Private drinking water wells are notregulated or tested by the state, so people with private wells are responsible for makingsure that their own drinking water is safe.

We have recommended that you do not use your well water for drinking and cooking.Should you switch to a different or a new well, we encourage you to routinely testthat well to ensure the safety of your drinking water. Since bacteria are the mostcommon problem in private wells, we would suggest that you also have the water testedfor coliform.

Lastly, California-certified water filters and treatment systems that you can purchase in stores are not intended to treat water with levels of contaminants that are above the health-based drinking water standard. Therefore, we do not recommend that you rely upon these filters and treatment systems to reduce the levels of nitrate, lead, and mercury measured in your well water.

If you have any questions about the information we have provided, please do nothesitate to call Tracy Barreau at (510) 622-4489 or Jackie Schwartz at (510) 622-4487.

Sincerely,

Jackie Schwartz, MPH
Environmental Health Scientist
Environmental Health Investigations Branch

Marilyn Underwood, Ph.D.
Staff Toxicologist
Environmental Health Investigations Branch


Enclosures

cc:

Harold Singer, Executive Officer
Lahontan Regional Water Quality Control Board
2501 Lake Tahoe Boulevard
South Lake Tahoe, CA 96150

Mike Plaziak, Acting Mojave Unit Chief
Lahontan Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

Joe Koutsky, AWRCE
Lahontan Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

William Vance, Assistant Secretary of Air and Water Programs
California Environmental Protection Agency
1001 "I" Street, 25th Floor
Sacramento, CA 95814

Lynn Baker, Staff Air Pollution Specialist
California Air Resources Board
1001 "I" Street, 6th Floor
Sacramento, CA 95814



DEPARTMENT OF   HEALTH SERVICESDEPARTMENT OF HEALTH SERVICES
1515 CLAY STREET, SUITE 1700
OAKLAND, CA 94612
(510) 622-4500


September 14, 2001

Resident/Property Owner
Hinkley, CA


Dear Resident/Property Owner:

We are writing to provide you with the results of the tests that the Lahontan RegionalWater Quality Control Board recently performed on water from your private well (locatedat ADDRESS). Your private well water was tested because it is located near the area ofthe groundwater that has been contaminated with chromium 6 (hexavalent chromium)by the Pacific Gas and Electric Company. We (the California Department of HealthServices Environmental Health Investigations Branch) recommended that the LahontanRegional Water Quality Control Board measure the levels of total chromium andchromium 6 in private wells located near the chromium 6 groundwater contamination.

The Lahontan Regional Water Quality Control Board had E.S. Babcock & Sonslaboratory measure the levels of total chromium and chromium 6 in your private drinkingwell water. In order to learn more about the characteristics and quality of thegroundwater, they also had NEL laboratories analyze your water for metals, mineralsand other inorganic compounds. At high levels, these compounds can make watereither unsafe or unpleasant (bad taste, odor or appearance) to drink. Copies of thelaboratory reports are included with this letter.

We reviewed the results of the tests that were performed on water from your privatewell. We also compared the levels of compounds in your water to the levels that areallowed in public drinking water systems. (The state of California regulates publicdrinking water systems in order to ensure the safety and the quality of public watersupplies.)

As we will explain in more detail in the remainder of this letter, the levels of totalchromium and chromium 6 in your drinking water do not pose a risk to yourhealth. However, the levels of nitrate, specific conductance, and total dissolvedsolids in your water do exceed public drinking water standards and therefore mayaffect the safety or the quality (taste, odor, appearance) of your well water.

Results for Total Chromium and Chromium 6

The California drinking water standard for total chromium was created in order to ensure that public water supplies are safe to drink. The drinking water standard for total chromium is 50 micrograms per liter (g/L). There is no specific drinking water standard for chromium 6.

Total chromium is made up of chromium 3 (trivalent chromium) and chromium 6. The Lahontan Regional Water Quality Control Board measured the levels of total chromium and chromium 6 in your water. The test results show that your private well water contains 13 g/L ppb total chromium and 1.5 g/L chromium 6.

The amount of total chromium in your private well water is below the drinking waterstandard for total chromium and therefore does not pose a risk to your health.

We have included a fact sheet that provides more information on chromium in drinkingwater and on the chromium drinking water standard.

Results for Nitrate

The California drinking water standard for nitrate was created to ensure that publicwater supplies are safe to drink. The drinking water standard for nitrate is 10 milligramsper liter as nitrogen (mg/L-N).

The test results show that the concentration of nitrate in your private well water is 12mg/L-N. This level is greater than the California drinking water standard of 10 mg/L-N.The source of the nitrate contamination of your well water is unknown; however, nitrateis commonly found in water supplies, especially in agricultural areas.

Pregnant women and young infants who drink water contaminated with high levels ofnitrate are the most at risk of developing serious health problems. However, thesehealth problems will stop once you are no longer exposed to nitrate. If you arepregnant or have a young infant (under six months old), we recommend that youuse different water (for example, municipal or bottled water) for drinking,cooking, and making infant formula.

We have included a brochure that provides more information on nitrate. The brochure istitled "Health Concerns Related to Nitrate and Nitrite in Private Well Water."

Results for Specific Conductance and Total Dissolved Solids

The drinking water standards for specific conductance and total dissolved solids were created in order to protect the quality (taste, odor, appearance) of public water supplies. The standard for specific conductance is 900 micromhos (S/cm), and for total dissolved solids is 500 milligrams per liter (mg/L).

The test results show that your private well water has 1760 S/cm specific conductance, and 1100 mg/L total dissolved solids. These levels are higher than the California drinking water standards. High levels of specific conductance and total dissolved solids may affect the taste, odor or appearance of your well water. However, these compounds do not put your health at risk.

Follow-up Testing

One water test does not provide enough information to fully understand the safety andquality of your water. For this reason, the Lahontan Regional Water Quality ControlBoard would like to take another sample of your well water in the near future. They willretest the water for nitrate, specific conductance, and total dissolved solids. LahontanRegional Water Quality Control Board will provide you with the results of these tests.

Recommendations for Private Well Owners

Many chemicals, metals, minerals and bacteria may be present in private wells andmay threaten the safety and quality of your drinking water. These compounds can comefrom both natural sources and human activity. Private drinking water wells are notregulated or tested by the state, so people with private wells are responsible for makingsure that their own drinking water is safe.

We encourage you to have your well water tested routinely to ensure the safety ofyour drinking water. Since bacteria are the most common problem in private wells, wewould suggest that you have your well tested for coliform on a periodic basis. TheLahontan Regional Water Quality Control Board did not perform a bacteria test onyour well water.

Lastly, California-certified water filters and treatment systems that you can purchase in stores are not intended to treat water with levels of contaminants that are above the health-based drinking water standard. Therefore, we do not recommend that you rely upon these filters and treatment systems to reduce the levels of nitrate, lead, and mercury measured in your well water.

If you have any questions about the information we have provided, please do not hesitate to call Tracy Barreau at (510) 622-4489 or Jackie Schwartz at (510) 622-4487.

Sincerely,

Jackie Schwartz, MPH
Environmental Health Scientist
Environmental Health Investigations Branch

Marilyn Underwood, Ph.D.
Staff Toxicologist
Environmental Health Investigations Branch


Enclosures

cc:

Harold Singer, Executive Officer
Lahanton Regional Water Quality Control Board
2501 Lake Tahoe Boulevard
South Lake Tahoe, CA 96150

Mike Plaziak, Acting Mojave Unit Chief
Lahanton Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

Joe Koutsky, AWRCE
Lahanton Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

William Vance, Assistant Secretary of Air and Water Programs
California Environmental Protection Agency
1001 "I" Street, 25th Floor
Sacramento, CA 95814

Lynn Baker, Staff Air Pollution Specialist
California Air Resources Board
1001 "I" Street, 6th Floor
Sacramento, CA 95814

Property Owner



DEPARTMENT OF   HEALTH SERVICESDEPARTMENT OF HEALTH SERVICES
1515 CLAY STREET, SUITE 1700
OAKLAND, CA 94612
(510) 622-4500


September 14, 2001

Resident/Property Owner
Hinkley, CA


Dear Resident/Property Owner:

We are writing to provide you with the results of the tests that the Lahontan RegionalWater Quality Control Board recently performed on water from your private well (locatedat address.). Your private well water was tested because it is located near the area ofthe groundwater that has been contaminated with chromium 6 (hexavalent chromium)by the Pacific Gas and Electric Company. We (the California Department of HealthServices Environmental Health Investigations Branch) recommended that the LahontanRegional Water Quality Control Board measure the levels of total chromium andchromium 6 in private wells located near the chromium 6 groundwater contamination.

The Lahontan Regional Water Quality Control Board had E.S. Babcock & Sonslaboratory measure the levels of total chromium and chromium 6 in your private drinkingwell water. In order to learn more about the characteristics and quality of thegroundwater, they also had NEL laboratories analyze your water for metals, mineralsand other inorganic compounds. At high levels, these compounds can make watereither unsafe or unpleasant (bad taste, odor or appearance) to drink. Copies of thelaboratory reports are included with this letter.

We reviewed the results of the tests that were performed on water from your privatewell. We also compared the levels of compounds in your water to the levels that areallowed in public drinking water systems. (The state of California regulates publicdrinking water systems in order to ensure the safety and the quality of public watersupplies.)

As we will explain in more detail in the remainder of this letter, the levels of totalchromium and chromium 6 in your drinking water do not pose a risk to yourhealth. However, the levels of nitrate, lead, mercury, chloride, specificconductance, sulfate, and total dissolved solids in your water do exceed publicdrinking water standards and therefore may affect the safety or the quality (taste,odor, appearance) of your well water.

Results for Total Chromium and Chromium 6

The California drinking water standard for total chromium was created in order to ensure that public water supplies are safe to drink. The drinking water standard for total chromium is 50 micrograms per liter (g/L). There is no specific drinking water standard for chromium 6.

Total chromium is made up of chromium 3 (trivalent chromium) and chromium 6. The Lahontan Regional Water Quality Control Board measured the levels of total chromium and chromium 6 in your water. The test results show that your private well water contains 6 g/L ppb total chromium and 0.53 g/L chromium 6.

The amount of total chromium in your private well water is below the drinking waterstandard for total chromium and therefore does not pose a risk to your health.

We have included a fact sheet that provides more information on chromium in drinkingwater and on the chromium drinking water standard.

Results for Nitrate

The California drinking water standard for nitrate was created to ensure that publicwater supplies are safe to drink. The drinking water standard for nitrate is 10 milligramsper liter as nitrogen (mg/L-N).

The test results show that the amount of nitrate in your private well water is 62 mg/L-N.This level is greater than the California drinking water standard of 10 mg/L-N. Thesource of the nitrate contamination of your well water is unknown; however, nitrate iscommonly found in water supplies, especially in agricultural areas.

Pregnant women and young infants who drink water contaminated with high levels ofnitrate are the most at risk of developing serious health problems. However, thesehealth problems will stop once you are no longer exposed to nitrate. If you arepregnant or have a young infant (under six months old), we recommend that youuse different water (for example, municipal or bottled water) for drinking,cooking, and making infant formula.

We have included a brochure that provides more information on nitrate. The brochure istitled "Health Concerns Related to Nitrate and Nitrite in Private Well Water."

Results for Lead

The California drinking water standard for lead was created to ensure that public watersupplies are safe to drink. The drinking water standard for lead is 0.015 milligrams perliter (mg/L).

The test results show that the amount of lead in your private well water is 0.089 mg/L.The amount of lead in your water is higher than the California drinking water standardof 0.015 mg/L.

Children under six years old are at the highest risk for lead poisoning. Lead poisoningcan harm the brain, nerves and kidneys of a young child and make it very hard for achild to learn, pay attention, and behave. Most children with lead poisoning do not lookor act sick.

There are many ways that children may be exposed to lead, including air, water, dust,soil and older paints that contain lead. We have included two brochures that providemore information on childhood lead poisoning and the ways that children may beexposed to lead.

A child who drinks water from your well and who is also exposed to lead from othercommon sources may be exposed to greater amounts of lead than is recommended. Ifyou have a young child who drinks water from your well, or if you have othersources of lead exposure in your home (for example, paint manufactured before1978), we recommend that you use different water (municipal or bottled). We alsorecommend that the child have a blood lead test. The blood lead test is the only wayto know if your child has lead poisoning. Your doctor or clinic can give your child a bloodlead test. You may also call the San Bernardino County Childhood Lead PoisoningPrevention Program at (909) 387-6305 for further information on lead poisoning and theblood lead test.

The source of the lead contamination is currently unknown. Because water was takenfrom your well and not from inside your house, we do know that the source of the leadcontamination is not your plumbing. The lead in your water could be coming from amaterial that was used to construct your well or from an outside source that hascontaminated the groundwater in your area. We recommend that you ask your wellconstructor if lead solder was used to construct your well. This information should berecorded in the drill records for your well.

Results for Mercury

The California drinking water standard for inorganic mercury was created to ensure thatpublic water supplies are safe to drink. The drinking water standard for inorganicmercury is 0.002 mg/L.

The test results show that the amount of inorganic mercury in your private well water is0.0029 mg/L. This level is above the California drinking water standard of 0.002 mg/L.

Exposure to very high levels of inorganic mercury salts can damage the kidney andnervous system. Young children are more at risk for health problems than adultsbecause mercury is more easily absorbed into their bodies. Because the level ofmercury in your well water is above the drinking water standard, we recommendthat you use water from a different source (bottled, municipal) for drinking andcooking.

The source of the mercury contamination in your well water is currently unknown.Mercury is used in batteries, and in some paints, pesticides and chemicals. If any ofthese items spill or are improperly disposed of near your well, the mercury in them canmove through the soil and reach the water in your well. We recommend that youcontinue to test for mercury in your well water (in order to better understand thecontamination) and that you try to identify the source of the mercurycontamination.

Results for Chloride, Specific Conductance, Sulfate, and Total Dissolved Solids

The drinking water standards for chloride, specific conductance, sulfate, and total dissolved solids were created in order to protect the quality (taste, odor, appearance) of public water supplies. The standard for chloride is 250 mg/L, for specific conductance is 900 micromhos (S/cm), for sulfate is 250 mg/L and for total dissolved solids is 500 mg/L.

The test results show that your private well water has 930 mg/L chloride, 4910 S/cm specific conductance, 880 mg/L sulfate, and 3490 mg/L total dissolved solids. These levels are higher than the California drinking water standards. High levels of chloride, specific conductance, sulfate and total dissolved solids may affect the taste, odor or appearance of your well water. These compounds do not put your health at risk.

Follow-up Testing

One water test does not provide enough information to fully understand the safety andquality of your water. For this reason, the Lahontan Regional Water Quality ControlBoard would like to take another sample of your well water in the near future. They willretest the water for nitrate, lead, mercury, chloride, specific conductance, sulfate, andtotal dissolve solids. Lahontan Regional Water Quality Control Board will provide youwith the results of these tests.

Recommendations for Private Well Owners

Many chemicals, metals, minerals and bacteria may be present in private wells andmay threaten the safety and quality of your drinking water. These compounds can comefrom both natural sources and human activity. Private drinking water wells are notregulated or tested by the state, so people with private wells are responsible for makingsure that their own drinking water is safe.

We have recommended that you do not use your well water for drinking and cooking.Should you switch to a different or a new well, we encourage you to routinely testthat well to ensure the safety of your drinking water. Since bacteria are the mostcommon problem in private wells, we would suggest that you also have the water testedfor coliform.

Lastly, California-certified water filters and treatment systems that you can purchase in stores are not intended to treat water with levels of contaminants that are above the health-based drinking water standard. Therefore, we do not recommend that you rely upon these filters and treatment systems to reduce the levels of nitrate, lead, and mercury measured in your well water.

If you have any questions about the information we have provided, please do nothesitate to call Tracy Barreau at (510) 622-4489 or Jackie Schwartz at (510) 622-4487.

Sincerely,

Jackie Schwartz, MPH
Environmental Health Scientist
Environmental Health Investigations Branch

Marilyn Underwood, Ph.D.
Staff Toxicologist
Environmental Health Investigations Branch


Enclosures

cc:

Harold Singer, Executive Officer
Lahanton Regional Water Quality Control Board
2501 Lake Tahoe Boulevard
South Lake Tahoe, CA 96150

Mike Plaziak, Acting Mojave Unit Chief
Lahanton Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

Joe Koutsky, AWRCE
Lahanton Regional Water Quality Control Board
15428 Civic Drive, Suite 100
Victorville, CA 92392

William Vance, Assistant Secretary of Air and Water Programs
California Environmental Protection Agency
1001 "I" Street, 25th Floor
Sacramento, CA 95814

Lynn Baker, Staff Air Pollution Specialist
California Air Resources Board
1001 "I" Street, 6th Floor
Sacramento, CA 95814

Property Owner


APPENDIX E: FACT SHEET ON CHROMIUM IN DRINKING WATER

Prepared by:
California Department of Health Services, Division of Drinking Water andEnvironmental Management and California Environmental Protection Agency,Office of Environmental Health Hazard Assessment

Click here to view Appendix E on the web http://www.oehha.ca.gov/public_info/facts/chrom6facts.html


APPENDIX F: INFORMATION BROCHURE: LEAD POISONING AND YOUR CHILDREN

Prepared by:
United States Environmental Protection Agency


Click here to view Appendix F in PDF format
(PDF, 214KB)


APPENDIX G: INFORMATION BROCHURE: LEAD POISONING: ARE YOUR CHILDREN IN DANGER?

Prepared by:
California Department of Health Services, Child Health and Disability Prevention Program and Childhood Lead Poisoning Prevention Branch


Click here to view Appendix G in PDF format
(PDF, 2.1MB)


APPENDIX H: FACT SHEET: HEALTH CONCERNS RELATED TO NITRATE AND NITRITE IN PRIVATE WELL WATER

Prepared by:
California Department of Health Services, Environmental Health Investigations Branch


Click here to view Appendix H in PDF format
(PDF, 232KB)

Table of Contents

  
 
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