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Water
Excerpts from the 2001 Consumer Confidence Report
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Report Date: |
April 04, 2002 |
We test the drinking water quality for many constituents as required by State and Federal Regulations. This report shows the results of our monitoring for the period of January 1 - December 31, 2000. The State allows us to monitor for some contaminants less than once per year because the concentrations of these contaminants do not change frequently. Some of our data, though representative, are more than one year old
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TERMS USED IN THIS REPORT : |
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Maximum Contaminant Level (MCL) : The highest level of a contaminant that allowed in public drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as is economically and technologically feasible. Secondary MCLs are set to protect the odor, taste, and appearance of drinking water.
Primary Drinking Water Standards (PDWS): MCLs for contaminants that affect health along with their monitoring and reporting requirements, and water treatment requirements.
Secondary Drinking Water Standards (SDWS): MCLs for contaminants that affect taste, odor, or appearance of the drinking water. Contaminants with SDWSs do not affect the health at the MCL levels.
ND: not detectable at testing limit
ppm: parts per million or milligrams per liter (mg/L) |
Public Health Goal (PHG) : The level of a contaminant in drinking water below which there is no known or expected risk to health. PHGs are set by the California Environmental Protection Agency.
Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the U.S. Environmental Protection Agency (USEPA).
Regulatory Action Level (AL): The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.
ppb: parts per billion or micrograms per liter (ug/L)
ppt: parts per trillion or nanograms per liter (ng/L)
pCi/L: picocuries per liter (a measure of radiation) |
The sources of drinking water
Both tap water and bottled water include 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 from human activity.
Contaminants that may be present in source water include:
- Microbial contaminants
, such as viruses and bacteria that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
- Inorganic contaminants
, such as salts and metals, that can be naturally-occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining , or 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 that are byproducts of industrial processes and petroleum production, and can 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.
In order to ensure that tap water is safe to drink, USEPA and the state Department of Health Services (Department) prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. Department regulations also establish limits for contaminants in bottled water that must provide the same protection for public health.
Tables 1, 2, 3, 4 and 5 list all of the drinking water contaminants that were detected during the most recent sampling for the constituent. The presence of these contaminants in the water does not necessarily indicate that the water poses a health risk. The Department requires us to monitor for certain contaminants less than once per year because the concentrations of these contaminants are not expected to vary significantly from year to year. Some of the data, though representative of the water quality, are more than one year old.
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Table 1 – sampling results showing the detection of Lead and copper |
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Lead and Copper
(and reporting units) |
No. of samples collected |
90th percentile level detected |
No. Sites exceeding AL |
AL |
MCLG |
Typical Source of Contaminant |
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Copper (ppm)
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30 |
0.04 |
0 |
1.3 |
0.17 |
Internal corrosion of household water plumbing systems; erosion of natural deposits; leaching from wood preservatives. |
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Table 2 – sampling results for sodium and hardness |
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Chemical or Constituent
(and reporting units) |
Sample Date |
Level Detected |
Range of Detections |
MCL |
PHG
(MCLG) |
Typical Source of Contaminant |
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Sodium (ppm)
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12/18/01 |
52 |
43 – 80 |
None |
None |
Generally found in ground and surface water |
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Hardness (ppm)
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12/18/01 |
40 |
9 – 83 |
None |
None |
Generally found in ground and surface water |
* Any violation of an MCL or AL is asterisked.
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Table 3 – detection of contaminants with a Primary Drinking Water Standard |
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Chemical or Constituent
(and reporting units) |
Sample Date |
Level Detected |
Range of Detections |
MCL |
PHG
(MCLG) |
Typical Source of Contaminant |
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Organic Chemicals
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Total Trihalomethanes (ppb)
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12/18/01 |
20 |
13 – 26 |
100 |
0 |
By-product of drinking water chlorination |
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Inorganic Chemicals
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Aluminum (ppm)
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12/18/01 |
0.2 |
ND – 0.75 |
1 |
0.6 |
Erosion of natural deposits; residue from some surface water treatment processes |
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Arsenic (ppb)
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12/18/01 |
22 |
14 – 35 |
50 |
N/A |
Erosion of natural deposits; Runoff from orchards; Runoff from glass and electronics production wastes |
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Chromium (ppb)
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12/18/01 |
0.7 |
ND – 5 |
50 |
100 |
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Fluoride (ppm)
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12/18/01 |
0.6 |
0.1 – 1.2 |
2 |
1 |
Erosion of natural deposits; Water additive which promotes strong teeth; Discharge from fertilizer and aluminum factories |
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Nitrate as Nitrogen (ppm)
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12/18/01 |
1.7 |
0.4– 3.6 |
10 |
10 |
Runoff and leaching from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits |
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Nitrite as Nitrogen (ppm)
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12/18/01 |
0.01 |
ND – 0.02 |
1 |
1 |
Runoff and leaching from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits |
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Radioactive contaminants
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Gross Alpha (pCi/L)
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1999 |
5.1 |
ND – 11 |
15 |
N/A |
Erosion of natural deposits |
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Uranium (pCi/L)
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1999 |
2.7 |
ND – 10 |
20 |
N/A |
Erosion of natural deposits |
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