Weaverville Community Services
District
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| TERMS USED IN THIS REPORT: |
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| Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in 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. 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). 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 Residual Disinfectant Level (MRDL): The level of a disinfectant added for water treatment that may not be exceeded at the consumer’s tap. Maximum Residual Disinfectant Level Goal (MRDLG): The level of a disinfectant added for water treatment below which there is no known or expected risk to health. MRDLGs are set by the U.S. Environmental Protection Agency. Primary Drinking Water Standards (PDWS): MCLs and MRDLs for contaminants that affect health along with their monitoring, reporting, 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. Treatment Technique (TT): A required process intended to reduce the level of a contaminant in drinking water. Regulatory Action Level (AL): The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow. Running Annual Average (RAA): running annual average of the most recent four quarters of sample results. Variances and Exemptions: Department permission to exceed an MCL or not comply with a treatment technique under certain conditions. N/A: not applicable ND: not detectable at laboratory testing limit NTU: Nephelometric Turbidity Unit, measurement of the turbidity (cloudiness) of water. ppm: parts per million or milligrams per liter (mg/L). 1 part per million corresponds to one minute in two years or a single penny in $10,000. ppb: parts per billion or micrograms per liter (ug/L).
µS/cm: microsiemens per cm, units of specific conductance or electrical conductivity (i.e. ions in water) |
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Type of water sources in use: |
Three surface water sources |
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Name & location of sources: |
East Weaver & West Weaver Creeks in Weaverville; Trinity River in Douglas City |
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Drinking Water Source Assessment information: |
Source water assessments were performed on all three water |
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sources in January 2003. These sources are considered most vulnerable to the following activities although no |
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contaminants were detected: East Weaver Creek – surface water source, no contaminants detected. |
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West Weaver Creek – Recent mining operation – historic, no contaminants detected. |
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Trinity River – Automobile - Gas stations, no contaminants detected |
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A copy of the complete assessment may be viewed at the California Department of Public Health, Division of |
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Drinking Water, 415 Knollcrest Drive, Suite 110, Redding CA 96002, by calling (530)-224-3265. |
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The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, and springs,. 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 stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
·Pesticides and herbicides, that may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.
·Organic chemical contaminants, including synthetic and volatile organic chemicals, that are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural application, and septic systems.
·Radioactive contaminants, that 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, the USEPA and the state Department of Public Health (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 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 allows us to monitor for certain contaminants less than once per year because the concentrations of these contaminants do not change frequently. Some of the data, though representative of the water quality, are more than one year old.
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Table 1 - coliform bacteria sampling results |
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| Microbiological
Contaminants |
Highest No. of detections |
No. of months in violation |
MCL |
MCLG |
Typical Source of Bacteria |
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| Total Coliform Bacteria |
0 |
0 |
More than 1 sample in a month with a detection |
0 |
Naturally present in the environment |
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| Fecal Coliform or E. coli |
0 |
0 |
A routine sample and a repeat sample detect total coliform and either sample also detects fecal coliform or E. coli |
0 |
Human and animal fecal waste |
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Table 2 - Lead
and copper sampling results |
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| Lead and Copper samples collected in 2006 |
No. of samples collected |
90th percentile level detected |
No. sites exceeding AL |
AL |
PHG |
Typical Source of Contaminant |
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| Lead (ppb) |
20 |
5.5 |
0 |
15 |
2 |
Internal corrosion of household water plumbing systems; discharges from industrial manufacturers; erosion of natural deposits |
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| Copper (ppb) |
20 |
374 |
0 |
1,300 |
170 |
Internal corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives |
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TAble 3 – sodium and hardness sampling results |
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| Chemical or Constituent samples collected in 2009 |
East Weaver |
West Weaver |
Trinity River |
MCL |
PHG (MCLG) |
Typical Source of Contaminant |
| Sodium (ppm) |
2.55 |
2.79 |
5.02 |
none |
none |
Generally found in ground & surface water |
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Hardness (ppm) |
32 |
66 |
80 |
none |
none |
Generally found in ground & surface water |
TAble 4 -
detection of contaminants with a Primary Drinking Water
Standard |
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| Chemical
or Constituent |
East Weaver |
West Weaver |
Trinity River |
MCL [MRDL] |
PHG (MCLG) [MRDLG] |
Typical Source of Contaminant |
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Total Trihaomethanes (ppb) [RAA reported] |
30.7 |
39.9 |
31.2 |
80 |
N/A |
Byproduct of drinking water chlorination |
| Haloacetic Acids (ppb) [RAA reported] |
56.7 |
56.7 |
20.0 |
60 |
N/A |
Byproduct of drinking water disinfection |
| Highest single Turbidity measurement for entire year measured every 4 hrs(NTU) |
0.34* |
2.0 |
0.25 |
0.3 NTU (95% of samples) |
N/A |
Soil runoff |
| Residual Chlorine (ppm) |
0.2 to 1.5 |
4 |
4 |
Drinking water disinfectant added for treatment |
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TAble 5 -
detection of contaminants with a Secondary Drinking Water
Standard |
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| Chemical or Constituent |
East Weaver |
West Weaver |
Trinity River |
MCL |
Recommended |
Typical Source of Contaminant |
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Sample collected: |
2005 |
2005 |
2009 |
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| Chloride (ppm) 05 |
0.38 |
0.7 |
6.3 |
500 |
250 |
Runoff/leaching from natural deposits |
| Copper (ppm) |
ND |
ND |
0.177 |
1.0 |
N/A |
Erosion of natural deposits; leaching from wood preservatives |
| Specific Conductance (µS/cm) |
78 |
143 |
185 |
1,600 |
900 |
Substances that form ions when in water |
| Sulfate (ppm) |
1.7 |
5.4 |
8.7 |
500 |
250 |
Runoff/leaching from natural deposits |
| Total Dissolved Solids (ppm) |
65 |
84 |
117 |
1,000 |
500 |
Runoff/leaching from natural deposits |
* Additional information regarding this turbidity result is provided later in this report.
Additional General Information on Drinking Water
Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that the water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the USEPA’s Safe Drinking Water Hotline (1-800-426-4791).
Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. USEPA/Centers for Disease Control (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (1-800-426-4791).
Summary Information for Elevated Results
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Finished water turbidities are measured every 4 hours from each of the three treatment plants. On very few occasions, |
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elevated turbidities were measured in samples from the East Weaver and West Weaver plants. However, the |
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performance standard of ≤0.3 NTU (in at least 95% of measurements taken each month) has always met. A summary |
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of these standards and our monitoring is presented in Table 6 below. |
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Table 6 - sampling results showing TREATMENT OF SURFACE WATER SOURCES |
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| Treatment Technique (a) (Type of filtration technology used) |
East
Weaver Plant: direct filtration |
| Turbidity Performance Standards (b) (that must be met through the water treatment process) |
Turbidity of the filtered water must: Be less than or equal to 0.3 NTU in 95% of measurements in a month. Not exceed 1 NTU at any time. |
| Lowest monthly percentage of samples that met Turbidity Performance Standard 0.3 NTU |
East
Weaver Plant: 99% |
| Highest single turbidity measurement during the year |
0.34 NTU in East Weaver Plant |
| Number of violations of any surface water treatment requirements |
None. |
(a) A required process intended to reduce the level of a contaminant in drinking water.
(b) Turbidity (measured in NTU) is a measurement of the cloudiness of water and is a good indicator of water quality and filtration performance. Turbidity results which meet performance standards are considered to be in compliance with filtration requirements.
Additional Information
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Weaverville CSD has applied for funding through the American Recovery and Reinvestment Act to upgrade the |
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filtration system at the West Weaver Plant. Construction is expected to begin within the next calendar year. |
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Please call our office if you have questions (530-623-5051). All the employees of Weaverville CSD are dedicated |
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to providing top quality water to every customer. We ask that all our customers help us protect our water sources, |
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which are the heart of our community, our way of life and our children’s future. |