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1998 Water Quality Information
State Standards and Water Quality Monitoring Individual water suppliers do not arbitrarily decide what constitutes “safe” drinking water. The U.S. Environmental Protection Agency and the California State Department of Health Services require all public water suppliers to meet stringent quality standards. Compliance is mandatory for public water utilities.In California, drinking water standards (also called Maximum Contaminant Levels, or MCLs) are established for two categories. Primary Standards are set for the protection of public health. Secondary Standards are set only for aesthetic qualities such as taste, odor and color, but do not represent any threat to health. The District maintains a monitoring program to sample and test all water sources in accordance with State and Federal standards. Should the District fail to monitor, or the District’s water exceed the MCLs allowable in the Primary Standards, it is required by law to notify all customers of the nature of the problem and any possible health effects. Some contaminants that are routinely monitored by the District are bacteria, turbidity, inorganic chemicals, metals, general minerals, volatile organic chemicals (VOCs), disinfection by-products (THMs), and radiation. The District has previously conducted monitoring for 28 additional Volatile Organic Chemicals for which the California Department of Health Services and the U.S. Environmental Protection Agency have not yet established standards. All results were below detectable levels. Based on these past results, the Department of Health Services has granted the District a monitoring waiver for those constituents considered unlikely to be found in our water sources. The table in this report shows our test results for 1998. Once again, the San Lorenzo Valley Water District is pleased to report that our water quality met or surpassed all State and Federal criteria for public health protection. In addition, information regarding the most frequently requested water quality constituents is shown as graphic displays on page 6. For additional information regarding water quality, or to obtain water quality information booklets, please contact the San Lorenzo Valley Water District at (831) 338-2153. WATER QUALITY ANALYSIS FOR 1998
Parameter Units MCL Surface Water Groundwater
Maximum Range Average Range Average
TESTING FOR PRIMARY STANDARDS Contaminant Level
Mandatory Health - Related Standards Established by State and Federal regulations
CLARITY
Turbidity NTU 1.0 0.03 - 0.20 < 0.4 0.25 - 1.5 0.6
MICROBIOLOGICAL
Coliform Bacteria
Presence/Absence % Samples >5.0% From Distribution System:Range: 0-2 Average:.16
Positive No Violations
ORGANIC CHEMICALS
Total Trihalomethanes mg/L 100.0 From Distribution System:Range: ND - 33 Average: 20
Benzene mg/L 1.0 ND ND ND ND
Carbon Tetrachloride mg/L 0.5 ND ND ND ND
1,2 - Dichlorobenzene mg/L 6.0 ND ND ND ND
1,4 - Dichlorobenzene mg/L 5.0 ND ND ND ND
1, 1 - Dichloroethane mg/L 5.0 ND ND ND ND
1,2 - Dichloroethane mg/L 0.5 ND ND ND ND
1,1 - Dichloroethylene mg/L 6.0 ND ND ND ND
Cis- 1,2- Dichloroethylene mg/L 6.0 ND ND ND ND
Trans- 1, 2- Dichloroethylene mg/L 10.0 ND ND ND ND
Dichloromethane mg/L 5.0 ND ND ND ND
1, 2- Dichloropropane mg/L 5.0 ND ND ND ND
1, 3- Dichloropropene mg/L 0.50 ND ND ND ND
Ethylbenzene mg/L 700.0 ND ND ND ND
Monochlorobenzene mg/L 70.0 ND ND ND ND
MTBE mg/L 70.0 ND ND ND ND
Styrene mg/L 100.0 ND ND ND ND
1,1,2,2,- Tetrachloroethane mg/L 1.0 ND ND ND ND
Tetrachloroethylene mg/L 5.0 ND ND ND ND
Toluene mg/L 150.0 ND ND ND ND
1, 2, 4 - Trichlorobenzene mg/L 70.0 ND ND ND ND
1,1,1,- Trichloroethane mg/L 200.0 ND ND ND ND
1,1,2,- Trichloroethane mg/L 5.0 ND ND ND ND
Trichloroethylene mg/L 5.0 ND ND ND-11 1.2
Trichlorofluoromethane mg/L 150.0 ND ND ND ND
1, 1, 2- Trichloro-1, 2, 2
- TriFluoroethane (Freon 113) mg/L 1200.0 ND ND ND ND Vinal Chloride mg/L 0.5 ND ND ND ND Xylenes mg/L 1750.0 ND ND ND ND INORGANIC CHEMICALS HEAVY METALS Aluminum mg/L 1.0 <0.1 <0.1 <0.1 <0.1 Antimony mg/L 0.006 <0.006 <0.006 <0.006 <0.006 Arsenic mg/L 0.05 <0.002 <0.002 0.002-0.017 0.002 Barium mg/L 1.0 <0.01 <0.1 <0.1 <0.1 Beryllium mg/L 0.004 <0.001 <0.001 <0.001 <0.001 Cadmium mg /L 0.1 <0.001 <0.001 <0.001 <0.001 Chromium mg/L 0.05 <0.01 <0.01 <0.01 <0.01 Cyanide mg/L 0.2 <0.02 <0.02 <0.02 <0.02 Fluoride mg/L 1.4 - 2.4 <0.2 <0.2 <0.2 <0.2 Lead mg/L 0.05 <0.005 <0.005 <0.005 <0.005 Mercury mg/L 0.002 <0.001 <0.001 <0.001 <0.001 Nickel mg/L 0.1 <0.01 <0.01 <0.01 <0.01 Nitrate (as NO3) mg/L 45 <1 -1.4 <1.0 <0.1-24 6.2 Nitrite mg/L 1 <0.5 <0.5 <0.5 <0.5 Selenium mg/L 0.01 <0.005 <0.005 <0.005 <0.005 Silver mg/L 0.05 <0.01 <0.01 <0.01 <0.01 Thallium mg/L 0.002 <0.002 <0.002 <0.002 <0.002 TESTING FOR SECONDARY STANDARDS Aesthetic Standards Established by the State and Federal regulations Color units 15.0 <3.0 <3.0 <3.0 <3.0 Odor Threshold units 3 <1.0 <1.0 <1.0 <1.0 Chloride mg/L 250 4.9-7.0 5.6 5.5-7.5 6.6 Copper mg/L 1.0 <0.05 <0.05 <0.05 <0.05 Foaming Agents (MBAS) mg/L 0.5 <0.02 <0.02 <0.02 <0.02 Iron mg/L 0.3 <0.05 <0.05 <0.05-0.16 0.13 Manganese mg/L 0.05 <0.015 <0.015 0.02-0.06 0.025 Sulfate mg/L 250 3.0-4.9 4.0 5.5-180 64 Zinc mg/L 5.0 <0.05 <0.05 <0.05-0.05 <0.05 Total Dissolved Solids mg/L 1,000 90-130 116 69-400 148 RADIOACTIVITY Gross Aplha Activity pCi/L 15.0 <3.0 <3.0 <3.0 <3.0 TESTING FOR ADDITIONAL CONSTITUENTS pH units No Standard 7.2-7.8 7.6 6.6-7.5 7.1 Total Alkalinity mg/L No Standard 53-64 57 26-180 81 Total Hardness (CaCO3) mg/L No Standard 48-58 53 25-315 119 Boron mg/L No Standard <0.1 <0.1 0.1-0.11 <.1 Calcium mg/L No Standard 14-16 15 8.7-115 60 Magnesium mg/L No Standard 3-5 4 <1-8.0 2.8 Potassium mg/L No Standard 1.6-2.0 1.8 0.8-1.7 1.2 Sodium mg/L No Standard 8-9.4 8 9.2-16 12 |
