2011 Annual Water Quality Report

Transcription

1 2011 Annual Water Quality Report

2 Our Commitment to Quality he Water Division of the Public Works Department T provides services to ensure that the City s water supply meets all state and federal water quality requirements. Water treatment in the City of Manhattan Beach consists of chlorination and blending of the City's imported and well waters. The City s Water Plant Operators sample water on a weekly basis throughout the City and send these samples to an independent laboratory for analysis. Manhattan Beach maintains an excellent record for having provided safe, high-quality water to its residents for nearly 100 hundred years. Staff within the Water Division also administer and operate a "Backflow Prevention Program." This program involves the annual inspection of existing backflow prevention devices as well as administering a testing program for all residential and commercial structures, new and existing, that require protection. The Backflow Protection Program's intent is to ensure that if there is a reduction in pressure in the City's water system, potentially contaminated water does not flow back into the potable water system and contaminate drinking water. Source Water Assessment he Metropolitan Water District of Southern T California completed a vulnerability assessment of its Colorado River and State Water Project supplies in Colorado River supplies are considered most vulnerable to contamination from recreation, urban/ storm water runoff, increasing urbanization in the watershed, and wastewater. State Water Project supplies are considered most vulnerable to contaminations from urban/storm water runoff, wildlife, agriculture, recreation and wastewater. A copy of the assessment can be obtained by contacting MWD at (213) The City of Manhattan Beach conducted a vulnerability assessment of its groundwater supplies in Groundwater supplies are considered most vulnerable to metal plating/finishing/fabricating, chemical/ petroleum processing/storage, automobile repair shops, automobile gas stations, dry cleaners, and historic gas stations. A copy of the assessment may be requested by contacting Brian Wright at (310) Water Conservation in Manhattan Beach Although this season s storms have lifted us out of the drought, it s critical that we continue to watch our water use in order to comply with Senate Bill X7 7 20x2020 Water Conservation Plan, requiring that the City reduce its per capita water use by 20% by the year City Staff, in collaboration with the Environmental Task Force Water Subcommittee, are developing a water conservation program aimed at continued water conservation measures consistent with Senate Bill X7 7 and the City s Water Conservation Ordinance. Please visit the City s website at for more information on the Water Conservation ordinance and ways to save water today! Hydrant Flushing Our message is water conservation, yet you may occasionally see a City of Manhattan Beach Water Division employee opening a fire hydrant in your neighborhood and allowing the water to flow. Although this appears as a waste of water, this is an essential part of our scheduled preventive maintenance program that ensures the delivery of a safe and high quality drinking water to our customers. This controlled operation flushes natural sediments and pipe corrosion from the water supply system that may cause color, odor or variation in the taste of the drinking water, none of which are health concerns. System flushing is the most effective and economical solution to cleanse the distribution system and to enhance water quality. After all, we are committed in our responsibility to maintain system integrity and to deliver the highest quality of drinking water to our customers.

3 Hard Facts on Hard Water Water hardness is one of the most common water quality concerns reported by consumers in the United States. Water that is considered to be hard is high in dissolved minerals, specifically calcium and magnesium. The minerals in hard water can cause spots to form on dishes that are washed in a dishwasher; or a scale to form on showerheads, drip irrigation emitters, and kitchen appliances. How fast mineral buildups occur depends on how hard the water is at your home. Please visit the City s website for additional information about Hard Water at : page=1977 Important Health Information 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 guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline ( ). All 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 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 ( ). You can also get more information on tap water by logging on to these helpful web sites: USEPA s web site water.epa.gov/drink/index.cfm Calif. Dept. Of Public Health web site drinkingwater/pages/default.aspx Substances That Could Be in Water 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. In order to ensure that tap water is safe to drink, the U.S. Environmental Protection Agency (U.S. EPA) and the California Department of Public Health 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. 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 can 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, which are by-products of industrial processes and petroleum production and which can also come from gas stations, urban stormwater runoff, agricultural applications, and septic systems; Radioactive Contaminants, that can be naturally occurring or can be the result of oil and gas production and mining activities.

4 How Do I Read the Report? Although we test for over 100 substances, regulations require us to report only those found in your water. The first column of the water quality table lists substances detected in your water. The next columns list the average concentration and range of concentrations found in your drinking water. Following are columns that list the MCL and PHG or MCLG, if appropriate. The last column describes the likely sources of these substances in drinking water. To review the quality of your drinking water, compare the highest concentration and the MCL. Check for substances greater than the MCL. Exceedence of a primary MCL does not usually constitute an immediate health threat. Rather, it requires testing the source water more frequently for a short duration. If test results show that the water continues to exceed the MCL, the water must be treated to remove the substance, or the source must be removed from service. ABBREVIATIONS < = less than NTU = nephelometric turbidity units mg/l = milligrams per liter or parts per million (equivalent to pci/l = picocuries per liter 1 drop in 42 gallons) SI = saturation index ND = constituent not detected at the reporting limit NA = constituent not analyzed ng/l = nanograms per liter or parts per trillion (equivalent to 1 drop in 42,000,000 gallons) DEFINITIONS µg/l = micrograms per liter or parts per billion (equivalent to 1 drop in 42,000 gallons) umhos/cm = micromhos per centimeter 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. 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. 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. 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. Primary Drinking Water Standard (PDWS): MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements, and water treatment requirements.

5 CITY OF MANHATTAN BEACH 2011 ANNUAL WATER QUALITY REPORT PRIMARY STANDARDS MONITORED AT THE SOURCE-MANDATED FOR PUBLIC HEALTH ORGANIC GROUNDWATER SURFACE WATER PRIMARY MCLG MAJOR SOURCES IN DRINKING WATER CHEMICALS (µg/l) AVERAGE RANGE AVERAGE RANGE MCL or (PHG) Volatile & synthetic organic compounds (l) ND ND ND ND - - Industrial INORGANICS Sampled from 2009 to 2011 (b) Aluminum (mg/l) ND ND (a) Erosion of natural deposits; residue from surface water treatment processes Barium (mg/l) ND ND 1 2 (a) Oil drilling waste and metal refinery discharge; erosion of natural deposits Beryllium (µg/l) ND ND ND ND 4 1 (a) Discharge from metal refineries, coal-burning factories, defense industries Cadmium (µg/l) ND ND ND ND (a) Internal corrosion of galvanized pipes; erosion of natural deposits; industrial Chromium (µg/l) ND ND ND ND Discharge from steel and pulp mills/chrome plating; erosion of natural deposits Fluoride (mg/l) (a) Erosion of natural deposits, water additive that promotes strong teeth Mercury (µg/l) ND ND ND ND (a) Erosion of natural deposits, discharge from refineries and factories, runoff Nickel (µg/l) ND ND ND ND (a) Erosion of natural deposits, discharge from metal factories Nitrate (mg/l as NO3) ND ND 0.6 ND (a) Runoff and leaching from fertilizer use/septic tanks/sewage, natural erosion RADIOLOGICAL - (pci/l) Once every 3 years or once every 9 years (results are from 2007 to 2010) (b) Gross Alpha (c) 1.4 ND-5.4 ND ND-3 15 (d) 0 Erosion of natural deposits Gross Beta NA NA ND ND-6 50 (d) 0 Decay of natural and man-made deposits Uranium NA NA 1.7 ND-2 20 (d) 0.43 (a) Erosion of natural deposits PRIMARY STANDARDS MONITORED IN THE DISTRIBUTION SYSTEM - MANDATED FOR PUBLIC HEALTH DISTRIBUTION SYSTEM PRIMARY MCLG MICROBIALS AVERAGE % POSITIVE RANGE % POSITIVE MCL or (PHG) Total Coliform Bacteria 0% 0% 5% 0% Naturally present in the environment Fecal Coliform and E.Coli Bacteria 0% 0% 0% 0% Human and animal fecal waste No. of Acute Violations DISINFECTION DISTRIBUTION SYSTEM PRIMARY MCLG BY-PRODUCTS (f) AVERAGE RANGE MCL or (PHG) Chlorine/chloramine Residual (mg/l) (g) 4.0 (h) Drinking water disinfectant added for treatment Trihalomethanes-TTHMS (µg/l) (n) 80 - By-product of drinking water disinfection Haloacetic Acids (µg/l) 8.4 ND By-product of drinking water disinfection Bromate (µg/l) 5.9 ND By-product of drinking water disinfection LEAD AND COPPER AT THE TAP DISTRIBUTION SYSTEM PRIMARY MCLG 30 sites sampled in %ILE # SITES ABOVE AL MCL or (PHG) Copper (mg/l) 0.12 (i) AL 0.3 (a) Internal corrosion of household plumbing, erosion of natural deposits Lead (µg/l) 7.22 (i) 2 15 AL 0.2 (a) Internal corrosion of household plumbing, industrial manufacturer discharges GROUNDWATER SURFACE WATER PRIMARY MCLG INORGANICS AVERAGE RANGE AVERAGE RANGE MCL or (PHG) Fluoride (mg/l) (a) Added to help prevent dental caries in consumers. SECONDARY STANDARDS MONITORED AT THE SOURCE-FOR AESTHETIC PURPOSES (Sampled in 2009 to 2011) Sampled in 2009 to 2011 GROUNDWATER SURFACE WATER SECONDARY MCLG AVERAGE RANGE AVERAGE RANGE MCL or (PHG) Aggressiveness Index (corrosivity) Non-corrosive - Natural/industrially-influenced balance of hydrogen/carbon/oxygen in water Aluminum (µg/l) (j) ND ND 112 ND (a) Erosion of natural deposits, surface water treatment process residue Chloride (mg/l) Runoff/leaching from natural deposits, seawater influence Color (color units) 3.8 ND Naturally-occurring organic materials Conductivity (umhos/cm) ,600 - Substances that form ions when in water, seawater influence Copper (mg/l) (j) ND ND ND ND (a) Internal corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives Foaming Agents (µg/l) ND ND ND Municipal and industrial waste discharges Iron (µg/l) 90 ND-180 ND Leaching from natural deposits, industrial wastes Manganese (µg/l) (m) ND ND 50 - Leaching from natural deposits MTBE (µg/l) (j) ND ND ND ND 5 13 (a) Leaking underground storage tanks, petroleum/chemical factory discharges

6 SECONDARY STANDARDS MONITORED AT THE SOURCE-FOR AESTHETIC PURPOSES (Continued) GROUNDWATER SURFACE WATER SECONDARY MCLG AVERAGE RANGE AVERAGE RANGE MCL or (PHG) Odor (threshold odor number) ND ND Naturally-occurring organic materials Silver (µg/l) ND ND ND ND Industrial discharges Sulfate (mg/l) Runoff/leaching from natural deposits, industrial wastes Thiobencarb (µg/l) (j) ND ND ND ND (a) Runoff/leaching from rice herbicide Total Dissolved Solids (mg/l) ,000 - Runoff/leaching from natural deposits Turbidity (NTU) Soil runoff SECONDARY STANDARDS MONITORED IN THE DISTRIBUTION SYSTEM-FOR AESTHETIC PURPOSES GENERAL DISTRIBUTION SYSTEM SECONDARY MCLG PHYSICAL CONSTITUENTS AVERAGE RANGE MCL or (PHG) Color (color units) ND ND Naturally-occurring organic materials Odor (threshold odor number) ND ND 3 Naturally-occurring organic materials ADDITIONAL CHEMICALS OF INTEREST FOOTNOTES Sampled in 2009 to 2011 GROUNDWATER SURFACE WATER NOTIFICATION (a) California Public Health Goal (PHG). Other advisory levels in this column are AVERAGE RANGE AVERAGE RANGE LEVEL (k) federal Maximum Contaminant Level Goals (MCLGs). Alkalinity (mg/l) (b) Dates listed are for groundwater sources only Boron (µg/l) NA NA ,000 (c) Gross alpha standard also includes Radium-226 standard. Calcium (mg/l) (d) MCL compliance based on 4 consecutive quarters of sampling. Chlorate (µg/l) NA NA 39 ND (e) MCL standard is for combined Radium 226 plus 228. Dichlorodifluoromethane (Freon-12) (µg/l) ND ND ND ND-58 1,000 (f) Running annual average used to calculate average, range, and MCL compliance. Hexavalent chromium (µg/l) NA NA (g) Maximum Residual Disinfectant Level (MRDL). Magnesium (mg/l) (h) Maximum Residual Disinfectant Level Goal (MRDLG). N-Nitrosodimethylamine (ng/l) NA NA 2.0 ND-8 10 (i) 90th percentile from the most recent sampling at selected customer taps.. ph (standard unit) (j) Aluminum, copper, and MTBE have primary and secondary standards. Potassium (mg/l) (k) Notification Levels are advisory and are not enforceable standards.. Sodium (mg/l) (l) Over 60 organic compounds are analyzed annually, and none were detected.. Tert-butyl alcohol (µg/l) NA NA ND ND 12 (m) Manganese was detected above the secondary MCL in in 2 wells in The Total Hardness (mg/l) manganesemcl is set to protect against unpleasant affects such as color, taste, Vanadium (µg/l) NA NA 1.1 ND odor, and staining of laundry and plumbing fixtures. A manganese MCL exceedence does not pose a health risk. ABBREVIATIONS (n) Trihalomehtanes were detected above the primary MCL at a single location in the < = less than pci/l = picocuries per liter distribution system twice in Some people who drink water containing NA = constituent not analyzed NTU = nephelometric turbidity units trihalomethanes in excess of the MCL over many years may experience liver, kidney, ND = constituent not detected at the reporting limit umhos/cm = micromhos per centimeter or central nervous system problems, and may have an increased risk of getting cancer. ng/l = nanograms per liter or parts per trillion (equivalent to 1 drop in 42,000,000 gallons) µg/l = micrograms per liter or parts per billion (equivalent to 1 drop in 42,000 gallons) mg/l = milligrams per liter or parts per million (equivalent to 1 drop in 42 gallons) DEFINITIONS 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. 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. 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. 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. Primary Drinking Water Standard (PDWS) : MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements, and water treatment requirements.