The Power of Information

National Drinking Water Database


South Tahoe Pud - Main - South Lake Tahoe, CA


Serves 60,000 people - Test data available: 2004-2009

This drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group (EWG) by the California Department of Public Health. It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources to protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes test results for this utility and lists potential health concerns.

 
This Drinking Water System
National Average
Exceed Health GuidelinesTests showing chemicals at concentrations above health guidelines established by federal and state health agencies. These guidelines are typically set at a levels that pose no significant health risk.
11 chemicals
4
Health Standard ExceedencesChemicals detected at concentrations above the legal limit, the Maximum Contaminant Level (MCLs) established by the U.S. EPA. Most MCLs are based on annual averages, so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.
3 chemicals
0.5
Pollutants FoundThe total number of contaminants detected since 2004, according to data provided by the state water agency.
31 chemicals
8
Tests ConductedThe total number of number of water quality tests conducted by water utilities and recorded in data provided by the state water agency.
26,567 tests
420

Contaminants Exceeding Health Guidelines

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Arsenic (total)Arsenic contaminates drinking water due to mining runoff, erosion of natural deposits, emissions from glass and electronics processing and the use of arsenical compounds as wood preservatives and pesticides.4.97 ppb
17.9 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
Yes
10 ppb
Alpha particle activityAlpha particles are a form of radiation released from mining waste pollutants and natural sources.5.63 pCi/L
21.18 pCi/L
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 pCi/L
Yes
15 pCi/L
1,2-Dibromo-3-chloropropane (DBCP)1,2-Dibromo-3-chloropropane is a persistent pesticide and groundwater contaminant associated with male sterility and severe reproductive toxicity; historically used as a soil fumigant on bananas and pineapples; banned by EPA in early 1980s.0.02 ppb
0.22 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
Yes
0.2 ppb
1,2-Dichloroethane1,2-Dichloroethane is a chemical used in the production of vinyl chloride; it is released as a pollutant from industrial chemical factories.0.08 ppb
2.8 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
No
5 ppb
RadonRadon is a radioactive breakdown product of radium and uranium in soil, rock and water; it is often present in groundwater.1976.58 pCi/L
4916 pCi/L
Yes
1.5 pCi/L
Legal at any levelThis is the Federal Limit. State Limits may be lower.
Radium-226Radium-226 is a radioactive element usually found around uranium deposits.0.29 pCi/L
0.66 pCi/L
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 pCi/L
No
5 pCi/L
Radium-228Radium-228 is a radioactive element usually found around uranium deposits.0.8 pCi/L
1.91 pCi/L
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 pCi/L
No
5 pCi/L
FormaldehydeFormaldehyde is a chemical found in plastics, resins used for rug and fabric coatings and adhesives for particle board; it is an air pollutant and probable human carcinogen and may form as a byproduct of tap water disinfection.12657.06 ppb
48000 ppb
Yes
1000 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
Lead (total)Lead is a metal that enters water by corrosion of household plumbing systems, discharge of industrial pollution and erosion of natural deposits.0.18 ppb
1.31 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
No
TetrachloroethyleneTetrachloroethylene (perc) is a common soil and groundwater contaminant used in dry cleaning and as a solvent in automotive and metalworking factories and other industries.<0.01 ppb
0.3 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
No
5 ppb
Combined Uranium (mg/L)Uranium is a radioactive element commonly found in most rocks; processed uranium ore is used for power generation and weapons manufacture.0.5 ppb
1 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
No
30 ppb
NOTE: Each dot in the above graph represents one month.
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

Other Detected Contaminants

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Combined Uranium (pCi/L)Uranium is a radioactive element commonly found in most rocks; processed ore is used for power generation and weapons manufacture.3.99 pCi/L
14.62 pCi/L
NoNo
15 pCi/L
BromideBromide is a naturally occurring element found in surface waters and groundwater and contributes to the formation of toxic tap water disinfection byproducts.9.53 ppb
30.5 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
NitrateNitrate enters drinking water sources from fertilizer runoff, leaching septic tanks, and erosion of natural deposits; it is also emitted by chemical, petrochemical and metal-finishing industries.0.27 ppm
0.76 ppm
No
10 ppm
No
10 ppm
Nitrate & nitriteNitrate and nitrite enter water from fertilizer runoff, leaching from septic tanks, and erosion of natural deposits.0.26 ppm
0.76 ppm
No
10 ppm
No
10 ppm
AcetaldhydeAcetaldehyde is a widely-used industrial chemical and common air pollutant; it is released into the environment from chemical manufacturing and from the combustion of fossil fuels.1.41 ppb
4 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
MTBEMTBE (methyl tert-butyl ether) is a fuel additive that had been used as an octane enhancer in unleaded gasoline; it contaminates groundwater due to spillage or leakage at gas stations, and has been banned or scheduled for phaseout in most states.0.02 ppb
0.6 ppb
No
13 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
ManganeseManganese is a naturally occurring element released from mineral deposits as well as industrial use.3.21 ppb
37.3 ppb
No
50 ppb
No
50 ppb
ChloroformChloroform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.0.02 ppb
1.3 ppb
No
5.7 ppb
No
80 ppb
GlyoxalGlyoxal is a synthetic chemical used for production of paper coatings, textiles and polymers and as an intermediate for making other chemicals; it is used as a disinfectant in medicine and may form as a byproduct of tap water ozonation.0.65 ppb
5.2 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
Chromium (total)Chromium is a metal that pollutes drinking water due to discharge from steel and pulp mills and erosion of natural deposits.1.48 ppb
9 ppb
No
100 ppb
No
100 ppb
VanadiumVanadium is a metal used as an alloying addition to iron & steel; it is discharged from ceramic, glass, textile, photography, metallurgy and rubber industries.3.32 ppb
5 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
Tert-Butyl Alcoholtert-Butyl alcohol is used in disinfectants, solvents, paints, laboratory chemicals and in numerous industrial processes; over one billion pounds were manufactured in 2006.0.05 ppb
3.2 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
CopperCopper is a naturally occuring metal and drinking water contaminant that enters tap water by corrosion of household plumbing systems and erosion of natural deposits.2.81 ppb
40.15 ppb
No
300 ppb
No
1000 ppb
Barium (total)Barium is a mineral that enters drinking water through drilling and mining waste runoff, discharges from chemical industries and erosion of natural deposits.6.14 ppb
38 ppb
No
700 ppb
No
2000 ppb
Total trihalomethanes (TTHMs)Total trihalomethanes constitute the sum of four disinfection byproducts: chloroform, bromodichloromethane, dibromochloromethane, and bromoform.<0.01 ppb
0.6 ppb
No
9.8 ppb
No
80 ppb
BromomethaneBromomethane is a pesticide used for soil, grain, indoor air and other applications, and a solvent used to extract vegetable and seed oils.0.11 ppb
6.9 ppb
No
10 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
Ethyl-t-butyl ether (ETBE)Ethyl-t-butyl ether is a synthetic chemical used as a fuel additive and an octane enhancer for gasoline.<0.01 ppb
0.25 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
Xylenes (total)Xylenes are a group of chemicals produced from petroleum and released as pollutants from chemical, plastics and synthetic fiber industries as well as printing, painting, and laboratory uses.<0.01 ppb
0.25 ppb
No
1800 ppb
No
10000 ppb
m- & p- XyleneXylene is a petroleum-derived solvent used in the printing, rubber, and leather industries, and as a cleaning agent, a thinner for paint, and an ingredient in paints and varnishes.<0.01 ppb
0.25 ppb
No
10000 ppb
No
10000 ppb
TritiumTritium is a pollutant from commercial nuclear reactors, research reactors and government weapons production plants.1393 pCi/L
1393 pCi/L
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
NOTE: Each dot in the above graph represents one month.
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

Contaminants Not Detected - 146 chemicals

1,1,1,2-Tetrachloroethane, 1,1,1-Trichloroethane, 1,1,2,2-Tetrachloroethane, 1,1,2-Trichloroethane, 1,1-Dichloroethane, 1,1-Dichloroethylene, 1,1-Dichloropropene, 1,2,3-Trichlorobenzene, 1,2,3-Trichloropropane, 1,2,4-Trichlorobenzene, 1,2,4-Trimethylbenzene, 1,2-Dichloropropane, 1,3,5-Trimethylbenzene, 1,3-Dichloropropane, 1,3-Dichloropropene, 1,4-Dioxane, 2,2-Dichloropropane, 2,3,7,8-TCDD (Dioxin), 2,4,5-t, 2,4,5-TP (Silvex), 2,4-d, 2-Chloroethylvinyl ether, 3-Hydroxycarbofuran, Acetone, Alachlor (Lasso), Aldicarb, Aldicarb sulfone, Aldicarb sulfoxide, Aldrin, Aluminum, Antimony (total), Aroclor 1221, Aroclor 1232, Aroclor 1242, Aroclor 1248, Aroclor 1254, Aroclor 1260, Asbestos, Atrazine, Baygon (Propoxur), Bentazon (Basagran), Benzene, Benzo[a]pyrene, Beryllium (total), Bromacil, Bromate, Bromobenzene, Bromochloromethane, Bromodichloromethane, Bromoform, Butachlor, Cadmium (total), Caffeine, Carbaryl, Carbofuran, Carbon tetrachloride, Chlordane, Chloroethane, Chloromethane, Chlorothalonil (Bravo), cis-1,2-Dichloroethylene, Cyanide, Dacthal, Dalapon, Di(2-Ethylhexyl) adipate, Di(2-ethylhexyl) phthalate, Diazinon (Spectracide), Dibromoacetic acid, Dibromochloromethane, Dibromomethane, Dicamba, Dichloroacetic acid, Dichlorodifluoromethane, Dichloromethane (methylene chloride), Dieldrin, Dimethoate, Dinoseb, Diquat, Endothall, Endrin, Ethylbenzene, Ethylene dibromide (EDB), Glyphosate, Hemellitol (1,2,3-trimethylbenzene), Heptachlor, Heptachlor epoxide, Hexachlorobenzene (HCB), Hexachlorobutadiene, Hexachlorocyclopentadiene, Hexachloroethane, Isopropyl alcohol, Isopropyl ether, Isopropylbenzene, Lindane, m-Dichlorobenzene, m-Xylene, Mercury (total inorganic), Methiocarb, Methomyl, Methoxychlor, Methyl ethyl ketone, Methyl isobutyl ketone, Metolachlor, Metribuzin, Molinate (Ordram), Monobromoacetic acid, Monochloroacetic acid, Monochlorobenzene (Chlorobenzene), n-Butylbenzene, n-Propylbenzene, Naphthalene, Nitrite, Nitrobenzene, o-Chlorotoluene, o-Dichlorobenzene, o-Xylene, Oxamyl (Vydate), p-Chlorotoluene, p-Dichlorobenzene, p-Isopropyltoluene, p-Xylene, Pentachlorophenol, Perchlorate, Picloram, Prometryn, Propachlor, sec-Butylbenzene, Selenium (total), Silver (total), Simazine, Styrene, Tert-Amyl-Methyl Ether, tert-Butylbenzene, Thallium (total), Thiobencarb (Bolero), Toluene, Total haloacetic acids (HAAs), Total polychlorinated biphenyls (PCBs), Toxaphene, trans-1,2-Dichloroethylene, Trichloroacetic acid, Trichloroethylene, Trichlorofluoromethane, Trichlorotrifluoroethane, Trifluralin, Vinyl chloride

Pollution Summary

31Total Contaminants Detected (2004 - 2009)

Bromide, Barium (total), Chromium (total), Copper, Manganese, Nitrate & nitrite, Nitrate, Vanadium, Bromomethane, MTBE, Acetaldhyde, Glyoxal, Chloroform, Total trihalomethanes (TTHMs), Xylenes (total), m- & p- Xylene, Tritium, Ethyl-t-butyl ether (ETBE), Combined Uranium (pCi/L), Arsenic (total), Lead (total), 1,2-Dibromo-3-chloropropane (DBCP), Formaldehyde, 1,2-Dichloroethane, Tetrachloroethylene, Radon, Combined Uranium (mg/L), Radium-226, Radium-228, Alpha particle activity

5Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Nitrate & nitrite, Nitrate, Bromomethane, Arsenic (total), 1,2-Dibromo-3-chloropropane (DBCP)

10Sprawl and Urban Pollutants
(road runoff, lawn pesticides, human waste)

Nitrate, Copper, Nitrate & nitrite, Lead (total), Arsenic (total), Tetrachloroethylene, MTBE, Xylenes (total), m- & p- Xylene, Ethyl-t-butyl ether (ETBE)

24Industrial Pollutants

Bromide, Barium (total), Chromium (total), Manganese, Nitrate & nitrite, Nitrate, Vanadium, MTBE, Acetaldhyde, Glyoxal, Xylenes (total), m- & p- Xylene, Tritium, Ethyl-t-butyl ether (ETBE), Combined Uranium (pCi/L), Arsenic (total), Lead (total), Formaldehyde, 1,2-Dichloroethane, Tetrachloroethylene, Combined Uranium (mg/L), Radium-226, Radium-228, Alpha particle activity

4Water Treatment and Distribution Byproducts
(pipes and fixtures, treatment chemicals and byproducts)

Total trihalomethanes (TTHMs), Chloroform, Formaldehyde, Glyoxal

15Naturally Occurring
(naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

Nitrate, Copper, Nitrate & nitrite, Barium (total), Lead (total), Arsenic (total), Manganese, Radium-228, Radium-226, Alpha particle activity, Combined Uranium (pCi/L), Chromium (total), Combined Uranium (mg/L), Radon, Bromide

12Unregulated Contaminants
EPA has not established a maximum legal limit in tapwater for these contaminants

Bromide, Vanadium, Bromomethane, MTBE, Acetaldhyde, Glyoxal, Tritium, Ethyl-t-butyl ether (ETBE), Tert-Butyl Alcohol, Lead (total), Formaldehyde, Radon

EPA Violation Summary

Violation CategoryNumber of Violations
MCL and Treatment
(click see violations)
5

Information on violations is drawn directly from EPA's national violations database in the Agency's Safe Drinking Water Information System. Analyses by others have raised questions about the quality of the information in EPA's database. For the purposes of this investigation, EWG is not showing below or including in our analyses, those violations for individual water suppliers that occurred on days for which the total number of violations assigned by EPA to that water supplier was greater than 20. This criteria was based on common characteristics of incorrect violations data as identified by water utilities, from a review of EPA's violations data by several hundred utilities prior to the release of EWG's investigation.