The Power of Information

National Drinking Water Database


Town of Hempstead Wd Utilities - Great Neck, NY


Serves 110,000 people

Tetrachloroethylene

Tetrachloroethylene (perc) is a common soil and groundwater contaminant used in dry cleaning and as a solvent in automotive and metalworking factories and other industries.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
90 days
Test Days Exceeding Legal LimitsNumber of days in which the samples taken in that day exceed the Maximum Contaminant Level (Depending on the contaminant and its MCL, that may or may not trigger an MCL violation. Some MCLs are based on averages spanning several months to a year)
26 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
159 days
Tests ConductedNumber of individual tests done for this contaminant
875 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
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.2.14 ppb
14.33 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
5 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.

Health Based and Legal Limits for Tetrachloroethylene

Health Based Limits for Tetrachloroethylene

StandardDescriptionLevel
Maximum Contaminant Limit Goal (MCLG)A 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
California Public Health GoalsDefined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.0.06 ppb
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.0.69 ppb
Maximum Contaminant Limit (MCL)The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.5 ppb
Lifetime health-based limit, non-cancer riskConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.10 ppb
Drinking Water Equivalent LevelA lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.500 ppb
Children's health-based limit for 1-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.2000 ppb
Children's health-based limit for 10-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.2000 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-02-013.58 ppb20140 to 41.1 ppb
2008-12-016.69 ppb950 to 44.3 ppb
2008-12-011.03 ppb1080 to 6.6 ppb
2008-11-014.31 ppb15100 to 38.5 ppb
2008-11-010 ppb110 ppb
2008-11-010 ppb110 ppb
2008-10-010 ppb330 ppb
2008-10-010 ppb660 ppb
2008-10-010 ppb110 ppb
2008-10-011.15 ppb860 to 7.6 ppb
2008-10-010 ppb330 ppb
2008-09-010 ppb770 ppb
2008-09-011.47 ppb21150 to 7.3 ppb
2008-09-0121.55 ppb+820 to 41.6 ppb
2008-09-017.3 ppb107.3 ppb
2008-09-010 ppb110 ppb
2008-08-010 ppb220 ppb
2008-08-010.78 ppb980 to 7 ppb
2008-08-011.83 ppb750 to 7.5 ppb
2008-08-0115.29 ppb+740 to 49.8 ppb
2008-08-010 ppb220 ppb
2008-08-010 ppb110 ppb
2008-08-010 ppb660 ppb
2008-07-010 ppb220 ppb
2008-07-010 ppb220 ppb
2008-07-017.5 ppb850 to 40.8 ppb
2008-07-016.8 ppb106.8 ppb
2008-07-013.57 ppb310 to 6.4 ppb
2008-07-010 ppb220 ppb
2008-06-011.69 ppb860 to 7.6 ppb
2008-06-013.22 ppb640 to 12.2 ppb
2008-06-013.21 ppb760 to 22.5 ppb
2008-06-010 ppb220 ppb
2008-06-010 ppb110 ppb
2008-06-010 ppb220 ppb
2008-05-010.5 ppb12110 to 6 ppb
2008-05-010 ppb880 ppb
2008-05-010 ppb110 ppb
2008-05-013.6 ppb420 to 7.4 ppb
2008-04-010 ppb330 ppb
2008-04-011.25 ppb650 to 7.5 ppb
2008-04-010 ppb220 ppb
2008-04-010 ppb110 ppb
2008-03-011.75 ppb430 to 7 ppb
2008-03-010 ppb110 ppb
2008-03-010 ppb220 ppb
2008-03-011.72 ppb530 to 5.1 ppb
2008-02-012.02 ppb530 to 6.1 ppb
2008-02-016.53 ppb950 to 38.5 ppb
2008-02-010 ppb220 ppb
2008-02-011.4 ppb101.4 ppb
2008-01-010 ppb220 ppb
2008-01-013.53 ppb310 to 7 ppb
2008-01-010 ppb110 ppb
2008-01-011.04 ppb870 to 8.3 ppb
2008-01-010 ppb660 ppb
2008-01-010 ppb110 ppb
2008-01-010 ppb110 ppb
2007-12-011.88 ppb430 to 7.5 ppb
2007-12-011.03 ppb320 to 3.1 ppb
2007-12-010 ppb770 ppb
2007-12-0113.67 ppb320 to 41 ppb
2007-12-010 ppb220 ppb
2007-11-014.9 ppb1170 to 34.5 ppb
2007-11-010.65 ppb11100 to 7.1 ppb
2007-11-010 ppb660 ppb
2007-11-010 ppb440 ppb
2007-11-010 ppb440 ppb
2007-11-010 ppb110 ppb
2007-11-010 ppb110 ppb
2007-11-010 ppb110 ppb
2007-11-010 ppb220 ppb
2007-10-014.89 ppb970 to 36.8 ppb
2007-10-014.87 ppb760 to 34.1 ppb
2007-10-011.9 ppb430 to 7.6 ppb
2007-10-012.62 ppb960 to 13.3 ppb
2007-09-010 ppb110 ppb
2007-09-011.13 ppb860 to 6.1 ppb
2007-09-012.76 ppb14120 to 32 ppb
2007-09-010.97 ppb760 to 6.8 ppb
2007-08-013.15 ppb1090 to 31.5 ppb
2007-08-013.11 ppb22170 to 45.3 ppb
2007-07-010.41 ppb980 to 3.7 ppb
2007-07-012.71 ppb12100 to 24.8 ppb
2007-07-010 ppb550 ppb
2007-07-010 ppb660 ppb
2007-07-010 ppb220 ppb
2007-07-010 ppb660 ppb
2007-06-010 ppb440 ppb
2007-06-011.4 ppb540 to 7 ppb
2007-06-012.5 ppb210 to 5 ppb
2007-06-013 ppb103 ppb
2007-06-0114.25 ppb420 to 36 ppb
2007-05-011.64 ppb1180 to 8 ppb
2007-05-015.14 ppb750 to 30 ppb
2007-05-010 ppb990 ppb
2007-05-010 ppb220 ppb
2007-05-010 ppb220 ppb
2007-05-010 ppb220 ppb
2007-05-018 ppb108 ppb
2007-04-014.53 ppb15110 to 46 ppb
2007-03-013.67 ppb310 to 6 ppb
2007-03-016.33 ppb650 to 38 ppb
2007-03-011.17 ppb650 to 7 ppb
2007-02-015.33 ppb960 to 40 ppb
2007-02-011.17 ppb650 to 7 ppb
2007-02-017 ppb107 ppb
2007-01-014.25 ppb12100 to 43 ppb
2007-01-010 ppb330 ppb
2007-01-011.14 ppb760 to 8 ppb
2007-01-010 ppb330 ppb
2007-01-010 ppb220 ppb
2007-01-010 ppb110 ppb
2007-01-010 ppb220 ppb
2007-01-010 ppb110 ppb
2007-01-010 ppb110 ppb
2006-12-010 ppb880 ppb
2006-12-016 ppb210 to 12 ppb
2006-12-012.33 ppb320 to 7 ppb
2006-12-0115.67 ppb+310 to 40 ppb
2006-11-0121 ppb+210 to 42 ppb
2006-11-010 ppb330 ppb
2006-11-011.33 ppb650 to 8 ppb
2006-11-013.33 ppb310 to 8 ppb
2006-10-0117 ppb+210 to 34 ppb
2006-10-012 ppb430 to 8 ppb
2006-10-0111.75 ppb420 to 40 ppb
2006-10-011.13 ppb860 to 7 ppb
2006-09-018 ppb1160 to 37 ppb
2006-09-011 ppb870 to 8 ppb
2006-08-010 ppb220 ppb
2006-08-010 ppb330 ppb
2006-08-010.7 ppb20180 to 7 ppb
2006-08-013.7 ppb47330 to 36 ppb
2006-06-014.27 ppb15110 to 36 ppb
2006-06-014.1 ppb20140 to 34 ppb
2006-05-0114.33 ppb310 to 35 ppb
2006-05-010 ppb110 ppb
2006-05-010 ppb660 ppb
2006-05-011.6 ppb540 to 8 ppb
2006-05-010 ppb220 ppb
2006-05-010 ppb330 ppb
2006-05-010 ppb220 ppb
2006-05-010 ppb220 ppb
2006-05-0113 ppb210 to 26 ppb
2006-05-012 ppb310 to 4 ppb
2006-04-010 ppb330 ppb
2006-04-0111.33 ppb620 to 28 ppb
2006-04-015.25 ppb430 to 21 ppb
2006-04-010.58 ppb12110 to 7 ppb
2006-03-011.13 ppb870 to 9 ppb
2006-03-014.86 ppb740 to 27 ppb
2006-02-0113 ppb210 to 26 ppb
2006-02-010.9 ppb1080 to 8 ppb
2006-02-012 ppb310 to 5 ppb
2006-01-012 ppb430 to 8 ppb
2006-01-015.11 ppb970 to 37 ppb
2006-01-013.5 ppb202 to 5 ppb
2006-01-010 ppb220 ppb