The Power of Information

National Drinking Water Database


Town of Hempstead Wd Utilities - Great Neck, NY


Serves 110,000 people

1,1-Dichloroethylene

Industrial chemical pollutant from manufacture of adhesives, synthetic fibers, refrigerants and plastic wraps.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
8 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)
8 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*
1,1-DichloroethyleneIndustrial chemical pollutant from manufacture of adhesives, synthetic fibers, refrigerants and plastic wraps.1.58 ppb
18 ppb
Yes
7 ppb
Yes
7 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 1,1-Dichloroethylene

Health Based Limits for 1,1-Dichloroethylene

StandardDescriptionLevel
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.7 ppb
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.7 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.10 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.330 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.1000 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
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.2000 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-02-013.05 ppb20150 to 26.6 ppb
2008-12-016.41 ppb950 to 29.5 ppb
2008-12-010.19 ppb1090 to 1.9 ppb
2008-11-013.47 ppb15110 to 23.6 ppb
2008-11-010 ppb110 ppb
2008-11-011.5 ppb101.5 ppb
2008-10-010 ppb330 ppb
2008-10-010 ppb660 ppb
2008-10-010 ppb110 ppb
2008-10-013.86 ppb860 to 22.8 ppb
2008-10-010 ppb330 ppb
2008-09-010 ppb770 ppb
2008-09-012.73 ppb21160 to 22.7 ppb
2008-09-015.08 ppb840 to 14.4 ppb
2008-09-018.1 ppb108.1 ppb
2008-09-010 ppb110 ppb
2008-08-010 ppb220 ppb
2008-08-010.14 ppb980 to 1.3 ppb
2008-08-015.26 ppb750 to 28.9 ppb
2008-08-015.14 ppb740 to 14.9 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
2008-07-012.08 ppb860 to 10.2 ppb
2008-07-010 ppb110 ppb
2008-07-018.3 ppb310 to 19.4 ppb
2008-07-010 ppb220 ppb
2008-06-014.34 ppb860 to 29.6 ppb
2008-06-011.95 ppb650 to 11.7 ppb
2008-06-011.17 ppb750 to 7.1 ppb
2008-06-010 ppb220 ppb
2008-06-010 ppb110 ppb
2008-06-010 ppb220 ppb
2008-05-010.15 ppb12110 to 1.8 ppb
2008-05-010 ppb880 ppb
2008-05-010 ppb110 ppb
2008-05-019.2 ppb420 to 30.8 ppb
2008-04-010.3 ppb320 to 0.9 ppb
2008-04-010 ppb660 ppb
2008-04-010 ppb220 ppb
2008-04-010 ppb110 ppb
2008-03-010 ppb440 ppb
2008-03-010 ppb110 ppb
2008-03-010 ppb220 ppb
2008-03-012.1 ppb430 to 8.4 ppb
2008-02-018.08 ppb530 to 31.1 ppb
2008-02-011.67 ppb970 to 9 ppb
2008-02-010 ppb220 ppb
2008-02-010 ppb110 ppb
2008-01-010 ppb220 ppb
2008-01-0114.2 ppb310 to 32.5 ppb
2008-01-010 ppb110 ppb
2008-01-010.18 ppb870 to 1.4 ppb
2008-01-010 ppb660 ppb
2008-01-010 ppb110 ppb
2008-01-010 ppb110 ppb
2007-12-010 ppb440 ppb
2007-12-019.3 ppb320 to 27.9 ppb
2007-12-010 ppb770 ppb
2007-12-010 ppb330 ppb
2007-12-010 ppb220 ppb
2007-11-013.47 ppb1170 to 15.6 ppb
2007-11-010 ppb11110 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
2007-10-011.06 ppb970 to 8.5 ppb
2007-10-011.46 ppb760 to 10.2 ppb
2007-10-010.33 ppb430 to 1.3 ppb
2007-10-014.07 ppb960 to 20.6 ppb
2007-09-010 ppb110 ppb
2007-09-013.06 ppb860 to 17.8 ppb
2007-09-011.66 ppb14110 to 9.2 ppb
2007-09-010 ppb770 ppb
2007-08-011.86 ppb1080 to 9.3 ppb
2007-08-010.77 ppb22190 to 8.7 ppb
2007-07-012.33 ppb1080 to 17.6 ppb
2007-07-010.71 ppb12110 to 8.5 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
2007-06-010 ppb550 ppb
2007-06-012.5 ppb210 to 5 ppb
2007-06-0118 ppb1018 ppb
2007-06-012.75 ppb420 to 6 ppb
2007-05-013.09 ppb1180 to 22 ppb
2007-05-010.09 ppb760 to 0.6 ppb
2007-05-010 ppb990 ppb
2007-05-010 ppb220 ppb
2007-05-010 ppb220 ppb
2007-05-010 ppb220 ppb
2007-05-016 ppb106 ppb
2007-04-011.53 ppb15130 to 18 ppb
2007-03-016.67 ppb310 to 16 ppb
2007-03-010.83 ppb650 to 5 ppb
2007-03-010 ppb660 ppb
2007-02-012.22 ppb960 to 12 ppb
2007-02-010 ppb660 ppb
2007-02-017 ppb107 ppb
2007-01-010.5 ppb12110 to 6 ppb
2007-01-010 ppb330 ppb
2007-01-012 ppb760 to 14 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
2006-12-010 ppb220 ppb
2006-12-014.33 ppb320 to 13 ppb
2006-12-014 ppb310 to 7 ppb
2006-11-013 ppb210 to 6 ppb
2006-11-010 ppb330 ppb
2006-11-010 ppb660 ppb
2006-11-015.33 ppb320 to 16 ppb
2006-10-014.5 ppb210 to 9 ppb
2006-10-010 ppb440 ppb
2006-10-013.25 ppb420 to 8 ppb
2006-10-012.38 ppb860 to 17 ppb
2006-09-014.18 ppb1160 to 17 ppb
2006-09-010 ppb880 ppb
2006-08-010 ppb220 ppb
2006-08-010 ppb330 ppb
2006-08-010 ppb20200 ppb
2006-08-011.91 ppb47370 to 20 ppb
2006-06-010.67 ppb15130 to 5 ppb
2006-06-012.6 ppb20140 to 13 ppb
2006-05-013.33 ppb310 to 6 ppb
2006-05-010 ppb110 ppb
2006-05-010 ppb660 ppb
2006-05-010 ppb550 ppb
2006-05-010 ppb220 ppb
2006-05-010 ppb330 ppb
2006-05-010 ppb220 ppb
2006-05-010 ppb220 ppb
2006-05-010 ppb220 ppb
2006-05-014.67 ppb310 to 10 ppb
2006-04-010 ppb330 ppb
2006-04-012.67 ppb620 to 4 ppb
2006-04-011.5 ppb430 to 6 ppb
2006-04-010 ppb12120 ppb
2006-03-010 ppb880 ppb
2006-03-013.43 ppb740 to 16 ppb
2006-02-013.5 ppb210 to 7 ppb
2006-02-010 ppb10100 ppb
2006-02-015 ppb310 to 13 ppb
2006-01-010 ppb440 ppb
2006-01-011.11 ppb970 to 6 ppb
2006-01-018 ppb202 to 14 ppb
2006-01-010 ppb220 ppb