Where 1,4-dioxane has turned up in drinking water
Check the results of more than 900 tests for the toxic substance in Long Island's faucets
Between 2013 and 2015, the Environmental Protection Agency asked water companies above a certain size to monitor water samples for 28 contaminants that are not now regulated under the Safe Drinking Water Act. As part of that process on Long Island, 932 tests were conducted for 1,4-dioxane, with 82 of those tests, or 8.8 percent, showing a presence of the substance at or above 1 part per billion, the level at which a state panel of experts recommended required treatment. Another 456 tests showed no detectable level of 1,4-dioxane, classified by the EPA as “likely carcinogenic to humans.”
Here are details of those tests, which were publicly released in 2016 and are the most recent nationwide testing available. While the state panel recommended a level of 1 part per billion, water companies are saying they have to prepare for treatment at 0.5 parts per billion. The maps and table below indicate how test results break down at both levels. You can read more about the dioxane debate here.
After nationwide testing results were release in 2016, individual water companies continued to test for 1,4-dioxane, and Newsday has requested those results. The Long Island Water Conference says that a survey of water providers found contamination above 0.5 parts per billion in 165 wells. Newsday has requested those results. To see the full list of 28,092 tests on Long Island from 2016 for the 28 contaminants, click here, and you can get a breakdown for any of the substances exceeding levels that the government is concerned about, at the water provider serving your neighborhood. This data was posted on Feb. 8, 2019.
The percentage of test results at or above 1 part per billion
Zoom to your neighborhood and click on your district. Or click on the magnifying glass in the lower left corner to enter your full address (include community and "NY") and go to your district that way. (You may have to hit "enter" twice.) Once there, click near your home to see district test results.
- Up to 25%
- Up to 50%
- Up to 75%
- Up to 100%
- 0%
The percentage of test results at or above 0.5 parts per billion
- Up to 25%
- Up to 50%
- Up to 75%
- Up to 100%
- 0%
Some small districts are not shown because they were not required by the EPA to test. Boundary information was not available for the St. James, Smithtown and Stony Brook water districts, so they do not appear on the map but are included in the table below.
Details on the 932 tests
Test levels with detectable amounts are designated as above 1 part per billion, 0.5 parts per billion, and above, or below, 0.35 parts per billion, the level the EPA says should cause concern. In the maps above and the table below, three providers at the time of testing -- Aqua NY- Sea Cliff, Aqua NY and Long Island American Water Corp. -- are now known collectively as New York American Water.
Water provider
Test result
| Water provider | Test result | Amount found parts per billion | Date |
|---|---|---|---|
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/10/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/10/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/26/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 07/11/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 07/10/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/18/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/04/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/04/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 03/14/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 01/28/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 01/02/2014 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 12/12/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/22/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/19/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/07/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/07/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/18/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/31/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/31/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/24/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/24/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/23/2013 |
| Water provider Suffolk County Water Authority, Area 23 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/29/2013 |
| Water provider Suffolk County Water Authority, Area 26 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/29/2014 |
| Water provider Suffolk County Water Authority, Area 26 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/29/2014 |
| Water provider Suffolk County Water Authority, Area 26 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/20/2014 |
| Water provider Suffolk County Water Authority, Area 26 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/03/2014 |
| Water provider Suffolk County Water Authority, Area 26 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/09/2013 |
| Water provider Suffolk County Water Authority, Area 26 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/17/2013 |
| Water provider Suffolk County Water Authority, Area 27 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/09/2013 |
| Water provider Suffolk County Water Authority, Area 27 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/17/2013 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/15/2015 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 07/27/2015 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/09/2015 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/09/2015 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/20/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/20/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/20/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/10/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/04/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/24/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/24/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/24/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/23/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/17/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/29/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/15/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/15/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/15/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/15/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/02/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/25/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/25/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 03/20/2014 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 12/09/2013 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 12/04/2013 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 12/04/2013 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/21/2013 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/05/2013 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/05/2013 |
| Water provider Suffolk County Water Authority, Area 30 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/17/2013 |
| Water provider Suffolk County Water Authority, Area 32 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/12/2014 |
| Water provider Suffolk County Water Authority, Area 32 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/07/2014 |
| Water provider Suffolk County Water Authority, Area 35 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/14/2014 |
| Water provider Suffolk County Water Authority, Area 35 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/08/2014 |
| Water provider Suffolk County Water Authority, Area 39 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/14/2014 |
| Water provider Suffolk County Water Authority, Area 39 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/03/2014 |
| Water provider Suffolk County Water Authority, Area 39 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/23/2014 |
| Water provider Suffolk County Water Authority, Area 39 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 03/05/2014 |
| Water provider Suffolk County Water Authority, Area 4 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/06/2013 |
| Water provider Suffolk County Water Authority, Area 4 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/01/2013 |
| Water provider Suffolk County Water Authority, Area 44 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/21/2014 |
| Water provider Suffolk County Water Authority, Area 44 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/28/2014 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/30/2014 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/30/2014 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/14/2014 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/14/2014 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/06/2013 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/06/2013 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/01/2013 |
| Water provider Suffolk County Water Authority, Area 53 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/01/2013 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/18/2014 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/14/2014 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/13/2013 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/06/2013 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/06/2013 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/15/2013 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/03/2013 |
| Water provider Suffolk County Water Authority, Area 54 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/03/2013 |
| Water provider Suffolk County Water Authority, Area 55 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/13/2013 |
| Water provider Suffolk County Water Authority, Area 55 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 11/13/2013 |
| Water provider Suffolk County Water Authority, Area 55 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/15/2013 |
| Water provider Suffolk County Water Authority, Area 55 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 05/15/2013 |
| Water provider Suffolk County Water Authority, Area 57 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/09/2015 |
| Water provider Suffolk County Water Authority, Area 57 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 08/19/2014 |
| Water provider Suffolk County Water Authority, Area 6 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 08/30/2013 |
| Water provider Suffolk County Water Authority, Area 6 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 08/20/2013 |
| Water provider Suffolk County Water Authority, Area 60 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/09/2014 |
| Water provider Suffolk County Water Authority, Area 60 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/01/2014 |
| Water provider Suffolk County Water Authority, Area 60 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/10/2014 |
| Water provider Suffolk County Water Authority, Area 60 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/01/2014 |
| Water provider Suffolk County Water Authority, Area 60 | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/01/2014 |
| Water provider Village of Freeport | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/29/2015 |
| Water provider Village of Freeport | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/29/2015 |
| Water provider Village of Freeport | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/29/2015 |
| Water provider Village of Freeport | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/27/2014 |
| Water provider Village of Freeport | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/27/2014 |
| Water provider Village of Freeport | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/27/2014 |
| Water provider Village of Hempstead | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 12/25/2013 |
| Water provider Village of Hempstead | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/18/2013 |
| Water provider Village of Mineola | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/24/2014 |
| Water provider Village of Mineola | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/22/2013 |
| Water provider Village of Rockville Centre | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/31/2013 |
| Water provider Village of Rockville Centre | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/31/2013 |
| Water provider Village of Rockville Centre | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/31/2013 |
| Water provider Village of Rockville Centre | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/29/2013 |
| Water provider Village of Rockville Centre | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/29/2013 |
| Water provider Water Authority of Great Neck North | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/04/2014 |
| Water provider Water Authority of Great Neck North | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/04/2014 |
| Water provider Water Authority of Great Neck North | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 09/04/2014 |
| Water provider Water Authority of Great Neck North | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 04/23/2014 |
| Water provider Water Authority of Western Nassau | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 07/21/2015 |
| Water provider Water Authority of Western Nassau | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 07/21/2015 |
| Water provider Water Authority of Western Nassau | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 06/23/2015 |
| Water provider West Hempstead Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 08/15/2013 |
| Water provider West Hempstead Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 02/21/2013 |
| Water provider Westbury Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 08/21/2014 |
| Water provider Westbury Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 01/30/2014 |
| Water provider Westbury Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 01/30/2014 |
| Water provider Westbury Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 10/01/2013 |
| Water provider Westbury Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 07/23/2013 |
| Water provider Westbury Water District | Test result Less than minimum level detectable | Amount found parts per billion Below detectable level | Date 07/22/2013 |
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