NYC Health
NYC Housing Authority

TO:                  Mayor Eric Adams

FROM:            Gregory Russ, Chair and Chief Executive Officer, New York City Housing Authority; Ashwin Vasan, MD, PhD, Commissioner, Department of Health and Mental Hygiene; and Rohit Aggarwala, PhD, MBA, Commissioner, Department of Environmental Protection 

CC:                 Anne Williams-Isom, Deputy Mayor for Health and Human Services; Meera Joshi, Deputy Mayor for Operations; and Jessica Katz, Chief Housing Officer 

DATE:              September 9, 2022

RE:                  Water testing at Riis Houses


The City has confirmed that unsafe levels of arsenic are not, and were never, present in the water supply at Jacob Riis Houses. The initial test results indicating unsafe levels of arsenic in the water are false, and the laboratory that produced those results issued a statement on September 9 confirming this fact.

On September 1, 2022, NYCHA received re-sampled test results from an outside vendor that indicated the presence of arsenic levels beyond safety thresholds in the drinking water supply at Jacob Riis Houses. An initial sample received on August 29, 2022 had indicated the presence of arsenic and a re-sampling was ordered. Once the re-sampled results were reported, NYCHA sought guidance from public and environmental health experts at DEP and DOHMH.

The agencies recommended that NYCHA investigate the laboratory methodologies. DOHMH advised NYCHA to evaluate the plumbing configurations for buildings associated with the presence of arsenic detection and conduct a possible source investigation since recent plumbing construction activities had occurred.

NYCHA issued a notification to Riis Houses residents to not drink or cook with the water beginning September 2, and NYCHA began distributing water on-site that same evening. DOHMH also advised NYCHA to flush the plumbing system and to resample as a precautionary measure. DEP immediately mobilized to collect confirmatory sampling from a nearby fire hydrant sampling location and the building’s point of entry. The DEP samples for the hydrant and the point of entry came back significantly below the federal standard for arsenic in drinking water on September 3.

In collaboration with and following guidance from DEP and DOHMH, NYCHA has since taken numerous steps to ensure the safety and quality of the water at Riis Houses. NYCHA flushed the water supply at the development and conducted extensive retesting of the water for arsenic, at both the source and point of delivery into apartments. Out of an abundance of caution, NYCHA has continued to advise Riis Houses residents to not drink or cook with the water and has distributed thousands of bottles of clean water to households in coordination with NYCEM.

Based on the expertise of City public health and environmental protection officials, we can confidently conclude that the water in Riis Houses does not contain arsenic at levels exceeding government standards for residential drinking water, and never did from the time the August tests were initiated.

On September 9, NYCHA received a statement from the lab, Environmental Management and Technologies (EMT), retracting the initial test results received on September 1. The statement confirms that the results showing elevated levels of arsenic were “incorrect.”

Summary of Results

This report from The LiRo Group — a nationally recognized, third-party vendor with a subcontracted laboratory that is certified by NYS Environmental Laboratory Approval Program (ELAP) for arsenic analysis — includes test results for water samples that were taken at approximately 140 locations, including both drinking water tanks serving Riis Houses, 135 apartment faucets and sinks, two faucets in the community center kitchens, both roof tanks, and points of entry. NYCHA has sampled every building. All locations returned test results that are well within the EPA standards for arsenic in residential drinking water.

127 locations, including all six locations that were previously identified as having unsafe levels of arsenic, were found to have undetectable levels of arsenic, or levels that are lower than the lab detection limit of 0.5 micrograms per liter (ug/L). At 13 locations, arsenic was detected at levels greater than 0.5 ug/L but lower than 1 ug/L, or ten times less than both the New York State Department of Health and the federal standard for safe residential drinking water, which is 10 ug/L.

New York City’s drinking water is among the best in the world. DEP scientists perform hundreds of thousands of analyses each year at our certified labs. Testing for arsenic was done 1,500 times last year; it was never detected. DEP is glad that the arsenic matter has now been resolved. 

Based on these test results, DOHMH is confident Riis Houses residents do not need to be concerned about arsenic in their water.

Attached Results

This includes DEP’s results from samples taken on September 2, EMT’s results from samples taken on August 13 and August 30, and LiRo Environmental’s results from samples taken on September 4 and 5. These results are reported on in the following documents:

EMT Laboratories retracted the results for the samples collected on August 30, 2022, because low levels of arsenic were inadvertently added to the samples by the laboratory. The values in the report represent laboratory contamination. There was no arsenic present in the drinking water itself.

While no arsenic was ever present in the drinking water for Riis Houses, NYCHA is conducting twice monthly testing of roof tanks, points of entry, and a representative sample of apartments for arsenic and bacteriological parameters using a New York ELAP-certified laboratory. This testing is being done to restore resident confidence in their drinking water. The results will be posted on this website following the sampling events. The first sampling event took place on September 24, 2022. All sample results met the applicable water quality standards, including that all arsenic results were non-detect.

Please read this presentation to learn more about New York City’s water supply, the water system at Riis Houses, and water testing:

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