Safe at Home? Lead in Tap Water Remains Issue in Some City Dwellings

Safe at Home?
Lead in Tap Water Remains Issue in Some City Dwellings 

PDF version available here.


Lead has been in the news and on the minds of many New Yorkers in recent months. The City Council is considering at least 23 bills that address various issues around lead exposure. As recent reports about the city’s public housing have underscored, lead paint is the predominant source of lead in city residences. But tap water can also be a source of lead. Numerous privately owned older, smaller residential buildings in New York have plumbing that contains a much higher level of lead than is currently allowed to be used in new construction.

In this report, IBO examines the potential scale of lead contamination in New York City tap water and the rules that set the standards for detection and amelioration. Overall, the city is in compliance with federal and state regulations for at-the-tap monitoring in residences. The city spends about $10 million annually treating the water supply with anticorrosive chemicals to help prevent lead from leaching into the water as it passes through lead pipes. The city also offers free lead-testing kits to any resident who requests one.

Among the specific findings from our study:

  • Since 1993, tap water samples have had on average lower levels of lead and fewer tests have exceeded the federal Environmental Protection Agency threshold for lead. Although most test results find no traces of lead, lead above the threshold continues to be detected in a small percentage of buildings.
  • Smaller, older buildings, especially those built in the 1920s and 1930s, generally have higher rates of lead tests above the federal threshold.
  • Based on test data from 2006 through 2016, the highest rates of tap water test levels exceeding the federal threshold were in community districts that included neighborhoods such as Ridgewood and Maspeth in Queens, Bedford Stuyvesant in Brooklyn, Co-Op City and Riverdale in the Bronx, and South Beach in Staten Island.

While the city meets federal and state regulations regarding lead in water, it is important to note that federal rules permit 10 percent of residential buildings in the Department of Environmental Protection’s annual compliance testing group to exceed the threshold for lead. There is no water lead standard for individual private residential buildings. In a city the size of New York, this means a substantial number of homes and families may be exposed to lead from their faucets. The city has no means to compel landlords or homeowners to remove lead leaching service lines or fixtures and landlords are not required to notify tenants or prospective tenants if a building has been found to have elevated levels of lead in the water or if renovation work may cause lead levels to temporarily rise.


The New York City Department of Environmental Protection (DEP) is responsible for providing clean water to the city’s 8.5 million residents. Approximately 1 billion gallons are delivered daily with around 90 percent of the water historically coming from the Catskill-Delaware watershed and the remainder from the Croton watershed. A system of reservoirs upstate provides water via aqueducts to the city, where it is treated and flows through the city’s water mains and into individual buildings. DEP regularly tests water quality at reservoirs, treatment facilities and in the distribution system and finds good quality water with virtually zero lead detected. Before water flows out of a residential tap, though, it must pass through the piping in private buildings—which may have plumbing fabricated with lead prior to laws prohibiting its use.

Lead was commonly used in residential plumbing, including in New York City, until its use was restricted by federal law. Service lines, the pipe that connects a building to the city’s water mains, were prohibited from containing lead for new installations in 1961. Previously, two inch and smaller diameter service lines commonly contained lead, while larger service lines did not contain lead. Amendments to the Safe Drinking Water Act, put in place in 1986, stipulated that states had to greatly reduce lead levels in solder by 1988. The Lead and Copper Rule, promulgated in 1991, restricted the percentage of lead that could be used in fixtures, which has been lowered in subsequent amendments to the rule. These regulations, however, only covered new construction, so the stock of existing lead plumbing was allowed to remain in use.

At the local level, New York City regulations prohibit lead service lines at private residences from being repaired if they are damaged, instead requiring that such lines be replaced with pipes that do not contain lead. New York City has no local requirement that undamaged lead service lines be replaced. Considering this regulatory framework and the age of the city’s housing stock, many small residential buildings likely contain lead in some facet of their plumbing system, and are therefore at risk of lead leaching into drinking water delivered to the tap.

The federal Environmental Protection Agency (EPA) has determined that there is no safe level of exposure to lead based on the best available science. The EPA has set the action level for at-the-tap lead contamination, however, at 15 parts per billion (ppb). The lead action level refers to the concentration of the contaminant, which if exceeded in more than 10 percent of tested homes, triggers requirements that a water system must follow. The lead action level is set higher than zero because of other considerations such as cost, public benefit, and the ability of public water systems to reduce contaminant levels through corrosion control. In comparison, the federal Food and Drug Administration has set the allowable lead limit for bottled water at 5 ppb.

Local Responsibilities. The regulatory burden for controlling lead levels falls on the city’s Department of Environmental Protection (DEP), as the EPA holds the public municipal water system responsible for lead contamination even where the source of contamination occurs in private buildings. Monitoring of the water lead level in private homes is meant to measure the need for and efficacy of corrosion control. Adding anticorrosion additives at water treatment plants is the most cost effective citywide control method to minimize lead leaching when water passes through lead pipes.

In accordance with the EPA Lead and Copper Rule and the New York State Sanitary Code, DEP is required to conduct at-the-tap monitoring in residences at risk for exposure to lead. DEP maintains a compliance sample of buildings known to have lead in their plumbing that agree to test their water at least annually for lead contamination. If more than 10 percent of the samples collected from the compliance pool are above the EPA’s 15 ppb action level, the city is considered to be out of compliance and must take action, which could include public education or adjustments to the water treatment process. New York State law requires that all schools comply with the 15 ppb EPA limit and DEP has coordinated the replacement of all known city-owned lead service lines. But there are currently no requirements to mandate removal of lead plumbing materials from private buildings regardless of the lead concentration in their tap water.

In addition to the compliance monitoring, DEP offers a free lead testing kit to any city resident who requests it. If a test shows lead in the water, this household is solicited to join the compliance pool. The compliance pool consists of several hundred households who test their water in exchange for a small credit on their water bill.

By examining these records of residential water sampling since 1993, the Independent Budget Office sought to understand the potential scale of lead contamination in New York City residential water taps. We identified building ages and sizes that are most at risk, and the parts of the city where at-the-tap lead water contamination is most prevalent.

Rates of Positive Lead Water Tests Falling

IBO analyzed changes in the average and median lead test results as well as the rate of tests exceeding the action level of 15 ppb for the free residential tests. As lead is no longer used in service lines or plumbing, these rates should gradually decline over time. We found lower average test results and fewer tests exceeding the EPA action level, but lead results above the action level continue to be detected in a small percentage of buildings.

The lead testing kits sent to residents who request them contain two testing bottles in order to check water exposed to different parts of the plumbing for different amounts of time.1 The first draw is taken after the water has been sitting in the pipe for at least six hours and represents water in extended contact with the fixtures and adjacent piping. The second draw is taken after flushing the pipes of stagnant water by running the water for a minute or two, representing water that has been exposed for only a short amount of time. DEP also recommends flushing as a way to reduce lead exposure in buildings that have lead in their plumbing, so the post-flush test measures the lead concentration after reasonable measures have been taken to reduce lead exposure.

To read the rest of the study, click here.

Print Friendly, PDF & Email
Share this Article: