Summary Data (as of 1/9/2017)

New Orleans water lead levels ranged from non-detect to 283.5 ppb (n=404 buildings, 1604 samples). Researchers tried to collect four samples per home (first draw, water after a 30 second flush, water after a 2 minute flush, water after a 5 minute flush or first-draw hot water). The figure below presents the number of homes by the maximum water lead levels.


The figure below presents the number of samples by water lead level.


The figure below presents the percent of buildings sampled with maximum lead levels that exceeded certain water lead level standards.


  • EPA’s Maximum Contaminant Level Goal (MCLG) (0 ppb and California Environmental Protection Agency’s Threshold Level (CAL-EPA PHG, 0.2 ppb)- EPA’s health based goal for lead in drinking water established in 1991. 96% of buildings had some detectable lead (detection limit is 0.2 ppb). California’s health based standard that was lowered in 2009 from 2 ppb to 0.2 ppb based on neurodevelopmental effects in fetuses and infants. An estimated 96% of buildings had maximum water lead levels that exceeded this standard (0.2 ppb was the detection limit).
  • U.S. Food and Drug Administration’s Allowable Level (FDA AL, 5 ppb)- FDA’s allowable lead level for bottled water set in 1994. Water lead levels > 5ppb have been associated with a one-point rise in children’s blood lead levels. An estimated 23% of buildings had maximum water lead levels that exceeded this standard.
  • World Health Organization’s Guidance Value (WHO GV, 10 ppb)- WHO’s provisional standard for lead in drinking water set in 2011, and partly based on treatment performance and analytical achievability. An estimated 8% of buildings had maximum water lead levels that exceeded this standard.
  • EPA’s Action Level (EPA AL, 15 ppb) – EPA’s regulatory standard established in 1991, used for evaluating water utility compliance with EPA’s requirements for lead in drinking water. It is not a health-based standard. An estimated 5% of buildings had maximum water lead levels that exceeded this standard.

Key Summary Points

  • Lead is common in New Orleans water delivery lines and in indoor plumbing of old homes
    • Lead can be introduced into water via lead connections and solder; brass faucet fixtures; galvanized steel pipes; and most significantly, by lead water service lines which can run from the street to the home.
    • Based on historical survey data, an estimated 65-80% of New Orleans’ water service lines are lead- most were put down as early as the 1830s. This may be an overestimate now due to efforts by the S&WB to replace water lines throughout the city.
  • New Orleans does not appear to have a lead in water problem as bad as Flint, Michigan’s
    • Approximately 40% of the first draw samples for Flint, MI were over 5 parts per billion (ppb or micrograms of lead per liter of water (µg/L)).
    • Based on our sampling of 404 buildings (n=1604 total samples), 23% of sites had a maximum water lead level over 5 ppb- not as bad as Flint, but still of concern.
  • New Orleans’ water meets the US Environmental Protection Agency’s (EPA) regulatory requirements.
    • EPA requires that no more than 10% of homes sampled exceed the lead Action Level (AL) of 15 ppb.
    • According to the New Orleans Sewerage and Water Board data, New Orleans meets regulatory requirements.
    • According to our data, which was not collected according to LCR standards, only 5% of homes we sampled exceeded 15 ppb of lead in water. It’s important to understand that we were unable to target high risk homes as required by the Lead and Copper Rule (LCR), thus even this amount is of concern.
  • It is the researcher’s opinion that meeting regulatory requirements is not indicative of water that is safe to women of child-bearing age, pregnant women or infants. There are several reasons for this:
    • The US Centers for Disease Control and Prevention (CDC) has determined that no amount of lead exposure is safe.
    • Even if a home water test doesn’t show any lead contamination, it may not mean the water is consistently safe if it is passing through lead pipes.
    • The EPA’s regulatory standard for lead in water (AL) is not a health-based standard.
      • It was established based on EPA projections that 25% of all Public Water Systems (PWS) will exceed 15 ppb.
      • The EPA does have a health-based goal, or Maximum Contaminant Level Goal (MCLG) for lead in drinking water- it is zero.
      • Only 17  buildings sampled by us (out of 404) had no detectable lead in their water- 96% of all buildings and 87% of all samples collected had detectable lead.
    • Water utilities achieve compliance when 90% of high-risk homes they sample release lead levels equal to or below 15 ppb.
      • This means that even when regulatory standards are met, 10% of the homes can still be contaminated with lead levels exceeding 15 ppb.
    • The researchers believe that if >10% of buildings sampled have water lead levels >5 ppb, the city has a serious lead in water problem.
      • This is because our sampling does not target “worst case” homes. We are waiting for information about the location of lead water service lines from the city.
      • Utilities, on the other hand, must collect 50% of their compliance samples from homes with lead pipe and the other 50% from homes with lead solder, as required by the LCR.
      • In addition, utilities are required to collect samples for regulatory compliance during the hottest months (July-Sept), when water lead levels are generally highest. This study collected water samples throughout the year- including low risk months.
      • Despite this, 23% of buildings sampled had water lead levels that exceeded 5 ppb.
    • Fetuses and infants are more susceptible to lead exposures.
      • Children can absorb 40-50% of an oral dose of water soluble lead, compared to adults, who can only absorb 3-10%.
      • The greatest risk of lead in water may be to infants fed with formula that has been reconstituted with unfiltered tap water- the CDC estimates that tap water may account for more than 85% of total lead exposure among infants consuming reconstituted formula.
      • Even very low doses of lead have been associated with irreversible adverse health effects.
      • Some effects include: decrease in IQ and academic achievement; increase in attention-related and problem behaviors; reduced fetal growth and birth weight; increased incidence of spontaneous abortions and preterm birth; and decreased fertility.
  • Perhaps most critically, our results reveal that prevailing exposure reduction guidelines recommended by water utilities and public health agencies, to flush water from the tap for 30 seconds to 2 minutes before using, may be inadvertently increasing lead exposures
    • Below are outreach materials from the New Orleans Sewerage and Water Board, EPA and Agency for Toxic Substances and Disease Registry (ATSDR), that were found online within the last three months directing people to flush their water for 30 seconds to 2 minutes to reduce lead exposure.
    • Yet 61% of the buildings we sampled had increased water lead levels after either 30-45 seconds, 2 minutes or 3 minutes of flushing.
      • 47% had increased water lead levels after 3-45 seconds of flushing.
      • 41% had increased water lead levels after additional 2 minutes of flushing.
      • 7% had increased water lead levels after additional 3 minutes of flushing (5-6 minutes total flush).
    • While longer flush reduced exposure, it is still difficult to get rid of lead in some water systems by flushing.  We are currently investigating what flush times would be most effective to reduce water lead levels. A good rule of thumb has been to flush the water for 5 minutes, then collect water in a bottle for use throughout the day.
      • However, we have seen cases where water lead levels increased after even a five minute flush of the system.
      • Thus, even if you water lead results come back low, you may still have a lead problem- it is hard to predict when lead particulates will detach and enter your water.




Last updated: 1/10/2017