In the aftermath of the water crisis in Flint, MI, many Water Authority customers no doubt have questions about lead in drinking water supplies. The Water Authority has prepared the following Q&A regarding the water system in Albuquerque. This article in the Feb. 28 Albuquerque Journal also provides some information (please note that the reporter uses “micrograms per liter” when he should say “milligrams per liter.
Q. What are the lead levels in Albuquerque’s water supply and do they meet federal standards?
A. The Lead and Copper Rule of the Safe Drinking Water Act has a lead action level of 0.015 mg/L for the 90th percentile sample (i.e., the sample where 90 percent of other samples contain LESS lead). The Water Authority has never exceeded the action level for lead. During the last round of sampling, in 2015, the 90th percentile sample for our system was 0.002 mg/L. The highest sample detected was 0.004 mg/L.
Q. Is there a history of lead use in Albuquerque’s water system?
A. In the 1990s, in anticipation of new EPA rules for lead and copper, the UNM Engineering Research Institute was contracted to perform a scientific analysis of lead use in the drinking water system. This included an exhaustive review of engineering drawings of water mains and service lines throughout the city’s history, interviews with senior operations personnel, and onsite inspections. The UNM team concluded that lead-based pipe materials were not used in the Albuquerque water system for utility-owned water mains. The review did identify some lead connections between the utility water main and the service line to the meter/curb stop. In known areas of installation, these lead components were excavated and removed, although we do not have records of how many. A utility policy was also developed to remove and replace any other utility-owned lead service components as discovered in the process of construction or repair of utility-owned water mains.
Q. Are there lead components remaining in the water system?
A. The Water Authority has no known water mains or utility-owned service lines made out of lead, and, as explained above, undertook an effort to remove other known lead components in the 1990s. Lead pipe may have been used at some residences to connect home plumbing to the water meter. The Water Authority does not have documented evidence or knowledge of what types of pipe materials were used at private residences or on privately owned property.
Q. What is the policy on lead replacement?
A. By policy, the Water Authority would remove and replace any utility-owned lead components discovered in the process of construction or repair of utility-owned water mains.
Q. What percentage of lead components have been replaced?
A. This was not recorded for posterity. Given the infrequency with which lead fittings are now encountered, we believe that the vast majority, if not all, were replaced during the ‘90s sweep.
Q. If there are any lead components, is there anything to prevent lead from getting into the drinking water?
A. The Water Authority has a corrosion control strategy to keep lead from reaching customers. When Flint changed sources to the Flint River, the river water was much more reactive to the pipes. The pipes were stripped of the protectant film of calcium (scale) and biofilm that are on the inside diameter of the pipes. When the corrosion happens on lead service lines, lead gets into the drinking water. The Water Authority has been monitoring the groundwater system for corrosion since 1988. Ground water has a stable alkalinity and pH which do not foster corrosive conditions for pipes and plumbing fixtures. When the water authority added surface water to the supply via the San Juan-Chama Drinking Water Project, corrosion was taken into consideration. An orthorphosphate corrosion inhibitor is added at the surface-water treatment plant to prevent corrosion. Each quarter our Compliance Division conducts sampling and voluntary monitoring of the water quality parameters most influential in the corrosion process. The surface water treatment process is routinely monitored to ensure that the finished water pH and alkalinity are as chemically similar to our existing ground water as possible to minimize the differences in water chemistry across the system.
Q. Why are lead levels not listed by zone in the Water Authority’s annual Water Quality Report?
A. Lead is not broken down by zone because sampling for lead does not occur by zone. Sampling is done every three years at select customer taps. Testing is performed on 50 homes built between 1982 and 1987, the last years when lead solder may have been used. These homes are not equally distributed throughout the system. Lead results from these homes are reported in the annual Water Quality Report that is mailed to all customers.
Q. I understand that lead isn’t a problem in the water distribution system, but I am concerned that there might be lead in my home plumbing. Are there any steps I should take?
A. An accredited laboratory such as Hall Environmental can test your water for lead and other contaminants at your expense, or you can request a free test from the Water Authority by filling out this online form. You may also wish to discuss your individual situation with a physician and consider having your children’s blood lead levels tested.