The nation’s water infrastructure the pipes, treatment plants and other critical components that deliver drinking water and remove and treat waste water have grown old. In many of our cities water pipes installed when systems were built have only been replaced when they break. The building service lines that connect homes and businesses to the water mains are often the original lines.
The cities distribution system usually stops at the property line when the homeowner or building owner becomes responsible. In some cities and communities (like Fairfax, VA) the property owner is responsible for the entire service line from the water main to the house (or other building). As Flint Michigan has made all of America aware many of our oldest water systems have lead service lines or lead solder in copper lines.
For decades instead of replacing lead pipes urban water companies (especially in poor cities) have used chemicals to control lead and other chemicals from leaching into the water supply. Many at the American Water Works Association and other trade groups have questioned the wisdom of this strategy, there is always some lead leaching and many of us believe that there is no safe level of lead in drinking water.
In 1986 lead pipes were finally banned in new construction and repairs by the federal government, but many cities banned lead pipe use much earlier out of health concerns. Most existing lead pipes are closer to years old, are in the older cities of the east coast and mid-west and should have been replaced in the normal course of preventive maintenance program. Unfortunately, that is not how we operate in the United States. A few cities, including Madison, Wisconsin, and Lansing, Michigan, have taken steps to remove all of their lead pipes. Such projects can cost tens of millions of dollars and have to paid for by including an increase in water bills and also paid by property owners. It was estimated by the American Water Association that there are 6.5 million lead pipes still in service in the United States while the EPA estimates that number at around 10 million. That does not even consider all the homes in America that have copper pipes with lead solder.
In 1991, EPA published a regulation to control lead and copper in drinking water. This regulation is known as the Lead and Copper Rule (also referred to as the LCR). The rule has undergone various revisions, but requires that: (1) water utilities optimize their treatment system to control corrosion in customers plumbing; (2) determine the tap water levels of lead and copper for customers who have lead service lines or lead-based solder in their plumbing systems; (3) rule out the source water as the source of significant lead levels; (4) if lead levels exceed action levels (0.010 mg/L) the supplier is required to educate their customers about lead and actions they can take to reduce their exposure to lead. If a water utilities’ corrosion control treatment plan continues to fail to reduce lead below lead action level it must begin replacing the lead service lines under its ownership.
In the 1990’s and early 2000’s when the lead action level was lowered, water utilities discovered that just as changes in water chemistry can disturb the protective biofilm, removing lead lines improperly, or taking out only a portion of a line ends up disturbing the coating intended to prevent lead leaching inside old pipes. Replacing only a section can induce a chemical reaction from the addition of other metals, like copper, in new sections of pipe. Lawsuits were recently filed in Flint, Michigan and Chicago, Illinois for failure to remove all their lead pipes. Many other utilities could face such lawsuits because we are a nation that waits for system or component failure before we replace something.
WSSC, DC Water, and Fairfax water have had lead testing programs in place since 1990’s. The problems of lead in household drinking water in Washington DC has been previously discussed. In light of the national conversation over concerns of lead in public drinking water, that there have been no problems identified in the Fairfax Water system nor the WSS system. Testing in the Fairfax Water system has not found elevated levels of lead in the drinking water. Since testing began in the early 1990s, Fairfax Water’s levels have tested well within the EPA’s compliance standards. In the most recent Lead and Copper Rule sampling period for Fairfax Water, 100 % of the samples tested were significantly below the EPA action level of 15 ppb. In fact, during the sampling period, 100 % of the Fairfax Water samples contained less than 1.5 ppb of lead. For a fee, concerned homeowners can have Fairfax Water analyze their water sample for lead.
WSSC has an older system that was established in 1918. In 2005, WSSC conducted a search to find and replace any lead pipes in the WSSC system, but the WSSC system extends only to the property line. Recall that in the early 2000’s it was discovered that replacing only a section of a lead service line can induce a chemical reaction from the addition of other metals, like copper, in new sections of pipe. In addition, many homes built before the 1986 EPA ban of lead solder may still contain sources of lead in the solder that was used to connect copper plumbing inside their homes. In accordance with EPA regulations, every three years WSSC conducts random sampling in certain homes built prior to the EPA ban. Based on the latest round of sampling in 2014, results for all homes tested were below 15 parts per billion (ppb) for lead, which is the EPA action level. Ninety-eight percent of those tested were below 2 ppb.
WSSC adds a corrosion inhibitor to their water. This corrosion inhibitor works by creating a coating on pipes that prevents them from leaching lead, but it’s still possible that some homes built prior to 1960 may still have lead service lines on their property. It is the homeowner’s responsibility to test their pipes and replace them. Concerned customers should contact WSSC’s Water Quality Center at 301-206-7575 about having their water tested.
No comments:
Post a Comment