POE treatment as a temporary alternative to lead service line replacement
It seems that every day you pick up the newspaper, read an article online or receive a water treatment industry email about another city or area reporting elevated lead levels in their service lines and policymakers searching for ways to eliminate those lead pipes. A recent national survey of community water systems suggests the number of lead service lines in the country could range from 6 million to 10 million, and may provide water for as many as 96 million people.
Lead is a colorless, odorless, tasteless and potent neurotoxin. A person simply does not know if they have lead in their water without proper testing, but testing only takes a snapshot of water characteristics for that day. If the water chemistry changes, then so could the contaminant levels.
Until they were banned in new home construction in 1986, lead-based products were used in more than 70% of homes to convey water because they were less expensive and more durable than iron. Lead pipes could easily be bent, allowing pipes to be shaped to conform to the contours of existing buildings or other structures. Lead can enter drinking water when service lines that contain lead corrode, especially where the water has high acidity or low mineral content that corrodes pipes and fixtures. Lead release is heavily influenced by the chemistry of the water delivered and by physical disturbances, such as road construction and water main replacements.
A short list of cities that have recently had to deal with a crisis as a result of drinking water lead contamination includes Milwaukee; Chicago; Denver; Providence, R.I; Flint, Mich.; Pittsburgh; Newark, N.J.; and Oakland, Calif.. With recognition of this problem from U.S. EPA Administrator Scott Pruitt, who has said that eradicating lead from drinking water is one of his top priorities and he is worried Americans are not “sufficiently aware” of the threat, lead in water is a major concern nationwide.
A High Cost
With more than 6 million lead service lines across the country—many of which are in the Northeast, Midwest, and older urban areas—the cost to replace these lines could exceed $275 billion nationally, particularly if the EPA alters existing rules to make them more stringent in the wake of the Flint crisis. EPA’s latest survey estimated the entire sector needs $385 billion in water infrastructure improvements through 2030, and this estimate includes only partial lead pipe replacement. In the city of Milwaukee alone, 70,000 residential properties currently face the issue of lead service lines from the city mains to the individual homes, and it is estimated that the total price for changing the laterals would be up to $756 million and take decades to complete—and there still is no guarantee this would alleviate the occurrence of lead in service lines and homes.
Being proactive to find a solution to this crisis is important not only for municipally supplied water, but also for wells. The design of a proper solution to filter soluble and particulate lead may be the key to the water treatment industry leading the charge and helping millions of people.
Excess lead levels can cause health problems in children and adults.
How Much Is Too Much?
The Safe Drinking Water Act requires EPA to determine the level of contaminants in drinking water at which no adverse health effects are likely to occur with an adequate margin of safety. These non-enforceable health goals, based solely on possible health risks, are called maximum contaminant level goals (MCLGs). EPA has set the MCLG for lead in drinking water at zero because lead is a toxic metal that can be harmful to human health even at low exposure levels. Lead is persistent, and it can bioaccumulate in the body over time. However, EPA’s action level for lead in drinking water is 15 ppb, and in 1994 the U.S. Food and Drug Administration set the maximum amount of lead allowed in bottled water at 5 ppb.
Furthermore, the Centers for Disease Control and Prevention and EPA recommend that “bathing, showering and washing dishes in lead-contaminated water should be safe, even if the water contains lead over EPA’s action level, as human skin does not absorb lead in water.” They state that “using dishes washed with water that has high levels of lead is not recommended. Sponge baths are recommended for children using a clean supply of water if possible.” They also suggest after bathing or showering in leaded water one should “wash [their] hands in chlorinated or bottled/boiled water. People with open wounds or who are immunocompromised should avoid showering in contaminated tap water.”
Children with lead poisoning can have learning and behavioral problems, hyperactivity, slow growth, and hearing loss. Symptoms such as tiredness, headaches, stomachaches, and iron deficiencies often are mistaken for other illnesses. Even low concentrations of lead in water can cause a significant increase in blood lead levels, and any damage is irreversible. The only way to find lead poisoning is through a blood test.
Testing & Certification
NSF/ANSI Standard 53 Drinking Water Treatment Units–Health Effects is used to test and evaluate the effectiveness of water treatment equipment used in homes for the reduction of chemicals that may be present in drinking water. This standard contains four primary sections and is tested and certified by an accredited third-party certification body for material safety, structural integrity, product literature, and evaluates the performance of the filter to reduce water contaminants.
The lead performance test created in NSF/ANSI 53 is rigorous. EPA’s action level for lead in drinking water is 15 ppb, but the influent lead level for NSF/ANSI 53 testing is 150 ppb, or 10 times the allowed level. NSF/ANSI 53 also requires testing at high and low pH levels to ensure the filter can remove lead in its ionic and particulate form. For the duration of the testing, the filter must reduce the influent lead concentration below 10 ppb.
The Pioneer lead and cyst removal system targets levels below 5 ppb. A point-of-entry (POE) filtration device, as certified to the NSF/ANSI 53, is a 0.5-µ nominal filtration level, which removes both particulate and soluble lead from the drinking water. Soluble lead must be chemically removed from water; particulate lead is like a tiny grain of sand that must be physically removed from water. The Pioneer POE filter is designed to remove both forms of lead contamination from the whole house in a single filter.
Pioneer binders are designed to chemically react with soluble lead to create an ionic bond, kinetically removing lead from the water. Ionic bonding is a chemical bond that involves the electrostatic attraction between oppositely charged ions and is the primary interaction occurring in ionic compounds. Ionic bonds form when a nonmetal (binder or adsorbent) and a metal (lead) exchange electrons.
The filter is engineered to physically remove and filter lead particles from water, which is often found as a result of corroded lead pipes.
Some filter solutions in the point-of-use (POU) marketplace address the removal of lead, but the filters are small, with low flow rates and short-rated life capacities, and they only address the use of water in a particular place in a home or business. What about water usage throughout the home? Does a homeowner need to install a POU device at every faucet, and is that economically the best solution?
POE devices typically have longer lives and higher flow rates, and are used for more than drinking water in a home or business. A POE water treatment system is installed on the consumer side of the meter with the express purpose of treating all the incoming water before it goes into the individual supply lines. Perhaps the solution for cities grappling with lead contamination lies in the water treatment industry, and specifically designed POE devices that filter all the water as it enters a home, rather than millions of dollars spent on changing water service lines that will take decades to replace with no guarantee this will solve the issue.