By Gary Battenberg
Two high-profile contaminants of concern
Lead in drinking water has been a major topic in the 24-hour news cycle here in North America for the past four years, specifically with reference to the Flint, MI incident. While lead is not new to those who understand the risks associated with exposure from drinking water, we understand how important it is to get the lead out of consumers’ water supplies. Millions of consumers across our country are understandably very concerned about the long-term health effects of lead poisoning from exposure in their tap water.
Recently, a new menace has reared its ugly head in the form of perfluorinated chemicals (PFCs), a large group of manufactured compounds that are widely used to make everyday products more resistant to stains, grease and water. The two most high-profile chemical compounds we hear about are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). US EPA has established a Lifetime Health Advisory action level for the sum of PFOA and PFOS at 70 parts per trillion (ppt). These compounds, called perfluoroalkyl or polyfluoroalkyl substances, are referred to by the acronym PFASs, with the lowercase ‘s’ indicating plurality of the two (combined) chemical compounds. Let’s look at these two issues and how our industry members have now become not just water treatment specialists, but now must be Risk Mitigation Specialists too.
Many of us can remember the days when remediation for chlorine, sediment, hardness, iron, pH correction, hydrogen sulfide and the like were the mainstay of our business. Standard equipment inventory included cartridge filters and automatic backwash filters for sediment and ferric iron (rust) removal; acid neutralizers for low pH correction; softeners to remove hardness minerals and chemical dosing pumps for oxidation, bacterial and corrosion control. Drinking-water filters were primarily carbon in granular activated form, which were sometimes plumbed to the cold water at the kitchen sink or supplied drinking water to a separate spigot mounted on the sink. The most common purifier at that time was the water distiller for those who didn’t like the taste of softened water for drinking. In the late 1970s and early 1980s, reverse osmosis drinking-water appliances were introduced to compete with these drinking-water products and are currently the most popular choice for producing high-quality life-support water.
As time progressed, other problems presented our industry with the task of removing contaminants, like methyl tertiary-butyl ether (MTBE), the gasoline oxygenate that replaced tetraethyl lead in gasoline in 1979; ammonium perchlorate, the rocket fuel produced by the Olin corporation and benzene, toluene and xylenes (BTX), the dry-cleaning chemicals that were introduced in the late 19th and early 20th centuries, dumped into the ecology with little or no thought given to the impact it would have on society in later years. These, along with a growing list of microbial contaminants, as well as inorganic and organic chemicals, present many challenges to water treatment dealers to specify efficient and reliable remediation and removal from our water supplies.
The lead crisis
As mentioned earlier, lead is not a new issue as far as water treatment specialists are concerned. It has long been known that lead is toxic to humans and has always had a maximum contaminant level goal (MCLG) of zero parts per million. Lead (Pb) is found in water as soluble (dissolved) and insoluble (particulate). It is present in three forms as lead hydroxide Pb(OH)2, lead carbonate PbCO3 and lead oxide Pb2O. Contamination sources are primarily lead service lines, solder containing lead and brass fittings and fixtures. In 1986, lead pipe and lead solder were banned because of the elution of lead into drinking water. As late as 1986, lead pipe was still used by public water utilities for transition through the foundation, where it was connected to the service plumbing of the house. Most solder sold and used today complies with the 2014 federal Safe Drinking Water Act. Additionally, low-lead brass fittings and fixtures are specified for new home construction or during kitchen and bath remodeling projects.
The Safe Drinking Water Act (SDWA) was enacted by the US Congress on December 16, 1974. Pursuant to the passage, US EPA was required to set and enforce the standards for drinking-water quality. The treatment action levels for meeting the national primary drinking-water regulations for lead in drinking water are as follows:
- SDWA action level: 0.015 mg/L
- World Health Organization (WHO) guideline: 0.01 mg/L
- Maximum contaminant level goal (MCLG): 0.00 mg/L
Potential health effects
Lead poisoning typically shows no symptoms; however, reactions such as irritability, weight loss, vomiting, constipation or stomach pain may occur. Many studies on effects of lead poisoning have been conducted over the years; children are at higher risk than adults and exhibit 30-75 percent greater absorption versus adult absorption rates of 11 percent. Pregnant women and young children are at even greater risk. These studies have revealed reduced intelligence, impaired hearing and decreased growth in children; damage to the brain, kidneys and bone marrow and damage to the nervous system and red blood cells. Reduced cognitive and neurobehavioral deficits are associated with blood levels of less than 10 micrograms per deciliter of blood (ug/dL) in children.
First, a water analysis must be obtained before an effective removal technology can be selected and only after careful investigation of its performance capabilities, based on results of competent product validation testing for specific contaminants to be reduced. Just as importantly, monitoring of the treatment product(s) must be diligently maintained to verify optimal performance. Proven treatment options include:
Lead reduction for POU or POE, utilizing a combination of activated carbon with a lead sorbent, can remove lead by particulate filtration and adsorption, as well as dissolved lead by adsorption.
Lead reduction using RO is proven to remove greater than 99 percent of both soluble and insoluble lead from drinking water, often yielding no detectable lead in the permeate.
Fractional, multiple effect and the more advanced vapor-compression designs have proven effective at removing lead from water.
Softening will reduce soluble lead at reduced flowrates of two to three gpm/ft3 but will NOT remove particulate lead. Soluble lead contributed by a lead service line connected to the house plumbing up to the inlet of the softener, installed at the point of entry, will be reduced but copper plumbing installed before 1986 will continue to contribute lead into the water, along with older brass plumbing fixtures and fittings. Testing immediately before and after the softener will confirm the reduction of soluble lead. For any (lead) contribution at a drinking-water tap, testing will confirm lead leaching from the service plumbing downstream of the softener. Lead presence at the tap indicates a POU drinking-water appliance is required to remove any remaining lead from the drinking water.
PFASs, the emerging contaminant of concern
Perfluorinated compounds (PFCs) have been in use for more than 60 years. To date, PFCs are virtually everywhere in our environment. They demonstrate high thermal, chemical and biological inertness—properties that make them useful for certain industrial purposes—but at the same time also result in environmental persistence and potential human health risk. Because these chemical compounds are extremely persistent, they are commonly referred to as forever chemicals because they were erroneously considered inert.
Since we now know what PFCs are and that they break down very slowly in the environment, that knowledge begs the question: ”When were these chemicals produced and how long have they been in our environment?” To answer that question, a look at the history will provide some perspective.
- 1947 PFC production starts at 3M Plant in Cottage Grove, MN.
- 1962 Internal Dupont document raises concerns about health risks.
- 1970s PFC vapor pressures and water solubility are published in chemical handbooks.
- 1981 Concern is raised about birth defects in children of female production workers.
- 1993 3M begins to monitor PFOA in (blood) serum from production workers. A parallel mortality study reveals excess occurrence of prostate cancer.
- 2000 3M announces plan to phase out production of PFOS with complete phase out by 2002.
- 2008 Health risk limits for PFCs in drinking water are issued.
- 2018 3M fined $850 million by state of Minnesota for groundwater contamination.
Where are they found?
As stated previously, PFCs are virtually everywhere in our environment. Examples include: personal care products (PCPs) such as hand creams, body lotions, sun screen, etc.; fast-food containers; water-proofing of raincoats; conformal-coating of electronics; stain-resistant carpet and upholstery; microwave popcorn bags and non-stick cookware (Teflon), to name a few.
Why is it still in our water supplies?
PFCs show high thermal, chemical and biological inertness that results in environmental persistence and potential human health risk. Until the 1980s, because these compounds were resistant to breakdown, they were erroneously considered inert, which contributed to underestimating the effects of immunotoxicity. These facts suggest that continued human exposure to even relatively low concentrations of PFASs in drinking water and/or the environment results in elevated biological burdens that may increase the risk of health effects.
How do we remove PFASs from our water?
The good news for those of us in the water treatment industry is that we have been treating these chemicals for many years without even knowing it. Tried and true technologies have been available since the early days of our industry. Properly specified granular activated carbon (GAC) filters and GAC contactors have been in use for commercial, industrial, institutional and laboratory installations for more than a century.
Commercial and residential products with sufficiently sized carbon pretreatment and post treatment yields very high-quality water for food and beverage processing, commercial humidification and many other applications where highly purified water is required.
GAC, powder activated carbon (PAC) and carbon block filters properly selected for challenge water conditions, with sufficient surface area for specified flowrate and removal capacity, yield exceptional water quality. Remember, it is important to monitor the treatment product(s), which must be diligently maintained to verify optimal performance.
Depending on the compound chemical makeup of the challenge water, anion exchange resin treatment may yield better performance. Currently there are numerous companies that are researching, developing and testing new resinous media for the specific remediation of PFASs.
New products specifically designed for PFASs removal are in the works and will be available in the near future to provide piece of mind for residential and commercial consumers alike.
The message here is the growth opportunity for risk mitigation at the dealer level. Astute manufacturers, dealers and distributors recognize the urgency of identifying the markets created by these menace contaminants and will find the certified treatment technologies for their clients and customers.
PFASs remediation is the proverbial political football with government agencies trying to find the solution to the problems but essentially kicking the can down the road to arrive at a collective consensus for identifying those who are responsible for the problem and ways to pay for the cleanup of the contamination. Until then, the professional water treatment dealer is uniquely qualified to remedy the problem at local and regional levels because of their education and expertise in water treatment technologies.
There are many avenues to identify these and other problems in your market. They are organizations and agencies that may need your help or they could provide direction to those contacts who can help you with entering the market. They include but are not limited to:
- Local water utilities
- Local health departments
- Environmental agencies, US EPA
- University programs
- County extension agents
- Radio, television, press releases, social media, etc.
Other opportunities include new home builders, local boards of realtors, recreational vehicle and travel-trailer manufacturers, campgrounds, community centers, schools, hospitals, restaurants, convenience stores, coffee shops, horticulture, aquaponics, hydroponics, etc. It is vital to remember to make sure you source and specify only certified and validated products that are approved by WQA, NSF, IAPMO (or other product certification bodies) and bear the appropriate validation labels, so that you and your customers are assured of highly effective and reliable remediation. Finally, remember, it is important to monitor the treatment product(s) and be diligent in maintenance and timely replacement for optimal performance.
About the author
Gary Battenberg is a Technical Support and Systems Design Specialist with the Fluid System Connectors Division of Parker Hannifin Corporation in Otsego, MI. He has 36 years of experience in the fields of domestic, commercial, industrial, high-purity and sterile water treatment processes. Battenberg has worked in the areas of sales, service, design and manufacturing of water treatment systems and processes utilizing filtration, ion exchange, UV sterilization, reverse osmosis and ozone technologies. He may be reached by phone at (269) 692-6632 or by email, [email protected]