Most residents have been fortunate to assume their water supply provides them clean, safe drinking water from a municipal system or a private well. In recent years, however, water quality has started to raise concern for a vast majority of the country.
According to a newly published Environmental Working Group report, more than one-third of the United States population has been exposed to harmful, lasting groundwater contamination of perfluorinated compounds (PFCs), like perfluoroalkyl substances (PFAS) and perfluorooctanoic acid (PFOA). As this contamination continues to be found at manufacturing and military sites across the globe, filtration solutions will be required on more systems that have traditionally only moved water.
PFCs are known as “forever contaminants,” which infiltrate groundwater supplies and do not break down naturally in the environment. These contaminants are being traced more frequently to water sources that end up in homes, commercial buildings and shockingly, our blood. As federal regulations protecting some water sources from chemicals like these have recently been reconsidered, it is critical to rethink traditional approaches to water quality to continue providing clean drinking water through all types of systems.
More Than Just Water Flow
While larger, managed municipal water supplies are reacting to PFC contamination with new treatment methods, the more than 100,000 small, ancillary water systems and 15 million U.S. households that rely on water wells and residential well pumps will need new solutions from trusted suppliers. Adding to the equation, existing water infrastructure—from both private and public sources—is easily stressed by service and management needs for contaminants that were not built to treat these contaminants, including PFAS, making treating and distributing safe drinking water more complex.
Much like any municipal system, water infrastructure varies based on the size and scale of the population it serves. Some fully private well systems are not required to be monitored for quality, thus any change in water treatment will lead to a new kind of water being delivered without the promise of testing for contamination. However, larger systems relying on pumped well water like highway rest stops, industrial facilities and camping or mobile home sites serve enough customers to be considered a regulated water system.
The spread of groundwater contaminants across the U.S. is driving providers of previously safe water sources to add forms of treatment that have never been needed before—particularly for buildings using pumped wells. While these new contaminants pose a growing concern for groundwater, existing well system manufacturers and suppliers can use established methods to provide innovative solutions to their customers and protect their reputation as a trusted clean water provider. Newly complicated threats must be considered in the planning and maintenance of water infrastructure to eliminate the contamination risks before they have the chance to go mistakenly undetected.
While larger systems can take years to upgrade treatment, smaller systems and responsive partners can move quickly to keep existing systems operating, avoiding decisions by facilities and homeowners to move to a new water supply method all together. Water treatments like ultraviolet can be employed at the well pump head site or before entry to the building that provide effective contaminant reduction against PFCs. When adopting this approach, it is necessary to consider how the addition of these systems may affect building water quality, get installed between the pump and the building plumbing, as those who manage the water supply will now be tasked with monitoring and maintaining water treatment equipment that may not have been common before.
Ensuring Water Safety
For both private and regulated water supplies, the quality of any additional treatment component comes down to the knowledge of the professional who designed, installed and maintains the system. These providers have a role in improving systems to meet these new contaminant needs, and water treatment manufacturers have quickly developed and tested new solutions that can be accessed.
For example, frequently employed methods to treat PFC from groundwater often include activated carbon media filters that can provide specific PFC reduction rates and lifetime data. Reverse osmosis is also a highly effective method to remove many contaminants from water, but capital and operations and maintenance (O/M) costs should be weighed carefully to see if water quality is poor enough to justify the increased costs and additional water waste.
Both forms of treatment can reduce target contaminants, but also are known for harboring and breeding opportunistic microorganisms inside the filter media or membranes. Because of this, special care should be taken to add microbial treatment after providing new treatment stages to ensure that microbial concentrations in water are not inadvertently increased.
New York Case Study
The effective response to PFC contamination in Hoosick Falls, New York, serves as one of the early and well-developed examples of a treatment system that allowed well water users to avoid costly interconnection projects to the nearest municipal system. The point of entry treatment (POET) systems developed and deployed by the N.Y. Department of Environmental Conservation and Arcadis, Inc., use specifically selected granular activated carbon (GAC) and ultraviolet light systems to allow hundreds of homeowners to continue using their existing well systems and water supply, even while the source water presents high levels of PFCs.
Many facilities may look to chlorine dosing for microbial control as it is readily used for systems at the larger scale, but it can pose cost and frequent maintenance issues quickly with smaller systems. Inaccurate or even “cautious” overdosing with good intentions of disinfectant chemicals in small systems will experience more severe swings in disinfectant and disinfectant by-product concentrations; lower water flow provides less dilution to smooth out delicate dosing rates.
Ultraviolet (UV) light systems serve as microbial control with no risk of overdosing or disinfection by-products and can readily be added at the end of any drinking water treatment system. UV lamp systems will still provide the most cost-effective option for flow rates of tens of thousands of gallons per minute, but UVC LED systems are also now available from organizations that can provide drinking water treatment at the point of use (immediately before dispensing from a tap) with less maintenance and lower total costs of ownership.
Ensuring Wells Continue to Operate
For those who have previously had access to safe groundwater, it is critical to know they can trust that the well pump supplier who installed or maintains their system is aware of all possible threats of contamination. Thus, suppliers must now understand the new challenges that come with traditional water quality methods and use a solution after the pump that safeguards water against contaminants from the source, ensuring the resulting quality at the point of use.
PFC contamination has started to close well sites across the country and over-stretch existing infrastructure systems to move homes off well water sources. But solutions like those used in Hoosick Falls can be deployed to keep wells open and ensure quality water.
With a third of the U.S. and millions of existing well systems at risk of providing contaminated water, it is paramount that system providers are prepared to support existing systems with new treatment solutions to keep these wells as viable water sources for homeowners and businesses.
