This article originally appeared in the October 2019 issue of Water Quality Products magazine as "Stepping Up"
Many in the water treatment industry have likely heard about per- and polyfluoroalkyl substances, or PFAS, and its emergence in some public and private water supplies above the U.S. EPA health advisory level of 70 ppt.
PFAS are a group of man-made chemicals that had been manufactured and used in a variety of industries since the 1940s. Within the PFAS family, PFOS and PFOA were the most produced and are the two most studied PFAS chemicals. They have been identified as contaminants of emerging concern by EPA. Some of the more common applications included stain- and water-resistant products, paints, cleaning and polishing products, and firefighting foam. These chemicals have been shown to be persistent in the environment and in the human body when ingested. In the early to mid-2000s, both chemicals were phased out of production and are no longer manufactured in the U.S. In May 2016, EPA released a non-enforceable lifetime limit that limited combined PFOA and PFOS exposure to just 0.07 ppb, or 70 ppt, in drinking water. This limit may drop as low as .02 ppb, or 20 ppt, based on recent information.
Recently, the town where one of H2O Care Inc.’s offices is located sent notices to its public water supply customers notifying them of a reportable level of PFAS above the EPA limit. The water supply is comprised of groundwater pumped from four different wells and one reservoir. After determining that one of the wells was the main problem, the town took it offline and the PFAS level dropped below the 70 ppt limit down to 56 ppt. The town had indicated in its notice that they were working on a solution to remove PFAS from the town’s water supply. Evidently, the source of the contamination was a manufacturer in town that previously used PFAS in its manufacturing and cleaning process.
In the days after the meeting, H2O Care’s phone began to ring, email inquiries started coming in and visits to the office increased. People did not know if or when the town was going to fix the problem, even though the PFAS level had dropped below the 70 ppt level. Also, the 56 ppt level was not low enough to make them feel safe. As a result, some wanted to take matters into their own hands. Some people did their research and had an idea of what needed to be done, but many had no idea what to do. The dealership considered point-of-entry (POE) versus point-of-use (POU) options for PFAS removal, on-going maintenance requirements and costs.
People on the town water supply had their water tested and had been notified of a potential problem so they could decide what to do. Private well owners, particularly those near the town’s well that had been taken offline or near the original source of the chemicals, did not have their water tested by the town. For these well owners that contacted H2O Care, the dealership strongly recommended getting the PFAS test performed by a certified lab. Unfortunately, it is an expensive test and the dealership had been experiencing a minimum three week wait period for results. From there, H2O Care could determine if a removal system was needed and decide which type, POE or POU, depending on the customers’ specific needs or desires.
POE vs. POU
Based on current research and available data, the main concern regarding exposure to PFAS in the human body is through the consumption of contaminated water. Skin absorption does not seem to be a concern, although it may be possible for some exposure this way.
For those people that simply did not want these chemicals entering their home, a POE system was recommended. For POE treatment, H2O Care has been recommending activated carbon filtration, but have been careful to recommend only products that have been tested to NSF/ANSI Standard 53 or P473 standards for removal of both PFOA and PFOS. This is important for two reasons. First, the dealership always tests water before and after system installations to make sure the systems are operating correctly. For example, a water softener installation or service will always receive pre- and post-water tests for hardness, iron or manganese to make sure it is working properly. However, the cost of a water test to make sure the carbon is pulling out enough of the PFOA and PFOS is expensive and a cost many consumers may not want to bear.
For those people only concerned about the drinking water, a reverse osmosis (RO) system has been the natural choice. In addition to feeding the dedicated RO faucet, H2O Care has been running lines to refrigerator water dispensers and ice makers, as well. RO is the less expensive of the two options, costing roughly half of the POE system. Cost is clearly a determining factor for many people. Families with young children have tended to want POE systems. Concerns ranged from kids drinking water out of non-treated faucets to possible absorption through the skin during bath time.
For restaurants and other food service operations, PFAS have created problems with customers. Restaurants have been providing free bottled water to customers, using bottled water for coffee and preparing food with bottled water, etc., all costly. The restaurant owners that have contacted H2O Care understand that they need to remove the PFAS from their water. Additionally, they need customers to feel confident that the system they have in place will absolutely provide them with safe water. This is not a simple task and how each manager handles it will vary based on their customer base.
Depending on the volume of water needed to be filtered, either a granular activated carbon (GAC) system or RO are alternatives that have been presented. Available space for an installation is almost always an issue in restaurants, which may limit options somewhat.
RO membrane and storage tank sizes are adjusted to fit the volume and space requirements. RO presents a challenge as RO water is not ideal for coffee, as some total dissolved solids (TDS) in the water produces a better product. TDS can be added back in with a calcite filter. In normal circumstances, a sediment/carbon line could run off the RO to the coffee maker, but H2O Care has not seen a small GAC filter that has been tested to meet NSF and ANSI standards for PFAS. Because of this, the restaurant potentially faces a testing requirement. If this sediment and carbon to coffee approach is selected, the manager must be diligent about replacing these filters at proper intervals or establishing a service schedule that will cover this adequately.
PFAS are beginning to show up in towns now that the health advisory contaminant level has been set by EPA and towns are testing for it. There will be an increasing number of water supplies that are faced with this issue in the future based on the widespread use of PFAS in this country prior to cessation of use. Fortunately, our industry is able to reduce or eliminate this health threat.