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1. Site Background

In 2014, the Horsham and Warrington Township Water Authorities conducted sampling in their public water supply wells, under the EPA third Unregulated Contaminant Monitoring Rule, and discovered PFAS contamination. Past use of aqueous film-forming foam (AFFF) is likely the source of the PFAS contamination on site.

In 2016, the EPA lifetime health advisory (HA) of 0.07 µg/L for PFOS or PFOA or combined PFOA and PFOS. Following the EPA lifetime HA: 1. Impacted public wells in the Horsham and Warrington public water supplies were taken off-line and filtration systems installed; 2. Private well users were provided alternative water sources (e.g. bottled water or public water connects); and 3. Site mitigation efforts have occurred.

2. What are PFAS?

PFAS are man-made chemicals that have been used in industry and consumer products worldwide since the 1950s. They have been used in non-stick cookware, water-repellent clothing, stain resistant fabrics and carpets, some cosmetics, some firefighting foams, and products that resist grease, water, and oil. PFAS do not occur naturally, but are widespread in the environment.

3. How can people be exposed to PFAS?

PFAS contamination may be in drinking water, food, indoor dust, some consumer products, and occupational settings. Most exposures occur through drinking contaminated water or eating food that contains PFAS. Most people in the United States and in other industrialized countries have some PFAS in their blood.

4. Will exposure to PFAS harm my health?

Some scientific studies suggest that certain PFAS may affect different systems in the body. More research is needed to understand, with certainty, if or how, exposure to PFAS in our water and food can affect people’s health.

• Scientists have studied lab animals exposed to high amounts of PFAS and have shown changes in the way their liver, thyroid, and pancreas work, as well as some changes in hormone levels. Because chemicals do not always affect animals and people the same way, scientists estimate how the exposure and effects in animals compare to what they would be in people.
• Some (but not all) PFAS build up in the human body. The levels of PFAS go down slowly over time once exposure stops. Scientists are studying how different amounts of PFAS in the body over time may affect human health.
•  Again, more research is needed, but some studies in humans have shown that certain PFAS may:
  •  Increased cholesterol levels;
  •  Decrease in response from the body to some vaccines (immune system);
  •  Increased risk of thyroid disease;
  •  Decreased fertility in women;
  •  Increase in the risk of high blood pressure or pre-eclampsia in pregnant women; or
  •  Lower infant birth weights.
  •  Increase the risk of some cancers

· At this time, scientists are still learning about the health effects of exposures to mixtures of PFAS.

5. Should I get my blood tested for PFAS?

We understand that some people may want to know the level of PFAS in their blood. While tests can measure the amount of PFAS in your blood, the results won’t tell you how PFAS will affect your health now or in the future. Most people in the United States have one or more specific PFAS in their blood, especially PFOS and PFOA. Talk with your health care provider about testing. Additional information on labs that offer testing is found below.

6. Can home water filters remove PFAS?

A number of studies have been conducted to determine the efficiency of filtration devices, for point-of-use filters. The results of these studies have shown that point-of-use filters can remove trace organic compounds. Based on these studies, there currently are three general types of filtration systems that can potentially can reduce PFAS levels in water, if properly maintained: granulated activated carbon – either in refrigerator, faucet, or pitcher filters and some filtration systems installed on your water line; reverse osmosis; or granulated activated carbon used with reverse osmosis. However, it is important to ensure the systems are maintained according to the manufacturer and that your water is tested.

Global public health organization NSF International has developed a test method and protocol to verify a water treatment device’s ability to reduce perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) to below the health advisory levels set by the U.S. Environmental Protection Agency (EPA). Consumers can find NSF International-approved devices by visiting: http://info.nsf.org/Certified/DWTU/

Click on “reduction devices” at the bottom of the page for PFOS and PFOA).

Additional community information on this topic is available from other states, including:

• The Michigan Department of Environmental Quality- https://www.michigan.gov/documents/deq/deq-dwmad-eh-swpu-FilterFactSheet_610096_7.pdf

7. What is the potential risk for PFAS in surface water near the site?

PFAS have been found in surface waters surrounding the Willow Grove site. Exposure to PFAS from non-drinking water sources would add to the potential risk. However, swallowing small amounts of PFAS during recreational activities in the nearby creek would not result in a significant exposure. Absorption of PFAS through the skin is not a major exposure route due to the physical characteristics of PFAS. These same characteristics cause most PFAS to remain in the water column and not separate into sediment or become volatilized into the air, thereby reducing the likelihood of exposures via contact with creek sediment or breathing while swimming. Currently, ATSDR, EPA and the Pennsylvania Fish and Boat Commission (PFBC) do not have screening values for PFAS in surface water. In addition, swimming or wading in natural bathing waters can put public health at risk due to an assumed presence of fecal coliform bacteria from natural sources. Care should be taken to prevent young children from swallowing any recreational water, and for any swimmers to wash afterward with an approved water source.  

8. Are fish near the site safe to eat?

PFAS don’t break down easily in the environment and can bioaccumulate and biomagnify in some wildlife, including edible portions of fish. Studies have shown that PFOS is measured more often and at higher concentrations in fish tissue than other PFAS compounds. The half-life of PFOS in fish is shorter than in humans or the environment. Thus, concentrations in fish decline more rapidly following declines in surface water concentrations.  

Fish consumption is a potential exposure pathway to PFAS, for both the general population and for people living near PFAS contaminated waters. In October 2021, the Pennsylvania Departments of Environmental Protection (DEP), Agriculture (PDA), and Health (DOH), along with the Pennsylvania Fish and Boat Commission (PFBC), announced a “Do Not Eat” advisory for all fish species caught in the Neshaminy Creek basin in Bucks and Montgomery counties due to “extremely high levels of the PFAS knows as perfluorooctane sulfonate (PFOS).” The advisory extends to all fish throughout the Neshaminy Creek basin, including Neshaminy Creek State Park and Tyler State Park.

In 2021, Pennsylvania adopted tiered meal advice for PFOS and began collecting and analyzing fish tissue samples for PFOS. Levels detected in fish tissue samples from the Neshaminy Creek watershed had levels over the 0.2 parts per million Do Not Eat advisory level.  As a result of the “Do Not Eat” advisory, the commission will discontinue fish stocking in the Neshaminy Creek basin until further notice. The commission will work to identify nearby replacement waters to redirect trout previously stocked in the basin to provide continued recreational angling opportunities for stocked trout. Fishing is still allowed in the basin, but anglers are urged to practice catch-and-release practices.  Additional information on Commonwealth fish advisories can be found here.

9. What do we know about plants or animals raised in PFAS-contaminated areas?

Studies have shown that PFAS can accumulate in plants grown in PFAS-contaminated soil or irrigated with PFAS-contaminated water. However, accumulation depends on multiple factors including the type of plant, concentration of PFAS in soil and water, and type of PFAS. An individual’s PFAS exposure from eating plants grown in soil or irrigated with water with PFAS depends on how much and how often they eat the contaminated plants. The Minnesota Department of Health (MDH) conducted a study of PFAS levels in homegrown produce, garden soil, and outdoor tap water from the eastern Twin Cities area in 2010. Please click here for more information.

Scientists are still learning how people may be exposed to PFAS by eating animals raised with contaminated food or water. Studies have shown that PFAS can build up in animal products. More research is needed to fully understand the risk of exposures and public health impacts from consumption of PFAS-contaminated food sources. The U.S. Food and Drug Administration (FDA) is focused on generating, applying and evaluating the science that is needed to estimate PFAS exposure from food. Please see the FDA website (https://www.fda.gov/food/chemicals/and-polyfluoroalkyl-substances-pfas) for more information about FDA efforts to estimate PFAS exposure from foods.

10. What are safe gardening practices for PFAS-contaminated areas?

Individuals can lower their risk of exposures by following safe gardening practices such as:

• Washing produce before consumption to remove soil/dust particles containing PFAS
• Increasing organic matter of the soil which can lower plants’ ability to accumulate PFAS
• Irrigating crops with rainwater or filtered water