PFAS chemicals have been discovered at levels deemed unsafe in the water at South Carroll High and Winfield Elementary schools, Carroll County Public Schools spokesperson Carey Gaddis said in an email Thursday.

The two schools are located about a mile apart, just outside the town of Sykesville in southern Carroll County.

Water fountains at both schools have been turned off and alternative water sources, including bottled and filtered water, are being provided until “a permanent solution is implemented,” according to a notice sent home with students at those schools. A notice will also be posted online, according to Gaddis.

PFAS — short for per- and polyfluo roalkyl substances — are human-made chemicals that have been used since the 1940s in a range of products including stain- and water-resistant fabrics and carpeting, cleaning products, paints, cookware, food packaging and fire-fighting foams. Known as “forever chemicals,” they do not break down.

Current research from the Maryland Department of the Environment suggests that high levels of PFAS may lead to high cholesterol; changes in liver enzymes; decreased infant birth weight; decreased vaccine effectiveness in children; increased risk of high blood pressure in pregnant women and increased risk of kidney or testicular cancer. Most Americans have likely already been exposed to some level of PFAS.

PFAS tests were conducted on July 29 at each county school whose water is sourced from a well, according to Gaddis. Runnymede, Sandymount and Mechanicsville elementary schools use well water, but water at each of those schools was deemed safe, she said.

Every other public school in Carroll County receives public water service, which makes it the responsibility of the local government to test the water and address elevated PFAS levels.

The Maryland Department of the Environment enforces federal regulations such as the National Drinking Water Regulation, which mandates that public water systems must implement solutions to reduce PFAS to meet the regulation standards by 2029. Public water systems are also required to monitor and provide the public information about PFAS levels by 2027.

“Although the (Environmental Protection Agency’s) regulations do not require any actions from our water system until 2027, we feel it is necessary to act now,” the notice states.

The regulation issued in April sets a maximum contamination level for six PFAS chemicals commonly found in drinking water. The levels are:

PFOA: 4 parts per trillion

PFOS: 4 parts per trillion

PFHxS: 10 parts per trillion

PFNA: 10 parts per trillion

HFPO-DA: 10 parts per trillion

Mixtures containing two or more PFHxS, PFNA, HFPO-DA and PFBS: Hazard index

South Carroll was found to have 15.6 parts per trillion of PFOA and 12.7 parts per trillion of PFOS while Winfield was found to have 11.5 parts per trillion of PFOA and 5.42 parts per trillion of PFOS, notices state. Another Winfield sample found 4.59 parts per trillion of PFOS.

In Howard County, tests found PFAS at seven schools and water use was discontinued at one, Lisbon Elementary, according to communications from the system. Each of the schools tested is in the northwestern region of the county and receives water from a well.

Five Harford County schools are also prohibiting students from consuming water at school after tests revealed excessive levels of PFAS. Harford County Public Schools’ upcoming capital budget request to the county will include money for remediation of PFAS-contaminated school wells, according to Manager of Communications Jillian Lader.

Maryland environmental officials in December began testing for PFAS in drinking water as schools and daycare centers served by wells. Of 200 schools and daycares tested, officials have identified at least 36 with levels of PFAS that exceed federal limits, spurring distributions of bottled water as students return to the classroom for a new school year.

Additionally, state officials recommend that anyone receiving drinking water from a well at home should test their water at least annually.

Baltimore Sun reporters Matt Hubbard and Christine Condon contributed to this article.