State officials on Thursday began offering free bottled water to people who live near the former naval air stations in Montgomery and Bucks Counties, which are blamed for contaminating public drinking wells.

The distribution of as many as two cases per day to residents in Warminster, Warrington, and Horsham Townships is a "precautionary action," Gov. Wolf said in a statement announcing the initiative.

It occurred on the same day that federal officials released new guidelines that set a lower bar for the level of acceptable water contamination than what has been used as the standard in Horsham and Warminster. It was not immediately clear if the change would affect efforts to reduce contamination in those communities.

Jeff Sheridan, Wolf's spokesman, said state environmental officials "would evaluate the appropriateness of continuing to provide bottled water" after reviewing the new advisory from the Environmental Protection Agency.

Perfluorinated compounds - which were commonly used in firefighting foams at the former naval air stations in Willow Grove and Warminster - were found in the drinking water there in 2014. Such contaminants have been linked to cancer and reproductive issues.

Local and state officials have worked with the Navy to take the contaminated wells off-line and offer bottled water to nearby residents whose private wells were contaminated.

The scope of health problems, and how many people might want or accept the free water, was unclear.

"We [already] use bottled water in my house and many of my neighbors do as well," said State Rep. Todd Stephens (R., Montgomery), who lives in Horsham and had pressed the governor's office to take action. "Many residents either have whole house filters that they had installed, or rely on bottled water for drinking and cooking."

As more have stepped forward with health concerns, federal and state lawmakers have pressed the Navy and EPA to answer questions about the contamination and health concerns.

"This is a step in the right direction," Reps. Patrick Meehan (R., Pa.) and Brendan Boyle (D., Pa.) said in a joint statement Thursday about the new EPA guidelines.

Levels of contamination in most of Horsham's wells still fall below the new advisory level, according to the township water authority's latest publicly available test results.

The free water was available Thursday afternoon at the Horsham Community Center. Distribution will resume Friday, with pickup available from 9 a.m. until 6 p.m.