Relief is coming for some Bucks County residents with tainted tap water. But others are still waiting.

A group of Bucks County homeowners forced to use bottled water for drinking, cooking, and more should soon have some relief from the plastic bottles — even though officials have still not determined the source of the contamination.

Almost three years after chemicals known as PFAS were found in the residents’ well water, the state Department of Environmental Protection is preparing to install treatment systems on the Perkasie-area homes.

Most of the affected homeowners have given the DEP permission to begin work, agency spokesperson Virginia Cain said Thursday. Inspectors will sample the water at each home, which is required to calibrate the treatment systems, then schedule appointments with each homeowner to install the filters.

» READ MORE: A dozen homes in Bucks County are confronting their own water contaminant crisis. But not because of military bases.

The dozen affected homes in East Rockhill and West Rockhill Townships make up one of two Bucks County communities where homeowners have been unable to safely use their tap water since 2016 or 2017. Both areas have been stuck in limbo as government officials determine who is accountable for the contamination. Frustrated with what they see as a lack of urgency from officials, residents say they just want to be connected to the clean public water supply.

PFAS contamination has affected scores of communities nationwide, including Horsham, Warminster, and Warrington Townships, where the chemicals entered the water supply after decades of use on nearby military bases. As Congress, the Environmental Protection Agency, the Department of Defense, and individual state governments grapple with — and sometimes argue about — how to confront the problem, community activists have raised alarms about potential effects of the chemicals, which have been linked to cancer and other health problems.

The PFAS in East Rockhill and West Rockhill is not believed to have come from area military bases, meaning the state rather than the Pentagon has been responsible for addressing the contamination.

This summer, the DEP agreed to provide treatment for the homes until a final investigation into the source of the contamination is complete. A permanent solution for the homes could be filters, public water, or something else, Cain said.

“Folks are starting to understand we’re not just saying, ‘Here are these treatment systems and we’re done,’” Cain said.

In another area of Bucks County, Hartsville in Warwick Township, a second group of residents has been on bottled water for three years and counting. The EPA still plans to do more testing there to figure out who is to blame for the contamination. The military has denied responsibility, and refused to fund public water hookups for the residents, though the Navy is currently paying for their bottled water. Testing at a local fire company over the summer revealed that the fire station could not be responsible for the contamination.

EPA spokesperson David Sternberg said Thursday that the agency "is actively involved in discussions with the Navy and Department of Defense about our next steps, which will include additional sampling.”