DuPont and two other companies will settle environmental claims concerning PFAS, commonly referred to as "forever chemicals," and pay New Jersey up to $2 billion, the companies announced Monday.

A consent order in the settlement between the Garden State and DuPont, Chemours and Corteva says remediation work will get underway at four sites that the state says discharged pollutants, including PFAS:

• Pompton Lakes Works in Pompton Lakes and Wanaque, Passaic County 
• Repauno Works in Gibbstown, Greenwich Township, Gloucester County
• Chambers Works, formerly Carneys Point works, in Pennsville and Carneys Point, Salem County
• DuPont Parlin site in Sayreville and Old Bridge, Middlesex County

PFAS, or perfluoroalkyl and polyfluoroalkyl substances, are a group of chemicals that have been around for decades and have now spread into the nation's air, water and soil. They are commonly referred to as "forever chemicals."

State Environmental Commissioner Shawn LaTourette said the deal with DuPont, Chemours and Corteva is the largest such settlement in the state's history. It calls for the companies to pay $875 million over 25 years to deal with contaminants, and create a remediation fund of up $1.2 billion. The companies will split the costs under the deal, which must still be approved by the courts.

The companies will also set up a $475 million reserve fund managed by a third party, which could be used if any of the companies go bankrupt or fail to complete remediation work required under the agreement.

DuPont said the settlement will resolve "all pending environmental and other claims" for "legacy" contamination claims at four sites where the companies operated in the state. It comes just months after the state said chemical manufacturer 3M has agreed to pay up $450 million to resolve lawsuits over natural resource contamination stemming from PFAS.

"Polluters who place profit above public well-being by releasing poisonous PFAS and other contamination in our State can expect to be held responsible to clean up their mess and fully compensate the State and its citizens for the precious natural resources they've damaged or destroyed," LaTourette said.

PFAS were manufactured by companies such as 3M, Chemours and others because they were incredibly useful. They helped eggs slide across non-stick frying pans, ensured that firefighting foam suffocates flames and helped clothes withstand rain and keep people dry.

The chemicals resist breaking down, though, meaning they linger in the environment.

Environmental activists say PFAS makers knew about the health harms of PFAS long before they were made public. The same attributes that make the chemicals so valuable – resistance to breakdown – make them hazardous to people.

PFAS accumulate in the body, which is why the Environmental Protection Agency set their limits for drinking water at 4 parts per trillion for two common types — PFOA and PFOS — that are phased out of manufacturing but still are present in the environment.