What Is Granular Activated Carbon and Point of Entry Treatment?

← Go Back

A filter with granular activated carbon (GAC) is a proven option to remove certain chemicals, particularly organic chemicals, from water. A Point of Entry Treatment (POET) water filtration system utilizes two GAC tanks that are connected to the plumbing system of a house or business. GAC has been classified as an EPA Best Available Technology (BAT) for the removal of many organic contaminants including PFOA.

Granular activated carbon is made from raw organic materials (such as coconut shells or coal), which are high in carbon. The organic material is heated, in the absence of oxygen, to increase (activate) the surface area of the carbon. The GAC water filtration system is filled with GAC material, which is periodically refreshed. As water passes through the filtration system the GAC removes certain chemicals that are dissolved in water by trapping the chemical onto the surface of the carbon. There are different types of GAC water filters that can be used in a variety of different applications. This includes large scale systems for municipal water treatment, as well as point-of-entry or point-of-use systems. 

Since the discovery of PFOA in Merrimack, Saint-Gobain Performance Plastics has agreed to POET filtration systems for affected private well users in proximity to the company’s facility whose test results show levels of more than 100ppt.