Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are reportedly detected in public drinking water supplies. The U.S. Environmental Protection Agency (EPA) considers these compounds emerging contaminants and PFOA and PFOS were placed on EPA’s Contaminant Candidate List and health advisory levels for them in drinking water were established at 70 ppt. NSF created protocol NSF P473, which established minimum requirements for materials, design, construction and performance of drinking water treatment systems to remove PFOA and PFOS. The basic test protocol methodologies for NSF P473 are based on organic contaminant reduction protocols under NSF/ANSI Standard 53 for activated carbon systems, and on health effects contaminant reduction protocols under NSF/ANSI Standard 58 for reverse osmosis (RO) systems.