In treatment facilities processing large quantities of water and wastewater, concrete is exposed to a harsh environment. Coatings help protect the concrete and prolong the life of the facility. They must be able to protect the concrete from attack by chemicals such as acids, sulfates, sugars, and fermenting liquids. Coatings that have proven particularly successful after sustained use in the field include epoxies, coal tar epoxies, and vinyls. Epoxies provide an extremely hard, durable finish for concrete. Coal tar epoxies are economical and develop good adhesion to concrete. Vinyl coatings dry fast and aren't temperature dependent for curing.