The problem with maintenance is particularly severe in many industrial installations. The corrosive atmosphere in chemical plants and paper mills requires great care in the selection of construction materials and techniques that will not be susceptible to deterioration. Prestressed Concrete vessels built with composite walls have performed well as mill water treatment tanks and reservoirs, chemical processing basins, and pulp storage chests lined with tile or fiberglass. Industrial plants build effluent water treatment facilities to combat stream pollution. As part of these installations, effluent treatment tanks are ideally built by the CROM system.