BlP The US Environmental Protection Agency (EPA) places limits on the quantities of toxic substances that may be discharged into the sewer system. Limits have been established for a variety of substances, including zinc, which is limited to 5.0g/L. If an industry is discharging zinc as (CaZn(OH)4), what is the maximum permissible molarity of that substance? M The US Environmental Protection Agency (EPA) places limits on the quantities of toxic substances that may be discharged into the sewer system. Limits have been established for a variety of substances, including zinc, which is limited to 5.0g/L. If an industry is discharging zinc as (CaZn(OH)4), what is the maximum permissible molarity of that substance? M