The treatment wastewater must meet discharge requirements imposed and enforced by the Environmental Protection Agency. Depending on the wastewater generator, these contaminants can be removed using a variety of proven techniques, which range from conventional primary and secondary municipal level treatment to local removal using septic tanks and leachfields. In primary and secondary treatment, contaminants are removed in sedimentation basins or in filtration processes. The removed material is referred to as sludge and is dewatered and hauled to a sanitary landfill for disposal. Sludge accumulated in a septic tank is pumped out and transported to the local treatment plant for additional processing and dewatering.
Landfills have requirements for wastewater sludge disposal.
The primary one requires the sludge to meet a minimum solids content. Other requirements may include maximum sludge concentrations for select inorganic and organic compounds that are detrimental to the environment and the public. Additionally, the disposal of sludge contaminated with hazardous materials is prohibited. The unit processes that generate sludge are described as well as the thickening and dewatering methods. The sludge disposal requirements for the local landfill are defined and the current quality control procedures used by the CMSA operations and laboratory staff to meet the landfill requirements are detailed.