In the 1950s and 1960s most public entities did not have design standards for collection systems. The public entities relied upon the Department to ensure the sewer collection systems connecting to their systems were properly designed and constructed.
In the 1970s more public entities started developing design standards for their sewer systems. This was done for several reasons. One reason was to standardize the materials and equipment used so operation and maintenance of these systems were simplified. This helped reduce spare parts inventories and meant maintenance workers did not have to become familiar with numerous types of pumps which in turn simplified training. Also, most public entities were developing or already had master plans for the overall sewer systems in their service areas. The local review of sewer plans helped ensure proposed sewer systems fit into the master plan and that future "bottlenecks" in the sewer system were not created due to undersized lines being installed in areas where growth was expected to occur.
Further, most owners of public sewer systems required sewer collection systems serving private developments, such as subdivisions which would connect to the public system, to be deeded over to them for operation, maintenance, and ownership. Prior to a public entity sending a letter of acceptance to the Department as part of the permit process, most public entities require that detailed plans and specifications on the proposed sewer collection systems to be submitted to them. The public entity reviews the plans and specifications to determine conformance with their standards of design and to determine if the proposed system fits into their overall sewer service plan. Once the local entity is satisfied that the proposed system meets their requirements, local approval is granted. This local approval normally serves as the letter of acceptance for the Department.
Since sewer plans and specifications are required by the SC Pollution Control Act to be submitted to the Department and the Department reviews these submittals, there were actually two reviews of the same plans - one review by the local entity and one review by the Department. This duplicate review was disconcerting to all. In order to eliminate the duplicate review of collection system plans and specifications and allow the Department to still meet its legal mandate to have regulatory control of sewer systems, the Department developed the Delegated Review Program (DRP) for collection systems.
In the Delegated Review Program, construction plans and specifications for collection systems are first submitted to a participating public entity. The public entity conducts the technical review of the project using their Department approved specifications and design criteria. The public entity also coordinates the project with the local 208 planning agency and, for projects in the coastal zone, the Department's Office of Ocean and Coastal Resource Management. Once the local entity completes its technical review and has obtained the 208 plan and coastal zone management plan conformance certifications, the project is submitted to the Department by the local entity with certification that the project meets the design standards and criteria of the approved local program.
The Department does not normally conduct another technical review of a project submitted through an approved local delegated review entity. The Department only conducts an administrative review and ensures that the receiving wastewater treatment facility has permitting capacity which has not already been committed to other proposed projects. Projects submitted to the Department under this program are normally permitted within two or three work days of their receipt by the Department.
The Department periodically conducts a detailed review of a DRP submittal to ensure a participating entity is properly administering the program. Normally no more than 10% of the DRP submittals are subjected to this level of review. Even then, these reviews are conducted in a timely manner. If serious problems are encountered with a participating entity's administration of the program, the Department can withdraw program approval.