System Performance

Metropolitan Sewer Subdistrict strives to maintain our sanitary sewer collection system at a high level of performance. The District performs proactive operations and maintenance activities system wide to maximize the useful life and capacity of its sewer collection system. The performance of all aspects of management, operation and maintenance of the system are monitored continuously by the use of data entered into established performance indicators. The performance indicators are evaluated annually utilizing a performance based standard.

Our staff provides all routine pipeline operations, maintenance, and system evaluation. Work orders and reports are generated during these activities and entered into our Management Information System. The information is then utilized to assess the collection system’s operational condition and requirements.

Metro’s program of operation and rehabilitation complies with the regulations of the South Carolina Department of Health and Environmental Control (SCDHEC), the guidelines and intent of the Environmental Protection Agency (EPA), Region 4 Capacity, Management, Operation and Maintenance (CMOM) Program and includes the following:

  • A Capacity Assurance Program to evaluate existing capacities of gravity sewer mains and pump stations. Metro’s program meets the requirements of SCHEC’s Regulation R.61-67, Standards for Wastewater Facility Construction.
  • An Operations and Maintenance Program including line cleaning, rights of way clearing, pumping facility inspections, and system capacity management. Metro’s Operation and Maintenance Summary (below) provides goals or milestones established each year and the result of the previous year efforts and accomplishments.

 Key Performance Indicators

  • A Sewer System Evaluation Survey Program including smoke testing, manhole inspections, line televising, capacity evaluation, and system condition rating in accordance with our established asset management program.
  • A current and maintained Geographical Information System/Maintenance Management System (GIS/MMS) defining and documenting the collection system inventory and work history which supports the rating and assets management system.
  • A Flow Monitoring Program to address and reduce inflow and infiltration (I/I) within Metro’s collection system. Flow monitoring is accomplished in accordance with regionally adopted procedures and reporting standards. The Peak Hourly Discharges are evaluated using the Renewable Water Resources ReWa Performance Standards Committee Memorandum. I/I reduction quantities are calculated annually (weather permitting).

Metro utilizes a consulting engineer to review Sanitary Sewer Evaluation Survey data obtained by Metro staff. The consulting engineer applies a level of condition to each sewer line evaluated and reviews this information with Metro staff. Together, we prioritize repairs and identify rehabilitation projects. These projects are budgeted and advertised for construction. When information indicates the necessity for immediate or emergency repair or replacement of pipelines or appurtenances, Metro calls upon our yearly maintenance contract to complete the repair (Find and Fix Program).

Metro’s commitment to continue to provide the highest level of operation and maintenance is illustrated by our sustained planning and funding of collection system rehabilitation projects. The District has spent an average of $2,000,000 per year in each of the last five years on our rehabilitation program. Our future financial planning dedicates $2,000,000 per year for the next ten years to accomplish our collection system rehabilitation goals.

The Metropolitan Sewer Subdistrict Commission and staff believe that a well planned and executed collection system operation and maintenance program provides the foundation for future growth and development within the District. Our program is designed to protect the local water quality and public health by reducing sanitary sewer overflows and system backups. In addition, Metro’s effective operations help to reduce and delay the need for expensive capital improvements to provide additional wastewater treatment plant capacity.

Proactive Results
The results of our proactive maintenance program are shown on the graph below. Metro’s average proactive man-hours for the past ten years average 98.8% per year with our reactive man-hours averaging only 1.2% per year. As you will see below, the ability to focus our man-hours on a proactive program has a direct impact on the number of stoppages and sanitary sewer overflows we experience during the year.