Collection System Analysis

The Collection System Analysis Section is responsible for the repair and rehabilitation of over 6,100 miles of sewer pipelines ranging in size from 6 inches to 144 inches in diameter, with over 127,000 manholes. Sewer depths range up to 80 feet.

This section is also responsible for implementing the Agreed Order (AO) requirements that were approved by the TCEQ. Implementation involves planning, analyzing and designing sewer rehabilitation projects, and implementing the Fats, Oils, and Grease (FOG) reduction program. The Collection System Analysis Section analyzes and issues work orders to operate the collection system and maintain the pipe network.

Requirements of the AO were summarized in a written plan prepared by the Collection System Analysis Section in 2004. The focus of the plan is to reduce the environmental impacts of Sanitary Sewer Overflows (SSOs) in 29 of the 40 service areas. This plan is comprised of both structural and non-structural components.

The structural component of the plan involves rehabilitating over 950,000 linear feet of sewer lines per year over a 10 year period. This amounts to rehabilitating 3% of the collection system per year versus the industry standard of 2% per year. Rehabilitation methods currently employed include point repair, remove and replace manholes, pipe bursting, slip-lining, and cured-in-place lining.

The non-structural component of the plan involves cleaning the collection system (including gravity sewers, lift station wet wells and force mains) and improving the information management system. This component involves cleaning and televising 20 million linear feet during the life of the agreement.

This section’s responsibilities include:

  • Scheduling and issuing sanitary sewer Cleaning and Televising (CTV) work orders.  CTV is an operation and maintenance tool that is part of the City’s preventative maintenance program. CTV reduces SSOs by cleaning sanitary sewer pipes throughout the City of Houston.  Reports generated when the sewer pipes are televised provide data on current pipe condition.  This data is used in the analysis for pipe rehabilitation and renewal.
  • Managing Excursion Tracking System (ETS) to track and report all SSOs that occur in the City of Houston.  In accordance with the TCEQ guidelines, the cause of each SSO is identified, and corrective measures are taken to prevent reoccurrences.
  • Planning, analyzing, and issuing work orders for sanitary sewer rehabilitation and pipe renewal, which is a program that repairs and replaces damaged sewer pipes and, when feasible, upgrades sewer pipes to current standards.  The sewer rehabilitation process helps repair system failures, meets goals established in the AO, and reduces the occurrence of Sanitary Sewer Overflows (SSO).
  • Identification of collection system Capital Improvement to upgrade and replace sanitary sewer pipes that could not be renewed through the rehabilitation process, and review other CIP to ensure that operation and maintenance needs are being met.