MANAGING SEWERS IN CREEKS

The City of Austin is under an Environmental Protection Agency Administrative Order (issued April 29, 1999) to remedy sanitary sewer overflows. The Administrative Order sets a final deadline of December 31, 2007 for the completion of the work necessary to address the notable sewage overflows. In order to comply with the Administrative Order, the City of Austin Water and Wastewater Department created a working team named Austin Clean Water Program (ACWP). The ACWP directed Infiltration/Inflow studies, Sanitary Sewer Evaluation Surveys and design solutions for Rehabilitation or Replacement of leaking sewer lines. Meeting these objectives is complicated by the following: a) the short timeframe; b) the fact that a large portion of the sanitary pipe system is in stream channels; c) stream channels with drainage areas over 64 acres are protected by a Critical Water Quality Zone (CWQZ); d) City of Austin Land Development Code prohibits development (including new construction or major rehabilitation of existing wastewater lines) in the CWQZ. The Water and Wastewater Department and the Watershed Protection and Development Review Department devised a dedicated, fast track permitting system that handles only Austin Clean Water Program Projects. The ACWP team also includes technical and permitting representatives from both Departments that are able to work with the design teams to ensure that: 1) where possible, new lines are located outside of the channel and CWQZ; 2) when the collection system must remain in the channel or CWQZ, the sanitary sewer collection system is protected from damaging flows; 3) the drainage infrastructure remains intact; 4) critical environmental features are preserved and protected.