Atlanta's Consent Decrees Drive a Substantial Commitment to Trenchless Sewer Rehabilitation

In 1998 and 1999, the United States Environmental Protection Agency (EPA) and Georgia Environmental Protection Division (EPD) completed settlement negotiations associated with two complaints against the City of Atlanta for various violations of the United States Clean Water Act and Georgia Water Quality Act. This resulted in the recording of the Consent Decree (CD) related to Combined Sewer Overflows (CSOs) and the First Amended Consent Decree (FACD) associated with Sanitary Sewer Overflows (SSOs). They mandated improvement of the City wastewater collection and transmission systems including wet-weather control for combined sewers, and rehabilitation and relief of capacity-limited sanitary sewers. The City's seven existing CSO control facilities experience a combined 300 discharge events per year. Additionally, over 550 SSOs (unpermitted discharges and spills to dry land) are experienced annually. The City wastewater collection and transmission systems include approximately 1600 miles of sewer mains and approximately 37,500 manholes. Fifteen percent of the system is comprised of combined sewers while 85 percent of the system consists of separate sanitary sewers. Six other governmental entities contract for wastewater treatment by the City including the Cities of Hapeville, College Park and East Point, and DeKalb, Clayton and Fulton Counties. Fifty-five percent of the sewage flows are generated by Atlanta and 45 percent by the wholesale agencies. The total benefiting population is 1.2 million. The 14-year phased approach under the FACD includes evaluation and rehabilitation of the sanitary system, and construction of capacity relief sewers that is estimated to cost approximately $2.2 billion. Additionally, the CD requires a $1.0 billion capital investment including disinfection improvements, new tunnel conveyance/storage and treatment facilities, and sewer separation in three combined sewer basins. Additionally, the FACD requires the preparation and implementation of management, operation and maintenance ("MOM") programs for the sanitary sewer system as a measure to help control SSOs. Full compliance with the CD and FACD is required by November 7, 2007 and July 1, 2014, respectively. Over 200 miles of small diameter sewers have been rehabilitated to date for the most part utilizing cured in place pipe. The City anticipates escalating its rehabilitation program to an average annual expenditure of $100 million over 8 years. This paper will overview the City's challenges with negotiating complex consent decrees with EPA/EPD and complying, to date, with some of the scheduled 900 interim and final consent decree compliance milestones. The paper will also describe the formation of the improvement program, locally known as `Clean Water Atlanta', that was formed to meet the requirements of the FACD and will also introduce the three other papers in this track relating to SSES and Rehab Selection Process (Paper Two), The GIS Hub (Paper Three), and Hydraulic Modeling (Paper Four).