DCWASA's Impervious Area Information System: Designed to Allocate the Costs of the Mandated Combined Sewer Overflow Long Term Control Plan

With the implementation of extended and more stringent requirements of the USEPA NPDES permits, many owner or Agencies Combined Sewer Overflow (CSO) systems have to dramatically change their water quality and discharge standards. Due to these revised requirements many Agencies are forced to evaluate their financial programs in combination with strategic requirements to implement a substantial capital program to become compliant. The D.C. Water and Sewer Authority ("Authority") is one of those agencies whose financial program did not support the required capital investments to reduce CSO discharges. For the Agency to be in compliance they had to evaluate an alternative approach to funding the necessary capital improvements. This evaluation was undertaken through a series of rate analysis workshops and the outcome was to implement an impervious area service charge for every landowner within the District. The Authority engaged local government officials and an intensive public involvement campaign to obtain approval to implement this impervious area charge within the District. The Authority identified existing data sources from local agencies to reduce the implementation and maintenance costs for the proposed system. Once data sources were identified the Agency engaged in a detailed systems engineering design process to implement the Impervious Area Information System (IAIS) and clean the data for use. The Authority identified its existing customers, accounts and locations from its Vertex Customer Information System and then underwent a data cleanup process to establish new account information to support the IA charges. The Authority developed a series of or suite of tools to manage, create/edit and maintain its IAIS, this suite of 32 tools were broken into five modules (manage premises (customers), manage impervious area (features), manage exceptions and service charges, search/report and system administration. This system accounts for continual updates of impervious data or features from multiple sources and maintaining customer information over time in management of new development and redevelopment. The IAIS is capable of housing and organizing vast amounts of data, providing the means for program staff to analyze this data through computerized processes and solutions. This paper will document the challenges and successes that the Authority has had in the development and implementation of a comprehensive, impervious area management, and billing system.