WEATHERING THE STORMS OF A COMBINED SEWER SYSTEM THROUGH EQUITABLE ALLOCATION OF STORMWATER COSTS: A Case Study for the City of Wheeling, West Virginia

Typical of many older Cities in the United States, the City of Wheeling operates a combined wastewater collection system handles wastewater and stormwater flows within the City's service area and from communities outside the City. Flows are conveyed to the City's wastewater treatment plant or by-passed directly into receiving waterways during periods of heavy rainfall. The City has a significant problem with untreated wastewater discharges during storm events.The City combines stormwater and wastewater operations under its Water Pollution Control Division. Combined operations include consolidation of annual operating budgets and capital improvement plans. Customer billing for retail wastewater service is based on water meter usage. Wholesale wastewater service billing is based on sewer meters located at the City limits. Prior to the study, the City had no clear picture of the cost associated with stormwater operations or stormwater cost responsibility of outside-City communities that use the City system. By default, unidentified stormwater costs have historically been solely recovered by metered usage.This paper presents the approach developed for Wheeling to separately identify system wastewater and stormwater operation costs and for allocating stormwater costs between retail and wholesale customers on an equitable basis. Assumptions and issues that relate to retail and wholesale customer allocations are discussed. Separation of the wastewater and stormwater costs for a combined wastewater system is beneficial in several ways. First is the identification of what it actually costs to provide such services. Second is verification of whether customer classes are paying their fair share of costs. Third is provision of useful information for forming a separate stormwater enterprise fund. As with any cost of service study, careful consideration must be given to developing an equitable basis for all costs allocations between retail and wholesale service.