Bringing It All Together: Integrating Collections System Management Efforts To Achieve Superior Performance
Abstract:Fairfax County's collection and transmission system, which was constructed beginning in the early 1940's, grew rapidly in the 1980's. The quality and material of construction in the early years of the System varied widely since stringent design and review/acceptance standards and formal system inspection and maintenance procedures were not developed and implemented until the 1980's. Then, in 1989, the County experienced a catastrophic sewer collapse affecting sewer service in one of the largest but oldest sewer sheds in the System.
In response to the sewer collapse and other wet-weather peak capacity issues, the County initiated a three-phase preventive maintenance program (Program). In the first phase, the County began a self-evaluation of the entire collection System including closed circuit television (CCTV) inspection and flow monitoring at strategic locations. This served as a foundation to initiate the second phase of the Program, a proactive sewer rehabilitation program and a pump station modernization program focusing on extending the useful life of sewer System structures. The third phase consisted of separating the County's inspection and cleaning activities to increase efficiency and reduce Sanitary Sewer Overflows (SSO's).
As the Program progressed, senior management recognized the need to provide additional engineering support and to improve communication between field and planning personnel to continuously support System management. To address these issues, management developed a comprehensive work plan that included:
Outsourcing of sewer lining and easement clearing work
Discontinuing ineffective repair and rehabilitation efforts
Conducting a detailed System capacity analysis
Developing an automated System inventory by its planning engineers
Implementing the field use of new technologies (SCADA, 360 degree TV cameras, and a computerized Sewer Maintenance Management System).
In addition, the Program also included improved financial planning techniques, integrating System revenue/cost, funding, and financing concepts to ensure that capital improvement requirements for the sewer rehabilitation program could be met on a pay-as-you-go basis. By proactively integrating engineering, finance, and operations and maintenance considerations, the County established an effective preventive maintenance program as well as the financial position to support long-term funding needs.
The County continues to develop integrated System management tools to support the broad range of wastewater management objectives. To assist managers in financial planning, the County uses both a 5-year financial forecast and a 25-year financial plan to evaluate the impacts of operation and maintenance records and capital budgets on System customers. Another planned step, linking GIS and asset maintenance records with the Capital Improvement Program (CIP), will provide County staff with more efficient access to asset management data. In the future, The County envisions a data information system that will link equipment maintenance histories, capacity utilization, real-time locations of SSO's, and asset features in an integrated decision support network for System managers.
With more than ten years of financial planning experience in support of an evolving asset management program, the County recognizes substantial benefits. The Program's integrated approach to asset management has stabilized annual operational and maintenance costs and largely eliminated the need to conduct large-scale reactive maintenance projects. More importantly, annual SSO occurrences have fallen well below industry averages.
On average, annual operating and maintenance charges average 9 million while preventive maintenance and rehabilitation expenditures and another 6 million a year. Combined, these expenses average slightly less than 15% of the Fairfax County Wastewater Management Program's annual expenditures. The competitive sewer charges are adequate to cover pay-as-you-go sewer infrastructure capital costs in addition to the traditional operation and maintenance and debt service payments for treatment plant upgrade and expansion projects. And as part of the rate structure design, the debt coverage ratio is routinely greater than 2.0, evidence that funds are available after paying operating and debt expenses to support an aggressive System rehabilitation Program.
Document Type: Research Article
Publication date: January 1, 2002
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