The stormwater runoff that doesn’t go to water treatment plants remains untreated and is transported through municipal separate storm sewer systems and can then be discharged into local water bodies. Since the 1987 Clean Water Act, the U.S. Environmental Protection Agency has regulated non-point-source pollution from stormwater. To measure surface runoff volume, municipalities have used stormwater best-management practice. While the EPA does require inspection and maintenance, there has been little research on the type and frequency of maintenance required and the costs involved. Most BMP projects only consider initial construction, but not life-cycle expenses.
With the disparate nature of current BMP maintenance tracking, researchers Ruochen Dong, Jacob D. Nelson, Savannah L. Cummins, and Jonathan L. Goodall tackled the need for a comprehensive database. This work focuses on assessing data stored in the Virginia Department of Transportation’s Highway Maintenance Management Systems. Their research, “Tracking the Cost of Maintaining Stormwater Best-Management Practice Facilities: The Role of Database Design and Data Entry Best Practices,” identifies costs associated with routine and nonroutine maintenance and the related challenges to analyzing data. Not surprisingly, having this data is useful for identifying the type, frequency, and cost of maintenance activities performed and will ultimately aid in determining life-cycle costs for BMPs. Further study is required, but the authors indicate that normalizing some of the tasks around BMPs could increase the efficiency of maintenance. Learn more about this research in the Journal of Sustainable Water in the Built Environment, at https://doi.org/10.1061/JSWBAY.SWENG-506. The abstract is below.
Abstract
Best-management practices (BMPs) are widely used to mitigate non-point source pollution from stormwater discharges. However, long-term operation and maintenance of stormwater BMPs have been an afterthought before the compliance requirement detailed in the Municipal Separate Storm Sewer Systems (MS4) permit. As a result, there is limited information available on the actual cost of maintaining BMPs. The objective of this research is to analyze the stormwater maintenance tracking database created by the Virginia Department of Transportation (VDOT) to (1) complete a preliminary cost analysis of routine and non-routine maintenance with respect to VDOT district or practice type and to (2) identify challenges encountered when processing the data for analysis and provide potential solutions relevant to other entities tracking BMP maintenance costs. The cost analyses presented in this study are preliminary based on the currently available data; however, they show insightful trends among the data collected by VDOT from 2018 to 2020. Namely, preventative maintenance actions appeared to greatly lower the need for non-routine or major repairs within the Virginia districts. Routine and non-routine maintenance costs were, on average, $375 per task and $812 per task, respectively. The cost of major repairs was approximately $63,000 per case. The most expensive routine maintenance tasks were basin BMPs (constructed wetlands, wet ponds, and extended detention ponds), averaging $400 per task. The most expensive non-routine maintenance tasks were infiltration BMPs (permeable pavement, infiltration practices, and bioretention), averaging $1,123 per task. Basin BMPs had the largest annual upkeep at $1,100 per year. Approaches for extending the current database design used by VDOT are discussed to address challenges identified through the analysis including data incompleteness, overloaded work orders, and the lack of controlled vocabulary. These lessons learned regarding database design can be useful to other agencies seeking to track and analyze stormwater maintenance activities and associated costs.
Get the details on how to more effectively track data to monitor municipal separate storm sewer systems in the ASCE Library: https://doi.org/10.1061/JSWBAY.SWENG-506.
