This guidance is intended to assist federal, state, regional, and local environmental professionals in tracking the implementation of best management practices (BMPs) used to control urban nonpoint source pollution. Information is provided on methods for inventorying BMPs, the design and execution of sampling programs, and the evaluation and presentation of results. The more regulated and stable nature of urban areas present opportunities for inventorying all BMPs versus the statistical sampling required to assess BMP implementation for agriculture or forestry. Inventorying BMP implementation requires establishing a program that tracks the implementation or operation and maintenance of all BMPs of certain types (e.g., septic tanks and erosion and sediment control practices). The guidance can help state and local governments by providing a subset of controls, both structural and nonstructural, that can be sampled for: • inspection programs, • maintenance oversight, and • implementation confirmation. The focus of chapters 3 and 4 is on the statistical approaches needed to properly collect and analyze data that are accurate and defensible. A properly designed BMP implementation monitoring program can save both time and money. For example, the cost to determine the degree to which pollution prevention activities are conducted by an entire urban population would easily exceed most budgets, and thus statistical sampling of a subset of the population is needed. Guidance is provided on sampling representative BMPs to yield summary statistics at a fraction of the cost of a comprehensive inventory. While it is not the focus of this guidance, some nonpoint source projects and programs combine BMP implementation monitoring with water quality monitoring to evaluate the effectiveness of BMPs in protecting water quality on a watershed scale (Meals, 1988; Rashin et al., 1994; USEPA, 1993b). For this type of monitoring to be successful, the scale of the project should be small (e.g., a watershed of a few hundred to a few thousand acres). Accurate records of all the sources of pollutants of concern, how these sources are changing (e.g., new development), and an inventory of how all BMPs are operating are vital for this type of monitoring. Otherwise, it is impossible to accurately correlate BMP implementation with changes in stream water quality. This guidance does not address monitoring the implementation and effectiveness of individual BMPs. It does provide information to help program managers gather statistically valid information to assess implementation of BMPs on a more general (e.g., statewide) basis. The benefits of implementation monitoring are presented in Section 1.3.
Number of Pages
Environmental Protection Agency
Minnesota Water Research Digital Library