Estimations/Loading Factors

Literature values may be used to characterize source contributions and/or pollutant load removals or reductions. Literature values represent actual conditions; these values are typically based on data observed and measured in similar regions or watershed conditions. Application of literature values often involves broad assumptions about site conditions, such as uniform distribution, percent imperviousness, connectivity, and regular maintenance. Literature values may include generalized estimations for pollutant loading, BMP removal rates, or effluent concentrations for land uses or BMPs, for example. Area-based loading factors are common literature values used to estimate pollutant source contribution by land use type. These are regionally adjusted literature values that estimate pollutant discharge (i.e., mass or concentration) from a land area (e.g., acre) for a given time (e.g., annually). Land use-based loading factors are typically specific to land use type to account for the different amounts of pollutants generated within each land use. Values rely on local storm water monitoring data and may also vary from region to region.

References for literature values include, but are not limited to:

Scale: Varies

Considerations: Methodology may be used during planning phase and implementation phase of stormwater program.