Pollutants

GeoSWMM can simulate the generation, inflow and transport of any number of user-defined pollutants. Required information for each pollutant includes: 

·       Pollutant name

·       Concentration units (i.e., milligrams/liter, micrograms/liter, or counts/liter) 

·       Concentration in rainfall

·       Concentration in groundwater

·       Concentration in direct infiltration/inflow

·       Concentration in dry weather flow

·       First-order decay coefficient.

Co-pollutants can also be defined in GeoSWMM. For example, pollutant X can have a co-pollutant Y, meaning that the runoff concentration of X will have some fixed fraction of the runoff concentration of Y added to it.

Pollutant buildup and washoff from the subcatchment areas are determined by the land uses assigned to those areas. Input loadings of pollutants to the drainage system can also originate from external time series inflows as well as from dry weather inflows.