treated effluent. The DSSAM Model is constructed to allow dynamic decay of most pollutants; for example, total nitrogen and phosphorus are allowed to be consumed by benthic algae in each time step, and the algal communities are given a separate population dynamic in each river reach (e.g.metabolic rate based upon river temperature). Sources throughout the watershed include non-point agricultural and urban stormwater as well as a multiplicity of point source discharges of treated municipal wastewater effluent. Subsequent to the first generation of DSSAM model development, calibration and application, later refinements were made. These augmentations to model functionality focussed on increased flexibility in modeling the diel cycle and also allowed inclusion of analyzing particulate nitrogen and phosphorus. In developing DSSAM III several changes in the model operation and scope were performed. Applications Numerous different uses of the model have been made including (a)analysis of public policies for urban stormwater runoff, (b) researching agricultural methods for surface runoff minimization, (c) innovative solutions for non-point source control and d)engineering aspects of treated wastewater discharge. Regarding stormwater runoff in Washoe County, the specific elements within a new xeriscape ordinance were analyzed for efficacy using the model. For the varied agricultural uses in the watershed, the model was run to understand the principal sources of adverse impact, and management practices were developed to reduce in river pollution. Use of the model has specifically been conducted to analyze survival of two endangered species found in the Truckee River and Pyramid Lake: the Cui-ui sucker fish (endangered 1967) and the Lahontan cutthroat trout (threatened 1970). When the model is used for surface runoff reaching a stream, this pollutant input can be viewed as a line source (e.g., a continuous linear source of pollution entering the waterway). See also Nonpoint source pollution SWAT model Stochastic Empirical Loading and Dilution Model Storm Water Management Model References External links U.S. Environmental Protection Agency TMDL program for the Truckee River Final TMDL waste loads for the Truckee Basin derived from the DSSAM Model Computer-aided engineering software United States Environmental Protection Agency Hydrology Water pollution