DSSAM Model

<h2 id="development-history">Development history</h2>

<p>Impetus to derive a quantitative prediction model arose from a trend of historically decreasing river flow rates coupled with jurisdictional and tribal conflicts over water rights as well as concern for river biota.  When expansion of the Reno-Sparks Wastewater Treatment Plant was proposed, the EPA decided to fund a large scale research effort to create  simulation software and a parallel program to collect field data in the Truckee River and Pyramid Lake.  For river stations water quality measurements were made in the <a href="/facts/Benthic_zone/N3lM6P7I">benthic zone</a> as well as the topic zone; in the case of <a href="/facts/Pyramid_Lake_(Nevada)/NoLlAHd8">Pyramid Lake</a> boats were used to collect grab samples at varying depths and locations.  Earth Metrics conducted the software development for the first generation <a href="/facts/Computer_model/Re6o8vzN">computer model</a> and collected field data on water quality and flow rates in the Truckee River.  After model calibration, runs were made to evaluate impacts of alternative land use controls and discharge parameters for treated <a href="/facts/Effluent/HPS1Akbo">effluent</a>.
</p><p>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 <a href="/facts/Alga/U1ftVKU3">algae</a> 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.
</p><p>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 <a href="/facts/Diel/q7gBSIDk">diel</a> 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.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
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<h2 id="applications">Applications</h2>
<p>Numerous different uses of the model have been made including (a)analysis of public policies for urban <a href="/facts/Stormwater/CX4EcIWu">stormwater</a> runoff, (b) researching agricultural methods for <a href="/facts/Surface_runoff/zPxoaA0D">surface runoff</a> minimization, (c) innovative solutions for non-point source control and d)engineering aspects of treated wastewater discharge.  Regarding <a href="/facts/Stormwater_runoff/zPxoaA0D">stormwater runoff</a> in <a href="/facts/Washoe_County%2c_Nevada/dRQ0NRUJ">Washoe County</a>, the specific elements within a new <a href="/facts/Xeriscape/CVyAwdQg">xeriscape</a> 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 <a href="/facts/Endangered_species/L7cIweSW">endangered species</a> found in the <a href="/facts/Truckee_River/L4JjvFAP">Truckee River</a> and <a href="/facts/Pyramid_Lake_(Nevada)/NoLlAHd8">Pyramid Lake</a>: the <a href="/facts/Cui-ui/sYdyGlns">Cui-ui</a> <a href="/facts/Catostomidae/XNjcIQ0R">sucker fish</a> (endangered 1967) and the <a href="/facts/Lahontan_cutthroat_trout/CgLP1BCV">Lahontan cutthroat trout</a> (threatened 1970).  When the model is used for <a href="/facts/Surface_runoff/zPxoaA0D">surface runoff</a> reaching a stream, this pollutant input can be viewed as a <a href="/facts/Line_source/E84Yhgyf">line source</a> (e.g., a continuous linear source of pollution entering the waterway).
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<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Nonpoint_source_pollution/uQHNGYC4">Nonpoint source pollution</a></li>
<li><a href="/facts/SWAT_model/Go8TDd9a">SWAT model</a></li>
<li><a href="/facts/Stochastic_Empirical_Loading_and_Dilution_Model/mV9uxI7N">Stochastic Empirical Loading and Dilution Model</a></li>
<li><a href="/facts/Storm_Water_Management_Model/SIQMHgKV">Storm Water Management Model</a></li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/20060420083848/http://www.epa.gov/OWOW/tmdl/cs13/cs13.htm">U.S. Environmental Protection Agency TMDL program for the Truckee River</a></li>
<li><a href="https://web.archive.org/web/20061006054332/http://ndep.nv.gov/bwqp/truckee1.pdf">Final TMDL waste loads for the Truckee Basin derived from the DSSAM Model</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>C.M.Hogan, Marc Papineau et al. Development of a dynamic water quality simulation model for the Truckee River, Earth Metrics Inc., Environmental Protection Agency Technology Series, Washington D.C. (1987) <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Guidance for Water Quality-Based Decisions: The TMDL Process (Report). Washington, D.C.: U.S. Environmental Protection Agency (EPA). April 1991. EPA 440/4-91-001. <a href="http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=00001KIO.TXT" target="_blank">http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=00001KIO.TXT</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>John Warwick, Truckee River spill model, University of Nevada-Reno (2002). <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Brock, J.T., C.L. Caupp, and H.M. Runke,  Evaluation of water quality using DSSAM III under various conditions of nutrient loadings from municipal wastewater and agricultural sources: Truckee River, Nevada.. Bureau of Water Quality Planning, Nevada Division of Environmental Protection, Carson City, Nevada (1992) <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
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DSSAM Model open-in-new

DSSAM Model