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Model Report


Last Revision Date: 07/11/2011 View as PDF
General Information Back to Top
Model Abbreviated Name:

Model Extended Name:

Model Overview/Abstract:
The Water Quality Analysis Simulation Program (WASP6), an enhancement of the original WASP (Di Toro et al., 1983; Connolly and Winfield,1984; Ambrose, R.B. et al.,1988). This model helps users interpret and predict water quality responses to natural phenomena and man-made pollution for various pollution management decisions. WASP6 is a dynamic compartment-modeling program for aquatic systems, including both the water column and the underlying benthos. WASP allows the user to investigate 1, 2, and 3 dimensional systems, and a variety of pollutant types. The state variables for the given modules are given in the table below. The time-varying processes of advection, dispersion, point and diffuse mass loading and boundary exchange are represented in the model. WASP also can be linked with hydrodynamic and sediment transport models that can provide flows, depths, velocities, and temperature, salinity and sediment fluxes.

WASP has been used to examine eutrophication of Tampa Bay, FL; phosphorus loading to Lake Okeechobee, FL; eutrophication of the Neuse River Estuary, NC; eutrophication Coosa River and Reservoirs, AL; PCB pollution of the Great Lakes, eutrophication of the Potomac Estuary, kepone pollution of the James River Estuary, volatile organic pollution of the Delaware Estuary, and heavy metal pollution of the Deep River, North Carolina, mercury in the Savannah River, GA. WASP is routinely used for TMDL determinations and waste load allocations.

Model Technical Contact Information:
Tim Wool
Watershed and Water Quality Modeling Technical Support Center
Athens, GA
Model Homepage: http://www.epa.gov/athens/wwqtsc

User Information Back to Top
Technical Requirements
Computer Hardware
Standard Desktop System. Higher performance machine maybe need for large simulations.
Compatible Operating Systems
Microsoft Windows 95 or Higher
Other Software Required to Run the Model
Optional Software Water Resources Database (WRDB). Database designed to store environmental information; WASP can query time series data from WRDB or plot model predictions vs. field data stored in WRDB.
Download Information
The WASP6 model is available to be downloaded.
Using the Model
Basic Model Inputs
Waterbody segmented in computational boxes, forcing functions such as: flow, dispersions, boundary concentrations, water temperature, light, kinetic constants and initial conditions. More complex the application the greater the input requirements.
Basic Model Outputs
User selects the output variables from the model. All model output can be viewed using a graphical/tabular post processor that is included with the model. It is easy to take results from the WASP model to other models or other software for analysis and/or publication.
User Support
User's Guide Available?
Watershed and Water Quality Modeling Technical Support Center maintains a WASP Users Manual and is included with the installation package. The Users Manual is periodically updated as the model is enhanced.

Model Science Back to Top
Problem Identification
WASP is a multi-pollutant type model. It has algorithms for:
1) conventional pollutants (nitrogen, phosphorus, dissolved oxygen, algae/periphyton, and sediment diagenesis);

2) Organic chemicals (3 chemicals and 3 sediment types) that can undergo sorption, volatilization, photolysis, biodegradation, ionization, hydrolysis; and

3) Mercury (Elemental Hg, Divalent Hg, Methyl Hg, 2 solids).
Summary of Model Structure and Methods
WASP is a mass balance model which allows the user to break a waterbody down into a series of control volumes. Depending upon the sub model selected the user can investigate conventional water quality problems such as: nitrogen, phosphorous, nutrients, dissolved oxygen, BOD, algae, periphyton, and salinity.

WASP also includes an organic chemical model that is capable of simulating the fate and transport of organic chemicals and simple metals. The model includes interactions `with three sediment types and allows reaction products for up to three chemicals.

Governing equations are solved numerically, both in space and time.

Model Evaluation
WASP has been tested against analytical solutions, and has been peer reviewed by such groups as the National Council on Air and Stream Improvement (NCASI), Army Corp of Engineers, South Florida Water Management District.

The model has an application history that spans 30 years and is used routinely in the US and world.

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