UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

DATE: 

SUBJECT: 

FROM: 

TO: 

September 28,2011 

Transmittal memo for the FIFRA Scientific Advisory Panel Consultation on the 

Two-dimensional Exposure Rainfall-Runoff Assessment (TERRA) Watershed 

Model and Its Use in the FIFRA Ecological Risk Assessment for Antimicrobial 

Uses of Copper 

Joan Harrigan-Farrelly, Director 

Antimicrobials Division (7510P) 

And 

Donald Brady, Ph.D., Director ~ Environmental Fate and Effects ElfvI 

Fred Jenkins, Ph.D. 

Designated Federal Official 

FIFRASAP 

Office of Science Coordination and Policy (7201 M) 

This memo transmits documents compiled or developed by EPA in preparation for the October 

25-26,2011 meeting of the FIFRA Scientific Advisory Panel (SAP) on the Two-dimensional 

Exposure Rainfall-Runoff Assessment (TERRA)l Watershed Model and Its Use in the FIFRA 

Ecological Risk Assessment for Antimicrobial Uses of Copper. The American Chemistry 

Council (ACC) submitted an aquatic exposure assessment for antimicrobial uses of copper using 

the TERRA model, which is also being transmitted. ACC's aquatic exposure assessment is 

unique because it was conducted on a watershed scale using a new model (TERRA). The Office 

I Please note that the name of the model under review was recently changed from Two-dimensional Runoff, 

Erosion, and Export (TREX) to Two-dimensional Exposure and Rainfall-Runoff Analysis (TERRA). This name 

change was made to avoid confusion with the Terrestrial Residue Exposure (T-REX) model that OPP uses to 

estimate pesticide concentrations for avian and mammalian food items (United States Environmental Protection 

Agency. 2008. Terrestrial Residue Exposure Model Version 1.4.1. www.epa.gov/oppefedlimodels/terrestriaVtrex). 
of Pesticide Programs (OPP) is seeking consultation from the SAP on the TERRA model and the 

appropriateness of its use in future FIFRA ecological risk assessments for antimicrobial uses of 

copper. 

OPP is submitting a large amount of background materials for SAP Panel member consideration, 

including the files necessary to run to the TERRA model. Several documents being submitted to 

the SAP were developed by ACC and Hydroqual Inc. or are from the open literature. The 

background materials will be available (1) in docket EPA-HQ-OPP-2011-0582 at 

regulations.gov, (2) in the general literature to the public or (3) provided electronically in PDF 

format to Panel members. Literature articles cannot be posted to the docket due to copyright 

restrictions. A summary of the materials being submitted to the panel for consideration and 

where these documents can be located is provided in Tables 1 and 2 below. 
Table 1. Background Material for October 25-26, 2011 Scientific Advisory Panel Meeting on the TERRA M

Material Transmitted File Name 

FIFRA 10(g) 

or © 

Protected 

Availability 

EPA-HQOPP2011-0582 DVD to Panel Members Other 

Charge Questions to the SAP TERRA SAP Charge Questions Final 9.28.11.pdf No • • EPA Background Document TERRA SAP EPA Background Document FINAL 9.28.11.pdf No • • HydroQual Inc. for American Chemistry Council Background Document 

Velleux-et-al-Antimicrobial-CuSummary-27September2011.pdf No • • 

Copper Transport and Fate Simulations and Evaluation of Estimated Environmental Concentrations for Copper-Based Antimicrobial Compounds 

Cu Transport_Fate Simulation Final Rpt 122109.pdf No • • 

TERRA Model Set-Up Instructions TERRA_TREX -Training-Guide- CompileCode-RunModel.pdf No • • http://www.eng

_old/Projects/TRTREX-Home.ht

TERRA Source Code 

Files included in the “TERRA_TREX-Source-Code Folder” 

No • 

http://www.eng_old/Projects/TRTREX-Home.ht

TERRA Example Simulations 

Files included in the “TERRA_TREX-Example Simulations Folder” 

No • 

http://www.eng_old/Projects/TRTREX-Home.ht

TERRA Watershed Modeling Framework User’s Manual 

TERRA_TREX-User-Manual-10-Jan-2011.pdf No • • 

http://www.eng_old/Projects/TRTREX-Home.ht

Literature Review: Comparison of Common Watershed Models for Rainfall, Runoff Sediment Transport, and Contaminant Transport and Fate 

Watershed-Modeling-LiteratureReview.pdf No • •
Table 2. Background Literature for October 25-26, 2011 Scientific Advisory Panel Meeting on the TERRA 

Journal Article Citation 

FIFRA 

10(g) or © 

Protected 

E

O

Raster-Based Hydrologic Modeling of SpatiallyVaried Surface Runoff Julian, P.Y., B. Saghafian, and F. L. Ogden. 1995. Water Resource Bulletin. 31:523-536. Yes The Two-Dimensional Upland Erosion Model CASC2D-SED 

Johnson, B.E., P.Y. Julian, D.K. Molnar, and C. C. Watson. 2000. Journal of the American Water Resources Association. 36: 31-42. Yes 

Peak Flow Forecasting with Radar Precipitation and the Distributed Model CASC2D 

Jorgeson, J., and P. Julien. 2005. International Water Resources Association Water International, 30(1): 40-49. Yes 

Simulation of Metals Transport and Toxicity at a Mine-Impacted Watershed: California Gulch, Colorado 

Velleux, M., P.Y. Julien, R. Rojas-Sanchez, W.H. Clements, and J. England, J. 2006. Environmental Science and Technology, 40(22):6996-7004. 

Yes 

Two-Dimensional Simulations of Extreme Floods on a Large Watershed 

England, J., M. Velleux, and P. Julien. 2007. Journal of Hydrology, 347(1):229-241. Yes 

Grid Scale Effects on Watershed Soil Erosion Models 

Rojas, R., M. Velleux, P.Y. Julian, and B. E. Johnson. 2008. Journal of Hydrologic Engineering. 13:9 793-802. Yes 

TREX: Spatially distributed model to assess watershed contaminate transport and fate 

Velleux, M., J. England, and P. Julien. 2008. Science of the Total Environment, 404(1):113-128. Yes 

Comparison of Green-Ampt and Curve Number Methods on Goodwin Creek Watershed Using SWAT 

King, K.W., J.G. Arnold, and R.L. Bingner. 1999. Transactions of the American Society of Agricultural Engineers 42(4): 919-925. Yes 

Metals fate and transport modeling in streams and watersheds: state of the science and USEPA workshop review 

Carsuso, B.S., T.J. Cox, R.L Runkel, M.L. Velleux, K.E. Bencala, D.K. Nordstorm, P.Y. Julian, B.A. Butler, C.N. Alpers, A. Marion, and K.S. Smith. 2008. Hydrological Processes. 22:4011-4021 

Yes 

The Biotic Ligand Model: A Historical Overview 

Paquin, P.R., J.W. Gorsuch, S. Apte, G.E. Batley, K.L. Bowles, P.G.C. Campbell, C.G. Delos, D.M. Di Toro, R.L. Dwyers, F. Galvez, R. W. Gensemer, G.G. Gross, C. Hogstand, C.R. Janssen, J.C. McGeer, R.B. Naddy, R.C. Playle, R.C. Santone, U. Schnider, 

W.A. Stubblefield, C.M. Wood, and K.B. Wu. 2002. Comparative Biochemistry and Physiology. Part C 133: 3-35. 

Yes 

 *At this time the Agency does not have copyright permission to disseminate these journal articles to the Panel members. Upon receipt the Agency will distribute the journal articles to the Panel.