Provisional Models and Tools Used in EPA’s Pesticide Endangered Species Biological Evaluations

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Introduction

Models and tools available on this webpage were developed for use in EPA’s pesticide biological evaluations (BEs) and are provided to allow the public access to these tools. Given that the scientific methods are continuing to evolve, EPA anticipates receiving input on these tools as they are used to support Endangered Species Act (ESA) consultations with U.S. Fish and Wildlife Service and National Marine Fisheries Service (the Services). EPA will consider public comments during these consultations and will incorporate input as appropriate. EPA may revise these tools as the Agency continues to use them to develop BEs and support ESA consultations. EPA also intends to make any updated versions of these tools available.

Other models and tools that EPA has developed and used for specific pesticide active ingredients are available on EPA’s webpages for individual BEs, which can be found here. EPA also uses a suite of standard risk assessment models to evaluate potential ecological exposure and risks to aquatic and terrestrial organisms to support pesticide registration and registration review decisions. Those models are available here.

Plant Assessment Tool (PAT)

The Plant Assessment Tool (PAT) is a mechanistic model that incorporates environmental fate and transport data to estimate pesticide concentrations in terrestrial, wetland, and aquatic plant habitats. PAT uses exposure estimates generated in the Pesticide in Water Calculator (PWC) version 2.001 and spray drift estimates from AgDRIFT® to calculate terrestrial, wetland, and aquatic exposures and risk quotients. PAT is implemented in Python and includes a graphical user interface, formation/decline calculations for the wetland and aquatic plant exposure zones, and increased compatibility for different PWC file inputs.

PAT v2.7.1

PAT version 2.7.1 replaces PAT version 2.7. PAT v2.7.1 corrects an error found in the internal batch file import routine, which under certain circumstances could have led to inaccurate results. After reviewing the methods of all EPA chemical teams using the model, the Agency is confident the bug did not affect their calculations. The PAT v2.7 manual is relevant for PAT v2.7.1.  

  • PATv2.7.1.zip (zip)
    • PAT is for a Windows environment. The zipped file contains the follow files:
      • PAT User Manual v2.7.pdf
      •  pwc batch tool v3.0.xlsx
      • PATv2.7.1 folder
        • PAT batch template external.csv
        • PAT batch template internal and single.csv
        • PAT_GUI.py
        • patv2_7_1.py
        • plant endpoints.csv
        • Plant_classification_2.csv
        • README.md
        • sdf.csv

PWC Scenarios for use with PAT v2.7.1

Prior to the release of new PWC Scenarios for Surface Water assessments, PAT v.2.7.1 made use of standard scenarios identifiable by the .scn file extension. Users can now find those standard scenarios and supporting weather files (identifiable by the .dvf file extension) here. 

Additionally, EPA developed wetland scenarios that represent the Standard PWC scenarios (include “STD” in their file names) with input parameters modified to represent the wetland waterbody under the custom waterbody option. These parameters are used in the Variable Volume Water Model (VVWM) Custom Waterbody inputs within the PWC to simulate estimated environmental concentrations of a pesticide in wetland habitats. More information on the use of Wetland Scenarios in PWC for PAT modeling is available in the PAT User Manual for v2.7.

PAT v2.8

PAT version 2.8 replaces PAT version 2.7.1. PAT v2.8 adds compatibility with the new PWC scenarios for surface water modeling and changes the assumption of the wetland benthic depth to 5 cm from 15 cm to match the benthic depth assumption in the PWC. Users should refer to the PAT-Compatible Scenarios for modeling outputs in PWC 2.001 that are used in PAT v2.8. 

  • PATv2.8.zip (zip)
    • PAT is for a Windows environment. The zipped file contains the follow files:
      • PAT User Manual v2.8.pdf
      • pwc batch tool v3.0.xlsx
      • PATv2.8.zip
        • PAT batch template external.csv
        • PAT batch template internal and single.csv
        • PAT_GUI.py
        • patv2_8.py
        • plant endpoints.csv
        • Plant_classification_2.csv
        • README.md
        • sdf.csv

PAT-Compatible PWC Scenarios for use with PAT v2.8

EPA developed scenarios that represent the new PWC scenarios for surface water modeling with input parameters modified to represent the wetland waterbody under the custom waterbody option. These parameters are used in the Variable Volume Water Model (VVWM) Custom Waterbody inputs within the PWC to simulate estimated environmental concentrations of a pesticide in wetland habitats. These scenarios are PAT-Compatible and are identifiable by the ScenarioName_mod.scn2 naming and file extension. Updated weather files for PWC modeling with PAT-Compatible scenarios are also available here (identifiable by the .wea file extension).  More information on the use of PAT-Compatible Scenarios in PWC for PAT modeling is available in the PAT User Manual for v2.8.

Overlap Tools

There are two tools available for generating the overlap for listed species assessments: the Use Data Layer (UDL) overlap tool and the Census of Agriculture (CoA) overlap tool. These tools provide conservative overlaps with pre-processed elements to efficiently assess listed species. These tools may be used in tandem, as they may both provide refinement based on different principles.

Census of Agriculture (CoA) Overlap Tool

The Census of Agriculture (CoA) Overlap Tool is designed for use in ESA assessments to maximize efficiency in estimating the potential overlap with use sites and listed species range and designated critical habitats. The tool uses county-level crop acreage data from the USDA CoA and species location spatial data from the Services to determine an upper-bound maximum potential percent overlap. The CoA tool (version 1.1) is implemented in Python with a graphical user interface for selecting use sites and geographic restrictions. This tool also accounts for off-site transport of pesticide residues post-application.

Version 1.1 replaces version 1.0 and incorporates updated species range and critical habitats, projection methods, and additional outputs.

Census of Agriculture Tool (zip)

Use Data Layer (UDL) Overlap Tool

The UDL Overlap tool supports ESA assessments by summarizing the co-occurrence between potential pesticide use sites and listed species location. This tool uses GIS based datasets when considering co-occurrence and compiles results as a percent overlap (i.e. the area of potential use and off-site movement found within the species location divided by the total area for the species). Generated using several publicly available land cover datasets, the EPA Use Data Layers (UDLs) delineate the potential pesticide use locations and areas where off-site movement could occur following application. The Services provide the datasets delineating species range and designated critical habitat. This tool generates outputs for species ranges and designated critical habitats separately and summarizes the resulting percent overlaps by use and off-site distance. When assessing impacts to threated and endangered species, the outputs from this tool are utilized to set the overlap category as low (<5% but>1%), medium(<10% but >5%) or high (>10%).

Magnitude of Effect Tool (MAGtool)

MAGtool v2.4

The Magnitude of Effect Tool (MAGtool) was created to help determine the magnitude of the effect of potential pesticide use on listed species. The output of the tool provides an estimate of the number of individuals of a given listed species that could potentially be impacted by a pesticide due to mortality losses or adverse sublethal effects. The tool also predicts the number of individuals of the listed species potentially impacted due to losses in their prey, pollination, habitat or dispersal (PPHD) vectors. The MAGtool combines toxicological information, species traits, exposure analysis and spatial results into one tool. Results may be generated for the species or critical habitat under different scenarios including variations in assumptions related to exposure, extent of pesticide usage on a crop (if available), and extent of pesticide usage for the species.

The MAGtool has gone through several iterations over the years. Previous versions of the tool are available on the webpages for the individual chemical BEs that used those versions, available here. This most recent update to the MAGtool is described in the user manual and includes predictions of preliminary jeopardy or adverse modification determinations as part of the output, based on the criteria described in the model documentation. 

A zip file, which contains the aquatic and terrestrial MAGtools, input files templates, as well as a Read Me file and associated model documentation is available here:  MAGtool v2.4 (zip)

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Last updated on August 21, 2024