Bergeson & Campbell, P.C. serves small, medium, and large pesticide product registrants and other stakeholders in the agricultural and biocidal sectors, in virtually every aspect of pesticide law, policy, science, and regulation.

By Jason E. Johnston, M.S.

On May 23, 2018, the U.S. Environmental Protection Agency (EPA) held an “Environmental Modeling Public Meeting” (EMPM).  As stated in the April 12, 2018, Federal Register notice announcing the meeting, the “EMPM provides a public forum for EPA and its stakeholders to discuss current issues related to modeling pesticide fate, transport, and exposure for pesticide risk assessments in a regulatory context.”  The overall theme of the EMPM was the quantitative use of surface water monitoring data. 

The morning session featured a series of presentations by representatives from EPA, the U.S. Geological Survey (USGS), and the Washington State Department of Agriculture concerning the development of a framework to use surface water monitoring data quantitatively in pesticide risk assessments.  A major focus of the presentations was the exploration and evaluation of the capabilities of the USGS recently-developed model SEAWAVE-QEX to improve the robustness of surface water monitoring datasets so that they might be used in pesticide risk assessments.  Further public presentations on the evaluation and development of the framework are scheduled at the American Chemical Society meeting to be held on August 19-23, 2018, in Boston, Massachusetts.  There are plans to hold a Scientific Advisory Panel meeting on the framework in 2019, but no exact date has been set. 

The afternoon session consisted of presentations by representatives of the registrant community.  Topics addressed included developments in the use of surface water monitoring data in quantitative risk assessment, a statistical analysis of non-targeted monitoring data at the watershed scale, the creation of a curated database of water and sediment monitoring data for synthetic pyrethroids, the use of high-resolution spatial and temporal monitoring data to parameterize watershed scale drift exposure predictions, and an evaluation of model predictability using monitoring data and refined pesticide use at the watershed level. 

Presentations from the May 23, 2018, EMPM will soon be posted to Docket No. EPA-HQ-OPP-2009-0879, accessible at www.regulations.gov.

Registrants should monitor these activities, as this effort at EPA represents a potential shift away from the current reliance exclusively on estimated water concentrations in quantitative human health and ecological risk assessments. 


 

By  Lisa M. Campbell and Susan Hunter Youngren, Ph.D.

The California Department of Pesticide Regulation (DPR) announced on February 26, 2015, a revision to the process for evaluation of the potential for a pesticide to move off-site into surface water when the pesticide is used in an urban area. The former evaluation method followed the U.S. Environmental Protection Agency (EPA) approach with California specific parameters. This revision will continue to use the EPA approach but allow incorporation of a module specific for California urban settings.

Potential adverse impacts on surface water from use of pesticides are assessed in California by DPR’s Environmental Monitoring Branch’s Surface Water Protection Program (SWPP) using EPA methodology. The SWPP uses the EPA evaluation method for proposed agricultural pesticide registrations based on PE5 (PRZM-EXAMS version 5) and Tier 2 modeling scenarios but there have been no consistent methods for assessing potential pesticide runoff on impervious surfaces in an urban setting. The new California urban module includes the following improvements that are designed to be further representative of urban conditions in California:

* Introduction of four types of surfaces by permeability and water sources;
* Consideration of pesticide transport induced by dry-weather runoff from impervious surfaces;
* Separation of impervious and pervious portions in the modeling scenarios;
* Use of prescheduled lawn irrigation;
* Characterization of residential and commercial/industrial areas to reflect California urban conditions; and
* Aggregations of water, sediment, and pesticide yields for the urban watershed.

The urban model is designed particularly for evaluating pesticides applied outdoors in areas with large amounts of impervious surfaces such as residential areas, commercial/industrial facilities, and highway and road rights-of-way applications. Pesticide products of interest would be those that have the potential for impact to surface waters through overspray to impervious surfaces in these areas