1,3-Dichloropropene Mitigation and Pilot Program E d g a r V i d - PowerPoint PPT Presentation

1,3-Dichloropropene Mitigation and Pilot Program E d g a r V i d r i o J u l y 9 , 2 0 2 0 S C I E N T I F I C R E V I E W PA N E L O N T O X I C A I R C O N TA M I N A N T S

Agenda 2 1 . B a c k g r o u n d 2 . M i t i g a t i o n A p p r o a c h 3 . P i l o t P r o g r a m 4 . C o n n e c t i o n o f P i l o t P r o g r a m t o A B 6 1 7 s e l e c t e d c o m m u n i t y : S h a f t e r 5 . Q & A

3 1,3-Dichloropropene(1,3-D) o Pre-plant soil fumigant used to control nematodes, insects, and disease organisms. o Major uses in California include fruit and nut trees, strawberries, grapes, and carrots crops. o Listed as a restricted material and requires a permit from the local county agricultural commissioner to apply. o Various mitigation measures to control exposure to 1,3-D have been in place since 1995. o DPR’s is proposing additional requirements focused on reducing short-term acute risk to children and infants.

4 Mitigation Approach o Options Generally Available to Address Acute Exposures: Increase distance between application and sensitive receptors o Limit amount of 1,3-D applied o Increase soil moisture requirements o Require use of lower-emitting application methods o o DPR used air monitoring data in combination with computer modeling (HYDRUS and AERFUM) to identify various mitigation measures. o Computer modeling indicates that use of totally impermeable film (TIF) tarps results in minimal additional mitigation measures needed to remain below regulatory targets.

5 Mitigation Approach o Use of TIF tarps is not feasible for all crops in SJV; DPR is exploring alternative options to reduce 1,3-D emissions to a level comparable to TIF tarps. o US EPA and DPR offer a 60% buffer zone reduction credit when TIF tarps are used in certain fumigant applications. o Computer modeling shows that 60% emission reduction equates to at least a 60% buffer zone reduction for most field sizes or application rates. o For this mitigation effort, DPR aims to reduce 1,3-D emissions by at least 60% compared to the standard 18” depth untarped application method. o DPR has identified several options that result in 1,3-D emission reductions of at least 60% compared to a standard fumigation 1 . 1 DPR Posted Mitigation Document: https://www.cdpr.ca.gov/docs/risk/rcd/13-d_pilot_mitigation_options_march_2020.pdf

6 Pilot Program o Considerations: o 1,3-D is extensively used [~12.6m lbs. applied (2011-2015)]. o No commercial-scale alternative currently available. o Proposed mitigation measures could be costly. o Not all proposed measures may be feasible or achieve the desired emission reductions. o Pilot Program to start in Fall 2020 in selected high-use areas near the towns of Delhi (Merced and Stanislaus Counties), Parlier (Fresno County), and Shafter (Kern County). o The Pilot Program may include the following emissions reduction options: o Fumigant injection at deeper soil depths o Increasing soil moisture o Complete and partial TIF tarping o Application rate reductions o Acreage limits o Setbacks from occupied sensitive sites

7 Pilot Program o Pilot Program Objectives: o To collect and evaluate monitoring data from new methods to validate computer modeling estimates, and o To evaluate feasibility of proposed mitigation options, and o To evaluate effectiveness of mitigation options aimed towards reducing emissions of 1,3-D for statewide implementation. o Air monitoring efforts during Pilot Program: o Weekly ambient air monitoring at a station within Pilot Program area. o Application-site monitoring studies to measure and validate emissions (flux) from proposed application methods.

8 Pilot Program and AB 617 Interaction

Questions? Thank You. Edga Edgar Vidr Vidrio, Chief Environmental Monitoring Branch California Department of Pesticide Regulation Edgar.Vidrio@cdpr.ca.gov