1,3-Dichloropropene Mi t igat ion and Pi lo t

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

2Agenda

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

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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.

1,3-Dichloropropene(1,3-D)

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o Options Generally Available to Address Acute Exposures:o Increase distance between application and sensitive receptorso Limit amount of 1,3-D applied o Increase soil moisture requirementso Require use of lower-emitting application methods

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.

Mit igat ion Approach

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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 fumigation1.

Mit igat ion Approach

1 DPR Posted Mitigation Document:https://www.cdpr.ca.gov/docs/risk/rcd/13-d_pilot_mitigation_options_march_2020.pdf

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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 depthso Increasing soil moistureo Complete and partial TIF tarpingo Application rate reductionso Acreage limitso Setbacks from occupied sensitive sites

Pilot Program

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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.

Pilot Program

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P i lot Program and AB 617 Interact ion

Quest ions?

Edgar Vidrio, ChiefEnvironmental Monitoring Branch

California Department of Pesticide Regulation

Edgar.Vidrio@cdpr.ca.gov

Thank You.