# Department of Pesticide Regulation

Mar y -A nn W a r m erdam 

### M E M O R A N D U M Arnold Schwarze negger Director Go v e rno r

TO: Randy Segawa, Environm ental Program Manager I Environm ental Monitoring Branch FROM: Bruce Johnson, Ph.D., Research Sc ientist III Original signed by Environm ental Monitoring Branch (916) 324-4106 DATE: Septem ber 24, 2007 SUBJECT: RECALCULATION OF 1,3- DICHLOROPROPENE EMI SSION FACTORS A previous m e morandum (Johnson 2006) calculated emission factors for shank-injected 1,3-dichloropropene based on two deep and two shallow flux studies (Gillis and Dowling, 1998; Knuteson et al., 1992; Knuteson et al., 1995). The m e thod required assump tion of a linear relationship between depth and cumu lativ e flux. W ith that assump tion, the four studies were com b ined to es timate a flux at 12 inches and 18 inches of depth. A simp ler approach, and one not requiring the assump tion of a linear relationship, is to divi de the four studies into two groups: shallow and deep and take simple averages for the tw o groups. Table 1 provides the revised cal culations and along with the previously values for comparison. The result in creas ed the s h allow facto rfrom 61% to 65% and increased the shallow with water treatm ents from 41% to 44%. The deep inje ction m e thod decreased from 41% to 26%. The recalculation does not a ffect the drip m e thod.

T a ble 1. S h ank inject ion met hods f o r1,3- d, r ecalc u la tion of emission f act o r s. Pe rcen t a ge b a s e d on Jo hn so n Rev i se d Me t h o d (20 06) Percen t a g e s No t es: Shallowinj e c t ion 6 1 6 5 B as ed on av er age of 2 s hallo w s t udie s Shallowinj e c t ion w / 3 w a tertr eatm ents 4 1 44 Bas ed on red u cing s hallowbr oadc as t by 33% Deep inje ction w / high per m eability tar p orno tar p - b r oadc as t 4 1 26 Bas ed on av er age of 2 deep s t udies

100 1 I Street • P.O. Box4015 • Sacramen to, Californ i a 9 581 2-40 15 • www
. c dpr.c a.g o v A Depart m e n t of the California En vironm ent al Protection Agency Prin te d o n re cycled p ap e r , 10 0 % p o s t-consu m e r--p ro ce sse d ch lorin e - fre e
.Randy Segawa Septem ber 24, 2007 Page 2

References Gillis, Matth e w J. and Kathryn C. Dowling. 1998. Effect of broadcas t an d row application m e thods on 1,3-dichloropropene emissions. Dow AgroSciences LLC, 9330 Zionsville Rd., 308/2E. Indianapolis, IN. Bolsa Research Pr oject #:BR730, Dow AgroSciences Study ID #: HEA95177. Johnson, Bruce. 2006. Mem o randum to Randy Sega wa dated Nove m b er 30, 2006 on Calculation of e mission potential factors for 1,3-dichloropr opene for five areas for periods from May 1 through October 31. Knuteson, Jam e s A., Da vid G. Petty, and Brad ley A. Shurdet. 1992. Field volatility of 1,3-dichloropropene in S a linas Valley California. DowElanco, Midland, MI. Knuteson, J.A., H.E. Dixon-Wh ite and D.G. Petty. 1995. Field volatility of 1,3-dichlororopropene in San Joaquin Valley California. DowElanco ENV93063.

### APPENDIX 3 Application Method Adjustm e nt Factors and Method Use Fractions for 1,3-Dichloropropene

# Department of Pesticide Regulation

Mar y -A nn W a r m erdam 

### M E M O R A N D U M Arnold Schwarze negger Director Go v e rno r

TO: Randy Segawa, Agriculture Program Supervisor IV Environm ental Monitoring Branch FROM: Bruce Johnson, Ph.D., Research Scien tist III Original signed by Environm ental Monitoring Branch (916) 324-4106 DATE: Nove m ber 30, 2006 SUBJEC T: CALC ULATION OF E M I SSION POTENTIAL FACT ORS FOR 1,3-DICHLOROPROPENE FOR FIVE AREAS FOR PERIODS FROM MAY 1 THROUGH OCTOB ER 3 1 Introductio n Emissions of volatile organic com pounds from pesticide applications are estim ated by the Departm e nt of Pesticide Regulation as follows: VOC e mitte d ( l bs) = EP * lbs pro duc t applie d (1) The Emission Potential (EP) is that fraction of a product that is a ssum e d to contribute to tropospheric VOCs. Several m e thods have been usedto m easure or estim ate EPs for different pesticide products. For m a ny fumi gants, includi ng 1,3-dichloropropene (1,3-d) products, EPs have historically been assum e d to be 100%. Howe ver, several studies have dem onstrated that a portion of applied 1,3-d does not volatilize from soil after ap p lication. The purpose of this m e morandum is to estim ate EP for 1,3-d in fi ve California regions during the May–October ozone season. Background The fumi gant 1,3-dichloropropene w a s suspended in April of 1990 when high air concentrations were found in Merced. R e introduction occurred in 1995 following field studies which m easured 1,3-d emissions. Initially, 1,3-d was applied only by shank injec tion. However, a subsequent for mulation of 1,3-d called InLi ne w a s brought to m arket which was applied by drip irrigation. In this m emorandum , I will firs t dis cuss develo pment of factors for shank injection and then developm ent of factors for drip application. Approach This approach relies on two strands of analysis, which are co mbinedto calculate the final factor. The first strand examines the inj ection and drip application m e thods and associated flux studies to estim ate a non-summ e r and summer flux fact or. The second strand examines by region the

100 1 I Street • P.O. Box4015 • Sacramen to, Californ i a 9 581 2-40 15 • www
. c dpr.c a.g o v A Depart m e n t of the California En vironm ent al Protection Agency Prin te d o n re cycled p ap e r , 10 0 % p o s t-consu m e r--p ro ce sse d ch lorin e - fre e
.Randy Segawa Nove m ber 30, 2006 Page 2

pounds of 1,3-d used in order to develop wei ghts for com bining the flux factors. The final calcu lation consists of th e use-weigh t ed aggregat e factor (EP) for each reg i on. You provided m e with a list of four regions to calculate in addition to the San Jo aquin region which I originally calcu lated. The five reg i ons are SanJoaquin Ai r Basin, Sacram ento Metro, Southeas t Desert, Ventura, and South Coast. Shank injection A 1,3-d flux study (Knuteson et al. 1992) conducted as part of the research effort yielded a volatilizatio n loss of 25%. In th is study, 1,3-d was injected at a depth of 18 inches. B ecause this study was done under relatively cool conditions during fall, an ad hoc factor of 40% (40/25=1.6x) was considered m ore appropriate for emissions from summ er tim e applications when warm er conditions m a y cause greater losses. Several m e moranda were written presenting si mulation work and discussing the concept of regulating 1,3-d by restricting use on a township basis (Johnson 1995ab, 1996). For injection depths shallower than 1 8 inches, a linear interpolation scheme was used. This schem e assum e d 100% volatilization at th e s oil surface (depth = 0) and 35% at a depth of 18 inches (Johnson, 1996). The 35% volatilization fraction was a weighted average of the summer and non-summ erapplication volatilization fractions. Current app r oaches to estim ating volatilization f l u x f o r injec t e d1,3-d assu m e either lin ear or nonlinear relationships between flux and injec tion depth (Cryer, 2005). G a n et al. (1998) reported flux data from laborat ory experim e nts using 1,3-d. T hose data dem onstrate a linear relationsh i p between volatilizati on fraction and injection depth for uncovered treatm e n ts at 20, 30, and 40 cm injection depths. Four field studies of 1,3-d flux from injection ap plication are depicted inFigure 1 along with the linear interpolation line from 100% to 40% over 0 to 18 inch depth. T h e cumu lative volatilizatio n f r action c al culations are based on m easured flux from commercial-s i zed field applic ation s. Field studies typically display high variability. In our own e xperience, based largely on back-calculated valu es from comm er cial-sized field applications of m e thyl bromide, coefficients of variation ranged from 38% to 52% for 24-hour flux fractions over 3 kinds of applications (Barry 1999). Consequently, in c onsideration of what I believe w ould be relatively high variation (in th e vertic al direction) in f i eld- to-f ield es tim ates inherent to Figure 1 and the observed linear relationship between volati lization fraction and depth observed in the laboratory (G an et al. 1998), a linear interpolation is probabl y a reasonable representation of the depth-flux relationship as a generalization of commercial applications.Randy Segawa Nove m ber 30, 2006 Page 3Percent Emission 10 0
90
80
70

0 5 10 15 20 2 5 M e a s ur ed Va l u e s I n t e r p ol a t i on sche m e



### A B

C 60
50
40
30
20 D ep t h ( i nc he s)

Fi g ur e 1. M eas ur ed v al ues and i n t er p ol a t i on s c h em e. A ( K nut es on et al

. 1992) , B ( t wo poi nt s , G i l l i s and D ow l i ng ( 199 8) ) , C ( K nut es on et

. a l

. 1995)

. Calculation of non-summer a nd summer injec t ion fac t or The volatilization factors are based on the following assum ptions: 1. Linear interpolation can be used to estim ate flux where 100% is assum e d to volatilize at the surface and a study prov ides emissio n s based on the study injection d epth

. 2. The California Data Managem e nt System (CDMS) database contains two types of entries for injec tion : “I njected 18 inches or de e p er” and “ I n j ected 12 to 17 inches.” Iwill use an 18 inch depth for the deep injection and a 12 in ch depth f o r the shallo w injection. 3. Summ er e missions are 1.6x hi gher than non-summ er e missions. The four studies depicted in Figur e 1 are prov id ed in tabu lar for m (Table 1). The first column is the fraction volatilized during the study. The third column i s the depth of injection. To interpolate for each stud y, a lin e is constructed running thro ugh (d epth, fraction vo latilized ) from the study and (0 inch depth, 100% volatilized). The last column in Table 1 shows the calculated volatilizatio n fraction at 18 inch depth using linear interpolati on based on each study ’s results. Equation 2 d i splays the f o rmula used to calculate these en tries

.Randy Segawa Nove m ber 30, 2006 Page 4

T ab l e 1. Four f l ux s t udi e s of 1 , 3- d s hank appl i c at i on . Li near I njectio n Interp olation d e pth i n to 18" D e pth F r actio n study B e dded or Da te of Fr a c tion Vo latilized M e tho d ( i nches ) not A pplicat ion R efer en ce Volatilized G illis and Dowling 0. 65 Shank 14 n o bed 10/29/ 1 995 1 998 0.55 G illis and Dowling 0. 65 Shank 12 bed 11 / 15/ 1 995 1 998 0.48
K nutes o n et 0. 26 Shank 20- 22 bed 5 / 5/ 199 3 a l . 1995 0.37 K nutes o n et 0. 25 Shank 18 n o bed 9/25/ 19 91 a l . 1992 0.25

A

v erag e 0.41 

# ( 1.0

− F 

# )

= 

## ( 0

− D i D 

## ) i 

## ( ) + 1.0 (2) F

18 18
In equation 2, F 18 is the estim ated f r action vo latilized at 18 inch depth, F Di is the f r ac tion volatilized in study i at depth Di. The average volatilization factor at 18 inches was 0.41. I have ignored that two of the studies were bedded and two of the studies were broadcast. Incorporating the resu lting average f r a ction at18 inches in to n ew equation results in

F

D 

## ( 1.0

− 0.41 

## ) ( )

= D + 1.0 = − 0.033 D + 1.0 (3) 0 1 8 

## (

− 

## ) This equation applies from 0 to 18 inches depth of injection for non-summ er shank applications. The sym bol s are F D =fraction of applied active in gredien tvolatilized at depth, D, in inches. Using equation 3 at 12 inches depth yiel ds a fraction of 0.61 [ = − 0.033 *12 + 1.0]

.Randy Segawa Nove m ber 30, 2006 Page 5

Since these studies were all conducted outside of summer season, the corresponding volatilization fraction during summ er applications would be (1 .6)*0.41=0.656, for the 18 inch depth and (1.6)*0.61=0.97 for the 12 inch depth. Calculation of non-summer and summer drip factor Two studies of tarped drip app lication were conducte d (Table 2). Study results were mutually consistent and 29% of the applied 1,3-d volatilized. One study (Knut eson et al. 1999) was
T ab l e 2. Tw o fl ux st u di es of 1, 3 - d dri p appli cat i o n.

Fra c t i o n Bedd ed or Da te of Vo latilized M e thod Tarped no t A pplic ation R efer e nce Knute s on et 0. 29 D r ip Y es bed ded 10/2/1998 al. 19 99 W es e nbeeck and P h illips 0. 29 D r ip Y es bed ded 12/ 6/1999 2000 conducted in Salinas, C a lifornia, while the othe r was conducted in Dougl as, Georgia. Applying the 1.6 summ er factor to 0.29 resulted in a f actor 0.46 for summer drip. For drip formulations (Telone EC, InLine) about 6% by product weight cons ists of inert ingredie nts. No applications using Telone EC were listedin the 2004 CDMS database. Table 3 summ arizes the drip and shank volatilization T a b l e 3. Fact o r summary factors. Shallow shank Drip Sh a llo w S h an k D ee p Sh ank No n- su mm er 0

. 290 0.610 0 .410 refers to a 1 2 inch depth , Su mm er 0

. 464 0.970 0 .656 while deep s hank refers to an 18 inch depth (or deeper). Drip ref ers to tarped drip applic ation s . Current lab el requ irem ents m andate tarp ing f o r drip applic ation s . Calculation of non-summer and summ er use w eights for five basins The next step was to determine the fraction of pounds applied in the five basins for the three application m e thods, split between n on-summ er and summ erm onths from May 1 through October 31. Summ er wa s defined as from June 21 to Sept 21 in clus ive. T h ese factors were estim ated using CDMS report of 2004 1,3-d use data. The fractions were based on pounds of 1,3-d applied. Applications liste d in the CDMS system are classi fied by m e thod. The five regions and associated counties that I used are San Jo aquin (Fresno, Ke rn, Kings, Madera, Merced, San Joaquin, Stanislaus, and Tulare); Sacram en to Metro (Sacram ento, Solano, Yolo, Placer, andRandy Segawa Nove m ber 30, 2006 Page 6

El Dorado); Southeast D esert (R iverside and San Bernardino); Ventura (V entura ); Sou th Coast (Los Angeles and Orange). The pounds were norm a li zed to the total for each region. The regions are clearly v aried in the use patterns ranging fro mthe Sacram en to-Metro region where 1,3-d is applied m ostly as deep shank in non-summer to the south coast region which is all drip during the summ er.
T a ble 4. Regi onal use w e ights f o r non-summer and method of appl ication for 1 , 3-d. Drip S h allo w Shan k D eep S h an k S acra m en t o -M etro No n - su mme r 0.000 0.0 00 0.820 Summe r 0.000 0.0 00 0.180 S E Desert No n - su mme r 0.122 0.0 19 0.000 Summe r 0.839 0.0 19 0.000 V en t u ra No n - su mme r 0.210 0.0 22 0.036 Summe r 0.733 0.0 00 0.000 S a n J oa q uin N on-s um m e r 0.002 0.0 04 0.466 Summe r 0.000 0.0 10 0.518 S outh Co a s t N on-s um m e r 0.000 0.0 00 0.000 Summe r 1.000 0.0 00 0.000

Calculationof regional emission potentials for 1,3-d volatiliz ation The calcu lation of the factors for each region was accom p lished by mu ltiplying the m e thod factors in T ab l e 5. Regional e m i ss i on Table 3 by the corresponding use weights in Table 4 p o te n tia ls fo r1 ,3 -d
. within each region and a dding the resulting products Emissio n Po ten t ial (Table 5 ) . For example, in the Sacram ento-Metro region, Sa cra m en t o - M e t ro 0. 4 5 there were n o drip or sh a llow shank applications. Hence SE Deser t 0. 4 6 the use weights were zero for drip and shallow shank. V ent u ra 0. 4 3 The emission potential ther efore was calcu lated as San Jo aqu i n 0. 5 4 0.41*0.82+0.656*0.18=0.454. The emission potentials So ut h Coast 0. 4 6 ranged from 0.43 to 0.54.

cc: Kean S. Goh, Ph.D., Agri culture Program Supervisor IV Terre ll Bar ry , Ph.D., Research Sc ien tist II IRandy Segawa Nove m ber 30, 2006 Page 7

References Barry, Terri Ph.D. 1999. Mem o randum to Ra ndy Segawa on m e thyl bromide e mission ratio groupings d ated Decem ber 2 1999. Cryer, Steven A. 2005. Predicting soil fumi gant air concentrations und er regional and diverse agronomic conditions. Jo urnal of Environm ental Quality 34 :2 197-2207. Gan, J., S.R. Yates, D. Wang, and F.F. Erns t. 1998. Effect of application m e thods on 1,3-dichloropropene volatiliz ation from soil under controll ed conditions. Journal of Environm ental Quality 27:432-438. Gillis, Matth e w J. and Kathryn C. Dowling. 1999. Effect of broadcas t an d row application m e thods on 1,3-dichloropropene emissions. Dow AgroSciences LLC, 9330 Zionsville Road, 308/2E. Indianapolis, Indiana. Bolsa ResearchProject #:BR730, Dow AgroSciences Study Identification num ber: HEA95177. Johnson, Bruce Ph.D. 1995a. Memorandum to John S. Sanders, Ph.D., on Proposal to regulate 1,3-d using township/range cap. Decem ber 7, 1995. Johnson, Bruce Ph.D 1995b. Mem o randum to Ronald J. Oshim aon Calculation of air concentrations at various township cap leve ls and comparison to previous simulation study results for 1, 3-D. December 20, 1995

. Johnson, Bruce Ph.D. 1996. Mem o randum to John S. Sanders, Ph.D., on Derivation of depth factors to apply to standard ga llons of 1,3-dichloropropene fo r dete rmining township gallons totals. January 16, 1996. Knuteson, Jam e s A., Da vid G. Petty, and Bradle y A. Shurdet. 1992. Field volatility of 1,3-dichloropropene in S a linas Valley, Ca lifornia. DowElanco, Midland, Michigan. Knuteson, J.A., H.E. Dixon-White, and D. G. Petty. 1995. Field volatility of 1,3-dichlororopropene in San Joaquin Valley, California. DowElanco ENV93063. Knuteson, J.A., S.C. Dol der, and J.P. Mueller. 19 99. Field volatility of 1,3-dichloropropene and chlorop i crinf r om shallo w drip ir rigation app lication of Telone C-35 EC to strawber ry beds with VIF tarp–Interim report. May 28, 1999. Dow Ag r oSciences L L C, Indianapolis, Indiana. 980070 (GH-C 4918).Randy Segawa Nove m ber 30, 2006 Page 8

W e senbeeck , I. Van and A. M. Phillips. 2000. Field volatility of 1, 3-dichloropropene and chlorop i crinfrom surface drip irrigation appl ication of In-Line to vegetable beds under polyethylene tarp. Global Environm ental Chemistry Laborator–Indianapolis Lab, Dow AgroSciences LLC, 9330 Zionsville Ro ad, Indianapolis, Indiana 46268-1054. Study identification num ber: 990072.