### Yu zhou Luo

, Nan Singhasemanon, Ke an S. Goh Calif ornia Department of Pes

ticide Regulation Sacr amento , CA 95812 10/28/2014

### CDPR’ s Surface W ater Pr ot ection Pr ogr am (S WPP) is developing a consis te nt , tr anspar en t, and fa st method fo r ev aluating new AI r egis tr ation pack ag es Initially designed fo r agricultur al uses by gener ally fo llowing USEP

A appr oaches fo r r egis tr ation ev aluation Impr ovements under development, including urban pes ticide uses, degr adates, California r eceiving w ater...

2Re siden tial (10ha) Commer cial/indus trial (10ha) Agricultur al (10ha) 10 ha: USEP

A recommended siz e of drainage area f or modeling purpose in regis tration evaluation and risk assessment 3

### No dat a: half- life, adsorption coefficients, et c., on imper vious surf

ace ar e not a va ilable No model is consis te nt ly used by USEP A for re gis tr ation ev aluation of urban pes ticides Fo r pos t - use risk assessmen t , USEP A dev eloped a modeling scenario for imper vious surf ace

4

### The model (“PRZM/EXAMS ”) with the modeling scenario (“San Fr ancisco imper vious surface”) is “ the mos t suitable available modeling approach f or imper vious runoff

” (USEP A EFED , 2013)

5

### The model (“PRZM/EXAMS ”) with the modeling scenario (“San Fr ancisco imper vious surface”) Kn own limit ations on landscape description and simulation design , e. g., Nationwide suburban data: 1⁄4 acr e house lot Buildings all surr ounded by lawns Optimiz ed lawn irrig ation by soil moistur e No dry - we ather runoff (urban dr ool) fr om pa ve d ar eas Assumed equal contributions of runoff fr om per vious and imper vious surfaces

6

### Based on California conditions, to impr ove urban landscape description re pr esen te d in the modeling appr oach To impr ove the simulation design fo r bet te r pr ediction of EE C (es timated en vir onmen ta l concen tr ation) fr om an urban catc hmen t

758 r esiden tial lots (1/4 acr e each) in a 10
- ha watershed (USEP A, 2007), link ed to a USEP A pond (1ha*2m) 8

### Impervious surface c over ag e (ISC): USGS landuse images, and Caltr ans urban boundaries (for San Fr ancisco - Oakland) Re siden tial density: OEHHA urban sur vey (Sacr amen to, Irvine, and San ta Cruz) House fo otprin t: American Housing Sur vey 2011 (for San Fr ancisco) 3 - ft wa lkw ayar ound a building 3 - ft pa ve d ar ea adjacen t t o lawns subject to unintended irrig ation Pr e - scheduled irrig ation: UCANR lawn w atering guide 9**USEP A**  **SWPP** Ov er all impervious fr action 50% 83% #lots per 10 ha w atershed 58 201.6 Lot siz e 1/4 acr e 1/12 acr e House footprint 1000 ft 2 (house) + 900 ft 2 (g ar age) 1500 ft 2 Driv eway 546 ft 2 546 ft 2 Sidew alk 268 ft 2 135 ft 2 Lawns 9075 ft 2 653 ft 2 Pave d w alkw ayr ound a house 0 501 ft 2 The above data are f

or residen tial watershed. Commercial/ industrial and urban righ t- of - way scenarios are also developed. 10PRZM for pervious

surface EXAMS PRZM for impervious surface EXAMS EEC=f P *EE C P +f IMP *EEC IMP Fo r r esiden tial, simplified as EEC=(EEC P +EE C IMP )/2 EEC = estimated en vironmen ta l concentration; f = fractional area, “P ” fo r per vious surf ace; “IMP ” fo r imper vious surf ace 10 - ha watershed USEP

A pond (1ha*2m)

11**Wa te**  **r** Pr ecipit ation only Pr ecipit ation + irrig ation **Pe rmeability**  Pe rv ious (

**f1** ) Imper vious (

**f2** ) P (

**f3** ) IMP (

**f4** ) **Tr ea**  **tmen t**  Tr ea te d

( **ft1** ) Un tr ea te d **ft2 ft3**  **ft4** Pe rvious surface Impervious

surface Pr ecipit ation Irrig ation (which ma y cause dry we ather runoff )

tr ea te d untr ea te d tr ea te d untr ea te d

12PRZM for

surface 1 PRZM for

surface 2 PRZM for

surface 3 PRZM for

surface 4

EXAMS **We ighted**  **aver ag**  **e** Ed ge - of- field flux es fr om each surface Ed ge - of- field flux es for the urban water shed

13**Modeling componen**  **ts USEP** 

**A SWPP**  Model PE5 (in te gr ate d PRZM EXAMS ) PRZM and EXAMS, separ ate simulations Modeling scenario 2 surfaces, USEP A tier - 2 modeling scenarios for California 4 surfaces, modeling scenarios r evised fr om USEP A Landscape description Re siden tial;

Commer cial/indus trial; Righ ts - of- way Modified for re siden tial and commer cial/indus trial; Righ ts - of- way(USEP

A) Simulation design Run PRZM - EXAMS fo r

each surface; re port the ave ra ge s of the two EXAMS r esults Run PRZM fo r each surface; aggr eg ate d r esulting flux es befor e EXAMS simulation 1415

### Upgr aded to PRZM5/VVWM Compar ed with landscape descriptions (“ Aliso Viejo” scenario) in the S WMM modeling (Winchell et al., 2014, PWG - ERA - 11) To r efine application ex te nt with urban insecticide sur vey re sults (Winchell, 2013, PWG - ERA - 02b), e. g., Fr action of households using outdoor insecticides Po ssibility of a pes ticide AI used in each application Pe rc en ta ge of surface ar ea of a use site

### SWPP Pr oduct Re gis tr ation R eview Pr ocess ( htt p://www .cdpr

.ca. gov/docs/emon/surfwtr/r eview .htm 

### ) Pa rt I “initial scr eening ” (Luo and Deng, 2012a) Pa rt II “r efined modeling ” (Luo and Deng, 2012b) Pa rt III “urban module” (Luo , 2014) User Manual (Ver sion 3.1) (Luo and Singhasemanon, 2014) 

### Risk assessmen t fo r urban pes ticide uses in “USEP A Ef fe cts Determinations fo r the California R ed - leg ged Fr og ” ( www .epa.gov/espp/lits tatus/effects/r edleg - fr og 

### )

17Yu zhou Luo , Ph.D . Re sear ch Scientis t III CDPR/EM/SWPP yuzhou.luo@cdpr

.ca. gov (916) 445 - 2090