University of Maryland Wye Research and Education Center Mapping the Spatial Extent of Depositional Areas in Agricultural, Urban and Residential California Streams with Suspected Pyrethroid Toxicity Lenwood W. Hall Jr. Ronald D. Anderson William D. Killen University of Maryland Wye Research and Education Center Queenstown, Maryland

Peer Reviewed Publication Hall, L. W. Jr., R. D. Anderson and W. D. Killen. 2012. Mapping the spatial extent of depositional areas in agricultural, urban and residential California streams: Implications for pyrethroid toxicity. Human and Ecological Risk Assessment 18: 368-392.

FINAL CONCLUSIONS The spatial extent of depositional areas (<16%) was low for all three types of streams and generally more dominant downstream Pyrethroid concentrations were greater in downstream areas except for Pleasant Grove Creek The “representativeness” of depositional areas should be addressed for the entire stream as stated in SWAMP protocols Spatial scale of depositional areas should be considered for 303 d listing of hydrophobic chemicals

Introduction Pyrethroid insecticides are used in residential and urban areas for structural pest control, landscape maintenance, and residential home and garden use and in agricultural areas for general pest control on various agricultural crops Pyrethroids have been identified at potentially toxic concentrations in agricultural, urban and residential streams in CA based on Hyalella toxicity tests. Sediment for Hyalella toxicity testing and chemical analysis is collected using a targeted sampling approach in depositional areas.

Introduction - Continued Depositional areas can be rare in various streams due to the presence of sandy sediment. “Representativeness” of targeted sampling is an issue that should be addressed according to SWAMP protocols. Pyrethroid residues at potentially toxic levels have been found in depositional areas from Del Puerto Creek (ag) , Arcade Creek (urban) and Pleasant Grove Creek (residential) resulting in 303 d listings. Sediment sampling issues addressed in this presentation extend beyond pyrethroids

Objectives Determine the spatial extent of depositional areas in agricultural, urban and residential California streams using wetted stream bed mapping Discuss the implications of the standard sediment sampling approach and stream depositional areas with respect to pyrethroid measurements

California Sampling Locations Arcade Creek Del Puerto Creek

Del Puerto Creek

Arcade Creek

Pleasant Grove Creek

Sediment Sampling Designs Targeted – bias worst case approach Random – basis for many statistical tests Stratified Random – i.e., randomly select from depositional areas as in SWAMP protocol Model based estimation – e.g. use TOC as a covariate and sample areas covering a range

Sediment Mapping Grid tool (1 x1 m) used to determine depositional and non-depositional areas by site 99 randomly selected sites from equally spaced lower, middle and upper segments (33 per segment) were evaluated Google Earth Pro was used to identify all possible sampling grids in the site selection process

PGC10

Pyrethroid Measurements in Sediment (Morse Labs) Bifenthrin Cypermethrin Cyfluthrin Deltamethrin Esfenvalerate Fenpropathrin Lambda – cyhalothrin Permethrin

Pyrethroid Measurements by Stream Del Puerto Creek – 3 random measurements from depositional and non-depositional areas for each of the 3 sections Arcade Creek – measurements from depositional areas at 11 bioassessment sites with 3 to 5 sites per stream section Pleasant Grove Creek – 2008 pyrethroid measurements in depositional areas from 21 bioassessment sites with 3 to 9 sites per section

Map showing 33 sites in lower section of Del Puerto Creek (~ 4 Map showing 33 sites in lower section of Del Puerto Creek (~ 4.5 km) with dark sections of pie chart representing the % depositional area

Map showing 33 sites in middle section of Del Puerto Creek (~ 4 Map showing 33 sites in middle section of Del Puerto Creek (~ 4.5 km) with dark sections of pie chart representing the % depositional area

Map showing 33 sites in upper section of Del Puerto Creek (~ 4 Map showing 33 sites in upper section of Del Puerto Creek (~ 4.5 km) with dark sections of pie chart representing the % depositional area

Mean Total Pyrethroid Concentrations By Section For Del Puerto Creek (ng/g) Depositional Non-Depositional

Summary Points - Del Puerto Creek 4% was depositional area Depositional areas were more dominant downstream Total pyrethroids were much higher in depositional areas vs. non-depositional areas and concentrations were much lower upstream

Map showing 33 sites in lower section of Arcade Creek (~ 8 km) with dark sections of pie chart representing the % depositional area

Map showing 33 sites in middle section of Arcade Creek (~ 8 km) with dark sections of pie chart representing the % depositional area

Map showing 33 sites in upper section of Arcade Creek (~ 8 km) with dark sections of pie chart representing the % depositional area

Total Pyrethroid Concentration by Section for Arcade Creek Sites (ng/g) Lower Section Middle Section Upper Section Arcade Creek Sites

Summary Points- Arcade Creek 15% was depositional area Depositional areas were more dominant downstream Total pyrethroids were much higher in downstream areas

chart representing the % depositional area Map showing 33 sites in lower section of Pleasant Grove Creek (~ 14 km) with dark sections of pie chart representing the % depositional area

chart representing the % depositional area Map showing 33 sites in middle section of Pleasant Grove Creek (~ 14 km) with dark sections of pie chart representing the % depositional area

chart representing the % depositional area Map showing 33 sites in upper section of Pleasant Grove Creek (~ 14 km) with dark sections of pie chart representing the % depositional area

Total Pyrethroids (ng/g) by Section from PGC Bioassessment Sites PGC Sites

Summary Points Pleasant Grove Creek 12 % was depositional area Total pyrethroids were much lower in the downstream section compared to the middle and upstream sections

FINAL CONCLUSIONS The spatial extent of depositional areas (<16%) was low for all three types of streams and generally more dominant downstream Pyrethroid concentrations were greater in downstream areas except for Pleasant Grove Creek The “representativeness” of depositional areas should be addressed for the entire stream as stated in SWAMP protocols Spatial scale of depositional areas should be considered for 303 d listing of hydrophobic chemicals

Summary of CA Sediment Mapping Studies Stream Year # Transects % Dep. Area Pyrethroids Measured BMIs Assessed Arcade Cr 2009 99 15 N Del Puerto Cr. 2010 4 Y Salinas Streams 2011 96 24 Pleasant Gr. Cr. 12 2012 5