Upper Ballona Creek Toxicity from Synthetic Pyrethroids: A Predictive Model Based on Land Use

Date / Time:
Tuesday, Oct 20 10:00am to 10:30am
Track / Session:
GIS Data Management / Advancing Stormwater Management and Research

Pyrethroid pesticide mass loadings in Ballona Creek Watershed were calculated using the Volume-Concentration Model with GIS to explore potential relationships between urban land use and impervious surfaces, and pyrethroid runoff flowing into Upper Ballona Creek. Volume-Concentration Model refers to a series of equations relating storm water runoff volume and storm characteristics, for which PLi = RV x EMCi estimates pollutant loads, where RV is the storm runoff volume and EMC is the average pollutant concentration during a storm event. While EMCs exist for a variety of pollutants and land uses, an EMC for pyrethroids has yet to be calculated. Based upon historical usage of pesticides, and assuming pyrethroid transport and fate are the same as diazinon, a method using 2003 pyrethroid and diazinon data from the California Department of Pesticide Regulation (CDPR) Pesticide Use Database (PUR), calculated pyrethroid EMC from diazinon geometric mean concentration from residential land use. EMC = 0.13 ug/L (0.02 ug/L x Total Reported Pyrethroid Reported Non-Agricultural Use ÷ by Reported Non-Agricultural Diazinon Use). EMCs for anything other than grouped residential and commercial land use were given a 0 μg/L. Rainfall was averaged from the past 10 years data (14.789 in) from the Los Angeles Almanac. Calculations were made per land use category in GIS (each land has its on RC) and then converted to g/L. Weighted overlay analysis and exponential decay were used to show the effects of pyrethroid mass, distance from the creek, and land use. GIS-Volume Concentration Model was calibrated against 2013 and 2014 dry and wet weather sampling data. This model has significant implications for determining mass loadings due to land use influence. GIS modeling offers a cost effective way to use real time data for a small amount of samplings and extrapolate information for a larger watershed area.

Primary Speaker:
Kazue Chinen, UCLA
My career interest in the environmental field is to bridge policy, science and engineering, particularly for countries with limited resources. My desire to pursue my DEnv degree in the Environmental Science and Engineering Program at UCLA comes from my awareness that to create the most effective environmental policy and solutions, there needs to be facilitated understanding and communication between communities, government agencies, and donors. As part of my problems course, I am currently working with the City of Los Angeles to track pyrethroid contamination in Ballona Creek Estuary through a GIS-Volume-concentration model, in particular from different urban land uses draining into Upper Ballona Creek. My research involves the development of a model that predicts pyrethroid pesticide mass loadings and provides a hot-spot analysis of the watershed based on land use, distance from the creek, and mass loadings. For my dissertation/internship I am interested in pursuing positions that involve project management and monitoring of water and sanitation programs as well as the implementation of specific sanitation and drinking water policy and regulations.