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A weight-of-evidence analysis using GIS, monitoring data, and simulation modeling, is being conducted to identify major sources of pesticide loadings to the Sacramento River, San Joaquin River, and Bay-Delta estuary. The objectives of this analysis are to improve decision making and optimize resource spending in understanding and mitigating pesticide exposure to sensitive and endangered species across a number of federal, state, and regional water quality programs. Results from this project are being used to: 1) provide further knowledge of the fate and transport of agricultural chemicals (e.g., copper, organophosphates) and emerging pesticides (e.g., pyrethroids); 2) match results to the location of sensitive species critical habitats; 3) identify and rank pesticide source areas; 4) evaluate implications of future pesticide use trends and changes in climatic conditions; 5) aid in developing plans to improve ecosystem quality and water quality by strategic placement of BMPs and hydrologic operations; 6) support future monitoring programs (strategic locations, sampling frequency); 7) link results to life cycle models currently under development for striped bass and delta smelt, as well as existing models for salmonids; and 8) provide a data-link to support other water quality models and population models.

A weight-of-evidence analysis is being conducted to identify major sources of pesticide loadings to the Sacramento River, San Joaquin River, and Bay-Delta estuary. The objective of this analysis is to improve decision making and optimize resource spending across a number of federal, state, and regional water quality programs.

As part of this project, a series of modeling scenarios were developed to compute the edge-of-field loading for 20 pesticides in the agricultural realm. An underlying challenge in this effort was to properly represent 3,500,000+ pesticide applications, on 100+ different crops and land uses, account for California’s unique management practices, and account for spatial-temporal climate effects in the period 2000 – 2008.

Using a geographic information system a super-agricultural land use layer was create to represent all potential pesticide use sites for the period of interest. In turn, this agricultural super layer was combined with the spatial component of the CA PUR , the PLSS sections, soils from the detailed soil survey and area of influence for selected CIMIS weather stations to determine all unique combinations (of chemical, soil and crop) that needed to be modeled and processed at the catchment level.

In this poster presentation we will provide insight in assumptions, methods, data sets, and modeling results to handle fast volumes of information required to compute edge-of-field pesticide loadings and determine co-occurrence with sensitive species in the spatial-temporal area of interest.

In order to meet USEPA federally listed threatened and endangered species spatial data requirements, the Generic Endangered Species Task Force (GESTF) was formed to develop a series of four spatial datasets that represent potential pesticide use sites. This poster describes the development and datasets that represent terrestrial use sites (crop, forestry and turf); an accompanying poster describes the aquatic use sites dataset. To generate the terrestrial use sites datasets, a GIS was used to compile US Department of Agriculture (USDA) National Agriculture Statistics Service Cropland Data Layer (NASS CDL) data for the 2009 growing season into a seamless dataset covering the continental United States. From this dataset, each CDL pixel was assigned to one of the GESTF’s use site classes according to strictly defined and documented methods. Forestry use sites were further refined using data from state level GAP Program databases. Potential pesticide use site area summaries were generated for each of the over 2.5 million NHDPlus catchment and upstream watersheds, allowing for ready integration of the use site data with existing NHDPlus data and tools. In order to maximize transparency and reproducibility, extensive metadata conforming to Federal Geographic Data Committee (FGDC) standards was generated for each use site dataset and, to the extent appropriate, project documentation and Quality Assurance / Quality Control were conducted following USEPA Good Laboratory Practices (GLP) guidelines.

A weight-of-evidence analysis is being conducted to identify major sources of pesticide loadings to the Sacramento River, San Joaquin River, and Bay-Delta estuary. The objective of this analysis is to improve decision making and optimize resource spending across a number of federal, state, and regional water quality programs.

As part of this project, a series of modeling scenarios were developed to compute the edge-of-field loading for 20 pesticides in the agricultural realm. An underlying challenge in this effort was to properly represent 3,500,000+ pesticide applications, on 100+ different crops and land uses, account for California’s unique management practices, and account for spatial-temporal climate effects in the period 2000 – 2008.

Using a geographic information system a super-agricultural land use layer was create to represent all potential pesticide use sites for the period of interest. In turn, this agricultural super layer was combined with the spatial component of the CA PUR , the PLSS sections, soils from the detailed soil survey and area of influence for selected CIMIS weather stations to determine all unique combinations (of chemical, soil and crop) that needed to be modeled and processed at the catchment level.

In this poster presentation we will provide insight in assumptions, methods, data sets, and modeling results to handle fast volumes of information required to compute edge-of-field pesticide loadings and determine co-occurrence with sensitive species in the spatial-temporal area of interest.

A weight-of-evidence analysis using GIS, monitoring data, and simulation modeling, is being conducted to identify major sources of pesticide loadings to the Sacramento River, San Joaquin River, and Bay-Delta estuary. The objectives of this analysis are to improve decision making and optimize resource spending in understanding and mitigating pesticide exposure to sensitive and endangered species across a number of federal, state, and regional water quality programs. Results from this project are being used to: 1) provide further knowledge of the fate and transport of agricultural chemicals (e.g., copper, organophosphates) and emerging pesticides (e.g., pyrethroids); 2) match results to the location of sensitive species critical habitats; 3) identify and rank pesticide source areas; 4) evaluate implications of future pesticide use trends and changes in climatic conditions; 5) aid in developing plans to improve ecosystem quality and water quality by strategic placement of BMPs and hydrologic operations; 6) support future monitoring programs (strategic locations, sampling frequency); 7) link results to life cycle models currently under development for striped bass and delta smelt, as well as existing models for salmonids; and 8) provide a data-link to support other water quality models and population models.

This poster is part of a series on the diagnosis of the magnitude and probable causes (including compound mixtures) of ecological impacts in field ecosystems. As part of ongoing research into the quantification and causation of ecological impacts in natural ecosystem communities, a comprehensive data set of a variety of stress factors, ecological community information, habitat quality and water chemistry were compiled for over 2,000 locations in Ohio. All data were geographically located and their respective co-occurrence in the landscape was determined using a Geographic Information System (GIS). Stressors include proportion of land use classes (including proximity to streams), nutrients and other agricultural factors, soil properties, and anthropogenic factors such as population, septic systems, storm water discharges, and habitat modification. Toxicants such as pharmaceuticals, household cleaning products and pesticides in waste water effluent were modeled for the entire study area. Monitored aquatic community information for fish (Index of Biologic Integrity, IBI) and macro invertebrates (Invertebrate Community Index, ICI) were used to define reference locations and ecological condition. Measured water chemistry data for each location included conductivity, BOD, and conventional pollutants such as nitrate, phosphorus, TSS, ammonia, and metals. Observed habitat characteristics at each site included attributes such as substrate composition, channelization, riparian vegetation, gradient, and QHEI values. Ultimately, these data were used for diagnostic evaluations using a variety of methods, including regression trees, neural-networks, weights of evidence/weighted linear regression, general linear modeling methods, and trait-based approaches (described in subsequent posters in this series).

In order to meet USEPA federally listed threatened and endangered species spatial data requirements, the Generic Endangered Species Task Force (GESTF) was formed to develop a series of four spatial datasets that represent potential pesticide use sites. This poster describes the development and dataset representing potential aquatic use sites; an accompanying poster describes the terrestrial use sites (crop, forestry and turf) datasets. National Hydrography Dataset Plus (NHDPlus) data covering the continental United States was used as the basis for developing the aquatic use sites dataset. Because flowing water bodies that are narrower than approximately 300’ are represented as lines in the NHDPlus data, all lines were ‘expanded’ using a Geographic Information System (GIS) to create a spatial dataset containing an area attribute for each water body. The width of each flowline was estimated using the average annual flow provided in the NHDPlus data along with assumptions about the width-depth ratio, and the resulting widths were categorized into predetermined width classes that were used to represent the water body widths. Overlapping confluences of varying size streams were processed using a hierarchical scheme so that larger streams and rivers took precedence over smaller water bodies. The resulting data were clipped to retain the ponds, lakes and large rivers that existed in the source NHDPlus data, and to ensure that no overlap existed when all surface water features were combined into a single spatial layer. In order to maximize transparency and reproducibility, extensive metadata conforming to Federal Geographic Data Committee (FGDC) standards was generated for each use site dataset and, to the extent appropriate, project documentation and Quality Assurance / Quality Control were conducted following USEPA Good Laboratory Practices (GLP) guidelines.

An analysis in California was undertaken to quantify the potential economic impact to agriculture in terms of revenue resulting from no spray setbacks of pesticides from urban / residential land use. The setback distances were proposed in the report, “Pesticides in the Air – Kids at Risk: Petition to EPA to Protect Children From Pesticide Drift”, submitted on October 13, 2009 by Earthjustice and Farmworker Justice on behalf of United Farmworkers et al. The report is concerned with the transport of organophosphate & carbamate pesticides from target agricultural fields by evaporation and atmospheric volitization and recommends 60’ (ground applications) and 300’ (aerial application) set backs from non-target sites like urban / residential land use types to reduce bystander exposure from spray drift.

Using medium resolution land cover in a Geographic Information System (GIS), two counties in California, Kern and Butte counties, were identified as falling in the upper distribution of counties with respect to the interaction of agriculture within 60’ and 300’ of urban / residential land use. High resolution (field scale) cropping spatial data & crop-specific production and value data were then used to calculate the acreage and dollar value for crops with the potential for pesticide application in the 60’ and 300’ buffers.

The additional economic impact of completely removing a field from production was calculated when at least 25% of the field was within the pesticide no spray set back. Total field retirement may be more economically viable than partial removal in some scenarios. The results indicated a significantly greater economic impact when entire fields were removed entirely from production. The calculated acreage and dollar values were compared with values reported in annual county agricultural crop reports, and the results are presented. This study highlights the importance of understanding the magnitude and degree to which no spray set backs impact the agricultural economy.