PWS_1.docx

PR #22-1200

Attachment 1

Performance Work Statement Pesticide Risk Support on Federal Lease Lands for the Klamath Basin NWR Complex December 3, 2021

I. INTRODUCTION

The Bureau of Reclamation (Reclamation) administers the Federal lease land (lease land) program under a cooperative agreement with the U.S. Fish and Wildlife Service (Service). The primary objective of the lease lands is to provide a commercial agricultural program using proven conservation practices with benefits for wildlife, including compliance with federal and state laws and policies. While responsible stewardship and integrated pest management (IPM) is required in all lease land contracts, these lands also provide an area for research and demonstration projects that strive to balance agriculture and wildlife habitat. Using the IPM approach for pest management, only approved pesticides may be applied on lease lands. Due to concerns about adverse impacts to wildlife and human health, it is imperative that pesticides are used in accordance with the approved U.S. Department of Interior (DOI) Pesticide Use Proposal (PUP) and the product label.

Under Section 7 of the Endangered Species Act (ESA), Reclamation is required to consult with the Service on the effects of its actions on ESA listed species. In 2007, a Programmatic Biological Opinion (BO 1-10-07-F-0056) was created titled Biological Opinion Regarding the Effects on Listed Species from Implementation of the Pesticide Use Program on Federal Leased Lands, Tule Lake and Lower Klamath NWRs. The BO outlined a process for assessing proposed pesticides for use on the lease lands. We use a Tier 1 screen level risk assessment which was adapted to the Lease Land pesticide use programmatic BO. Due to the controversial nature of the use of pesticides on the lease lands, it is imperative that Reclamation acquire the services of a contractor that (1) is highly knowledgeable in the field of pesticides, toxicology, and ecology, (2) has successfully completed screening level risk assessments, and (3) has experience with analyzing the effects of pesticides on wildlife in wetland ecosystems.

The proposed action to be evaluated within this assessment of pesticides proposed for use on lease lands and their associated use patterns for agricultural crops within the lease lands, consistent with the management objective above. The process will involve applying toxicological and environmental fate analyses to determine potential effects of the proposed pesticide use on wildlife resources. Specific requests for proposed pesticides to be included in the lease land approved pesticide list are made by agricultural users who lease the subject lands, and representatives of government and private businesses that provide technical assistance to the lease land agricultural community. Ultimately, the contractor will develop chemical profiles, and associated products, for each active ingredient requested each year, following the specific instructions listed in this document and the process outlined within the Programmatic Biological Evaluation.

This PWS is identical to previous work performed under contract 140R2018Q0066.

II. PURPOSE

Each year pesticides are proposed that are recommended as useful production tools for producers on the lease lands. An ESA Section 7 biological opinion developed in 2007 provides needed Section 7 compliance required by DOI and Service pesticide use policy. The BO outlined a process for assessing proposed pesticides for use on the lease lands. The purpose of this Performance Work Statement is to create a contract that facilitates the evaluation of proposed pesticides, and associated active ingredients, in accordance to process outlined in the BO.

III. TYPE OF CONTRACT

Firm fixed priced per unit service contract. Cost will be on a per unit (hereafter assessment) basis. Each assessment will reflect 1 active ingredient (AI) from a pesticide proposed for use at the Klamath Basin NWR Complex. Each assessment will have a cost commensurate to the complexity of the assessment type. The type of assessments will be as followed:

1) ”Simple” assessment- A new PUP chemical profile in which it is assumed the availability of information for the AI is limited, and therefore, less time will be required to complete the assessment.

2) ”Complex” assessment- A new chemical profile in which there is generally more information available for these AIs, and therefore, more time will be required to complete each assessment. Complex assessments are generally older ingredients, sometimes with environmental fate and toxicity data available for first order degradates. However, if information for first order degradates is available, or triggers concern, the evaluation of first order degradates may require a separate assessment. This will be negotiated by the COR and contractor prior to beginning the assessment.

3) Chemical profile update of Previously Evaluated AIs – Previously evaluated AIs will be reviewed, and the risk assessments will be updated with new input parameters as necessary such as application rates, methods, etc.

IV. AUTHORITY

Fish and Wildlife Coordination Act (16 U.S.C. 661-667e; the Act of March 10, 1934; Ch. 5A; 48 Stat. 401). Section 661 authorizes the Secretary of Interior “to make surveys and investigations of the wildlife of the public domain, including lands and waters or interests therein acquired or controlled by an agency of the United States.”

V. BACKGROUND

The Kuchel Act of 1964 (P.L. 88-567) further defines the purposes of the Lower Klamath and Tule Lake NWRs, to include the lease lands. The refuges are dedicated to wildlife conservation and the lands administered for the major purpose of waterfowl management, but with full consideration to optimum agricultural use.

Lower Klamath NWR was established in 1908 covers 46,912 acres of open water, wetlands, berms, and croplands. On the Oregon side of the refuge in Area K, approximately 5,525 acres are leased by growers for grain, grass hay, and seasonal livestock grazing. Under current policy, row crops may not be grown in Area K.

Tule Lake NWR was established in 1928 and encompasses 39,116 acres of croplands and open water. The open water areas and the marsh are located in Sumps 1A and 1B, Discovery Marsh and Hovey Point. Sumps 1A and 1B are connected by the English Channel and have a combined surface area of 13,000 acres and a maximum depth of 3.6 ft. They are confined by a system of levees or dikes and serve a multipurpose function including endangered species habitat (proposed critical habitat) for the Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers, habitat for migratory waterfowl and other indigenous wildlife, irrigation and flood control. In addition to the endangered Lost River and shortnose suckers, the Bald eagle (Haliaeetus leucocephalus), formerly listed as threatened, is known to visit this refuge. Bald eagle visits during late spring and summer are rare. These listed species are addressed, with regard to lease land and Refuge cooperative farming programs, and integrated pest management, in numerous biological opinions.

The Tule Lake lease land farming program consists of approximately 15,000 acres located predominantly in two distinct locations, Sump 2 and Sump 3. Although up to 25% of the total lease land area may be legally planted to row crops with the remainder planted to small grains and soil building crops, historically row crops account for less than 20 percent of the total lease land acreage (i.e., Lower Klamath and Tule Lake lease lands combined) and less than 30% of the Tule Lake lease lands. This is primarily because row crops are not grown on the Lower Klamath lease lands. Row crops include potatoes, onions, and horseradish while small grains include wheat, barley, and oats. Alfalfa is also grown and falls into the category of soil-building crops. Typically annual row crops, potatoes or onions, are grown in a three-year crop rotation with small grains (e.g., small grain–row crop–small grain) on each lot.

These crops, together with the waste grain and potatoes from the lease lands are a major food source for migrating and wintering waterfowl. Wildlife observation throughout the year and waterfowl hunting in the fall are popular activities within the lease lands.

Site specific information on wildlife use, some pesticide residues, soil types, and climatic data is available upon request.

VI. MANDATORY CONTRACTOR REQUIREMENTS

Contractor’s direct experience in successfully completing screening level risk assessments following the EPAs "Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, USEPA (2004)" is mandatory.

Contractor’s in-depth knowledge of, and direct experience in properly assessing the ecological risk from the use of pesticides (e.g. herbicides, fungicides, biofungicides, and bionematicides) that are commonly associated with alfalfa, onions, potatoes, and small grains is mandatory.

Contractor’s direct experience utilizing the AgDrift and TREX models for pesticide risk assessments is mandatory.

Contractor’s experienced in conducting literature searches on pesticide properties for the purpose of utilizing data for Ecological Risk Assessments is mandatory.

Contractor must have the capacity to produce and submit a final screening level risk assessment for proposed pesticides in the manner described in the Performance Work Statement within 65 calendar days from the initiation of the contract if less than 10 assessment are being conducted (may be extended to 85 days if greater than 10 are requested). Timeline begins the day following a submitted work request.

The deliverables for this contract are expected to be derived from existing literature; no site-specific field work is expected or required.

All work related to development of the chemical profiles, and associated products, will be organized and completed in coordination with Reclamation staff specifically the Contracting Officer's Technical Representative (COR).

VII. TASKS

Contractor will complete the following general tasks:

Task 1 - Literature Review of Ecotoxicology Data;

Task 2 - Literature Review of Environmental Fate Data; and Task 3 - Determination of Terrestrial and Aquatic Estimated Environmental Exposure, including calculation of Risk Quotients.

Scientific literature search will be conducted through available online databases and capped at first 10 high‐relevance articles. The following online databases will be used for compiling information for the PUP chemical profiles:

– Compendium of common names ‐ http://www.alanwood.net/pesticides/

– ECOTOX ‐ https://cfpub.epa.gov/ecotox/ecotox_home.cfm

– PAN Pesticide Database ‐ http://www.pesticideinfo.org/

– Pesticide Properties Database ‐ http://sitem.herts.ac.uk/aeru/ppdb/en/

– ARS pesticide properties database ‐ https://www.ars.usda.gov/northeast‐ area/beltsville‐md/beltsville‐agricultural‐research‐center/crop‐systems‐and‐ global‐change‐laboratory/docs/ppd/pesticide‐list/

– EXTOXNET ‐ http://extoxnet.orst.edu/

– EPA Pesticide Chemical Search ‐ https://iaspub.epa.gov/apex/pesticides/f?p=CHEMICALSEARCH:1:

– EPA Pesticide Product Label Search https://iaspub.epa.gov/apex/pesticides/f?p=PPLS:1

– CA Dept of Pest Regulation Tox Data Reviews ‐ http://www.cdpr.ca.gov/docs/risk/toxsums/toxsumlist.htm

– CA Dept of Pest Regulation Environmental Fate Reviews http://www.cdpr.ca.gov/docs/emon/pubs/envfate.htm

The final contract will include a Chemical Profile (Appendix B) and a Determination Summary (Appendix C) .Contractor will present information following instructions and examples listed in Appendixes B-C, which includes: instructions on how to complete a Chemical Profile, an example of a Chemical Profile, and an example of a Determination Summary. In addition final model runs on T-REX and AgDRIFT models will be saved and submitted with the final product. Three general types of assessments will be conducted, depending on the type of AI, a “Simple” assessments, “Complex” assessments, and Programmatic Reviews of Previously Evaluated AIs. The differentiation of the different types is based on level of effort.

Task 1 – Literature Review of Ecotoxicology Data

Contractor will collect available toxicological endpoint data for acute and chronic toxicity to mammals, birds, fish, aquatic invertebrates, aquatic plants, and pollinators. If no data is listed for a particular taxonomic group the statement “No data cited in references” will be recorded in the appropriate data entry. Also all references used to select toxicological endpoint data will be cited enclosed in parentheses following the recorded data.

The toxicological endpoint used in the ecological risk assessment for each taxonomic group will be highlighted in the data set. This will usually be the endpoint associated with the most sensitive species in a taxonomic group. If a less sensitive species toxicological endpoint is selected for use a statement will be included in the data set briefly explaining the rationale for selecting an endpoint of a less sensitive species. Toxicological endpoints for aquatic species will be limited to freshwater species. Toxicology data associated with first order degradates will be included, if available.

Mammalian LD50 - For all test species listed in the scientific literature record the oral lethal dose (LD50) in mg/kg bw (body weight) or mg/kg diet. Most common test species listed in scientific literature are rats and mice.

Mammalian Reproduction - For all test species listed in the scientific literature record the appropriate reproductive test procedure(s) (e.g., generational studies (preferred), fertility, new born weight, etc.), test results (e.g., LOEC, NOEL, NOAEC, etc.) in mg/kg, and list references for each data entry. Most common test species listed in scientific literature are rats and mice.

Avian LD50 - For all test species listed in the scientific literature record the oral lethal dose (LD50) in mg/kg bw (body weight) or mg/kg diet. Most common test species listed in scientific literature are bobwhite quail and mallard duck. Use of this data to select toxicological endpoints for risk assessment to birds will be subject to availability of and secondary to Avian Dietary LC50 data.

Avian Dietary LC50 - For all test species listed in the scientific literature record the dietary lethal concentration (LC50) in ppm. Most common test species listed in scientific literature are bobwhite quail and mallard duck. Use of this data to select toxicological endpoints for risk assessment to birds is preferred over Avian LD50 data.

Avian Reproduction - For all test species listed in the scientific literature record the appropriate reproductive test procedure(s) (e.g., early life cycle, reproductive, etc.), test results (e.g., LOEC, NOEL, NOAEC, LOAEC, etc.) in ppm, and list references for each data entry. Most common test species listed in scientific literature are bobwhite quail and mallard duck.

Fish LC50 - For all test freshwater species listed in the scientific literature record the lethal concentration (LC50) in ppm. Most common test species listed in scientific literature are bluegill, rainbow trout and fathead minnow. Test results for many game species may also be available.

Fish Early Life Stage (ELS)/Life Cycle - For all test freshwater species listed in the scientific literature record the appropriate test procedure(s) (e.g., early life cycle, life cycle, etc.), test results (e.g., LOEC, NOEL, NOAEC, LOAEC, etc.) in ppm, and list references for each data entry.

Other - For all test aquatic invertebrate and non-vascular and vascular plant species listed in the scientific literature record the environmental concentration (EC50) in ppm. Most common test invertebrate species listed in scientific literature is the water flea, Daphnia magna, honey bee (Apis spp.), Green algae (Selenastrum capricornutum) and pondweed (Lemna minor) are frequent test species for aquatic non-vascular and vascular plants, respectively. Toxicology data for honeybees will also be included in the literature review, if available.

B. Task 2 – Literature Review of Environmental Fate Data Contractor will conduct a literature review, including citations/sources, on the following environmental fate data:

Persistence – Defined as the potential for a pesticide to remain in the environment. Persistence is generally measured as the time it takes for half of the amount of pesticide to dissipate or degrade. Half-life units are usually expressed in days. Another measure of pesticide persistence is dissipation time (DT50). Dissipation time represents the rate at which a pesticide degrades and its movement from a site, whereas half-life describes the rate of degradation only. As with half-life units for dissipation is usually expressed in days.

All half-life or dissipation data that may be useful for inclusion in a quantitative or qualitative analysis will be included in the review. Available half-life degradation mechanisms such as: photolysis, chemical, and microbial degradation will be included in the review. First-order degradation products and associated half-life will be recorded when the data is available.

Soil Absorption – The degree of pesticide adsorption to soil particles and organic matter (Kerle, et. al., 1996) is expressed as the soil adsorption coefficient (Koc). The soil adsorption coefficient is generally expressed as micrograms of pesticide per gram of soil (ug/g), and can range from near zero to the thousands. All soil absorption that may be useful for inclusion in a quantitative or qualitative analysis will be included in the review, citation/sources are expected.

Solubility – Water solubility describes the amount of pesticide that will dissolve in a known quantity of water. The water solubility of a pesticide is expressed as milligrams of pesticide dissolved in a liter of water (mg/l or ppm). All solubility data that may be useful for inclusion in a quantitative or qualitative analysis will be included in the review, citation/sources are expected.

Volatilization - Pesticides may volatilize from soil and plant surfaces and move off-target into the atmosphere. The potential for a pesticide to volatilize is determined by the pesticide’s vapor pressure which is affected by temperature, absorption, soil moisture and the pesticide’s water solubility. Vapor pressure is often expressed in mm Hg. To make these numbers easier to compare, vapor pressure will be multiplied by 107 producing a vapor pressure index. All volatilization data that may be useful for inclusion in a quantitative or qualitative analysis will be included in the review, citation/sources are expected.

Translocation - Indicate whether or not the pesticide will move (translocate) within plant tissue after application. Also include the translocation mechanism if cited in the scientific literature.

Bioaccumulation - Record the water/octanol partition coefficient (Kow), bioaccumulation factor (BAF), and/or the bioconcentration factor (BCF) reported in the literature. If the Kow, BAF or BCF is not reported, sometimes bioaccumulation potential is reported in general categories such as high, moderate, low or no potential for bioaccumulation.

C. Task 3 - Determining Estimated Environmental Exposure and Risk Quotient Calculation

Terrestrial EEC - The estimated environmental concentration (EEC) for terrestrial exposure will first be calculated using the USEPA screening-level approach (USEPA, 2004). This approach varies depending on the proposed pesticide application method. For spray applications, exposure is determined using the Kanaga nomogram method (USEPA 2005a, USEPA 2004, Pfleeger et al. 1996) which is used to estimate exposure through dietary intake of a single pesticide. The computer program used is the USEPA’s Terrestrial Residue Exposure model (T-REX) version 1.2.3 (USEPA 2005b). The Kanaga nomogram method uses the maximum pesticide application rate (i.e., pounds active ingredient per acre), number of applications, application interval (i.e., days), pesticide half-life (i.e., days) and duration of exposure (i.e., time weighted average (TWA) in days) to estimate the initial pesticide residue concentration on general food item categories for terrestrial vertebrate species. Specific information on the proposed application method, timng, number of applications, and application rate will be incorporated into the model. These categories are short grasses (<20 cm tall), tall grasses (>20 cm tall), broadleaf plants/small insects, and fruits/pods/seeds/large insects, with an EEC of 240, 110, 135, and 15 ppm, respectively. Although these categories do not reflect the carnivorous diet of bald eagles, they represent potential exposure through the diet of avian and mammalian prey items. This approach will provide a conservative screen for compounds that do not biomagnify. Additional variable inputs included in the T-REX model are the weight of the surrogate species and Mineau scaling factors (Mineau, et. al. 1996). Body weight of two common test species, bobwhite quail and mallard, are included in the T-REX spreadsheet by default. Body weights of other organisms (Table 1) are entered manually. The Mineau scaling factor takes into account that small-bodied bird species may be more sensitive to pesticide exposure than would be predicted by body weight alone. Mineau scaling factors are entered manually. The values range from 1 to 1.55 and are unique to a particular pesticide or group of pesticides. Without specific information to select a scaling factor a default value of 1.15 is used. Entering zero is also an option if it is determined that body weight does not influence toxicity of pesticide(s) being assessed. The results (i.e., outputs) from the T-REX Kanaga nomogram are presented as average and upper bound estimates. Upper bound estimates will be used for predicting environmental concentration of pesticides and ecological risk. This approach will contribute to a conservative estimate of ecological risk. All models will reflect application type (e.g. broadcast, in-furrow, banded) and formulation (e.g. granular, liquid). These adjustments can be made on the INPUTS tab of the TREX model. The USEPA’s Terrestrial Residue Exposure model (T-REX) version 1.2.3 (USEPA 2005b) contains a submodel which automates Kanaga exposure calculations for granular pesticides and treated seed.

TREX uses the following equation to calculate a risk quotient based on the estimated environmental concentration. The EEC is divided by the surrogate LD50 toxicological endpoint multiplied by the body weight (Table 1) of the surrogate.

Risk Quotient = Estimated Environmental Concentration / [LD50 (mg/kg) * body weight (kg)]

As with other risk assessments a risk quotient exceeding a Level of Concern is a presumption of unacceptable ecological risk. A risk quotient less than a Level of Concern is a presumption of acceptable risk.

Table 1. Average body weight of selected terrestrial wildlife species often used in research to establish toxicological endpoints (Dunning 1984).

A Kanaga nomogram will be used to produce a maximum EEC value and an average daily concentration value over a specified interval of time referred to as a time-weighted-average (TWA), as created by T-REX residue exposure models. Maximum EEC will be used as the EEC input for both acute and chronic risk assessments in the screening-level assessment. The initial or maximum EEC produced by the Kanaga nomogram represents the maximum expected instantaneous or acute exposure to a pesticide. Acute toxicity endpoints are determined using a single exposure to a known pesticide concentration typically for 48 to 96 hours. Contractor will also, provide the number of days the estimated environmental concentration exceeds the Level of Concern, in order to gain insight into chronic risk.

The length of time used to calculate the TWA can have a substantial effect on the exposure estimates and there is no standard method for determining the appropriate duration for this estimate. The T-REX model assumes a 21-week exposure period which is equivalent to avian reproduction studies designed to establish a steady-state concentration for bioaccumulative compounds. However, this does not necessarily define the true exposure duration needed to elicit a response. Pesticides which do not bioaccumulate may achieve a steady-state concentration earlier than 21 weeks. The duration of time for calculating TWAs will require justification and will not exceed the duration of exposure in the chronic toxicity test, approximately 70 days for the standard avian reproduction study. An alternative to using the duration of the chronic toxicity study is to base the TWA on the application interval. In this case, increasing the application interval will suppress both the estimated peak pesticide concentration and the TWA. Another alternative to using TWAs is to consider the number of days that a chemical is predicted to exceed the LOC.

Exposure to metabolites and degradation products that are known to be toxicologically significant will be assessed using the same quantitative procedures used to assess direct exposure to the parent compound provided sufficient applicable data is available for the degradation products. Assessments of degradation products will be limited to first-order degradation, and will be dependent on available data.

Iterative changes to application rate, number of applications and application interval should be made to achieve an estimated environmental concentration which produces an acceptable risk quotient value. Final input values must be compliant with the pesticide use patterns described in the product label.

Selection of a Level of Concern for comparison to a risk quotient value is based on the likelihood of a taxonomic group (listed or nonlisted) to be present in or near the action area (Table 2). When assessing risk contractor will assume the Lost River and shortnose suckers are continuously present within the action area. Therefore, the selection of the Level of Concern for fish will be for listed species (e.g., 0.05). Bald eagle presence within the lease lands is seasonal. The selection of the Level of Concern for bald eagles will be the value for listed species (e.g., 0.1) from October through April, and for non-listed species (e.g., 0.5) from May through September.

Table 2. Presumption of unacceptable risk for birds, fish, and mammals (USEPA 2004).

Aquatic EEC - The primary pathway of exposure of fish to spray applied products is assumed to be particle drift immediately following aerial, ground and chemigation pesticide application. The AgDRIFT computer model will be used to assess this spray drift pathway. The AgDRIFT® model version 2.1.1 will be used to estimate drift of pesticides to Refuge aquatic resources from aerial and ground pesticide applications.

The AgDRIFT model is composed of submodels called tiers. Contractor will use the Tier I Ground submodel to assess ground pesticide applications, and the Tier III Aerial Agricultural submodel for assessment of aerial pesticide applications. Tier outputs are dependent on inputs. Inputs are based on pesticide use proposal restrictions, input from local applicators, local environmental conditions, and spatial characteristics of sumps, canals and drains within the Federal lease lands (Table 3).

Iterative changes to a pesticide’s use pattern (i.e., application rate, number of applications, application interval and buffer zone) may be made to calculate an initial or maximum estimated environmental concentration which produces a risk quotient value that does not exceed the appropriate level of concern (Table 2). Additive effects of multiple applications (if applicable) to the EEC value will be calculated, and highest value will be used to determine risk quotient. This will be used to determine the optimum buffer zone for a pesticide use pattern. Final application rate, number of applications, and application interval for a specific pesticide product must be compliant with the pesticide product label. Distance between the nearest wetted or sprayed edge of a pesticide application to the nearest edge of a sensitive site such as a water body is defined as the buffer zone. Minimum buffer zones are listed on Table 4.

Spray Drift. – The Spray Drift Task Force AgDRIFT Tier III Aerial Agricultural submodel requires twenty variable inputs in order to calculate an estimated pesticide concentration deposited a given distance from the edge of a treatment site. The type of aircraft, spray equipment configuration such as boom extent and nozzle selection, and operational environment including wind direction, wind speed, nonvolatile fraction of the spray material and boom height can have a substantial effect on potential pesticide drift.

Four different aircraft models are currently used to apply pesticides to crops within the federal lease lands. Each aircraft has different flight and operational characteristics influencing pesticide drift produced during flight operations. Contractor will use, as a surrogate, the aircraft configuration that produces the greatest drift potential (Table 5).

Table 3. Input variables for AgDRIFT simulations used to determine aquatic estimated environmental concentrations.

Table 4. Minimum buffer zones used on the lease lands.

Table 5. Predicted initial average pesticide concentration (ppt) due to drift from different aircraft configurations at incrementally greater distance from an application site.

Wind direction is assumed to be perpendicular to and blowing toward the edge of the field (e.g., -90o) nearest the sensitive site being modeled. This will produce the maximum possible exposure. Wind speed will be assumed to be a constant maximum 7 miles per hour in the models. Pesticide applications on the Federal lease lands by Service policy must be discontinued when wind speed exceeds 7 miles per hour.

Spray droplet size distribution is assumed to be ASAE medium for risk assessment purposes. An ASAE fine to medium droplet size distribution is the recommended default value by the Spray Drift Task Force in lieu of site specific information regarding application equipment setup and operation. Interviews with local commercial pesticide applicators (Buske, et. al., 2004) indicate a medium spray droplet distribution is achievable without sacrificing pesticide efficacy and, in some instances, is routinely used. Assuming a medium spray droplet size distribution is routinely produced by spray equipment on the lease lands will produce a neutral estimate for exposure and ecological risk.

The boom height used in models will be 8 feet for aerial applications and 20 inches (e.g., low boom input for AgDrift model) for ground applications. The Spray Drift Task Force reports that typically the boom height for aerial applications is 7 to 8 feet (SDTF, 1997). Local aerial applicators report the boom height to be 6.5 to 8 feet (Buske, et. al., 2004). Boom height for ground applications will depend upon nozzle type. Commercial applicators report regular flat fan nozzles are frequently used for ground applications, although flood tip nozzles may be used in some instances. Nozzle manufacturers recommended boom height for these types of nozzles is 20 inches. The current assumption of an aerial boom height of 8 feet and 20 inches for ground applications will produce a neutral estimate of drift potential for aerial and ground applications.

Averaging Times for Aquatic Exposure. – Contractor will assume an instantaneous peak concentration for acute risk assessments. For acute risk assessments there is no averaging time for exposure. The use of the instantaneous peak assumes that instantaneous exposure is of sufficient duration to elicit acute effects comparable to those observed over more protracted exposure periods tested in the laboratory, typically 48 to 96 hours. In the absence of data regarding time-to-toxic event analyses and latent responses to instantaneous exposure risk will likely be overestimated.

For chronic exposure risk assessments, the averaging times considered for exposure are commensurate with the duration of invertebrate life-cycle or fish-early life stage tests (i.e., 21-28 days and 56-60 days, respectively). Response profiles (i.e., time to effect and latency of effect) to pesticides likely vary widely with mode of action and species and should be evaluated on a case-by-case basis as available data allow. Nevertheless, because the USEPA relies on chronic exposure toxicity endpoints based on a finding of no observed effect, the potential for any latent toxicity effects or averaging time assumptions to alter the conclusions of an acceptable chronic risk assessment prediction is limited. The extent to which duration of exposure from aqueous concentrations overestimate or underestimate actual exposure depends on several factors. These include localized meteorological conditions, runoff characteristics of the watershed (i.e., soils and topography), the hydrological characteristics of receiving waters, environmental fate of the pesticide active ingredient, and the method of pesticide application. It should also be understood that chronic effects studies are performed using a method that holds water concentration in a steady state. This method is not likely to reflect conditions associated with pesticide runoff. Pesticide concentrations in the field increase and decrease in surface water on a cycle influenced by rainfall, pesticide use patterns and degradation rates. Due to the dependency of this assumption on several undefined variables risk associated with chronic exposure may in some situations underestimate risk and in other situations overestimate risk.

The EEC value derived from this process will be divided by the surrogate LD50 toxicological endpoint multiplied by the body weight (Table 2) of the surrogate to determine a risk quotient.

Risk Quotient = Estimated Environmental Concentration / [LD50 (mg/kg) * body weight (kg)]

VIII. Literature Cited

Dunning, J.B. 1984. Body weights of 686 species of North American birds. Western Bird Banding Assoc. Monograph No. 1.

Kerle, E.A., J.J. Jenkins, and P.A. Vogue. 1996. Understanding pesticide persistence and mobility for groundwater and surface water protection. Extension Publication EM 8561, Oregon State University Extension Service, Corvallis, OR. 8 pp.

Mineau, P., B.T. Collins, and A. Baril. 1996. On the use of scaling factors to improve interspecies extrapolation to acute toxicity in birds. Reg. Toxicol. Pharmacol. 24:24-29.

Pfleeger, T.G., A. Fong, R. Hayes, H. Ratsch, C. Wickliff. 1996. Field evaluation of the EPA (Kanaga) nomogram, a method for estimating wildlife exposure to pesticide residues on plants. Env. Toxicol. Chem. 15:535-543.

Spray Drift Task Force. 1997a. A summary of ground application studies. Spray Drift Task Force, Macon, Missouri. 5 pp.

Spray Drift Task Force. 1997b. A summary of chemigation application studies. Spray Drift Task Force, Macon, Missouri. 5 pp.

Spray Drift Task Force. 1997c. A summary of aerial application studies. Spray Drift Task Force, Macon, Missouri. 7 pp.

U.S. Environmental Protection Agency. 2005a. Technical overview of ecological risk assessment risk characterization; Approaches for evaluating exposure; Granular, bait, and treated seed applications.

U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, D.C. http://www.epa.gov/oppefed1/ecorisk_ders/toera_analysis_exp.htm.

U.S. Environmental Protection Agency. 2005b. User’s Guide TREX v1.2.3. U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, D.C. 22 pp. http://www.epa.gov/oppefed1/models/terrestrial/trex_usersguide.htm.

U.S. Environmental Protection Agency. 2004. Overview of the ecological risk assessment process in the Office of Pesticide Programs, U.S. Environmental Protection Agency: endangered and threatened species effects determinations, Office of Pesticide Programs, Washington, D.C. 101 pp.

Appendix A. Instructions for Completing the Pesticide Use Proposal Chemical Profile

The following instructions are for completing the Pesticide Use Proposal Chemical Profile. All sections and categories will be completed. If no information is listed for a section or category an explanatory note citing the reason for no data entry will be recorded in the appropriate section or category. Following a general review of pertinent literature resources (Appendix D) appropriate general information, toxicological endpoints, incident reports, environmental fate, ecological risk assessments, proposed pesticide use pattern, justification and possible alternatives for the proposed pesticide use pattern, and literature citations shall be recorded on the Pesticide Use Proposal Chemical Profile. Each data entry will be referenced with all applicable references cited. Following review of available data ecological risk assessments will be calculated and recorded in the ecological risks section of the Chemical Profile.

Date: Record the date in which the Chemical Profile is completed. Chemical Profile (e.g., currently approved pesticide use patterns) will be periodically reviewed and updated. Reviews will be every four years. Each review date should be recorded on the Profile to document when the Profile was reviewed and updated. All previous review dates should remain listed in reverse chronological order to establish a complete administrative record.

Trade Name: Record the trade name on the pesticide label. Include the full trade name and suffix that describes the formulation (i.e., WP, DG, EC, L, SP, I, II or 64) and concentration of the active ingredient. The suffix often distinguishes a specific product among several pesticides with the same name indicating differences in formulation or percent active ingredient, or other difference.

Common chemical name: Record the common name listed on the pesticide label or material safety data sheet for the active ingredient. The common name of a pesticide is the name listed as the active ingredient on the title page of the product label immediately following the trade name, and material safety data sheet, Section 2: Composition/ Information on Ingredients.

Pesticide Type: Record the type of pesticide. Use one of the following terms: dessicant, fungicide, fumigant, growth regulator, herbicide, insecticide, pisicide, rodenticide, etc.

EPA Registration Number: This number will be identified as the EPA Registration Number (e.g., EPA Reg. No.) appearing on the title page of the label and Material Safety Data Sheet, Section 1: Chemical Product and Company Description. Do not mistake the EPA Establishment Number for the EPA Registration Number which is usually located near the Registration Number.

Pesticide Class: List the general chemical class the pesticide represents. For example, malathion is an organophosphate, carbaryl is a carbamate, etc. It would also be helpful to list the group classification. For example, strobulin fungicides (e.g., azoxystrobulin) is a Group 11 fungicide.

CAS (Chemical Abstract Service) Number: This number is often located in the 2nd section (Composition/Information on Ingredients) of the Material Safety Data Sheet. The MSDS table listing components usually contains this number immediately prior to or following the percent composition.

California (CA) and Oregon (OR) Registration: Determine whether or not a pesticide and its proposed use pattern is registered for use in California and/or Oregon. Enter an “Active” if the pesticide product and use pattern is registered for use in the respective state, or “Not Active” if the proposed product and use pattern is not registered. This information can be retrieved from on-line databases maintained by the California Department of Pesticide Regulation and Oregon Department of Agriculture (Appendix D).

Other Ingredients: Inspect the most recent Material Safety Data Sheet for the proposed pesticide product. Include any compounds in the pesticide formulation not listed as an active ingredient that are described as toxic or hazardous, or regulated under the Superfund Amendments and Reauthorization Act (SARA), Comprehensive Environmental Response, Compensation, and Liability Act (CEECLA), Toxic Substances Control Act (TSCA), Occupational Safety and Health Administration (OSHA), State Right-to-Know, or other listed authorities. These are usually found in sections of the Material Safety Data Sheet titled “Hazardous Identifications”, “Exposure Control/Personal Protection”, and “Regulatory Information”. If concentration of other ingredients is available for any compounds identified as toxic or hazardous include that information in the Chemical Profile, too. Material Safety Data Sheet(s) may be obtained from the manufacturer, manufacturer’s website or from an on-line database maintained by Crop Data Management Systems, Inc. (Appendix D).

Toxicological Endpoints: Toxicological endpoint data must be collected for acute and chronic toxicity to mammals, birds, fish, aquatic invertebrates and aquatic plants. Data will be recorded for all species listed in the scientific literature. If no data is listed for a particular taxonomic group the statement “No data cited in references.” will be recorded in the appropriate data entry. Also all references used to select toxicological endpoint data will be cited enclosed in parentheses following the recorded data.

The toxicological endpoint used in the ecological risk assessment for each taxonomic group will be highlighted in the data set. This will usually be the endpoint associated with the most sensitive species in a taxonomic group. If a less sensitive species toxicological endpoint is selected for use a statement will be included in the data set briefly explaining the rationale for selecting an endpoint of a less sensitive species. Toxicological endpoints for aquatic species will be limited to freshwater species.

Mammalian LD50: For all test species listed in the scientific literature record the oral lethal dose (LD50) in mg/kg bw (body weight) or mg/kg diet. Most common test species listed in scientific literature are rats and mice.

Mammalian Reproduction: For all test species listed in the scientific literature record the appropriate reproductive test procedure(s) (e.g., generational studies (preferred), fertility, new born weight, etc.), test results (e.g., LOEC, NOEL, NOAEC, etc.) in mg/kg, and list references for each data entry. Most common test species listed in scientific literature are rats and mice.

Avian LD50: For all test species listed in the scientific literature record the oral lethal dose (LD50) in mg/kg bw (body weight) or mg/kg diet. Most common test species listed in scientific literature are bobwhite quail and mallard duck. Use of this data to select toxicological endpoints for risk assessment to birds will be subject to availability of and secondary to Avian Dietary LC50 data.

Avian Dietary LC50: For all test species listed in the scientific literature record the dietary lethal concentration (LC50) in ppm. Most common test species listed in scientific literature are bobwhite quail and mallard duck. Use of this data to select toxicological endpoints for risk assessment to birds is preferred over Avian LD50 data.

Avian Reproduction: For all test species listed in the scientific literature record the appropriate reproductive test procedure(s) (e.g., early life cycle, reproductive, etc.), test results (e.g., LOEC, NOEL, NOAEC, LOAEC, etc.) in ppm, and list references for each data entry. Most common test species listed in scientific literature are bobwhite quail and mallard duck.

Fish LC50: For all test freshwater species listed in the scientific literature record the lethal concentration (LC50) in ppm. Most common test species listed in scientific literature are bluegill, rainbow trout and fathead minnow. Test results for many game species may also be available.

Fish Early Life Stage (ELS)/Life Cycle: For all test freshwater species listed in the scientific literature record the appropriate test procedure(s) (e.g., early life cycle, life cycle, etc.), test results (e.g., LOEC, NOEL, NOAEC, LOAEC, etc.) in ppm, and list references for each data entry. Most common test species listed in the scientific literature are bluegill, rainbow trout and fathead minnow. Test results for many game species may also be available.

Other: For all test aquatic invertebrate and non-vascular and vascular plant species listed in the scientific literature record the environmental concentration (EC50) in ppm. Most common test invertebrate species listed in scientific literature is the water flea, Daphnia magna. Green algae (Selenastrum capricornutum) and pondweed (Lemna minor) are frequent test species for aquatic non-vascular and vascular plants, respectively.

Environmental Fate: Environmental fate data is important for determining how long a pesticide will remain in the environment, expected environmental concentration over time, mechanisms for degradation and partitioning in the environment. This information will also indicate the potential for off-target movement of a pesticide and the environmental conditions conducive to off-target movement. Information will be recorded for pesticide mobility (i.e., water solubility), persistence, bioaccumulation, and whether or not a pesticide mode of action is systemic.

Mobility: Record the soil adsorption coefficient (Koc) and/or water solubility (mg/l or ppm) of the proposed pesticide. Also record any qualifying data that may be pertinent to interpreting the potential for a pesticide to move off-target and contaminate natural resources.

Persistence: Persistence is the potential for a pesticide to remain in the environment. Half-life is the amount of time required for one-half of the amount of a pesticide in the soil or water to dissipate or degrade. Half-life (DT50) units are usually expressed in days. Record all half-life data that may be useful for interpretation or inclusion in a quantitative or qualitative analysis. Half-life data is usually available for aquatic and terrestrial environments including the mechanisms for degradation/metabolism and by-products. Field dissipation half-life is the preferred half-life data. However, in lieu of field dissipation data soil half-life or aerobic soil metabolism is germane for terrestrial applications. Hydrolysis, aerobic or anaerobic metabolism depending upon habitat conditions is germane for aquatic habitats. Generally the longest aquatic and terrestrial half-life will be selected for inclusion in quantitative analysis. Record degradation mechanisms which may include photolysis, microbial, and chemical degradation and associated half-lifes.

Record first-order degradation and metabolism by-products if this information is cited in the literature. A separate risk assessment may be necessary for by-products.

Translocation: Indicate whether or not the pesticide will move (translocate) within plant tissue after application. Also include the translocation mechanism if cited in the scientific literature.

Bioaccumulation: Record the water/octanol partition coefficient (Kow), bioaccumulation factor (BAF), and/or the bioconcentration factor (BCF) reported in the literature. If the Kow, BAF or BCF is not reported, sometimes bioaccumulation potential is reported in general categories such as high, moderate, low or no potential for bioaccumulation.

Ecological Risk: Record results of the estimated risk quotient for birds, mammals (e.g., Kanaga nomogram), fish (e.g., AgDrift computer model), and other species of interest (e.g., AgDrift computer model).

Avian & Mammalian: Record the assessed pesticide use pattern (application rate, number of applications, method(s) of application). Record the calculated risk quotient for each food item category for both acute and chronic toxicities.

Fish: Record the treatment buffer distance, a minimum default distance equal to 25 feet, in which the calculated risk quotient is equal to one. Include risk assessments for acute and chronic toxicities, and all proposed methods of application. The AgDrift computer model reports estimated environmental exposure for both aerial and ground applications in parts per trillion (ppt). Convert parts per trillion to parts per million for ease of comparing estimated environmental concentration to the selected toxicological endpoint. Toxicological endpoints recorded in the pesticide use proposal chemical profile are reported in parts per million.

Other species: This includes risk assessments for aquatic invertebrates, amphibians, and aquatic vascular and non-vascular plants. Record the treatment buffer distance, a minimum default distance equal to 25 feet, in which the calculated risk quotient is equal to one. Include risk assessments for acute and chronic toxicities, and all proposed methods of application. The AgDrift computer model reports estimated environmental exposure for both aerial and ground applications in parts per trillion (ppt). Convert parts per trillion to parts per million for ease of comparing estimated environmental concentration to the selected toxicological endpoint. Toxicological endpoints recorded in the pesticide use proposal chemical profile are reported in parts per million.

Agronomics: Record the maximum number of applications, the maximum application rate (pounds active ingredient per acre) and the minimum application interval (days) proposed in the pesticide use proposal. Also report target pest(s) and alternative pesticide(s) previously approved for use or are currently under consideration for use under the proposed action. This information will be provided to the contractor.

References: List all scientific resources used to provide information for the Chemical Profile. Use standard literature citation procedures, and sequentially number the literature citations. All data entries will be individually referenced with all applicable references cited.