HERBICIDE USE, AN ASSESSMENT OF HUMAN HEALTH AND ECOLOGICAL RISK

Transcription

1 HERBICIDE USE, AN ASSESSMENT OF HUMAN HEALTH AND ECOLOGICAL RISK FOR DANIEL BOONE NATIONAL FOREST Prepared by: ROBERT SITZLAR, FOREST SILVICULTURIST DAVID TAYLOR, FOREST BOTANIST April

2 USDA NON-DISCRIMINATION POLICY STATEMENT DR USDA Equal Opportunity Public Notification Policy (June 2, 2015) In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or USDA s TARGET Center at (202) (voice and TTY) or contact USDA through the Federal Relay Service at (800) Additionally, program information may be made available in languages other than English. To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online at and at any USDA office or write a letter addressed to USDA and provide in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C ; (2) fax: (202) ; or (3) program.intake@usda.gov. USDA is an equal opportunity provider, employer and lender. I

3 Table of Contents Introduction... 1 Resource Indicators and Measures... 4 Affected Environment... 4 Existing Condition... 4 Management Direction... 4 Desired Condition... 4 Regulatory Framework... 4 Environmental Consequences... 5 Methodology... 5 Alternative A No Action... 6 Direct, Indirect and Cumulative Effects... 6 Alternative B Proposed Action... 6 Direct and Indirect Effects... 8 Clopyralid... 9 Endothall Glyphosate Treatment # Glyphosate Treatment # Glyphosate Treatment # Glyphosate Treatment # Glyphosate Treatment # Glyphosate Treatment # Glyphosate Treatment # Imazapic Treatment Imazapyr Treatment # Imazapyr Treatment # Imazapyr Treatment # i

4 Triclopyr Formulations Triclopyr Treatment # Triclopyr Treatment # Triclopyr Treatment # Triclopyr Treatment # Triclopyr Treatment # Triclopyr Treatment # Triclopyr Treatment # Cumulative Effects Alternative C (No Herbicides) Direct, Indirect, and Cumulative Effects List of Tables Table 1: Resource Indicators and Measures for Assessing Effects from using herbicides... 4 ii

5 INTRODUCTION The Invasive Plant Species Treatment proposal includes application of herbicides as a treatment method to control invasive plant species. The Forest Service places high priority on human and ecological health and safety. This is one of the reasons why the use of pesticides in forestry activities on National Forests must be based on analysis of effectiveness, specificity, environmental impact, economic efficiency and human exposure. To assess the potential health effects of pesticides used in major forest programs and activities, pesticide Human Health and Ecological Risk Assessments are prepared. These documents are used to determine the probability of adverse effects to humans, wildlife, and the environment from the use of pesticides. ( Forest managers frequently make decisions regarding the use of pesticides on forest lands. These decisions must be based not only on the effectiveness of these tools, but also on an understanding of the risks associated with their use. For the pesticides commonly used by the Forest Service in its management activities, Human Health and Ecological Risk Assessments (HERAs) are prepared. In these documents, the process of risk assessment is used to quantitatively evaluate the probability (i.e. risk) that a pesticide use might pose harm to humans or other species in the environment. It is the same assessment process used for regulation of allowable residues of pesticides in food, as well as safety evaluations of medicines, cosmetics, and other chemicals. The Forest Service incorporates relevant information from the HERA into environmental assessment documents prepared for pesticide projects, and are used to guide decision-making and to disclose to the public potential environmental effects. Risk is defined as the likelihood that an effect (injury, disease, death or environmental damage) may result from a specific set of circumstances. It can be expressed in quantitative or qualitative terms. While all human activities carry some degree of risk, some risks are known with a relatively high degree of accuracy, because data have been collected on the historical occurrence of related problems (e.g., lung cancer caused by smoking, auto accidents caused by alcohol impairment, and fatalities resulting from airplane travel). For several reasons, risks associated with activities including exposure to chemicals such as pesticides cannot be so readily determined. The process of risk assessment helps evaluate the risks resulting from these situations. When evaluating risks from the use of pesticides proposed in a NEPA planning document, reliance on U.S. EPA s pesticide registration process as the sole demonstration of safety is insufficient. The Forest Service and Bureau of Land Management were involved in court cases in the early 1980 s that specifically addressed this question (principally Save Our Ecosystems v. Clark, 747 F.2d 1240, 1248 (9th Circuit, 1984) and Southern Oregon Citizens v. Clark, 720 F. 2d 1475, 1480 (9th Cir. 1983)). These court decisions and others affirmed that although the Forest Service can use U.S. EPA toxicology data, it is still required to do an independent assessment of the safety of pesticides rather than relying on FIFRA registration alone. The Courts have also 1

6 found that FIFRA does not require the same examination of impacts that the Forest Service is required to undertake under NEPA. Further, Forest Service assessments consider data collected from both published scientific literature and data submitted to U.S. EPA to support FIFRA product registration, whereas U.S. EPA utilizes the latter data only. The U.S. EPA also considers many forestry pesticide uses to be minor. Thus, the project-specific application rates, spectrum of target and non-target organisms, and specialized exposure scenarios evaluated by the Forest Service are frequently not evaluated by U.S. EPA in its generalized registration assessments. Risk assessment documents and worksheets have been developed for a number of pesticides that are used by the Forest Service. Existing risk assessments may be used in lieu of a projectspecific risk assessment. ( Risk assessment worksheets are a computational tool developed for the USDA Forest Service by Syracuse Environmental Research Associates, Inc. (SERA). These worksheets perform many of the calculations used in the Human Health Risk Assessments and Ecological Risk Assessments prepared for many of the pesticides used by the Forest Service. The basic idea of these worksheets is to isolate the computations from the discussions of the computations. The worksheets contain very little discussion and they are intended as a tool to make risk assessment calculations easier to understand and review. Pesticide Coordinators and other technical specialist familiar with HHRAs and ERAs can use these worksheets to develop risk values for the pesticide application rates and application scenarios specific to their particular pesticide project. The Invasive Plant Species Treatment proposal, Alternative B, includes use of the following attachments for each of the herbicides listed below: Clopyralid 1. Human Health and Ecological Risk Assessment Final Report, SERA, Inc., 12/5/ Worksheet (1) (One Microsoft Excel spreadsheet) Endothall 1. Human Health and Ecological Risk Assessment Final Report, SERA, Inc., 11/27/ Worksheet (1) (One Microsoft Excel spreadsheet) Glyphosate 1. Human Health and Ecological Risk Assessment Final Report, SERA, Inc., 3/25/ Worksheet (7) (Seven Microsoft Excel spreadsheets) Imazapic 1. Human Health and Ecological Risk Assessment Final Report, SERA, Inc., 12/23/ Worksheet (1) (One Microsoft Excel spreadsheet) 2

7 Imazapyr 1. Human Health and Ecological Risk Assessment Final Report, SERA, Inc., 12/16/ Worksheet (2)(Two Microsoft Excel spreadsheets) Triclopyr 1. Human Health and Ecological Risk Assessment Final Report, SERA, Inc., 5/24/ Worksheet (14) (Fourteen Microsoft Excel spreadsheets) Worker Exposure: 1. Revised and Corrected Reassessment of Worker Exposure Rates - Final Report, SERA, Inc., 10/13/2013 Disclosure of effects will be evaluated by the Responsible Official in reaching a determination on whether the action significantly affects the quality of the human environment. Significantly as defined by the Regulations for Implementing the Procedural Provisions of the National Environmental Policy Act (40 CFR ) requires consideration of both context and intensity. The context of significance of impacts would be based on effects to workers applying herbicide, public use, vegetation, and wildlife occurring in the local vicinity; the term local being defined as the sites where herbicide treatments occur. The intensity of significance refers to the severity of impact: 1. Impacts may be both beneficial and adverse; 2. The degree to which the action affects public health or safety; 3. Impacts to unique characteristics of the geographic area such as proximity to historic or cultural resources, park lands, prime farmlands, wetlands, wild and scenic rivers, or ecologically critical areas; 4. The degree to which the effects on the quality of the human environment are likely to be highly controversial; 5. The degree to which the possible effects on the human environment are highly uncertain or involve unique or unknown risks; 6. The degree to which the action may establish a precedent for future actions with significant effects or represents a decision in principle about future consideration; 7. Whether the action is related to other actions with individually insignificant but cumulatively significant impacts; 8. The degree to which the action may adversely affect districts, sites, highways, structures, or objects listed in or eligible for listing in the National Register of Historic Places or may cause loss or destruction of significant scientific, cultural, or historical resources; 3

8 9. The degree to which the action may adversely affect an endangered or threatened species or its habitat that has been determined to be critical under the Endangered Species Act of 1973; 10. Whether the action threatens a violation of Federal, State, or local law or requirements imposed for the protection of the environment. Scoping resulted in the Responsible Official identifying an issue related to using herbicides: The forest-wide use of herbicides to eradicate invasive plants will cause persistent water pollution, terrestrial wildlife habitat destruction and threat to human health. RESOURCE INDICATORS AND MEASURES Table 1: Resource Indicators and Measures for Assessing Effects from using herbicides Resource Element Human Health Ecological Risk Resource Indicator Measure Address: Purpose and Need, or key issue? Hazard Quotient (HQ) Hazard Quotient (HQ) AFFECTED ENVIRONMENT EXISTING CONDITION HQ Less than 1.0 (<1.0) HQ Less than 1.0 (<1.0) YES YES Source (Forest Plan S/G; law or policy, BMPs, etc.) Forest Plan Standard DB-VEG-8 Forest Plan Standard DB-VEG-8 This section is not applicable because herbicides are not a resource; rather, herbicides are a tool to be used by managers to accomplish an objective. In this case to control and/or eradicate invasive species as described in the proposal. The results of this analysis will be used by resource specialists to help address the impacts to various resources such as vegetation, wildlife, water, and human health and safety. MANAGEMENT DIRECTION DESIRED CONDITION See Proposal. REGULATORY FRAMEWORK See Proposal Environmental Justice, EO of February 11, 1994 Sites where herbicides would be used is dependent on the presence of invasive species and are not determined based on proximity to low-income or minority populations. Use of herbicide as 4

9 part of this project on other state, federal, or private lands would only occur with written permission of the land-owner. ENVIRONMENTAL CONSEQUENCES METHODOLOGY For each herbicide proposed for use an analysis of risk was conducted using the SERA Risk Assessment spreadsheets. Treatment methods and application rates were entered into these spreadsheets. The output is a series of Hazard Quotients (HQ) for human health and for ecological resources that represent extreme situations. The spreadsheet discloses HQs for a variety of scenarios including accidental exposure and situations that are highly unlikely occurrences within treatment areas. Several of the scenarios result in HQs that exceed 1.0. This does not mean that unacceptable impacts exist or the action should not occur. The results from the spreadsheet assessments were interpreted and project design criteria and protective measures taken into consideration. The result of this interpretation is that the use of these herbicides as proposed are within the range of acceptable risk (HQ<1.0) to human health and ecological resources. Hazard Quotients for accidental scenarios, while they provide additional information, are not applicable to the proposed activities. That is, the Forest Service does not propose to have accidents. Interpretations of the HQs are summarized below. The results from this analysis will be used by resource specialists to incorporate into consideration of impacts to their respective resources. Assumptions Label direction would be followed PPE would be used Forest Plan Direction would be followed Proposed application rates analyzed would not be exceeded Applications would be supervised by forest service certified applicators or Kentucky certified applicators Accidental spills are not planned Application rates are maximum planned, lower amounts may be applied Aquatic Zone, for this assessment, is within 30 feet of a water body Areas treated with herbicide will be posted/signed for a minimum of 30 days Treatment shall not be performed during rain, snow, sleet, dew and/or when the same is expected within the following six-hour period. Information Sources The Human Health and Ecological Risk Assessments for the herbicides were prepared for the Forest Service by Syracuse Environmental Research Associates, Inc. and are considered to be the best available science. 5

10 Spatial and Temporal Context for Effects Analysis For herbicide applications, the spatial boundary will be the area(s) treated with herbicide. The proposal includes a maximum of 800 acres of NFS lands could be treated annually using herbicides. An additional 160 acres of non-national forest lands could be treated under agreement. Temporal boundaries would be 30 days following application to allow for absorption and biological degradation of the chemical. ALTERNATIVE A NO ACTION DIRECT, INDIRECT AND CUMULATIVE EFFECTS Treatment of invasive species from this proposal would not occur. However, existing and new authorizations to use herbicides would continue. ALTERNATIVE B PROPOSED ACTION This alternative includes the use of herbicides on a maximum of 800 acres annually on national forest system lands and a maximum of 160 acres annually on non-national forest system lands, with agreement of the landowner. These treatments and acres are in addition to authorizations that currently exist or future proposals. Project Design Features The proposal includes several design criteria that would be implemented when using herbicides. 1. Measures outlined in Forest Service Manual 2150, Pesticide-Use Management and Coordination, and Forest Service Handbook , Pesticide Use Management and Coordination Handbook, would be followed. 2 Any NNIP species within 10 feet of a federally listed or proposed species, R8 Regional Forester s sensitive species, or forest rare species with 25 or fewer sites on the Forest would be treated in the least disruptive manner practical. Any use of herbicides would involve the deployment of an appropriately sized sheet of cardboard, stiff plastic or other inert and impervious material between the NNIP species and the federally listed or sensitive species. 3 The application method for herbicide that provides the least exposure to workers and non-target species while maintaining effectiveness would be preferentially used. DB-VEG-7. No class B, C, or D chemical is to be used on any project, except with Regional Forester approval. Herbicides listed in the table below may be used only for the treatment methods shown. 6

11 Classification of chemical/method combinations. TREATMENT METHOD CLASS A CLASS B CLASS C CLASS D Manual ground: Cut surface DIC, GLY, IMZ, PIC, TRA None None None Basal stem DES, KER, LIM, TRE None None None Soil spot HEX TEB None None Foliar spray FOS, GLY, HEX, IMZ, KER, None TEB None LIM, PIC, SMM, TRA, TRE Mechanical ground: DES, DIC, FOS, GLY, HEX, TEB None None IMZ, PIC, SMM, TRA, TRE KEY: DIC = Dicamba HEX = Hexazinone PIC = Picloram DES = Diesel IMZ = Imazapyr SMM = Sulfometuron Methyl FOS = Fosamine KER = Kerosene TEB = Tebuthiuron GLY = Glyphosate LIM = Limonene TRA = Triclopyr Amine TRE = Triclopyr Ester DB-VEG-8. Herbicides will be applied at the lowest rate effective in meeting project objectives and according to guidelines for protecting human and wildlife health. Application rate and work time must not exceed levels that pose an unacceptable level of risk to human or wildlife health. The USDA Forest Service, Southern Region standard for acceptable level of risk requires a Margin of Safety (MOS) >100 or, Hazard quotient (HQ) <1.0. DB-VEG-9. Monitor weather and suspend project if temperature, humidity, or wind becomes unfavorable according to the criteria below: Ground: Temperatures Higher than ( F) Humidity Less Than (%) Wind (at Target) Greater Than (MPH) Hand (cut surface) n/a n/a n/a Hand (other) Mechanical (liquid) Mechanical (granular) n/a n/a 10 DB-VEG-10. Use only nozzles that produce large droplets (mean droplet size of 50 microns or greater) or streams of herbicide. Nozzles that produce fine droplets may be used only for hand treatment, where distance from nozzle to target does not exceed eight feet. DB-VEG-11. Areas treated with herbicides are to be clearly posted with notice signs to warn visitors of the treatment. DB-VEG-12. No herbicide is to be applied aerially. DB-VEG-13. No soil-active herbicide will be applied within 30 feet of the dripline of non-target vegetation specifically designated for retention (e.g., den trees, hardwood inclusions, adjacent stands) within or next to treated area. DB-VEG-14. Do not apply triclopyr within 60 feet of known occupied gray, Virginia big-eared, or Indiana bat hibernacula or known maternity tree. DB-VEG-15. Do not apply 2,4-D or 2,4-DP. DB-VEG-16. No broadcast treatment using herbicide is to be made within 60 feet of any known PETS plant species. DB-VEG-17. No soil-active herbicide is to be applied within 60 feet of any known PETS plant species. 7

12 DB-VEG-18. Application equipment, empty herbicide containers, clothing worn during treatment and skin are not to be cleaned in open water or wells. Mixing and cleaning water must come from a public water supply and be transported in separate, labeled containers. DB-VEG-19. No herbicide shall be applied within 30 horizontal feet of lakes, wetlands, perennial or intermittent springs (seeps) and streams. However, herbicides approved for aquatic use may be used when such treatment is required to control invasive plants. DB-VEG-20. Necessary buffer zone areas must be designated before making herbicide treatments so applicators can easily recognize and avoid the buffer area. DB-VEG-21. Herbicide mixing, loading, or cleaning areas in the field are not to be located within 200 feet of private land, open water or wells, or other sensitive areas. DB-VEG-30. No herbicide may be broadcast within 100 feet of private land or 300 feet of a private residence, unless the landowner agrees to closer treatment. DIRECT AND INDIRECT EFFECTS Herbicides are a tool and not a resource. Therefore there are no effects to herbicides. The use of herbicides could have effects to resources and have been analyzed using the Human Health and Ecological Risk Assessments for the herbicides, rates and application methods proposed. The Risk Assessments disclose impacts in the form of a Hazard Quotient (HQ). A HQ that is less than 1.0 is considered to be acceptable risk (Forest Plan, Standard DB-VEG-8). The results of the risk assessments are summarized in Appendix A. Risk Assessments include analysis at a Central, Lower and Upper levels. The HQs in the Central column are used to determine level of risk. With the advent of the SERA risk assessments, an Extreme Value Risk Assessment approach was taken in which almost no values used in a risk assessment are presented as a single number. Instead, most numbers used in calculating risk values are expressed as a central estimate and a range, which is sometimes very large. The central estimate In the summaries, many of the Risk Assessments resulted in HQs that are greater than 1.0. On the surface this may be alarming, but further consideration of the assumptions used in the Risk Assessments, applying the design criteria and a probability of occurrence is a reasonable way to further refine the HQs from the Risk Assessments. 8

13 Clopyralid Target species forbs and kudzu Application Method Directed Foliar Maximum Application Rate lbs/acre Hazard Quotient Summary: Worker Accidental and general exposures are all less than 1.0 HQ General Public Acute and chronic exposures are all less than 1.0 HQ Terrestrial Animals Acute and chronic exposures are less than 1.0 HQ Aquatics Fish, aquatic invertebrate and Algae are all less than 1.0 HQ Aquatic macrophyte (plants) HQ=8.0 for accidental spills. The assessment assumes that in the very extreme case of an accidental spill of a large amount of the herbicide into a relatively small body of water, sensitive aquatic plants could be damaged (Clopyralid RA, 4.4.1). It is speculative to say that a spill would occur. Forest Service activities would not have large amounts of the herbicide on hand and would not have them in close proximity to water. The following Forest Plan Standards further minimize the probability of occurrence: DB-VEG-18 - Application equipment, empty herbicide containers, clothing worn during treatment, and skin are not to be cleaned in open water or wells. Mixing and cleaning water must come from a public water supply and be transported in separate, labeled containers; and DB-VEG-19 - No herbicide shall be applied within 30 horizontal feet of lakes, wetlands, perennial or intermittent springs (seeps) and streams. However, herbicides approved for aquatic use may be used when such treatment is required to control invasive plants. For these reasons the HQ for aquatic macrophytes is less than 1.0. Terrestrial Plants (sensitive) exposure from runoff HQ=3.0 This scenario assumes 50 inches of annual rainfall on clay soils. Scenarios with loamy or sandy soils had a much lower HQ. The vast majority of the soils on the forest are loam and sand soils (Soil and Water Resource Report, p. 5). In addition, treatment shall not be performed during rain, snow, sleet, dew and/or when the same is expected within the following six-hour period, which will allow the herbicide time to dry and adhere to the treated surface. Organic material on the ground surface would also slow runoff and spread. For these reasons the HQ for terrestrial plants (sensitive) exposure from runoff is less than 1.0. Terrestrial Plants (sensitive) exposure from drift HQ=1.1 at a distance of 500ft. This scenario assumes a low boom broadcast application, which is not the proposed directed foliar application method. Drift science is imprecise without detailed at-time-of-application measures, but NEPA does allow for addressing incomplete or unavailable information. General 9

14 worst case scenarios can be modeled to provide relative potential impacts should drift occur. Variables such as wind speed, temperature, humidity, sprayer droplet size, slope, distance from nozzle to target, angle of nozzle relative to the ground, and the amount of time spent applying the herbicide all impact whether drift occurs and if so, how far it travels. A Forest Plan standard (USDA FS 2004, Standard DB-VEG-9, p. 2-25) limits herbicide application to weather conditions designed to minimize or eliminate drift conditions. Application of this herbicide will be done with a hand sprayer which produces larger droplet sizes (minimum droplet size at DB- VEG10, p. 2-25). These drops tend to settle quickly from the air column. Applying herbicide close to the target plant generally results in less drift as more of the mixture is intercepted by the plant before movement away from the site can begin. Spraying vegetation no higher than shoulder high (nozzle essentially parallel to the ground) reduces the amount of herbicide exposed to the air column and wind currents. This particular herbicide is mostly effective on composites and legumes. Since herbicides are designed to kill plants, a lot of drift on non-target plants would be expected to result in damage or death of the plants if susceptible to the herbicide, and it follows HQs for such plants would be high. Forest Plan standards and the application method here limit the potential for drift. For these reasons the HQ for terrestrial plants (sensitive) exposure from drift is expected to be less than

15 Endothall Target species Aquatic submergent plants Application Method Direct application to water Maximum Application Rate 3.5 ppm (6.88 lbs ae/acre-foot) Hazard Quotient Summary: Worker Accidental exposure The HQ was not assessed in the Risk Assessment. The HQ may be higher than general exposure. Using the granular formulation reduces the risk over the liquid formulation. If accidental contact occurs, workers would remove contaminated clothing and wash as soon as exposure occurs. (Endothall RA , p.39) For this reason the HQ for Worker general exposure is less than 1.0. Worker General Exposure HQ=4.0 Endothall is a dermal irritant. Applicators will wear PPE that minimizes direct contact with skin and eyes. A breathing mask will be worn to minimize inhaling dust component of the herbicide. The granular formulation is much less toxic than liquid formulations with respect to dermal exposure (skin irritation) (Endothall RA, , p.39) For this reason the HQ for Worker general exposure is less than 1.0. General Public Accidental acute exposures are less than 1.0 HQ except where a child consumes water should a spill occur, HQ=15.0. The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into water available for consumption highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. Treatment will not occur in close proximity to areas used for municipal water such as Laurel River Lake, Lake Cumberland or Cave Run Lake. For these reasons the HQ for General public exposure where a child consumes water is less than 1.0. General Public Non-accidental acute exposures are less than 1.0 HQ except where a child consumes water, HQ=3.0 (Same as for accidental exposure) For these reasons the HQ for General public exposure where a child consumes water is less than 1.0. General Public Chronic/longer term exposures are all less than 1.0 HQ Terrestrial Animals Acute and chronic exposures are less than 1.0 HQ. Aquatic Species exposures are less than 1.0 HQ unless noted below: 11

16 Accidental acute exposures: o Fish sensitive HQ=10 o Invertebrate sensitive HQ=3 o Invertebrate tolerant HQ=1.0 o Macrophyte sensitive HQ=3,944 o Macrophyte tolerant HQ=10 o Algae sensitive HQ=1.0 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into any water highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. The following Forest Plan Standard further minimizes the probability of occurrence: DB-VEG-18 - Application equipment, empty herbicide containers, clothing worn during treatment, and skin are not to be cleaned in open water or wells. Mixing and cleaning water must come from a public water supply and be transported in separate, labeled containers. For these reasons the HQ for Aquatic Species is less than 1.0. Non-Accidental acute exposures: o Fish sensitive HQ=1.9 o Macrophyte sensitive HQ=761 o Macrophyte tolerant HQ=2.0 Treatment would not occur in areas inhabited by species requiring special protection, such as federally listed species. Some macrophytes are target species to be eliminated. For these reasons the HQ for Aquatic Species is less than 1.0. Chronic/longer term exposures: o Macrophyte sensitive HQ=37 Treatment would not occur in areas inhabited by species requiring special protection, such as federally listed species. Some macrophytes are target species to be treated. For these reasons the HQ for Aquatic Species is less than

17 Glyphosate Treatment #1 Target species grasses, forbs and woody plants Application Method Directed Foliar Application Rate 3.75 lb a.e./acre (2.0% solution) Hazard Quotient Summary: Worker Accidental and general exposures are all less than 1.0 HQ General Public Acute and chronic exposures are all less than 1.0 HQ Terrestrial Animals Acute and chronic exposures are less than 1.0 HQ Aquatics exposures are less than 1.0 HQ unless noted below: Accidental acute exposures: o Fish sensitive HQ=79 o Fish tolerant HQ=8 o Amphibian sensitive HQ=95 o Amphibian tolerant HQ=1.5 o Invertebrate sensitive HQ=50 o Invertebrate tolerant HQ=1.6 o Macrophyte sensitive HQ=46 o Algae sensitive HQ=46 o Algae tolerant HQ=1.0 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into any water highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. The following Forest Plan Standards further minimize the probability of occurrence: DB-VEG-18 - Application equipment, empty herbicide containers, clothing worn during treatment, and skin are not to be cleaned in open water or wells. Mixing and cleaning water must come from a public water supply and be transported in separate, labeled containers; and DB-VEG-19 - No herbicide shall be applied within 30 horizontal feet of lakes, wetlands, perennial or intermittent springs (seeps) and streams. However, herbicides approved for aquatic use may be used when such treatment is required to control invasive plants. For these reasons the HQ for Aquatic Species is less than 1.0. Herbivorous or predatory insects Acute exposure: exposures are less than 1.0 HQ unless noted below: o Short grass HQ=1.0 13

18 Application treatments will be directed foliar and some over spray will likely come in contact with short grasses but to a limited extent, only around the target plant. For these reasons the HQ for Short grass is less than 1.0. Terrestrial Plants exposure from runoff HQ is less than 1.0. Terrestrial Plants (sensitive) exposure from drift HQ=1.7 at a distance of 500ft. Terrestrial Plants (Tolerant) - exposure from drift HQ=8 at a distance of 0ft. Drift science is imprecise without detailed at-time-of-application measures, but NEPA does allow for addressing incomplete or unavailable information. General worst case scenarios can be modeled to provide relative potential impacts should drift occur. Variables such as wind speed, temperature, humidity, sprayer droplet size, slope, distance from nozzle to target, angle of nozzle relative to the ground, and the amount of time spent applying the herbicide all impact whether drift occurs and if so, how far it travels. A Forest Plan standard (USDA FS 2004, Standard DB- VEG-9, p. 2-25) limits herbicide application to weather conditions designed to minimize or eliminate drift conditions. Application of this herbicide will be done with a hand sprayer which produces larger droplet sizes (minimum droplet size at DB-VEG10, p. 2-25). These drops tend to settle quickly from the air column. Applying herbicide close to the target plant generally results in less drift as more of the mixture is intercepted by the plant before movement away from the site can begin. Spraying vegetation no higher than shoulder high (nozzle essentially parallel to the ground) reduces the amount of herbicide exposed to the air column and wind currents. Since herbicides are designed to kill plants, a lot of drift on non-target plants would be expected to result in damage or death of the plants if susceptible to the herbicide, and it follows HQs for such plants would be high. For tolerant plants, a HQ at 0ft implies direct spray of that plant. Only target plants are intended to receive direct spray. Application treatments will be directed foliar and some over spray will likely come in contact with other vegetation but to a limited extent, only around the target plant. Forest Plan standards, project design criteria and the application method limit the potential for drift. For these reasons the HQ for terrestrial plants (sensitive & tolerant) exposure from drift is less than

19 Glyphosate Treatment #2 Target species Woody plants Application Method Cut-stump Application Rate 3.75 lb a.e./acre (undiluted) Hazard Quotient Summary: Worker Accidental and general exposures are all less than 1.0 HQ General Public - exposures are less than 1.0 HQ unless noted below: o Accidental acute exposure by a child consuming water following a spill into the water, HQ=7 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into water available for consumption highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. Treatment will not occur in Forest Plan Prescription Area Source Water Prescription Area zone 1. For these reasons the HQ for General public exposure where a child consumes water is less than 1.0. Terrestrial Animals Acute and chronic exposures are less than 1.0 HQ Aquatics exposures are less than 1.0 HQ unless noted below: Accidental acute exposures: o Fish sensitive HQ=3,785 o Fish tolerant HQ=363 o Amphibian sensitive HQ=4,542 o Amphibian tolerant HQ=170 o Invertebrate sensitive HQ=2,422 o Invertebrate tolerant HQ=79 o Macrophyte sensitive HQ=2,216 o Macrophyte tolerant HQ=1.1 o Algae sensitive HQ=2,216 o Algae tolerant HQ=48 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into any water highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. The following Forest Plan Standards further minimize 15

20 the probability of occurrence: DB-VEG-18 - Application equipment, empty herbicide containers, clothing worn during treatment, and skin are not to be cleaned in open water or wells. Mixing and cleaning water must come from a public water supply and be transported in separate, labeled containers; and DB-VEG-19 - No herbicide shall be applied within 30 horizontal feet of lakes, wetlands, perennial or intermittent springs (seeps) and streams. However, herbicides approved for aquatic use may be used when such treatment is required to control invasive plants. For these reasons the HQ for Aquatic Species is less than 1.0. Non-accidental acute exposures: o Amphibian sensitive HQ=1.0 Application will be direct to the cut-stump area. Contact with amphibians is unlikely as treatment occurs within minutes of the stump being cut and because of the extremely small area of overspray that occurs. The probability of an amphibian being in the target zone at time of treatment and immediately after is highly unlikely. For these reasons the HQ for Amphibian sensitive is less than 1.0. Herbivorous or predatory insects - Acute exposures are less than 1.0 HQ Terrestrial Plants exposure from runoff HQ is less than 1.0. Terrestrial Plants (sensitive) exposure from drift HQ=1.7 at a distance of 500ft. Terrestrial Plants (Tolerant) - exposure from drift HQ=8 at a distance of 0ft. Drift science is imprecise without detailed at-time-of-application measures, but NEPA does allow for addressing incomplete or unavailable information. General worst case scenarios can be modeled to provide relative potential impacts should drift occur. Variables such as wind speed, temperature, humidity, sprayer droplet size, slope, distance from nozzle to target, angle of nozzle relative to the ground, and the amount of time spent applying the herbicide all impact whether drift occurs and if so, how far it travels. A Forest Plan standard (USDA FS 2004, Standard DB- VEG-9, p. 2-25) limits herbicide application to weather conditions designed to minimize or eliminate drift conditions. Application of this herbicide will be done with a hand sprayer which produces larger droplet sizes (minimum droplet size at DB-VEG10, p. 2-25). These drops tend to settle quickly from the air column. Applying herbicide close to the target plant generally results in less drift as more of the mixture is intercepted by the plant before movement away from the site can begin. Spraying vegetation no higher than shoulder high (nozzle essentially parallel to the ground) reduces the amount of herbicide exposed to the air column and wind currents. Since herbicides are designed to kill plants, a lot of drift on non-target plants would be expected to result in damage or death of the plants if susceptible to the herbicide, and it follows HQs for such plants would be high. For tolerant plants, a HQ at 0ft implies direct spray of that plant. Only target plants are intended to receive direct spray. Application treatments will be cut stump which is very directed and the potential for over spray is limited. If any over spray occurs, it would be 16

21 around the target plant.. Forest Plan standards, project design criteria and the application method limit the potential for drift. For these reasons the HQ for terrestrial plants (sensitive & Tolerant) exposure from drift is less than

22 Glyphosate Treatment #3 Target species Woody plants Application Method Hack-n-squirt Application Rate 0.63 lb a.e./acre (50% solution) Hazard Quotient Summary: Worker Accidental and general exposures are all less than 1.0 HQ General Public - exposures are less than 1.0 HQ unless noted below: o Accidental acute exposure by a child consuming water following a spill into the water, HQ=3 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into water available for consumption highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. Treatment will not occur in Forest Plan Prescription Area Source Water Prescription Area zone 1. For these reasons the HQ for General public exposure where a child consumes water is less than 1.0. Terrestrial Animals Acute and chronic exposures are less than 1.0 HQ Aquatics exposures are less than 1.0 HQ unless noted below: Accidental acute exposures: o Fish sensitive HQ=1,893 o Fish tolerant HQ=182 o Amphibian sensitive HQ=2,271 o Amphibian tolerant HQ=35 o Invertebrate sensitive HQ=1,211 o Invertebrate tolerant HQ=39 o Macrophyte sensitive HQ=1,108 o Algae sensitive HQ=1,108 o Algae tolerant HQ=24 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into any water highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. The following Forest Plan Standards further minimize the probability of occurrence: DB-VEG-18 - Application equipment, empty herbicide containers, 18

23 clothing worn during treatment, and skin are not to be cleaned in open water or wells. Mixing and cleaning water must come from a public water supply and be transported in separate, labeled containers; and DB-VEG-19 - No herbicide shall be applied within 30 horizontal feet of lakes, wetlands, perennial or intermittent springs (seeps) and streams. However, herbicides approved for aquatic use may be used when such treatment is required to control invasive plants. For these reasons the HQ for Aquatic Species is less than 1.0. Herbivorous or predatory insects - Acute exposures are less than 1.0 HQ. Terrestrial Plants exposure from runoff HQ is less than 1.0. Terrestrial Plants (sensitive) exposure from drift HQ=1.2 at a distance of 100ft. Terrestrial Plants (Tolerant) - exposure from drift HQ=1.4 at a distance of 0ft. Drift science is imprecise without detailed at-time-of-application measures, but NEPA does allow for addressing incomplete or unavailable information. General worst case scenarios can be modeled to provide relative potential impacts should drift occur. Variables such as wind speed, temperature, humidity, sprayer droplet size, slope, distance from nozzle to target, angle of nozzle relative to the ground, and the amount of time spent applying the herbicide all impact whether drift occurs and if so, how far it travels. A Forest Plan standard (USDA FS 2004, Standard DB- VEG-9, p. 2-25) limits herbicide application to weather conditions designed to minimize or eliminate drift conditions. Application of this herbicide will be done with a hand sprayer which produces larger droplet sizes (minimum droplet size at DB-VEG10, p. 2-25). These drops tend to settle quickly from the air column. Applying herbicide close to the target plant generally results in less drift as more of the mixture is intercepted by the plant before movement away from the site can begin. Spraying vegetation no higher than shoulder high (nozzle essentially parallel to the ground) reduces the amount of herbicide exposed to the air column and wind currents. Since herbicides are designed to kill plants, a lot of drift on non-target plants would be expected to result in damage or death of the plants if susceptible to the herbicide, and it follows HQs for such plants would be high. For tolerant plants, a HQ at 0ft implies direct spray of that plant. Only target plants are intended to receive direct spray. Application treatments will be cut surface which is directed and the potential for over spray is limited. If any over spray occurs, it would be around the target plant. Forest Plan standards, project design criteria and the application method limit the potential for drift. For these reasons the HQ for terrestrial plants (sensitive & tolerant) exposure from drift is less than

24 Glyphosate Treatment #4 Target species Woody plants (aquatic emergent or aquatic zone) Application Method Cut-stump (aquatic formulation) Application Rate 3.75 lb a.e./acre (undiluted) Hazard Quotient Summary: Worker Accidental and general exposures are all less than 1.0 HQ General Public - exposures are less than 1.0 HQ unless noted below: o Accidental acute exposure by a child consuming water following a spill into the water, HQ=7 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into water available for consumption highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. Treatment will not occur in Forest Plan Prescription Area Source Water Prescription Area zone 1. For these reasons the HQ for General public exposure where a child consumes water is less than 1.0. Terrestrial Animals Acute and chronic exposures are less than 1.0 HQ Aquatics exposures are less than 1.0 HQ unless noted below: Accidental acute exposures: o Fish sensitive HQ=363 o Fish tolerant HQ=9 o Invertebrate sensitive HQ=67 o Macrophyte sensitive HQ=2,216 o Macrophyte tolerant HQ=1.1 o Algae sensitive HQ=790 o Algae tolerant HQ=3 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into any water highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. The following Forest Plan Standard further minimizes the probability of occurrence: DB-VEG-18 - Application equipment, empty herbicide containers, clothing worn during treatment, and skin are not to be cleaned in open water or wells. Mixing 20

25 and cleaning water must come from a public water supply and be transported in separate, labeled containers. For these reasons the HQ for Aquatic Species is less than 1.0. Non-accidental acute exposures: o Macrophyte sensitive HQ=3 o Algae sensitive HQ=1.2 Application will be direct to the cut-stump area. Contact with aquatics is minimal as treatment occurs to the stump being cut and because of the extremely small area of overspray that occurs. The small amount that reaches the water would be immediately diluted and become less to injure non-target species. For these reasons the HQ for Aquatics is less than 1.0. Terrestrial Plants exposure from runoff, No Exposure Assessment. The HQ was not assessed in the Risk Assessment. This treatment uses the same lbs ae/acre and concentration as the cut-stump outside of the aquatic zone (Glyphosate Treatment #2); therefore the HQs in this treatment would likely be similar. For these reasons the HQ for terrestrial plants is less than 1.0. Terrestrial Plants (sensitive) exposure from drift, No Exposure Assessment Terrestrial Plants (Tolerant) - exposure from drift, No Exposure Assessment. The HQ was not assessed in the Risk Assessment. This treatment uses the same lbs ae/acre and concentration as the cut-stump outside of the aquatic zone (Glyphosate Treatment #2); therefore the HQs in this treatment would likely be similar. See Glyphosate Treatment #2 above for further discussion. For these reasons the HQ for terrestrial plants (sensitive & Tolerant) exposure from drift is less than

26 Glyphosate Treatment #5 Target species Woody plants, forbs and grasses (aquatic emergent or aquatic zone) Application Method Directed Foliar (aquatic formulation) Application Rate 3.75 lb a.e./acre Hazard Quotient Summary: Worker Accidental and general exposures are all less than 1.0 HQ General Public - Acute and chronic exposures are all less than 1.0 HQ Terrestrial Animals Acute and chronic exposures are less than 1.0 HQ Aquatics exposures are less than 1.0 HQ unless noted below: Accidental acute exposures: o Fish sensitive HQ=8 o Invertebrate sensitive HQ=1.2 o Macrophyte sensitive HQ=46 o Algae sensitive HQ=16 The scenario described above is highly conservative and designed to demonstrate the worst case scenarios for purposes of the risk assessment. They are regarded as extreme and some are to the point of limited plausibility. Following Forest Plan direction and project design criteria makes an accidental spill into any water highly unlikely. This is an extreme and unlikely scenario with a probability of occurrence near zero. The following Forest Plan Standard further minimizes the probability of occurrence: DB-VEG-18 - Application equipment, empty herbicide containers, clothing worn during treatment, and skin are not to be cleaned in open water or wells. Mixing and cleaning water must come from a public water supply and be transported in separate, labeled containers. For these reasons the HQ for Aquatic Species is less than 1.0. Non-accidental acute exposures: o Macrophyte sensitive HQ=3 o Algae sensitive HQ=1.2 Application will be directed foliar. Contact with other emergent aquatics would be minimal. This treatment can be used within close proximity to protected species such as federally listed, by using barriers or direction of spray. The small amount that reaches the water surface would be immediately diluted and become less likely to injure non-target aquatic species. For these reasons the HQ for Aquatics is less than 1.0. Aquatics (Surfactant (X-77)) exposures are less than 1.0 HQ unless noted below: Accidental acute exposures: 22