Aquatic Pesticide Application Plan for the San Francisco Estuary Invasive Spartina Project This plan addresses herbicide application activities undertaken by the coalition of ISP partner agencies in the effort to eradicate non-native, invasive Spartina from the San Francisco Estuary. Prepared by Drew Kerr Under contract to Olofson Environmental, Inc. 1830 Embarcadero Cove, Suite 100 Oakland, CA 94606 510-536-4782 for the State Coastal Conservancy San Francisco Estuary Invasive Spartina Project 1330 Broadway, 13th Floor Oakland, CA 94612 March 2014 Current funding for the San Francisco Estuary Invasive Spartina Project comes from the California State Coastal Conservancy and grants from the California Wildlife Conservation Board. Table of Contents Table of Contents .................................................................................................................................... i List of Figures ......................................................................................................................................... ii Appendices ............................................................................................................................................. ii INTRODUCTION ........................................................................................................................................ 3 1. DESCRIPTION OF THE WATER SYSTEM.................................................................................................. 4 2. TREATMENT AREA ................................................................................................................................ 4 3. DESCRIPTION OF TARGET WEED SPECIES.............................................................................................. 5 3.1. ATLANTIC SMOOTH CORDGRASS (SPARTINA ALTERNIFLORA) AND ITS HYBRIDS .................................... 6 3.2. CHILEAN CORDGRASS (SPARTINA DENSIFLORA) AND ITS HYBRIDS ...................................................... 6 3.3. ENGLISH CORDGRASS (SPARTINA ANGLICA) ................................................................................... 7 3.4. SALT-MEADOW CORDGRASS (SPARTINA PATENS) ........................................................................... 8 4. AQUATIC HERBICIDES, ADJUVANTS AND APPLICATION METHODS ....................................................... 9 4.1. AQUATIC HERBICIDES USED FOR SPARTINA TREATMENT .................................................................. 9 4.1.1. Imazapyr. .................................................................................................................................... 9 4.1.2. Glyphosate. ............................................................................................................................... 10 4.2. DEGRADATION BYPRODUCTS .................................................................................................... 11 4.2.1. Imazapyr Degradation .............................................................................................................. 11 4.2.2. Glyphosate Degradation ........................................................................................................... 12 4.2.3. Water Quality Impacts Relative to Degradation ....................................................................... 13 4.3. HERBICIDE APPLICATIONS METHODS FOR INVASIVE SPARTINA ........................................................ 13 4.4. SURFACTANTS ........................................................................................................................ 14 5. FACTORS INFLUENCING CHOICE TO USE HERBICIDE ........................................................................... 15 6. GATES AND CONTROL STRUCTURES ................................................................................................... 16 7. SECTION 5.3 EXCEPTION ..................................................................................................................... 17 8. WATER QUALITY MONITORING PLAN (WQMP) .................................................................................. 17 8.1. MONITORING SITE SELECTION ................................................................................................... 17 8.2. SAMPLING DESIGN .................................................................................................................. 18 8.3. FIELD SAMPLING PROCEDURES .................................................................................................. 18 8.3.1. Equipment Calibration .............................................................................................................. 19 8.3.2. Field Data Sheets ....................................................................................................................... 19 8.3.3. Sample Shipment ...................................................................................................................... 19 8.4. SAMPLE ANALYSIS ................................................................................................................... 19 8.4.1. Assessment of Field Contamination .......................................................................................... 20 8.4.2. Lab Quality Control & Data Quality Indicators .......................................................................... 20 8.5. RECEIVING WATER MONITORING TRIGGERS ................................................................................ 20 9. PROCEDURES TO PREVENT SAMPLE CONTAMINATION ...................................................................... 21 10. APPLICABLE WATER QUALITY BEST MANAGEMENT PRACTICES ....................................................... 21 10.1. SPILL PREVENTION AND CONTAINMENT .................................................................................... 21 10.2. ENSURING AN APPROPRIATE APPLICATION RATE ........................................................................ 22 10.3. EDUCATING APPLICATORS IN AVOIDANCE OF POTENTIAL ADVERSE EFFECTS .................................... 23 10.4. COORDINATION TO PROTECT WATER SUPPLIES .......................................................................... 23 10.5. PREVENTING FISH KILL FROM AQUATIC HERBICIDE APPLICATIONS ................................................. 23 San Francisco Estuary Invasive Spartina Project i. 2014 Aquatic Pesticide Application Plan 11. EVALUATION OF ALTERNATE, NON-CHEMICAL CONTROL METHODS ................................................ 23 11.1. NO ACTION ALTERNATIVE ...................................................................................................... 24 11.2. PREVENTION ........................................................................................................................ 25 11.3. MECHANICAL METHODS ........................................................................................................ 25 11.3.1. Hand-pulling and manual excavation ..................................................................................... 25 11.3.2. Mechanical excavation, maceration and dredging ................................................................. 26 11.3.3. Mowing, burning, pruning, and flaming ................................................................................. 27 11.4. CULTURAL METHODS ............................................................................................................ 28 11.4.1. Tarping (Solarization) .............................................................................................................. 28 11.4.2. Flooding and draining ............................................................................................................. 29 11.5. BIOLOGICAL CONTROL ........................................................................................................... 30 11.6. HERBICIDE ........................................................................................................................... 31 11.7. LEAST INTRUSIVE TREATMENT METHOD ................................................................................... 31 11.8. SELECTING THE MOST APPROPRIATE HERBICIDE FORMULATION ................................................... 32 REFERENCES ........................................................................................................................................... 33 List of Figures Figure 1. Locations of 2014 Spartina Control Program treatment sites ...................................... 5 Appendices 1. Chemical properties, degradation rates, environmental fate, and toxicity of imazapyr, glyphosate, and aquatic surfactants evaluated for Spartina control 2. Field Data Collection Form 3. Chain of Custody form 4. Laboratory Quality Assurance Plan, Pacific Agricultural Laboratory 5. General Site Safety & Materials Handling Guidelines and Procedures for Spartina Control Projects in the San Francisco Estuary 6. Adjacent Waterways for Spartina Treatment Sites (2014) San Francisco Estuary Invasive Spartina Project ii. 2014 Aquatic Pesticide Application Plan Introduction The San Francisco Bay Estuary (Estuary) supports the largest and most ecologically-important expanses of tidal mudflats and salt marshes in the contiguous western United States. This envi- ronment naturally supports a diverse array of native plants and animals, but over the years many non-native species have been introduced, and some now threaten to cause fundamental changes in the structure, function, and value of the Estuary's tidelands. Among