Street Address/Site Name: Davis Wetlands, 45400 Country Road 28H
Detailed Location of Application Site: Road tops and edges, spot spraying around pump structures, around equipment, and other notable areas.
Posting and Notification: A notice of 72 hours will be given before the application. No applications will be in the vicinity of playgrounds, schools or picnic areas. Additionally, this area will be locked down restricting the use of pedestrian traffic.
Pesticide Products:
Product (W/ active ingredients): CAPSTONE Aminopyralid 2.22% Triclopyr 16.22%
EPA Reg #: 62719-572
Pesticide Type: Herbicide
City Use Type: Tier 2 Hazard. Limited use, more restrictive
Product (W/ active ingredients): Round up Custom – Glyphosate, N-(phosphonomethyl) glycine 53.8%
EPA Reg #: 524-343
Pesticide Type: Herbicides
City Use Type: Tier 1 limited use, most restrictive. Primary use on levee and pond road tops and edges.
Product (W/ active ingredients): ACTIVATOR 90 – Alkylphenol ethoxylate, alcohol ethoxylate and tall oil fatty acid 90% Constituents ineffective as spray adjuvant 10%
EPA Reg #: CA Reg. No. 34704-50034
Pesticide Type: Activator – Non-ionic surfactant penetrant
City Use Type: Tier 2 Hazard. Limited use, more restrictive
Target Pests: Pepper weed, short-pod mustard, black mustard, Italian thistle, yellow star thistle, milk thistle, fluellin, other annual weeds and grasses.
Justification for Use: This herbicide use is justified due to the need for safe access to these critical infrastructure facilities year –round. PW staff need to be able to safely access stations, roads and facilities throughout the year to perform maintenance and react to changing conditions during the rainy season. Similarly, keeping vegetation controlled on the road tops is important to allow safe public access to the Wetlands. The chemical identified here will provide effective control of the broad range of vegetation that is found in and around the listed sites. All applications will be applied where runoff into bodies of water or drains will be unlikely.
Pepper weed is of particular concern because there is no reliable way to control it without herbicide. Mechanical cultivation or hand hoeing are not options because the plant can reproduce from vegetative material and these methods will actually increase the infestation. The plant can cause damage to stations and road tops because it’s large, tuberous roots can undermine pipes, foundations and other facilities. There is no reliable way to kill these weeds using non-chemical methods at the scale they exist on the sites
Explanation of IPM Methods Used: Staff will only use herbicides in the areas identified above. All other acreage included in water management areas is maintained without pesticides. Areas that can be mowed or trimmed will receive those treatments, as needed to keep access clear and fire risk low. Crews will do hand trimming, and pruning in areas that mowing is not accessible by tractors.
Strategies to Prevent Future Applications: Effective, well-timed control will decrease pesticide usage over time because less seed and reproductive material will be present in the soil. However, the need for access to secure public safety may affect this trend, depending on conditions such as rainfall amounts, timing and ground temperature. We propose to reduce our use in the following ways:
Use herbicides to provide log-term control summer of weeds and promote the growth of annual grasses in certain areas. In this scenario, crews will mow in late spring/early summer to provide safe access without the maintenance requirement of dealing with summer weeds like star thistle and mustard.
Practice responsible vehicle access during wet months to prevent road damage and the need for repair work that is a vector for invasive species.
Clean and maintain all equipment before and after use to prevent the transfer of seeds and plant materials between sites and/or into sensitive areas.
Continue to promote the use of tree canopy to shade conveyance channels and prevent weed growth that blocks flow here at the Plant and Wetlands.
Continue to use weed eaters and other mechanical means to control as much as possible to reduce the amount of herbicide usage.
More information on the IPM Program, including the current Policies and Procedures guidance, can be found on the City's webpage: Integrated Pest Management
