Proposed Dates of Use: May 13th, 2024 – May 17th, 2024; as weather conditions and operational factors permit

Street Address/Site Name: 45400 Country Road 28H, City of Davis Wastewater Treatment Plant

Detailed Location of Application Site: Road tops, edges, rock beds, decomposed granite areas, cracks, walkways, fence lines, bone yard, gravel parking areas, near process equipment, and other similar infrastructure. Round up to be used on road tops, edges, rock areas where run off is unlikely to occur.

Posting and Notification: Site notifications will be posted at least 48 hours before application at site entrances and will remain posted for 24 hours, and via the pesticide application electronic notification system. 

Pesticide Products: Lifeline, Capstone, Activator 90, Scythe, Round up Custom

Product (W/ active ingredients): LIFELINE - Glufosinate-ammonium  24.5% 
EPA Reg #: 70506-310 (CAS No.77182-82-2)
Pesticide Type: Herbicides
City Use Type: Tier 3. Least Hazardous. Least Restrictive.

Product (W/ active ingredients): CAPSTONE - Aminopyralid 2.22% Triclopyr 16.22%
EPA Reg #: 62719-572
Pesticide Type: Herbicide
City Use Type: Tier 2. Less Hazardous. Less Restrictive.

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. Less Hazardous. Less Restrictive.

Product (W/ active ingredients): SCYTHE- Pelargonic Acid 57%
EPA Reg #: 10163-325
Pesticide Type: Herbicides
City Use Type: Tier 2. Less Hazardous. Less Restrictive.

Product (W/ active ingredients): Round up Custom – Glyphosate 53.8%
EPA Reg #: 524-343
Pesticide Type: Herbicides
City Use Type: Tier 1. Most Hazardous. Most Restrictive. Primary use on levee and pond road tops and edges. Rock area around clarifiers and solids building. All areas are closed to the public during applications.

Target Pests: Tier 2 & 3 Use - Various broadleaf weeds and grasses. Tier 1 Use - Pepper weed, short-pod mustard, black mustard, Italian thistle, yellow star thistle, milk thistle, fluellin, & other annual weeds

Justification for Use: Staff are required to maintain safe, year-round vehicle access, including the ability to safely access stations, roads and levees throughout critical infrastructure facilities. Additionally, the Treatment Plant has a regulatory requirement to keep levees free of vegetation for state inspectors. The products listed will provide effective control of the broad range of weedy vegetation that is found in and around the listed sites. By performing well-timed herbicide applications, Staff will be able to reduce the amount of unwanted vegetation.

Pepperweed is of particular concern because there are currently no reliable methods to control pepperweed without herbicides. Mechanical cultivation or hand hoeing are not viable options of control due to the plant’s ability to reproduce from segmented vegetative material. These methods will actually increase the infestation. Pepperweed can cause damage to stations and road tops because of their large, tuberous roots which can undermine pipes, foundations and other facilities. 

Explanation of IPM Methods Used: Staff will only use herbicide in the areas identified above. All other acreage included within the water management areas are maintained without pesticides. Areas that can be mowed or trimmed will receive those treatments, as needed to keep access clear and fire risk low. Staff will continue to do hand trimming, and pruning in areas not accessible to mowing equipment.

Strategies to Prevent Future Applications: Reducing the reliance on future applications through the following actions.

• Practice responsible vehicle access during wet months to prevent road damage and the need for repair work that may promote weed growth.
• 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 use hand and power tools to keep control of the weeds as much as possible.
• Keep Oxidation ponds maintained per state recommendations.

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.

Additional comments: This justification will allow staff to continue to meet their mandate for public health and safety, while reducing the overall reliance on conventional pesticides. Staff have extensive experience with vegetation management and leverage their knowledge to protect the public from off-target risks associated with all Pesticide/Herbicide applications. 

More information on the IPM Program, including the current Policies and Procedures guidance, can be found on the City's webpage: Integrated Pest Management