ATTACHMENT A
AQUATIC PESTICIDE APPLICATION PLAN (APAP)
For
The City of Oakland
Lake Merritt
Prepared By:
LakeTech, Inc.
2021 Brush St
Oakland, California 94612
www.laketech.com
July 2024
1 Contents
Description of Water System ........................................................................................................................ 2 Description of Treatment Area ..................................................................................................................... 2 Weeds and Algae Subject to Control ............................................................................................................ 2 Aquatic Pesticides Used ................................................................................................................................ 3 Decision Factors for Using Aquatic Pesticides .............................................................................................. 3 Gates, Control Structures, and Inspection Schedule .................................................................................... 3 SIP Categorical Exception .............................................................................................................................. 4 Monitoring and Reporting Program (MRP) ................................................................................................... 4 Preventing Sample Contamination ............................................................................................................... 7 Descriptions of BMPs to be Implemented .................................................................................................... 7 Examination of Possible Alternatives ............................................................................................................ 8
1 Figure 1: Hydrographic Map of Lake Merritt
2 Description of Water System
Lake Merritt, a 145-acre lake in downtown Oakland, California, suffers from water quality issues. Its 4,000-square-mile watershed is primarily urban, contributing to the lake being listed as impaired under the Clean Water Act for low dissolved oxygen (DO) and trash. The lake must maintain a minimum DO level of 5 mg/L, a standard set for tidally influenced waters connected to San Francisco Bay and downstream of the Carquinez Bridge.
Lake Merritt connects to the Bay via culverts and flood control gates on the Lake Merritt Channel. A tide gate, managed by the Alameda County Flood Control and Water Conservation District, regulates water exchange between the lake and the bay, with flow direction determined by lake and tidal levels. Several creeks feed into Lake Merritt, including Glen Echo, Pleasant Valley, Wildwood, and Indian Gulch Creeks.
Description of Treatment Area
The treatment area will vary depending on the species being controlled. Harmful Algal Blooms (HABs) are typically concentrated in the surface layer during bloom conditions, but they can be found throughout the water column.
For this site, the application area is the same as the treatment area for this program.
Weeds and Algae Subject to Control
The red tide that affected Oakland and the San Francisco Bay in 2022 and 2023 was caused by a specific type of algae called Heterosigma akashiwo.
This microscopic organism is a type of flagellate, meaning it has a tail-like structure that helps it move. It thrives in shallow, warm waters with lots of nutrients, which unfortunately makes the San Francisco Bay a suitable environment for it to bloom.
While not directly toxic to humans, H. akashiwo can cause significant harm to marine life. The algae bloom can deplete oxygen levels in the water, leading to fish kills and other ecological damage.
It's important to note that not all algal blooms are caused by the same organism. Different types of algae can cause blooms, and some can even produce toxins that are harmful to humans and animals.
Therefore, this permit shall be intended for the control of any algae species or cyanobacteria that may pose a threat to the health and safety of persons, animals, or the environment.
3 Aquatic Pesticides Used
Provided in Table 1 below are the aquatic pesticides that may be used in the algae control program within Lake Merritt. The need for treatments is based on treatment thresholds which include water quality, cell counts and visual monitoring.
Decision Factors for Using Aquatic Pesticides
Herbicide/
Algaecide Active
Ingredients
Degradation By-products Application
Method
Adjuvant
Hydrogen Dioxide
(peroxide)
Water and Oxygen subsurface
injection/ granular
spreader
Not Applicable
Sodium Carbonate
Peroxyhydrate
Breaks down to sodium carbonate and
hydrogen peroxide in the water -
hydrogen peroxide breaks down into
water and oxygen
Granular spreader Not Applicable
Peroxyacetic Acid Water, oxygen and carbon dioxide Surface Spray/ subsurface injection
Not Applicable
Gates, Control Structures, and Inspection
Schedule
The control structures at the 7th street bridge are controlled by the Alameda County Flood Control and Water Service District 1. All gates and structures under their jurisdiction are managed and maintained according to the operating procedures outlined within the Alameda County Hydrology & Hydraulics Manual2
1 https://acfloodcontrol.org/
2 https://acfloodcontrol.org/the-work-we-do/the-work-we-do-hydrology-manual/
4 SIP Categorical Exception
The City has not been granted a short-term or seasonal exception under the State Water Board Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California. The city does not intend to use any of the active ingredients listed under this program and therefore will not be applying for the SIP.
Monitoring and Reporting Program (MRP)
Water quality monitoring will be performed in compliance with the Monitoring and Reporting Program (MRP) for Water Quality Order NO 2013-0002-DWQ and amending orders as of the writing of this APAP.
Samples will be collected and analyzed per MRP guidelines as stated in the General Permit, Attachment C, Table C-1. Monitoring Requirements.
Table 1: Monitoring requirements per NPDES General Permit
5 Monitoring for the City may be performed by a contractor or by in-house staff. Monitoring locations will be determined for each treatment event, based on the treatment area. Monitoring frequency will follow the schedule set forth by the NPDES general permit and is summarized below:
Background Monitoring
Background monitoring samples shall be collected in the application area just prior to (up to 24 -hours in advance of) an application event.
Event Monitoring
Event monitoring samples shall be collected outside of the treatment area, immediately after the application event, but after sufficient time has elapsed such that treated water would have exited the treatment area.
Post-event Monitoring
Post-event monitoring samples shall be collected within the treatment area within one week after application.
One full set of three samples (Background, Event and Post-Event) will be collected during each treatment from the representative site(s) treated within the Estuary.
Sample Analysis
Any laboratory analysis shall be conducted at a laboratory certified for such analysis by the California Department of Health. All analyses shall be conducted in accordance with the latest edition of “Guidelines Establishing Test Procedures for Analysis of Pollutants” (Guidelines), promulgated by the USEPA (Title 40 CFR Part 136)i.
Sample Preservation and Delivery
Samples will be collected in appropriate containers as instructed by the lab performing the analysis.
Should an analytical method require preservation or filtration in the field, that will occur. Once collected and labeled, samples will be immediately placed in a dark, cold (~4C) environment, typically a cooler with ice. Delivery of samples to the laboratory will be accomplished within the labs specified hold times for the sample method.
Annual Reporting
An annual report will be submitted to the appropriate Regional Water Quality Control Board (RWQCB) by March 1 of the year following treatment. If no algaecide or aquatic herbicide treatments are done that year, a letter stating no applications have been done will be sent to the appropriate RWQCB in lieu of an annual report.
6 7
Preventing Sample Contamination
This section is not applicable because the City only intends to use peroxide-based pesticides which do not require any lab analysis.
Descriptions of BMPs to be Implemented
The City will implement the following BMPs:
Spill Prevention and Containment
All pesticide applications will be contracted out to a California Department of Pesticide Regulation – licensed Pest Control Business (PCB). PCB staff are required to undergo training according to the California Department of Pesticide Regulation’s Pesticide Safety Information Series, including Leaflet PSIS N-2 “Storing, Moving, and Disposing of Pesticides in Non-Agricultural Settings”ii . This leaflet includes accepted BMPs to prevent spills or contamination and in the event of a spill, it includes measures to contain pesticide products, apply absorbent material, and remove products to a proper disposal location. Label and SDS sheet instructions for the products being applied will be followed and reporting will commence as required by local, state, and federal laws.
Ensure Appropriate Rate
The City shall obtain a written recommendation from a licensed Pest Control Advisor (PCA) to ensure that applications are made in accordance with the product labels. The City will further ensure that applications are performed by licensed or qualified individual from the Pest Control Business contracted to perform an application.
Education
The City shall confirm that the contractor provide evidence that its staff have active licenses and/or have undergone pesticide handler safety training, including the products selected for use at their site, as required by DPR. Applicators shall be familiar and comply with the contents of this APAP prior to making an application.
Planning and Coordination
The General Permit requires that every calendar year, at least 15 days prior to the first application of pesticides, a discharger shall notify potentially affected public agencies and post the notification on its website.
The City will post on its website and submit a notification in accordance with Section VIII.B Public Notice Requirements. The notification will include the following entities:
8 ● San Francisco Regional Water Quality Control Board
● California Department of Fish and Wildlife
Preventing Fish Kills
All pesticide applications will be performed by a professional applicator who has received training specific to the product(s) to be used. The PCA written recommendation will include rates of application and any warnings or conditions that limit the application so that fish are not adversely affected. All manufacturers label instructions for rates and mixing and precautions to prevent fish kills will be followed.
Examination of Possible Alternatives
Physical Controls.
Mechanical and manual removal of aquatic weeds and filamentous algae is performed throughout the late spring and summer. The City utilizes a mechanical harvester. Material is transferred to a trailer or shore conveyor at the boat ramp. This method is not feasible for the control of planktonic algae species. There are currently no feasible solutions to physically or mechanical remove planktonic algae from larger surface water systems.
Artificial circulation: The City has installed surface aeration systems and may consider the installation of additional devices. Planktonic algae species may be susceptible to increased water movement.
Cultural Controls
Light Attenuating Dyes. Are not a suitable options due to the tidal nature of the system.
Stakeholder Outreach and Education. The City’s Watershed and Stormwater Management Division will implement a program to inform the stakeholders about use of chemicals for harmful algal bloom control via the City’s website and stakeholder meetings.
Managing Salinity. Is not a suitable options due to the tidal nature of the system.
Maintaining Cooler Water Temperature. Is not a feasible option due to the tidal nature of the system.
Biological Controls
Use of Predators and Competitors. The City may implement the use of biological control strategies if suitable solutions become available/permissible. Examples may include the introduction of
9 species that pray on nuisance organisms or the introduction of competitors such as organisms that rely on the same food or energy/nutrient source as the pests. Floating wetland islands are one tool used to increase periphyton. There are also products manufactured to increase periphyton and to manipulate the microbial loop within the Estuary’s food chain. These may be considered for use to compete with pests for phosphorus, nitrogen, or other micronutrients.
Chemical Controls (non-pesticidal)
Use of Nutrient Sequestering Products. The City may implement the application of products designed to sequester nutrients to reduce pest growth. These products may be applied to the water itself or installed in filter bags at storm drains, gates or suspended in the water column. Examples include but are not limited to: BioChar, PhosFlow, Poseidon Pellets, GeoProX, ACH, Alum, and other flocculants containing aluminum, lanthanum, or other trivalent metals.
End of APAP
i https://www.ecfr.gov/current/title-40/chapter-I/subchapter-D/part-136 ii https://www.cdpr.ca.gov/docs/whs/pdf/hs1743.pdf