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The City’s Redwood Shores Lagoon is subject to seasonal infestations of aquatic weeds <br />and algae. Aquatic pesticides are employed as a component of the City’s Integrated <br />Pest Management (IPM) program. The City’s Aquatic Pesticide Application Plan (APAP) <br />describes the lagoon's operations, Best Management Practices (BMPs), the existing <br />aquatic weed control program, and the lagoon's self-monitoring water quality program. <br />The APAP application and Notice of Intent (NOI) are submitted to the Regional Water <br />Quality Control Board for approval in compliance with the monitoring requirements for <br />an NPDES General Permit for the use of aquatic pesticides in Redwood Shores <br />Lagoon. <br /> <br />Potential dischargers are required to have coverage under this Permit to apply aquatic <br />pesticides for aquatic weed control if the water being treated discharges into waters of <br />the United States; the City has such coverage. The purpose of the general permit is to <br />substantially reduce liability incurred for releasing water treated with aquatic herbicides <br />into waters of the United States. The Permit requires compliance with the following: <br /> <br />· The Policy for Implementation of Toxics Standards for Inland Surface <br />Waters, Enclosed Bays, and Estuaries in California, also known as the <br />State Implementation Plan or SIP; and <br />· The California Toxics Rule (CTR); and <br />· Applicable Regional Water Quality Control Board (RWQCB) Basin Plan <br />Water Quality Objectives (WQOs) <br /> <br />Nuisance aquatic vegetation in and along the City’s water quality detention basins and <br />associated channels includes, but is not limited to, widgeon grass and filamentous <br />algae. PWS uses Reward® (diquat), Earth Tee, and Cutrine-Plus to control one or both <br />of these aquatic plants. Additionally, PWS desires to use aquatic algaecides containing <br />copper on an “as-needed” basis. The concentration of copper needed to effectively <br />control aquatic weeds typically exceeds SIP water quality criteria. Although the SIP <br />prohibits discharge of copper in excess of applicable water quality criteria into receiving <br />waters, Section 5.3 of the SIP allows for short-term or seasonal exceptions if <br />determined to be necessary to implement control measures for resource or pest <br />management (i.e., algae or weed control) conducted by public entities. Staff has <br />concluded that it meets the criteria for gaining a Section 5.3 SIP exception. <br /> <br />Pursuant to this exception and as part of the City’s IPM program, the City proposes to <br />apply aquatic algaecides and/or aquatic herbicides containing copper on “an as needed <br />basis” to control algae and/or aquatic vegetation, when determined to be the most <br />effective treatment measure, in the Redwood Shores Lagoon (the Project). Control of <br />this vegetation is necessary in order to maintain the aesthetic quality, aquatic habitat, <br />and recreation within the area. Additionally, among the lagoon’s purposes is to serve as <br />a stormwater retention basin to provide urban flood protection by storing surface runoff <br />during high tide periods in San Francisco Bay. The presence of aquatic vegetation, <br />including algae, may impede the flow of water into and out of the lagoon and as a result, <br />compromise the lagoon’s ability to effectively act as a storm water retention basis. <br />6.3.A. - Page 2