§ 20939. CIWMB -Control of Excessive Gas Concentrations
(a) A landfill gas control system shall be designed to:
(1) Prevent methane accumulation in on-site structures from exceeding the level specified in § 20921(a);
(2) Reduce methane concentrations at the disposal site permitted facility boundary to the level specified in § 20921(a);
(3) Reduce trace gas concentrations to the requirement specified in § 20921(a); and
(4) Provide for the collection, treatment, and disposal of landfill gas condensate produced within the disposal site. Condensate generated from landfill gas control systems shall not be recirculated into the landfill unless the landfill has a liner and a properly operating leachate collection and removal system and analysis of the condensate demonstrates, to the satisfaction of the EA, that such recirculation into the landfill will not harm the public health or safety or the environment and the applicable RWQCB has approved such discharge pursuant to § 20200(d).
(b) Subsurface landfill gas control systems may include, but are not limited to, one or more of the following:
(1) Active perimeter or interior control systems which are designed to accommodate the maximum expected flow rate from the disposal site and provide access for system monitoring and flow rate adjustment. The control system shall be operated to ensure that gas is controlled at a sufficient rate without overpulling, to maximize control and not production, and to ensure adequate control for compliance with § 20921(a).
(2) Perimeter air injection systems which shall be installed in native soil between the refuse and the area to be protected. Injection wells shall not be located in the refuse. The system shall be designed and operated to prevent air infiltration into the landfill but maintain landfill gas concentrations to compliance levels.
(3) Passive systems, including cutoff trenches, slurry walls, and vent trenches, when used shall be constructed with an impermeable geomembrane liner. The passive systems shall be installed to the depth of permanent low seasonal ground water or keyed into a low permeability layer below the limit of migration.
(c) Landfill gas control measures to protect structures and public health and safety shall include one or more of the following:
(1) Flexible membrane liners,
(2) Active collection systems,
(3) Passive collection systems designed to be upgraded to an active system,
(5) Ignition source control,
(6) Utility collars installed within structures and outside in trenches, and
(d) To ensure that the landfill gas control system is operating at optimum efficiency to control landfill gas, the operator shall provide for system monitoring and adjustment.
(e) To provide for the safe, efficient operation of the landfill gas control system, the operator shall implement a maintenance program in accordance with the following requirements:
(1) A site-specific operations and maintenance manual shall be maintained and kept current to reflect any expansion or modifications to the gas control system;
(2) An operations and maintenance manual shall provide for periodic inspections and servicing of gas control equipment; and
(3) Operations and maintenance shall be recorded and the records shall be retained by the operator.
(f) Construction Quality Assurance/Quality Control
(1) The operator shall be responsible for providing inspections, as needed, to ensure the integrity of the system.
(2) Prior to construction, the designer shall obtain and review all applicable test reports, shop drawings, and manufacturer's certificates to verify that all equipment used or to be used in the gas control system has been manufactured in accordance with industry standards.(1. Renumbering of former subsections 20937(b)-(g)(2) to new section 20939, including amendment of section and Note, filed 8-21-2007; operative 9-20-2007 (Register 2007, No. 34). 2. Editorial correction of subsections (a)(4) and (b)(1)(Register 2007, No. 40).)
Note: Authority cited: Sections 40502 and 45020, Public Resources Code. Reference: Sections 43021 and 43103, Public Resources Code.
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