CORRESPONDENCE_1977-2017 - Laserfiche WebLink

Home Browse Search

LEA Advisory#51—Disposal Sitr..Postclosure Land Use ® Page 4 of 5 gas migration into structures. 6. Pilings(27 CCR 21190(e)(6-7)) Construction of deep foundations with pilings in waste is a special case normally requiring a licensed geotechnical engineer. Detailed plans and specifications are necessary to ensure that penetrations of final cover are adequately sealed and that appropriate corrosion resistance is provided. Check to ensure depth of piles does not penetrate any bottom liner unless approved by the RWQCB. 7. Modification or Replacement of Low Permeability Layer(27 CCR 21190(d)) Is the site required to have a low permeability layer in the final cover? For sites that ceased accepting waste prior to January 1, 1988, this determination is frequently made by the RWQCB, but the LEA has authority to require a low permeability layer if necessary to protect public health and safety and the environment(e.g., landfill gas control). If a low permeability layer is required, does the proposal include modification or replacement of the low permeability layer of the final cover? If so, approval by the LEA and RWQCB is required (27 CCR 21190(d)), and grading plans, specifications, and CQA plans should also be included. 8. Land Use on Final Cover(27 CCR 21190(a-c)) Is the postclosure land use change within areas underlain by final cover or waste? If so, the land use should be evaluated with respect to potential settlement and damage to the final cover. The evaluation should include an estimation of the potential settlement as a result of the activity and whether or not the settlement is tolerable for the integrity of the final cover and the activity proposed. If there is the potential for significant settlement the methods for monitoring and repair should be included. Is the addition of a soil cover needed to protect public health and safety(e.g., to prevent public contact with waste)? If so, plans and specifications for the additional cover should be included. Local (City, County, or Regional) Project Approvals Reviewers of postclosure land use proposals should also note that separate local permits or approvals (e.g., building, grading, conditional use, air district)may be required for the project depending on local codes and ordinances. Conflicts can arise due to the overlapping reviews and approvals of these agencies. Therefore, LEAs should contact the other applicable local agencies as early in the development of the postclosure land use project as possible to help coordinate the reviews and approvals. Technical Assistance Staff from the CIWMB Remediation, Closure, and Technical Services Branch is available to LEAs, other agencies, and project applicants for technical assistance on disposal site postclosure land use. Licensed engineers from the branch are also available to the LEA if requested to assist in the review and approval of postclosure construction projects. Site Inspections A major aspect of disposal site inspections for postclosure land use is to ensure that there is no change or expansion in land use activities without prior comment or approval as required. For example, LEAs have been faced with unauthorized construction activities on disposal sites where a significant landfill gas hazard is suspected, and no control systems have been planned. This situation would constitute a violation of 27 CCR 21190 and would warrant prompt enforcement action by the LEA to address the problem. LEAs should also inspect approved projects under construction to ensure that the approved plans and specifications are being addressed. If the LEA observes a potential threat to public health and safety or the environment at a site with an existing or approved new postclosure land use activity a violation or area of concern should be issued. Examples of such observations would include, but not be limited to: http://www.ciwmb.ca.gov/LEAAdvisory/51/ 2/20/2008