AgdaPkt 2016-02-08 Closed and Joint SA PFA

Browse Search

was performed according to the project’s geotechnical recommendations. Based upon the visual assessment, staff and consultants determined that the soil condition was not optimal for the planned improvements because the existing subsurface stabilization issues may reoccur if unaddressed. In order to achieve a quality play surface for the community, staff worked with the consultants and negotiated with the contractor on an alternate solution. This alternative solution is consistent with the soil treatment already being implemented at Griffin-Bechet Field per plan. The proposed solution involves additional excavation, placement of additional fill, lime treatment and drainage system adjustments. Staff recommends Council approve additional funds in part to accomplish this additional excavation and subgrade preparation work. The cost of this work would total approximately 10% of the contract amount. Additionally, during the earthwork and grading improvement work, soil tests were conducted on excess soils to be disposed of offsite by the contractor at a landfill that receives clean topsoil. The tests are conducted as standard protocol to identify the presence of various soil contaminants such as heavy metals, petroleum products, particulates from airborne auto pollution or pesticides. If these are identified and measured above certain levels established by Cal EPA, soil is re-characterized and must be disposed of at Class II landfills licensed to handle certain soils. Test results indicated that the topsoil from both Griffin-Bechet and McGarvey Fields is unsuitable for disposal at the originally intended topsoil landfill but is qualified for disposal at a Class II landfill. The additional cost of disposal to a Class II landfill would total approximately 6% of the contract amount. Upon beginning construction at Mitchell Field, vertical deviations in the existing playing surface were observed that were not present during initial project design work, and may have established since that time. The solution to best prevent reoccurrence here is less intensive than the lime treatment needed on Griffin-Bechet and McGarvey Fields, however additional, localized excavation and placement of fill will be required to properly prepare the area for turf placement. The additional cost of this work would total approximately 4% of the contract amount. When the construction contract was awarded, City Council authorized the City Manager to increase the contract amount, if necessary, up to 10% of the contract amount. Upon evaluating the impact of the above-mentioned unforeseen conditions and the anticipated costs to address them, staff determined that with 20% attributed to the above-mentioned conditions, and a 10% initially-approved contingency, an increase in contract amount up to 30% total would allow the project to be completed as recommended. 6.3.A. - Page 2