Laserfiche WebLink
<br />Redwood Shores Lagoon Dredging Project <br />Scope of Services - Moffatt & Nichol <br /> <br />will likely include in-water disposal options (lagoon as well as Bay), and numerous upland/ <br />wetland! reuse options in and around City limits. This initial list of disposal sites will be <br />screened to identify the potentially practicable alternatives for the City, and further analysis will <br />be performed that considers the following factors to identify the truly practicable <br />alternatives( s): <br /> <br />. Cost <br /> <br />. Logistics of dredging, transportation, disposal <br /> <br />. Institutional (ownership, zoning, etc.) <br /> <br />. Regulatory <br /> <br />. Preliminary impacts to ecosystem <br />. Preliminary impacts to local community <br /> <br />The alternatives analyses will be consistent with adopted policies (as described in the L TMS <br />environmental documents and the L TMS Management Plan). A draft copy of the SAP will be <br />provided to the City for comment prior to submission of a final copy to members of the DMMO. <br />M&N and KLI will present the SAP to the DMMO at one of their bi-weekly meetings. <br /> <br />Deliverable: Sediment Sampling & Analysis Plan (Draft & Final) <br /> <br />Task 1.4 - Perform Sediment Sampling and Testing <br /> <br />Sampling and testing of dredged material in SF Bay is typically carried out according to the <br />Inland Testing Manual published by the EPA and USACE, and the Upland Testing Manual <br />supplemented by Public Notices 99-3 and 01-01 published by USAGE. <br /> <br />Once DMMO approval of the SAP has been obtained, the areas to be dredged will be sampled <br />with a 4-inch diameter direct push core consisting of an aluminum core barrel, a stainless-steel <br />core cutter and catcher and a polyethylene core liner. Goring will take place from a 17 ft <br />Boston Whaler or a small pontoon barge. All cores will be advanced to project depth plus 0.5- <br />1.0 feet for over-dredge allowance. <br /> <br />Compositing will be used to prepare the samples required for testing. The number of <br />composite areas and the number of coring locations within each composite area will be <br />determined using guidance from Public Notice 01-01. Assuming 60,000 cubic yards of <br />dredged material, a minimum of eight cores are required, which could be composited down to <br />two samples for testing. However, because of the size and geometry of the Lagoon, we <br />anticipate dividing the Lagoon into three composite areas (west of Bridge Pkwy, Bridge to <br />Shell Pkwy, and east of Shell Pkwy) with five cores in each area. <br /> <br />Upland Disposal Option <br /> <br />If an upland disposal site is identified, which has not yet been characterized, it may also <br />require sampling and testing in order to evaluate site soils for containment dike construction <br />(assuming hydraulic dredging). Based on the required area to accommodate approximately <br />60,000 cy of sediment, we recommend collecting five cores and combing them into a single <br />composite sample for testing. A stainless-steel hand auger will be used to sample the top two <br />feet of soil. <br /> <br />The testing program would be adequate to cover RWQCB requirements for beneficial reuse in <br />wetlands or levees. The requirements for "non-cover" wetlands creation are less stringent <br /> <br />3 <br />