Peyton Slough
Project:
Site Cleanup Requirements for Rhodia Inc. Martinez Facility to Remedy
Contaminated Sediments In and Adjacent to Peyton Slough.
Owner: Rhodia Inc., Houston, TX
Engineer: URS Corporation, Oakland, CA
Project Value: $10,475,156
Project Duration: March 2004 ~ June 2006
Purpose: To provide a long term remedy for contaminated sediments by excavation of a new alignment of Peyton Slough, construction of a new tide gate structure in the new alignment, excavation and removal of contaminates adjacent to the existing slough, closing of the existing slough and backfilling to grade to isolate contaminants and create new wetlands, and to restore the site area by revegetation of selected disturbed areas.
Construction Activities:
- Site area demolition, stripping, and Staging Area preparation of 15.8 acres.
- Placement and removal of 49,000 CY of recycled aggregate base rock for temporary access roads.
- Construction of a diversion structure at the confluent of the existing and new slough channels consisting of a temporary sheet pile cutoff wall, temporary by-pass pipe and earth berm.
- Salvage and relocation of endangered and rare plant species.
- Excavation of 26,000 CY contaminated soils for placement at an on-site disposal area capped with 28,000 SY of asphalt concrete paving.
- Excavation of 32, 000 CY of existing wetland grasses and bay mud to form the new Peyton Slough Alignment.
- Fill and grade the site upland wetland area with 26,000 CY of selected on-site bay mud and imported bay mud materials.
- Construction of a new 400 CY tide gate structure at the new Peyton Slough alignment providing new equipment with an automated control system for on-site or remote supervisory access.
- Dewatering the existing slough and placement of 38,000 CY of selected on-site fill and imported bay fill materials to cap contaminated bottom sediments and to fill the slough to the grade of the adjacent wetlands.
- Grading the site area and placement of storm water collection systems for control of the site area surface runoff onto the wetlands.
- Site vegetation restoration and erosion control of selected areas by placement of erosion control fabrics, seeding, and planting of selected wetland plant species.