ETIC was retained to conduct soil removal activities at the Marsh Landing-GenOn Power Generating Station in Contra Costa County, California. The project included contaminated soil excavation at three locations (Excavation A, B, and C), shoring, dewatering, waste disposal, backfill, compaction, and site restoration. ETIC implemented surgical excavation operations as the excavation areas were near energized fiber optic conduits and transected Excavation C.
ETIC obtained grading and electrical permits from the Contra Costs County Department of Conservation and Development-Building Inspection Division for the project and all fieldwork was conducted in accordance with Contra Costa County permit requirements, including implementation of best management practices (BMPs) for storm water pollution prevention at the site prior to initiation of fieldwork. In addition, Underground Service Alert (USA) was contacted prior to the initiation of fieldwork and was updated monthly.
ETIC’s shoring subcontractor, installed sheet pile shoring around all three excavation areas and a combination of vacuum soil excavation and hand digging methods were used near the energized fiber optic conduits. Prior to using the vacuum soil excavation and hand digging methods, overburden soil was removed using a small excavator. Once the shoring was completely installed, ETIC commenced excavation activities and off-hauled all excavated soil in accordance with the Excavation Plan. All excavated soil was transported for disposal by ETIC’s preapproved waste transport subcontractor. The total volume of excavated and off-hauled soil amounted to 562 tons or approximately 350 cubic yards. ETIC then backfilled the excavation areas and restored the site.
Benefits & Value
A third party conducted subsurface utility clearance during a previously soil investigation and cleared the site for excavation. ETIC project personnel followed the company’s behavior-based safety program job safety analysis for excavation activities and conducted a second subsurface utility clearance in which the energized fiber optic conduits were located within the excavation areas. ETIC worked with the project engineer to revise the shoring design and excavation plan to prevent damaging the fiber optic conduits. By conducting the second subsurface utility clearance, ETIC prevented disturbance to the fiber optic conduits responsible for communication to and from the generating station.
Client: Major Utility Client
Location: Antioch, California
Duration of Project: December 2010 – April 2011