Envirocon performed this work under contract with the City of Rialto. The site was located adjacent to the current City of Rialto wastewater treatment plant.  The intent of the project was to obtain clean closure of the site in order for a developer to construct a bio-solids treatment plant.
   
The Rialto Landfill operated in the 1960s and 70s and accepted yard waste and street cleaning material from the local communities. In addition to this waste, bio-solids from the waste water treatment plant were deposited in the landfill. The landfill was closed in the 1980s.

Envirocon’s scope of work included the excavation and sorting of 160,000 cubic yards of material. Approximately 70% of the material was excavated and re-used on site.  An additional 30,000 cubic yards of clean soil was imported, blended, and compacted to meet the finished grade requirements.

Envirocon began this project by constructing an access road from the disposal site to the borrow and screening area.  Material was excavated and directly loaded into off-road haul trucks and taken too the screening area.  Excavation continued to the limits of the landfill area and to a depth of 53 feet.  Larger debris was segregated during the excavation process and stockpiled for later disposal off site. 

Envirocon utilized two power screens with Grizzley attachments to sort out debris and trash and obtain clean material for backfill.  Screened material was stockpiled and blended with 30,000 cubic yards of on-site borrow material.  After blending, soil was loaded into off-road haul trucks in order to backfill the excavation.  Backfill was compacted to 95% density in 8-inch lifts.  Envirocon imported 30,000 cubic yards of material to bring the site to final grade for future construction.

Debris from the screening operation was sorted into stockpiles for various waste streams.  Concrete, metals, and wood debris were recycled at nearby facilities.  Bio-solids and municipal wastes were taken to Class I and III landfills.

Envirocon removed a 48-inch sewer outfall pipe in order to remove waste below the pipe.  After removal and replacement of the underlying soils, Envirocon installed a new sewer outfall pipe.

The project completed on schedule and under budget with zero safety incidents.

Envirocon completed the following tasks under this contract:

• Excavating and removing 160,000 cubic yards a landfill;
• Sorting large debris from excavated soil;
• Screening of trash, concrete, wood, metal and other debris from the excavated soils; and
• Placing and compacting imported soils to bring site to final grade.