PROJECT: Prairie State Generating Company (PSGC) Cells 3 & 4 Construction
LOCATION: Marissa, IL 

PROJECT SUMMARY
Bloomsdale Excavating was contracted to construct two, separate ash containment cells totaling 56 acres which also included geomembrane liners, leachate piping and drainage layers.

Cell 3: 

• Covered 12 acres
• Clearing and grubbing
• Hauled 300,000 cubic yards of material excavation to another area on site
• Placed 100,000 cubic yards of compacted, 3’ thick clay liner
• Managed geomembrane subcontractor
• 5,500 feet of fusion welded HDPE leachate piping and a 1’ thick drainage layer of aggregate (made up of 80,000 tons of sand) was placed.

In total, Bloomsdale Excavating moved 400,000 cubic yards of material in four months, averaging 12,000 cubic yards daily.   
The permeability of clay rarely meets design require-ments initially.  In the case of Cell 3, the clay was too dry to meet the permeability requirements. Bloomsdale created a plan of disking and watering the clay in the cut areas and used a water cannon on the slopes of the fill areas to meet the design requirements.

Cell 4:

• Covered 44 acres
• Completed on a T&M basis, saving PSGC money
• First T&M contract awarded by PSGC
• Eight month project scope
• Moved nearly 800,000 cubic yards of material, including 600,000 cubic yards of general excavation
• Placed 200,000 cubic yards of compacted clay liner, and 6,500 feet of fusion welded HDPE leachate pipe
• 70,000 cubic yards of bottom ash was used for the drainage layer.

The project began in the fall during a particularly wet season and with mass excavation beginning from an old creek channel, continuously wet conditions would pose some initial challenges. Bloomsdale Excavating designed a permanent waste/stockpile area located on an other-wise unusable piece of property to keep the project on schedule.