McGrath & Associates has completed the first phase of site work on Ameren Missouri’s $8.5 million MLK Switching Station in St. Louis. The company will begin the second phase of construction in April.
The 13.8kV switching station is located at 1901 Martin Luther King Drive. The entire MLK switching project cost is estimated at $42.5 million. The station is part of a larger Ameren Missouri investment to upgrade the electric service in downtown St. Louis in the coming decades.
The 10-week first phase, performed during one of the coldest and snowiest winters on record, included mass excavation, soil reclamation and soil remediation. The second phase of construction includes a perimeter fence, new city sidewalk and 70 structural piers with 11 concrete pad foundations. The combined estimated cost for site work performed by McGrath in these two phases is $1.4 million.
During the site work phase, McGrath recycled as much existing material as possible rather than haul debris to a landfill and import new rock fill. A Grizzly rock separator was used to remove large chunks of unusable concrete, limestone and debris from the soil. Suitable fill materials were returned to the site, placed and compacted under the direction of a soils engineer to create a stable base for the station structures.