HRSD Atlantic Treatment Plant Expansion
This $150 million treatment plant expansion increased plant capacity by 18 million gallons per day and presented a unique challenge because the existing plant remained operational during construction. MRCE’s subsurface investigation, testing and engineering design employed pre-loading to improve soft compressible soils for plant support. This ground improvement allowed the use of shallow foundations instead of deep pile support saving considerable cost and time. 40 foot high surcharge fill was placed adjacent to operating plant structures without impacting existing structures. The surcharge fill slopes were designed using mechanically stabilized earth (MSE) to increase load at the perimeter of the fill and prevent damage to existing structures. Underpinning and jacking was designed to support utilities below the surcharge fill.