Basin 3 & 4 Flocculation & Sedimentation Improvements - Washington Aqueduct - Washington DC   3

US ARMY CORP OF ENGINEERS - BALTIMORE DISTRICT intends to issue an invitation for bid for a firm-fixed price contract.

The project consists of implementing upgrades and improvements to the four flocculation and sedimentation basins and ancillary supporting structures and utilities to include, but not limited to:

a. Installation of new transformers and switchgears.

b. Structural concrete repairs including concrete spall repairs and sealing of joints and cracks in all four basins.

c. Modifications to existing structural framing and metal stairs within existing stairwells.

d. Replacement of twelve horizontal flocculator assemblies with new stainless steel flocculators in Basins 3 and 4.

e. Installation and integration of Adjustable Speed Drive (ASD) systems for flocculator control in Basins 3 and 4.

f. Improvement of the existing custom hose less residuals vacuum collection systems in Basins 3 and 4.

g. Replacement of the existing basin flush water piping systems in Basins 3 and 4.

h. Installation of above and below grade ductile iron and stainless steel liquid process pipe, and valves.

Major constraints of this project include the following:

a. All work is being performed at an operational water treatment plant that must remain in service at all times.

b. The Basins 3 and 4 can only be taken out of service during the winter low season of November to March which must be coordinated with other outage needs at the treatment plant. The basins cannot be taken out of service simultaneously. All work needing to be performed inside the basins must be completed within that time frame.

c. The basin intermediate slab surfaces and walkways have limited weight restrictions.

d. Access into the lower level portions (including flocculators and residuals collectors) of Basins 3 and 4 is limited.

e. The worksite is a secure facility with specific access and personnel requirements.

The anticipated construction duration is August 15, 2023 thru August 14, 2026. The magnitude of construction is between $10,000,000 and $25,000,000.

The invitation for bid will be uploaded to the Procurement Integrated Enterprise Environment (https://piee.eb.mil) and www.sam.gov on or about 15 June 2023.