HWC assisted the City of Terre Haute with a major upgrade and expansion of their wastewater treatment facility as part of the Combined Sewer Overflow (CSO) Long-Term Control Plan (LTCP) and to address depreciation and compliance issues with the 24 MGD facility.

First, HWC completed design and engineering services for the biosolids storage and handling portion of the City’s Wastewater Treatment Facility Upgrade and Expansion project. The $120 million project was completed in 2015 and included improvements to all areas of the facility to accommodate peak flows of up to 48 million GPD as required by the approved CSO LTCP. The biosolids storage portion of the project included 10 million gallons of storage capacity provided by four 2.5 million-gallon, pre-stressed concrete storage tanks with aeration and mixing systems contained in two buildings that serve a pair of the new tanks. The design also incorporated liquid sludge loading stations and associated piping and incidental work to that area of the project site. As part of a team of consultants completing the overall project, HWC completed this portion of the project with an approximate construction cost of $20 million. 

Following completion of the plant expansion project, and in accordance with updated NPDES permit requirements, HWC provided design and construction inspection services for a $2 million phosphorus removal project for the 48 MGD wastewater treatment plant.  

As a result of new effluent limits imposed on the WWTP by the NPDES permit, HWC initially developed a compliance plan to identify the needed facilities for submission to the Indiana Department of Environmental Management (IDEM). HWC was responsible for the design of the chemical feed system and improvements to the anoxic system for biological phosphorus removal, which included 30” diameter anoxic piping and tank modifications, as well as the addition of chemical storage tanks, feed pumps, feed piping, and building renovations.

HWC also provided construction administration assistance, serving as the primary contact with the owner for the State Revolving Fund (SRF) to provide project financing.