Attica, IN

CSO LTCP Phases 2/Wastewater Treatment Facility Renovation

HWC worked with Attica, Indiana to complete Phase 2 of the City’s mandated CSO LTCP project. 

The City’s CSO Long-Term Control Plan required a second and final phase, which included floatables screening of flows from the single remaining overflow outfall to remain operational and storage of approximately 750,000 gallons of combined sewer flows to meet IDEM’s design storm criteria. HWC was hired to develop a Preliminary Engineering Report for the CSO project and necessary improvements at the treatment facility to address depreciation and compliance needs. 

The plan developed included improvements at the treatment facility, including:

• New influent/CSO screening structure, which complied with the floatables control requirement of the CSO LTCP and fine screening for all influent flows
• New 750,000 gallon per day average flow/1.2 MGD peak flow oxidation ditch for biological treatment to replace the current trickling filter process
• Conversion of existing primary clarifiers to secondary clarifiers
• Conversion of the existing trickling filter tanks to CSO storage tanks, which will be filled by dedicated CSO pumps in the retrofitted influent wet well
• Chemical feed systems and piping for nutrient (phosphorus) control
• Implementation of a new plant-wide SCADA system for both biological and wet weather process control

Due to the re-utilization of existing structures and conversion to a new biological treatment process, significant construction sequencing considerations were required in the design of the project. HWC held working sessions with the plant staff during design and with both the contractor and staff during construction to ensure minimization of operational disruptions were realized through demolition and sequencing of construction activities.

The total project cost was approximately $5.5 million. HWC provided planning, design, construction engineering, and inspection services for the project.

Greenwood, IN

Western Regional Interceptor

HWC completed the design of the Western Regional Interceptor, which resulted from a master planning effort completed in conjunction with an IDEM-Agreed Order. The project included a new regional interceptor for the western sanitary sewer service area for the City of Greenwood, Indiana. The interceptor flows via gravity from White River Township to relieve the City’s existing interceptors in the old downtown area and east side, which were at capacity and experiencing surcharging and overflows. The new interceptor runs from SR 135 at the southeast end to SR 37 to the northwest. It generally follows Turkey Pen Creek and Honey Creek and runs adjacent to, or in between, several subdivisions that have experienced significant growth over the last 25 years. The interceptor connects to Citizens Energy Group’s existing 102” diameter South Marion County Regional Interceptor.

The interceptor ranges in size from 15’ to 60’ in diameter, allowed for 10 lift stations to be decommissioned, and included multiple sections constructed via trenchless technology due to road and waterway crossings.

The $65 million project was constructed in two phases and was completed in 2023 utilizing the guaranteed savings project delivery method.

Project Highlights:

• Project Construction Cost: $60 Million
• Approximately 55,000’ of gravity sewers ranging in size from 8” to 60” diameter
• Approximately 10,000’ of 24” diameter force main
• Jack and bore installations at several locations including SR 37, SR 135, Indiana Railroad, and several of the major County road crossings
• Pleasant Run Creek crossing, consisting of two parallel 42” pipes as required to maintain adequate cover under the creek
• Elimination of 10 existing pump stations
• Right-of-way easement acquisition for approximately 250 parcels along the interceptor route

Clinton County, IN

I-65/SR 28 Utilities

Based on economic development and utility planning studies completed by HWC, Clinton County retained HWC to complete design and construction phase services of the recommended project for wastewater and water utilities near I-65 and SR 28. This project included new wastewater collection and water supply facilities to serve existing and potential development near the I-65/SR 28 interchange, as well as unincorporated areas along the SR 28 corridor, west of the City of Frankfort and west of CR 450.

Previously, no public water or wastewater facilities existed in the project area. The scope of work included approximately 10,000’ of gravity sewers (ranging in size from 8” to 15”), two triplex lift stations, approximately 4,000’ of dual 6” and 8” force mains, approximately 18,000’ of dual 8” and 12” force mains (directionally drilled), approximately 24,000’ of 18” water main with associated hydrants and valves, four crossings of SR 28 via jack and bore, and an automatic flushing station to maintain water quality.

Significant land right-of-way acquisition was required for the infrastructure necessary to construct the project. The water and wastewater facilities were connected to the City of Frankfort’s systems, and wastewater treatment for the proposed wastewater collection system is provided by the City of Frankfort. The project was completed in 2021 at a project cost of approximately $15 million.

Due to available funding, a second phase including a 500,000-gallon elevated water tank was designed by HWC and completed in 2023.

Terre Haute, IN

Wastewater Treatment & Phosphorus Removal

Indianapolis, IN

Michigan Road Wastewater Treatment Plant Expansion – Clay Township Regional Waste District

This project consisted of the planning, design, and construction phases for the Michigan Road Wastewater Treatment Plant Expansion. The planning phase created a master plan to allow up to 12 MGD treatment capacity on the existing plant site for this fast growing area northwest of Indianapolis in Hamilton County, west of Carmel, and east of Zionsville.

The $7.5 million project called for design of a 1.5 MGD plant expansion for a average design plant capacity of 2.55 MGD. The design incorporated a new state-of-the-art preliminary treatment building with odor control, vertical loop reactors to handle peak flows experienced by the District, a secondary clarifier, a return activated sludge pumping station, chemical feed system, solids handling improvements, a UV disinfection system, and post aeration. The 3 existing secondary clarifiers were retrofitted with effluent launder covers and the weirs were modified after they were found to be out of level during the planning phase. The project underwent a staggered construction sequence to facilitate the plant’s need to remain completely in service while the new facilities were constructed.

As mentioned the District service area is experiencing rapid growth and to accommodate this rapid growth strong emphasis was put into the expandability of each structure/process with many sized for the next expansion of another 1.5 MGD.