So What's the Solution?

The solution to the City's CSO problem is the Terre Haute Clean Water – CSO Reduction Program which is designed to improve the water quality of the Wabash River in the City of Terre Haute. This multi-year initiative is comprised of sewer overflow reduction projects described in the City's CSO Long Term Control Plan (LTCP) that will be conducted over the next 20 years, at an estimated cost of $125 million. The Program also includes reducing overflows through enhanced operating procedures included in the City's CSO Operational Plan under the Nine Minimum Controls (NMC) program. The City's CSO Reduction Program will reduce the number of overflows from approximately 37 down to 6 in a typical year and eight of the ten existing CSO outfalls will be closed off completely.

Solution Mechanisms

Through the City’s NPDES permit for wastewater discharges to the Wabash River, the Environmental Protection Agency (EPA) and the Indiana Department of Environmental Management (IDEM) required the City of Terre Haute and all CSO communities to solve their CSO problem to acceptable levels through a two-step process. First, the CSO Operational Plan was developed which prescribed operational measures in the wastewater utility which are focused on minimizing the volume of CSO flows. This document and its requirements has been completed and implemented by the City with annual updates completed on the methods and procedures required in the plan. The second step included the development of a Long Term Control Plan (LTCP) which evaluated alternatives for controlling CSO’s through modifications and improvements to the wastewater system which allow for CSO reduction over time to an acceptable level. The LTCP’s development and requirements are described separates and a copy of the document in its entirety is provided for reference in the Resources section.



What Solutions did the City consider?

As presented in the LTCP, the City considered a wide range of solutions to reduce the volume and frequency of CSO’s. These solutions included the following schemes which were evaluated and screened to only those methods which were deemed feasible for the Terre Haute system:

  • Combined sewer separation (constructing new sanitary or storm sewers to eliminate introduction of storm water into the sanitary system)
  • Storage Facilities – “in-line” storage utilizing existing oversized sewers, or “off-line” facilities including tanks, basins, etc. to hold CSO flows
  • Relief sewers to convey CSO flows to points of treatment or storage
  • Satellite treatment facilities to treat and discharge CSO flows at an outfall
  • Expansion of treatment facilities
  • Tunnels to store and convey CSO flows deep underground

After evaluation, these concepts were applied to develop comprehensive plans in the LTCP for review.



How will we achieve this goal?

The program combines the following strategies to achieve this goal:

  • Miscellaneous "common" alternatives to consolidate outfalls, capture floatable material and allow for storage of combined flows in sewers.
  • Revisions to CSO diversions to allow for increased CSO control and storage of comvined sewage flows in trunk sewers.
  • Expanding the Wastewater Treatment Plant to treat more flow during wet weather .
  • A 33 MGD high rate treatment facility for CSO flows at the former International Paper (IP) Brownfield site.
  • A new main pump station to replace the existing facility constructed in 1965.
  • A new large diameter CSO gravity sewer interceptor along the Wabash River between Fairbanks Park and the new main lift station to convey flows to the main lift station for transfer to the WWTF or the new high rate facility.
  • Green infrastructure in selective basins to potentially reduce the size of or eliminate gray infrastructure at CSO 010.
  • CSO storage facilities at the north end of the CSO system. (dependent upon success of green infrastructure initiatives.
Goals

The following goals were established during Citizens Advisory Committee and Technical Committee meetings of the LTCP development and used to develop the CSO control alternatives during the evaluation process:

  • Comply with IDEM requirements (NPDES permit requirements and level of CSO control
  • Reduce in-stream bacteria from CSOs
  • Eliminate / reduce CSOs 005, 006, 007 and 008 in Fairbanks Park
  • WWTP Improvements to increase capacity to 48 MGD
  • Maximize Flow to the WWTP prior to CSO discharges
  • Control and eliminate floatables material from CSOs in accordance with NPDES permit requirements
  • Provide CSO protection within wellhead protection zone
  • Reasonable user rate burden increase based on total project cost with consideration given to phasing the proposed work
  • Review and implementation of odor control at WWTP

Priority Areas

Federal and State policies require communities to give highest priority to controlling sewage overflows in "sensitive areas" and certain areas including areas near schools and parks. No areas were technically qualified as “sensitive areas” but based on recommendations from the Citizens Advisory Committee in the LTCP process, the outfalls around Fairbanks Park will be considered a priority.



When Will The Projects Be Built?

The program will be implemented in five phases, ending in 2032. The city requested sufficient time to build projects in a planned and orderly manner; minimize disturbance to neighborhoods; accurately evaluate the effectiveness of each project; secure rights of way; coordinate technical, manpower and material needs; as well as to manage the financial burden on ratepayers over time.


Item Description Dates
CSO LTCP Phase 1 IP Lagoon rehabilitation, add 2nd FM at existing main lift station to high rate treatment facility, combine CSO’s 004 and 011 with new floatable controls there. Combine CSO’s 009 and 010 with new floatable controls there plus other common alternatives. 2012 - 2015
CSO LTCP Phase 2 Construct new main lift station, add 2nd phase of high rate treatment facility, and initial phase of green infrastructure implementation in Basins 009/010 2016 - 2019
CSO LTCP Phase 3 Construct CSO Interceptor from 004 to new min lift station, final phase of green infrastructure implementation in Basins 009/010 2020 - 2023
CSO LTCP Phase 4 Construct CSO Interceptor from 008 to 004 Monitor success of Green Infrastructure in Basins 009/010 2024 - 2027
CSO LTCP Phase 5 Construct Storage Facility at 010 2027 - 2030

A more detailed schedule of requirements is presented in Section 10 of the LTCP.

Who is Paying?

The actual cost to residential monthly sewer bills is projected in the LTCP but will ultimately depend on several factors and the decisions we make together as a community which include:

  • The effectiveness of the selected plan which will be measured through monitoring and will dictate the requirements of the final control measures.
  • State and federal regulatory approval of the City’s plan
  • The sources of funding, which might include low-interest loans.
  • The financing method and time allowed to repay any loans
  • Changes in technology that might reduce costs

What Benefits Will We See?

When the federally-mandated CSO control plan is complete at the end of 2032, the projects will provide community benefits through solutions designed to:

  • reduces CSO volume discharging to the river by 72%
  • result in 96% capture of wet weather flow
  • eliminates the CSOs in Fairbanks Park
  • result in no more than six overflows in a typical year at the remaining CSOs.
  • reduce the number of CSO events per year (based on a "typical" year) from 37 to 6 times per year

How Will We Monitor Our Progress?

There will be periods of post-construction monitoring between each phase of the implementation schedule. The program will include the following elements:

  • A method for reporting on the volume, duration and frequency of any remaining overflows on an annual basis. This will be accomplished through continuous flow monitoring of outfalls, updating and application of the collection system model, or a combination of both. Rainfall data will be gathered from the City’s network of rain gauges.
  • A system to measure the degree to which any CSO storage facilities are filled.
  • A receiving water program to evaluate E. coli conditions in the river. The program could be structured similarly to that employed to obtain information for the LTCP and may include additional instream sampling, application of the receiving water model or a combination of both.

This information will be used to evaluate the performance of CSO controls as compared to the performance predicted in the LTCP. The evaluations will help determine the need for future modifications to the LTCP or improvements to the controls measures proposed in accordance with SEA 431, the City will conduct a periodic review not less than every 5 years after the approval of the LTCP as shown on the implementation schedule. The City will:

  • Submit a document to IDEM demonstrating that the LTCP has been reviewed.
  • Update the LTCP as necessary to document the results of post-construction monitoring of installed CSO abatement projects
  • Submit any amendments to the LTCP to IDEM for review
  • Implement control alternatives determined to be cost-effective

Any recommended future changes regarding the post-construction monitoring program that was previously developed for an earlier phase could be later modified as part of the 5 year CSO LTCP review and re-evaluation process.


Be Part of the Solution - How You Can Help!

Although we sometimes take it for granted, the conditions of our streams, creeks, and the Wabash River impact our quality of life in many ways. When it rains, storm water carries pollutants to catch basins and drainage ditches which then flow to our creeks or the Wabash River. Sometimes these facilities are located on our property. These facilities provide a direct link to the waterways in Vigo County. When you leave pet waste in your yard, when you drop litter on the street, or when you place chemicals on your yard prior to a rain storm it is the same as depositing those materials directly into the waterways. Also, when it rains, sump pumps, washing machines, and dishwashers fill sanitary sewers and contribute to sewer overflows. When these overflows occur, streams become loaded with pollutants that can cause sickness with human contact.


  • Every year millions of gallons of combined sewage, stormwater, and debris overflow to the Wabash River.
  • The overflows cause increased E. coli readings and other pollution to the river.
  • The City of Terre Haute is undertaking a program to reduce the number of overflows to the river.
  • The goal of the CSO Reduction Program is to have a cleaner city, resulting in a cleaner river.