The Path Forward – A Long Term Control Plan

Heartland of America Park

The City is in the process of developing a Long Term Control Plan that will address the water quality and human health concerns associated with their CSOs. The City has agreed with NDEQ to have the LTCP “substantively complete” by October 2007. A final version of the LTCP – with a construction schedule – will be submitted to the NDEQ by October 2009. Control projects identified in the final LTCP will take many years to implement, perhaps 15 to 20 years.

The LTCP will include an assessment of the various drainage basins in the City, and look at the specific problems and solutions in each basin, as well as across the community. We will identify evaluation criteria to assess potential solutions, including benefits, drawbacks, timeframes and cost. Technical experts and community members will both play a significant role in evaluating potential solutions to our CSO problem.

The Omaha CSO Control Program initially developed a comprehensive computer model of the combined sewer system. The selection of a Program Management Consultant was completed in January 2006. The team of CH2M HILL (providing overall LTCP preparation and coordination), along with HDR Engineering Inc., and Lamp, Rynearson & Associates (LRA) were selected to:

• Coordinate the development of a comprehensive LTCP
• Provide computer modeling of the combined sewer system
• Initiate an accelerated study of the North Downtown area (Burt-Izard Basin)
• Manage nine additional City-selected basin consultant study teams

The City has also contracted with the University of Nebraska - Omaha to provide:

• Assessment of how much Omaha can afford to spend on additional clean water investments
• Alternatives for financing the improvements
• Analysis of the impacts on the community

Affordability will determine the magnitude of the investment and the time necessary to implement the selected controls.

The City has partnered with the U.S. Geological Survey to meet two goals: 1) establish a water quality sampling program on various Papillion Creek tributaries and the Missouri River; 2) at selected CSO outfalls, establish water quality background information and characterization data on overflows, for use in developing the LTCP.

The City has also initiated flow metering at the CSO outlets and in the CSO basins. This information will be used to further calibrate the computer model of the sewer system, so that the magnitude of CSOs that occur during typical rain events can be quantified.

Types of CSO Controls

CSOs can be controlled by constructing various features or systems. Types of CSO Controls that will be considered in the LTCP include the following:

• Sewer Separation – The existing single-pipe combined sewer system can be separated to carry its two components, stormwater, and sewage. New sewers must be installed to convey either the sanitary sewage or stormwater. The existing sewers are then used to carry the other flow.

• Satellite Treatment – This involves providing treatment of overflows at outlying or satellite locations. Treatment technologies located at CSO outfalls can address different pollutant constituents, such as settleable solids, floatables, and bacteria. Technologies can range from simple screens to high-rate sedimentation with disinfection.

• Storage and Treatment at Existing Facilities – Basins, tunnels, and added in-line pipe capacity can be used to temporarily store combined sewage for eventual treatment at the wastewater treatment plants, after a wet weather event subsides. In order to handle the additional flow, wastewater treatment plants may require expansion of treatment capacity or solids handling systems.

Pioneer Courage Park

Riverfront Development

Opportunities for Multiple Benefits

In addressing the CSO problem, the City may also be able to create other benefits:

• Addressing “Sewer Back-up” Problems – In conjunction with the evaluation of the system for CSO controls, the sewer system will be evaluated for prevention of sewer back-ups into homes and businesses.

• Improving Drainage and Street Flooding – Evaluation of improvements to the sewer system will include provisions to improve drainage and reduce street flooding occurrences, where possible.

• Potential for Community Benefits – Depending on the alternatives selected for improvements to the sewer system, opportunities for improvements to streets, landscaping, parks, and other utilities (water, gas, electrical, etc.) may be considered for inclusion during construction.

• Community Redevelopment – Where redevelopment is planned, coordination with sewer system improvements can provide opportunities for economies of scale and other efficiencies in construction of both projects.

Organization of the Program Team

The City of Omaha has contracted with a Project Management Team (PMT), headed by CH2M HILL and including HDR Engineering and LRA. In addition, Lovgren Marketing Group will coordinate Public Participation aspects of the project.

Basin Study Teams

Each of the 10 drainage basins within the combined sewer area has a Basin Consultant Team assigned to develop and evaluate CSO control alternatives for each basin. These basins, and the corresponding consultant teams, are as follows: (Basins Map)

Project Schedule

Efforts to identify and then construct CSO controls will take place in phases over the next couple of decades. The planning/public input phase will occur first, with the development of a LTCP, followed by a long period of implementation and construction of the controls in a phased manner.

Study / Planning Phase

In 2005, the NDEQ notified the City of the following desired deadlines for developing and implementing a LTCP:

• Submit a “substantively complete” LTCP by October 2007
• Submit a final LTCP by October 2009
• Implement CSO controls by 2024.

The City has agreed to meet the 2007 and 2009 dates. However, until the LTCP is complete, the City has informed NDEQ it cannot commit to meeting the 2024 date for complete implementation.
As currently envisioned, the “substantively complete” LTCP will include: identification of short-term CSO control projects; identification of long-term CSO control projects from the basin studies (subject to later refinement); cost estimates, a preliminary implementation plan that reflects affordability criteria, and a proposed endpoint for the controls, and a list of needed refinements for the final LTCP.

Design & Construction Phase

In addition to evaluation of controls that will provide CSO control in the long-term, the City will evaluate what short-term measures can be taken to reduce CSOs. It is anticipated that design and construction of short-term projects will commence after substantive completion in October 2007. Design and construction of the long-term control projects will commence after final approval by the NDEQ of the LTCP.

Potential Costs of CSO Control Measures

The magnitude and frequency of CSO events and their impact on river water quality will determine the types of CSO controls and their anticipated cost. Total costs will be distributed equitably over the users of the entire collection system.

The actual cost to control CSOs is not known at this time, but based on other cities' experience; it could range from $500 million to several billion dollars. The following table shows CSO program cost comparisons with other cities.