Program Delivery Plan
What is the Program Delivery Plan?
The City of Baton Rouge/Parish of East Baton Rouge (City/Parish) has contracted with CH2M HILL to prepare a Program Delivery Plan (PDP). This PDP provides a summary of the Sewer System Overflow (SSO) and Wastewater Facilities Program. The three parts of the program are:
- Capacity improvements
- Sewer rehabilitation
- Wastewater treatment and storage
This historical document describes a total of 87 wet weather projects to be constructed by January 1, 2015 at an estimated total program cost of $1.3 billion in 2007 dollars. These costs include the construction, design engineering, construction engineering and management, and program management. There are three additional projects previously undertaken by the C-P, which will be included in the Program for a total of 90 projects. Those additional projects are the Remedial Measures Action Plan (RMAP1) projects.
The goals of the program include the following activities:
- Reduce excess wet weather flows that cause SSOs
- Rehabilitate the collection system
- Increase the hydraulic capacity of the collection system
- Accommodate growth in project areas
- Comply with wastewater treatment plant National Pollutant Discharge Elimination System (NPDES) permit
- Comply with the terms of the Consent Decree
In the preparation of the PDP, the locations of known overflows are given highest priority in order to reduce the frequency of these overflows. Areas of the collection system that were found to have excessive levels of infiltration or inflow were identified for rehabilitation.
Hydraulic capacity improvement projects are sized to accommodate predicted peak wet weather flows and anticipated growth in the project areas. Peak wet weather flows were predicted based on a 2-year frequency, 12-hour duration previously selected design storm.
Capacity Improvements
Capacity improvement projects will reduce hydraulic bottlenecks in the system and convey wet weather flows to new upstream storage facilities or the Wastewater Treatment Plants (WWTPs). These projects will include installation of larger pipes or constructing parallel pipes to increase conveyance capacity, as well as replacement of pump stations to handle future wet weather peak flows. The new sewers will either replace existing sewers that are too small, or supplement existing systems at locations where additional capacity is needed. The goal for installing new sewers is to improve the system’s ability to carry increased volumes of wastewater to our treatment plants. Pump stations transfer wastewater from one portion of the sewer system to another. This ability is extremely valuable during and after periods of heavy wastewater flows, as upgraded pump stations and stations in peak condition can capture greater amounts of wastewater and move it through the system more effectively.
The capacity improvements portion of the Program consists of 51 projects located throughout the C-P. The first projects started in 2007, and the rest of the projects are to begin in subsequent years. Approximately, seven to twelve projects will begin construction every year from 2008 through 2013, and design and construction will be continuous through 2014. Approximately 370,000 linear feet of gravity sewer, 540,000 linear feet of force main, and 150 pump stations will be upgraded as a part of the capacity projects.
Capacity improvement projects are defined based on three factors:
- Computer "InfoWorks Model" comparison of existing capacity to predicted peak wet weather flows
- Physical evidence of inadequate capacity based on City/Parish Department of Public Works (DPW) records
- Predicted growth in demand for wastewater capacity
Sewer Rehabilitation
Areas targeted for sewer pipe rehabilitation work are those in which flow monitoring has indicated the highest levels of Inflow and Infiltration (I/I). Comprehensive rehabilitation projects will proceed using a process developed and implemented by the Program Management Team (PMT) in association with Department of Public Works (DPW) technical staff discussed briefly below. The I/I reduction plan for these projects has the following goals:
- Identify and reduce stormwater inflow sources into sanitary sewers
- Identify and reduce Rainfall Dependent Infiltration (RDI) sources in sanitary sewers
- Reduce overflow events
- Increase the sewer system useful life
- Minimize public inconvenience
The process chosen for rehabilitation and/or reconstruction is generally referred to as "Find and Fix." As the process description suggests, there are two phases to the process. The first phase is to find, or identify areas that require rehabilitation or reconstruction, and the second phase is to determine the best engineering solution to fix the problem. After the “Find” phase, some portions of the system may not require rehabilitation. In those portions of the system, the Engineer will recommend "No Action".
Sewer system rehabilitation projects will be implemented to repair or replace
components of the system that are defective and permit excessive infiltration
and inflow. Currently, the rehabilitation portion of the program consists of 30 construction projects located throughout the City/Parish. The first projects will begin in 2008, and the rest will begin in subsequent years. Four to six projects will begin construction each year. Design and construction will be continuous through 2014. Approximately 5 million feet of the gravity sewer will be inspected as a part of these rehabilitation projects.
Wastewater Treatment and Storage Projects
There are six WWTP projects included in the PDP:
- SWWTP – Immediate Action Project (IAP)
- SSO Odor Control
- Choctaw storage>
- Hooper Storage
- South WWTP – Phase 1 Wet Weather Improvements
- South WWTP – Phase 2 Wet Weather Improvements
The wet weather treatment capacity of the South WWTP will be expanded to accommodate the predicted peak flow of 200 million gallons per day (MGD) after peak shaving storage and to accommodate wet weather flows from the Central WWTP, which will be consolidated with the South WWTP.