The city of Shreveport entered into a consent decree with the U.S. Environmental Protection Agency (EPA) and the State of Louisiana in May 2014 to resolve litigation of sanitary sewer overflows (SSOs). The consent decree relates specifically to violations of the federal Clean Water Act within the city’s sewer collection system and at the wastewater treatment plants. This agreement set forth an aggressive plan for repairs and upgrades over a 12 year schedule.
An SSO occurs when raw sewerage overflows or leaks from a sewer pipe before it has been treated a wastewater treatment facility. The overflow can occur at a pump station, a maintenance hole, broken pipe or cleanout.
Sewers can develop cracks and breaks, or become clogged by tree roots or grease. Sometimes an area’s population grows beyond the capacity of the existing sewer system. Any of these problems can cause the sewers to overflow into waterway or back up into households.
To resolve these issues the city is repairing and/or replacing broken pipes and other drainage structures. Additionally improvements are to be made at treatment plants to ensure they have the capacity to receive and treat all of the wastewater that flows into them, and to meet discharge limits once treated.
The consent decree included the following requirements;
a. assessment and remediation of the sanitary sewer system in 5 separate geographic areas
b. evaluation and remediation of lift stations and force mains in the 5 separate geographic areas
c. development of a computerized hydraulic model of the sanitary sewer system
d. development of a collection system management, operation and preventive maintenance program.
At the time the decree was executed, the estimate for all required work was $350 million. The latest estimate is approximately $1 billion. The scope of the necessary work was underestimated due to the lack of information on the water and sewer systems.
Shreveport has just executed a contract with a new consent decree project manager. The full transition of the management program is anticipated to take 3 months.
In the meantime, the city has made good progress in complying with the consent decree, although the tight deadlines have resulted in management challenges with contractors, scheduling of work, notification of citizens of areas to be affected and cost monitoring.
The EPA can grant extensions of Clean Water Consent Decrees , and it is expected that Shreveport will soon start negotiating for an extension for compliance.
Justifications for the extension include the progress made to date by the city, the new project manager, and the new city administration. Additional compelling reasons include the excessive scope of work required versus what was anticipated plus potential cost savings and other efficiencies that can be effectuated by additional time for completion of the necessary work.