Presentation Abstract
The Water Works and Sewer Board of the City of Prichard,
AL is a suburb of Mobile, AL and provides water and wastewater service to
approximately 25,000 customers. Since 2003, the Board has been under a Consent
Decree agreement with the State of Alabama as a result of repeated SSOs within
the system. The Consent Decree was an all-encompassing agreement that required
the Board to overhaul both of its wastewater treatment plants, inspect and
improve all of their pump stations, institute an improved CMOM program and
reduce I&I in the collection system. The City of Prichard and the Board has
limited financial resources and was challenged to find cost effective methods to
meet the requirements of the Consent Decree. This presentation will focus on the
I&I reduction strategy developed by the Board and their consulting engineers and
highlight the successes in SSO reduction that have been achieved.
Since being hired by the Board in 2002, the Superintendent has been working to
improve collection system maintenance program. The mandate set out by the State
provided the necessary initiative to move the program forward faster than ever
before. The Board relies on traditional investigation methods such as
smoke-testing and flow monitoring to identify leaks in the system. Initially,
the Board completed the investigations internally until approximately 25% of the
system was tested. Then an outside contractor was brought in to finish the smoke
and flow testing. This method freed up personnel to address leaks and illegal
connections. Defects are addressed based on a ‘low hanging fruit’ approach – in
other words, the simplest repairs get done first. More complex repairs will be
bundled together as a construction contract and bid out to reduce costs. A
central component of the I&I reduction program is an aggressive sewer cleaning
effort. Since 2004, over 800 tons of debris has been removed from the Board’s
interceptors and trunk lines. Cleaning is prioritized based on field
observations, pipe diameters, and importance of each lines’ operation for the
system.
The cumulative results of these efforts are producing measurable improvements.
The volume of SSO released has been reduced by 75% compared to one year ago,
despite receiving record rainfalls which led to nearly 150% more precipitation
in 2005 compared to 2004. At the same time the Board has been able to maximize
its use of internal resources to complete most of the work.