Project: Installation and Maintenance of Sewer Flow Monitors
Client: DeKalb County - Water and Sewer Department
Location: DeKalb County, Georgia
Objective: This project was initiated to provide real-time wastewater flow information to quantitatively define the impact of Inflow & Infiltration (I&I) throughout the County Sewer System.
In 2004, Metals & Materials Engineers (MME) was awarded an annual contract for the Installation and Maintenance of Sewer Flow Monitors throughout DeKalb County. This was a more aggressive initiative to quantify suspected I&I problem and to determine the condition and limitations that exist in critical areas of the over 2,100 miles of sewer piping in the county. The objective was to install and maintain several hundred sewer flow monitors over a 3 to 5-year period. With such a real-time data acquisition system in place, DeKalb County engineers would be able to perform hydraulic modeling and localizing of I&I indications for in-depth inspection prioritization.
Since contract inception, MME has installed 20 rain gauges and 95 sewer flow monitors while maintaining these and the County’s pre-existing, older monitors. While typical flow monitoring systems are polled by hand, or with buried phone lines, this system was formulated around a cellular system that “pushes” data from the individual monitors into the main Oracle database for engineering interpretation. With this concept of real-time data, the system can automatically notify appropriate personnel of an event that is outside tolerance (zero flow, surcharged manholes, suspected spills, etc.). MME has formed alliances with flow monitoring manufacturers that develop software to eliminate the time consuming process of utilizing Manning and Continuity equations to reduce data, but now automatically provides that information via a web-based data system. Once a sufficient number of monitors are in place, it will be possible to incorporate this and other sources of system data into a master program that can provide strategic planning models, rainfall impact models and other proactive studies that will better prepare the County for most incidentals.