Jacob Groby, Superintendent of Quality Control for St Bernard Parish, stands next to the valve box containing the flushing unit. |
In the summer of 2008 the Parish's Sewer & Water Division started to notice a drop in water quality from their quarterly water samples which are required by the Department of Health. They also started to get complaints from residents saying that there was a chemical taste in the water and it looked rusty and yellow and sometimes had a septic smell to it. In further testing by the Department of Health they also found that the ammonia build up was higher than normal.
Jacob Groby, Superintendent of Quality Control for the Parish, met with the Federal Emergency Management Agency (FEMA) and explained that the poor water quality was due to transformations in the distribution system and the storage tanks.
"Our water quality was being affected by loss of physical integrity such as contaminant intrusion due to breaks, repairs and lower than normal flows, which was causing us to show lower than normal chlorine levels, higher than normal nitrate levels and elevated bio-film growth in our distribution system," Groby said.
Hurricane Katrina had not only caused damage to the system, but the loss of population meant low usage, which lead to low velocities that resulted in the accumulation of ammonia and other sediments. There was simply not enough population to use the water they were producing. In the Murphy Buy Out zone, usage had dropped from 180 + homes to a mere 35. Without a formal flushing program, nitrification was taking place more now than ever.
To make matters worse, the Department of Health and Hospitals informed St Bernard Parish in March of 2010 that they were in danger of being in non-compliance with water quality regulations and were now required to submit for Initial Distribution System Evaluation (IDSE) monitoring.
St Bernard Parish needed a pro-active flushing system solution and contacted Todd Burnett, President of Coastal Process, LLC, to find a suitable system.
The Singer Valve Total Automatic Purging System (TAPS) was chosen for its heavy duty design, AWWA valve compliance and its ease of programming, Burnett said. The compact size was also an advantage for handling and installation.
While there are a variety of different valve sizes, St. Bernard parish used the 40mm (1.1/2") valve which optimizes the flushing process for their pipe size as it provides the correct velocity to pull fresh water into each zone. This, coupled with the pressure sustaining feature, scours and cleans the pipes which reduces corrosion and has dramatically improved water quality.