Quote:
Originally Posted by retiredguy123
The OP's question was about how long it takes. The article you posted is from 18 months ago and doesn't say anything about how long you need to leave the hydrants open. 1.5 hours seems like a lot of water to waste, especially if they are opening every hydrant.
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There are two types of hydrant flushing. The short flush of every hydrant is done for a short period. In NC this flush was done by the Fire Dept. personnel who went from hydrant to hydrant throughout the entire system. They verified that the hydrants were functioning properly.
Line flushing is done typically at
selected hydrants at the end of a long run and is aimed at flushing out accumulated deposits and sometimes due to dirty water and frequent plugging of filters. There is at least one thread on TOTV referring to quick dirt accumulations in potable water filters. In addition some systems inject higher amounts of Chlorine and measure the free chlorine residual of the flushed water to ensure a good clean system before hot weather starts. One such hydrant was at my driveway in NC and the flushing continued for 1 to 2 hours from one hydrant. They tested and continued to flush until the proper free chlorine residual was reached. This flushing and testing was done by the water supplier technicians. There is no set length of flushing. The flushing continues as long as it takes to get clearer water or the target free chlorine residual. This could be an hour or two. IMHO that was what the OP observed that Jacobs personnel were doing for the hour plus time period.