Top articles for 1999 included a hydrant flusher from Environmental Enhance-ments. This surprise hit was a Product Focus for February 1999. It drew 357 reader service responses.
The product featured was Hydro-Guard?, an automatic flushing device that can be programmed to flush water lines without supervision, helping solve disinfectant residual and water quality problems without the need for manual flushing programs.
It was a timely addition to the market because Safe Drinking Water Act Amendments will require that water utilities reduce the maximum chlorine residual at any point within their distribution system to no more than 4 mg/l while at the same time maintaining a minimum chlorine residual at all points in the system of no less than 0.2 mg/l free chlorine or 0.6 mg/l combined chlorine.
Also, since it is automatic, hydrants equipped with the system don?t have to be flushed manually, which helps water utilities to be more efficient. Used by operators to maintain distribution system water quality, they help reduce bacterial presence and control biofilm by flushing out stale water with low disinfectant residuals.
The flusher is constructed of noncorrosive and weather-resistant materials, and weighs approximately 46 pounds. It contains three main components ? the Controls Module, a hand-held programmer and the Mechanical Module.
Collier County, Fla., used the flushing system on a dead-end street, raising the chlorine residual in that stretch of pipe to more than 3 mg/l. To obtain this reading, the line at first had to be flushed for 4 minutes every night at a rate of approximately 150 gpm. The length of time for flushing was then reduced to obtain a target average of 2 mg/l chlorine residual maintenance level.
?Historically, water utilities focused their efforts on treatment,? said Craig J. Pajer, Business Development Director at EE&T. ?Now, due to customer concerns and federal regulations, more focus is being given to distribution systems to make certain that water quality has not deteriorated as it is delivered to the customer.