Storage Tank Mixing Systems – 2015
The presence of disinfection by-products (DBPs) in the water supply has been a concern for BCWA during the past few years. DBPs are formed from the interaction of chlorine with naturally occurring organic compounds – such as decaying plants and leaves – which are present in all surface reservoirs. The length of time chlorine is in contact with these naturally occurring organic compounds is also a factor. BCWA receives all of its water supply from the Scituate Reservoir, so the water travels a great distance before it gets to out consumers, and is reacting with the chlorine along the way.
DBPs can be greatly reduced by adding mixing and aeration systems in storage tanks. The two-million gallon Bay View storage tank located in Bristol was the first tank to have this equipment installed. This project has been completed and is operational.
BCWA is presently installing mixing and aeration equipment in the Fountain Avenue storage tank located in Barrington. This project will include new piping that will improve circulation in the tank by having the water enter the tank near the top, and exit at the bottom. Additional pipes will also be added that will spray water into the tank.
BCWA has also completed the installation of a new automatic chlorine monitoring and injection system at the main connection to the East Bay Pipeline, which is the source of the water supply from Providence and the Scituate Reservoir. This equipment and technology will assist in optimizing the use of chlorine to control disinfection byproducts while maintaining proper levels of chlorine for disinfection purposes.