UPDATE: A $3.2-million water main project is underway. Contractors for Tennessee American Water are installing a new pipe to supply water to thousands of customers in North Chattanooga.

The pipe though will be underwater in the Tennessee River and requires crews to blast rocks to make way for the new system.

The new 30-inch water main will start on the south side of the river at the water plant and go all the way across to the north side near Heritage Landing.

Currently, two pipes beneath the Tennessee River delivers water to about 20,000 homes and businesses in North Chattanooga.

In 2016, Tennessee American Water decided to build another pipe, because one of the two broke.

"We just came to the conclusion that we really needed to have a third pipe for a situation like that to happen again," said Daphne Kirksey with TAW.

A barge sits on the river now, where contractors will drill deep into the bedrock and use dynamite to blast a path for the new water main.

"Once the rock is broken up they'll excavate it and push it to the side, so they're building a trench where they will lay the new pipe," she explained.

The blasting will happen after 5 p.m. each day for the next few months, when it happens boaters will have to stay 300 feet away. People on the Riverwalk will be held back a thousand feet for 30 minutes while materials are brought to and from the shore.

"It's for safety reason because this is involving dynamite, it's involving blasting," Kirksey said.

Safety personnel will be at each end to make sure people stay away. Don't expect to see the water move or feel vibrations on the ground when the blast happens. However, you will hear a notification if you're nearby.

"When the blast is about to take place in the river there will be air horns sounded multiple times," Kirksey said.

Tennessee American Water says this project will not interrupt water service until the very end when they connect the lines, they expect this to happen in the fall.

The last time a water main was installed to supply water to north Chattanooga was in 1963.

This portion of the project will take about two to three months, then they'll begin laying pipe. We'll keep you up to date on the progress.

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PREVIOUS STORY: On Tuesday evening, June 26 (pending weather), Tennessee American Water will begin excavating across the Tennessee River in anticipation of installing a new 30-inch water main. 

The process involves using a small charge to crack the rock, which is then excavated from the riverbed leaving a trench.  This trench will later be utilized for installing the new pipe.  The blasting process takes less than 10 minutes and the work is performed from a barge.  

Tennessee American Water began the $3.2 million project to install a 30-inch pipe in the Tennessee River in May. This new pipe will be one of three - and the largest - that delivers water to the 20,000 customers on the north side of Chattanooga, Red Bank and Signal Mountain. The pipe adds redundancy and resiliency to the water delivery system to assure reliable water services.

 "Safety of the community and environment are top priorities," said Kurt Stafford, engineering manager for Tennessee American Water. "We have worked closely with various agencies such as the Chattanooga Fire Department, TVA, U.S. Army Corps of Engineers and the Tennessee Wildlife Resource Agency (TWRA) to follow all guidelines. The impact is very minimal and most people will not notice that the blasting has occurred since it takes place several feet under water."

Some useful facts about the activity on the water and Riverwalk during the blasting schedule are:

• When blasting is performed, it will take place after 5 p.m. and the contractor Reynolds will have two boats – one upstream and one downstream about 300 feet – to make sure the radius is clear around the barge.  An air horn will be sounded multiple times before the procedure.

• This means that users of the water behind the Tennessee American Water plant will need to wait until the all-clear from Reynolds. • Users of the river should only be impacted for 10 minutes.

• The Riverpark behind the Tennessee American Water plant will be temporarily closed for approximately 30 minutes while the discharge materials are delivered to and from the barge, at the beginning and end of the day.

• This portion of the project will take around two to three months.