WATERTOWN — The city is completing major repairs to the century-old dosing station dam that stops untreated water from leaking into a settling coagulation basin in the Black River.
Work began on the dam, near Route 3 across from Heather Acres apartments, earlier this month and is expected to be finished during the second week of August. The $428,000 project entails constructing an 8-inch-thick cement face along the downstream wall of the 300-foot-long dam.
In 2010, the first phase of the repairs was completed on the upstream side of the dam. This time, Acts II Construction, Gouverneur, the same contractor that did the first phase, has been repairing the other side of the dam, the downstream section.
Before the 2010 work, some 1.5 million gallons of untreated water a day seeped through a number of cracks in the dam. That amount was cut down to about one-third when the first phase was finished. Workers also will check to see if any additional channel leaks exist under the dam.
City Engineer Kurt W. Hauk said untreated water was bypassing the chemical dosing station, the first phase of the city’s water treatment process.
“It’s an important project for us,” Mr. Hauk said, adding that the repairs to the dam were the most extensive since it was built during the early part of the last century.
The leaks were driving up the cost of treating water that goes through the dosing station. It will enhance the pretreatment process and cut down on having to use more chemicals.
To make the repairs, divers got into the water and installed a Portadam at the site before draining some of the basin’s water.
This phase of the project is on time and within budget. Five other contractors submitted bids for the work, while Acts II was the low bidder. The city is using a $450,000 bond to finance the project.
The city paid Acts II $330,450 to complete the first phase.
Five city employees were suspended without pay this winter when it was discovered that they had urinated into the untreated water while they occupied a barge-like craft during a dredging operation at the basin.