City switches from chlorine to disinfect drinking water

Moving to a safer option, the Aberdeen City Council voted unanimously this week to approve switching from chlorine gas to a newer technology to disinfect the city’s drinking water.

“I am so excited,” said Aberdeen Council President Pete Schave after 11 council members voted unanimously to approve the contract with HDR Engineering Inc. to replace the existing gas chlorination system. (Kathi Hoder was excused).

The gas chlorination will be replaced with a “safe, reliable, highly effective alternative to chlorine gas,” said Water Systems Manager Mike Randich in an email.

That system involves using sodium hypochlorite, or what Public Works Chairwoman Margo Shortt called salt, water and electricity, to disinfect the water.

The city has been using the one-ton cylinders of the gas for nearly 100 years, Randich said. “It’s very effective, fairly inexpensive, but very dangerous.”

The filter plant has been on-line for close to 14 years and the city has been concerned both about operator safety and the safety of students at Wishkah School and residents near the plant, he said.

“The tipping point for us in requesting this upgrade has been the lack of quality control from our only chlorine provider,” Randich said. The city has had to return two full cylinders this year due to inconsistent flow rates.

The replacement with a hypochlorite system will cost $47,900 and has a $5,000 contingency attached. The project should take six months.

It has become common for cities to switch to safer disinfectant methods, such as the use of sodium hypochlorite, which has been in use for 20 years or so, Randich said.

Wastewater

Meantime, Kyle Scott, wastewater manager, said he hopes to replace the use of chlorine gas in the disinfection of wastewater at the plant at 1205 W. State St. with ultraviolet light as soon as funding allows.

That could cost at least $5 million. The project is in the capital plans but has not been budgeted for, he said. Scott was at the meeting Wednesday night to receive the eighth consecutive outstanding performance award to his department by the state Department of Ecology.

Achieving the award isn’t easy, he said. There are 330 treatment plants in the state and only one third receive the award. As a winner eight years in a row, the department has the 12th longest streak in the state, he said.

“This award is for the 15 men and one woman” who turn out to do a job that “is not glamorous 24 hours a day, seven days a week, 365 days of the year,” he said. He shook hands with Mayor Bill Simpson and added, “See you next year.”