An engineering-services contract for the city’s water treatment plant is on the Ketchikan City Council agenda Thursday.
The $37,000 contract with CH2M Hill would allow a testing phase to move forward. This follows approval by the Alaska Department of Environmental Conservation for the city to test a second chlorine injection following an ultraviolet light treatment.
The state has yet to approve the city’s planned chloramination treatment process, which was meant to reduce byproducts from chlorine treatment while still meeting strict disinfection guidelines. The state has allowed the city to move forward with the UV treatment, in the meantime.
In a memo to the Council, Water Division Manager John Kleinegger says that using the UV treatment increases disinfection, but it also reduces the amount of chlorine in the water, which makes the levels of chlorine too low by the time the water reaches the farthest points of the system. Adding more chlorine at the beginning of the process will fix that problem, but increases the amount of byproducts, which have been linked to cancer in laboratory animals.
This new plan calls for less chlorine at the initial stage, then the UV light treatment, then a secondary chlorine injection. They believe that will keep chlorine levels at the correct level, and not increase the byproducts.
The CH2M Hill contract will test that hypothesis.
Also Thursday the Council will vote on a second reading of an ordinance that would place a hospital improvement bond proposal on the Oct. 1 municipal ballot.
The meeting starts at 7 p.m. in City Council chambers. Public comment will be heard at the start of the meeting.
