Reservoirs likely source of Smithers water contamination: CAO

Reservoirs likely source of Smithers water contamination: CAO

The boil water notice is into its third week and will continue as more work and tests are done.

The Town of Smithers remains under a boil water notice for a third week.

The notice came into place Sept. 1 and efforts are still being made to cleanse the water.

“As close as we are able to determine, it is likely that the source of contamination are the reservoirs. Direct water sampling from both reservoirs performed Monday, Sept 11 prior to the start of the reservoir disinfection on Sept. 12 have shown positive results there,” said chief administrative officer for the Town, Anne Yanciw.

Before a boil water notice is lifted, Northern Health and the Town need to see a consistent residual level of disinfectant at the sampling sites for eight days in a row. The sampling being done now is to measure the level of disinfectant at the sites.

Yanciw stated before a boil water notice is removed, remaining corrective actions include submission of multiple samples, taken 24 hours apart, showing the absence of total coliforms and E.coli, and consultation with the Environmental Health Officer.

The consecutive clear samples required need to be taken after the chlorine residual is removed from the system. This can only be determined through sampling and testing.

“We are exercising a procedure of draining and refilling the reservoirs to ensure that the disinfectant is dispersed effectively throughout the system. This will force a more complete turnover of water in the reservoirs,” she said.

How the water system works

Information provided by the Town explains how water is distributed throughout Smithers.

There are three wells throughout town that provide water to about 5,400 buildings. The first well is located on Nineteenth Avenue by the public works building. It’s 268 feet deep and is in a sand and gravel aquifer with a 12-inch telescoping screen. The pumphouse located at the public works yard is used for annual chlorine flushing of the water mains in the spring.

Well number two is on Victoria Street and in the same aquifer as the Nineteenth Avenue well. It has a similar screen as the first well and is 193-235 feet deep. According to the Town, it is confined from potential contamination from the old landfill site.

The last well is at Riverside Park adjacent to the Bulkley River and is 92 feet deep. The aquifer that it sits on is a ‘very dirty silty,’ but easily developed gravel one. It too has a similar sized screen and is 64-85 feet deep.

The water once pumped from the wells is stored in two reservoirs that float on the system. One of the reservoirs holds 265,000 gallons of water and is about 10 feet deep. The other holds 1 million gallons and is 25 feet deep. Both have a single inlet/outlet and they are flushed each year.

The main reservoir is on Moncton Road. It was built in 1975 and was cleaned in 2005, which removed three inches of sediment from the bottom.

The smaller reservoir is located on Zobnick Road and was built in 1950. It has two compartments and is underground. It’s only accessible by manhole. A 1999 inspection deemed the inside condition to be satisfactory and the bottom was also cleaned. According to the latest information from the Town, it was last cleaned in September 2015.

The water lines are flushed each May using injection pumps. Liquid chlorine is injected through the first and third wells to the amount of 0.2 mg/L while flushing.

There is no treatment plant.

As for why the Town of Smithers doesn’t keep large amounts of chlorine on site, it’s simple.

“Chlorine loses it’s strength when it sits … It loses it’s concentration and you don’t know if you have the strength that you require.” Yanciw stated. “Because we currently have a program of disinfection once per year, we purchase enough for that.”

There could be some changes to prevent such an occurrence in the future. According to Yanciw, they have a few options and one might be to increase the amount of chlorine put into the system at a higher concentration still once a year, or they may flush the system twice a year.

The Town states the 2017 watermain looping project is isolated and is not responsible for the issue. It will be tested to AWWA standards before being connected to the existing watermain system, re-flushed and put into service.

SmithersSmithers council

 

The system in which chlorine is injected into the Town of Smithers water.

The system in which chlorine is injected into the Town of Smithers water.