The annual reports for the city’s drinking water supply and the waste water treatment plant showed few problems in 2015.
The water quality report indicated there was only one issue, as the four tests for total trihalomethanes (TTHMs) exceeded 100 parts per billion (ppb). The levels of TTHMs have been reduced in recent years, but the annual average is still above 100 ppb.
“We are working toward another raw water source in Rafferty (Dam) that contains less organics and therefore less TTHMs will be forced during disinfection,” Sutter wrote in his report.
Trihalomethanes (THMs) are a disinfection byproduct, and are not an immediate risk, but over time, THM ingestion is a suspected carcinogen. Each individual sample is not to exceed 350 ppb, and the annual average is not to exceed 100 ppb. The average TTHM count in Estevan’s water supply was 125 ppb last year, which was up from 114 ppb in 2014.
Sutter hopes that when the water supply source is switched to Rafferty, the TTHMs will drop below 100 ppb. A preliminary study has already taken place, but it’s a multi-million dollar project, and it has not received funding from the Building Canada program.
The other tests were compliant with provincial standards. Some of those tests are taken biennially, annually or quarterly; others happen more frequently. There were 156 bacteriological samples, 365 on-site fluoride tests and 52 off-site fluoride tests.
“There was less run-off last year than there was in previous years, so generally when we have less run-off, that means the dilution factor (changes) in Boundary Dam, which is our water supply, and the dissolved minerals get a little more concentrated,” said Sutter.
The disinfection system for the water supply is also working very well, he said. None of the samples taken throughout the system had any signs of bacterial contamination.
As for the waste water treatment plant (WWTP), the new bio-solids processing building is finished, but due to supplier issues, the equipment that was to be placed inside was not delivered as of Dec. 31, 2015.
“We have been reassured that the equipment is coming, but it will not arrive until the spring of 2016,” Sutter wrote in a report. “This is causing us to keep the equipment that was to be replaced in this facility up and running, which is getting exceedingly harder to do. The bio-solids building is now slated to go online by June 2016.”
Also, Stantec Consulting was hired to do a detailed design of an efficiency upgrade to the WWTP facility. The outdated equipment will be replaced. The equipment was budgeted at $1 million, and was supposed to be tendered last year, but it was not completed and will be forwarded to this year.
“These upgrades are required to keep the plant operational, and to raise the efficiency so that the inevitable expansion of the whole facility can be delayed for a few more years to give the city the time required to develop a financial plan to fund a system-wide expansion,” he wrote.
Even though the effluent quality spiked from time to time last year, the holding ponds have been able to buffer these spikes, and the effluent-leaving Cell J meets the requirements to operate.
The waste water treatment system was designed for a maximum daily flow of 6,000 cubic metres of water per day, and in 2015, they surpassed that total in three of 365 days. The volumes treated have dropped from 2014, which Sutter attributes to the sliding economy, so the plant operated within its capacity for much of the year.
