By Andy Labdon
At last week’s council meeting Derek Melsted, the town’s contracted Class 2 Water and Treatment Distribution Operator, addressed council on concerns over the water treatment supply to Wadena.
Melsted opened by commenting on the surprisingly high volume of water going through Wadena’s water system. This, Melsted said, is putting stress on the filters and suggested an investigation as to the cause of the increase over the last six years. The average expected amount of water used in the winter should be approximately 340 cubic meters (approximately 90,000 gallons per day) for the town, he said. In the summer, this can rise to between 550 to 650 cubic metres of water a day, or approximately 145,000-175,000 gallons.
On April 17, 2019, the water volume for the day measured approximately 720 cubic meters when it should be around the 400-cubic-metre mark.
Melsted recommended that all vacant properties be checked for leaks and that the leaks would more than likely be in the lines as there has been no noticeable increase in meter readings. He suggested that all the utility hole covers be lifted to check the volume of water running through the sewers. One leak that was running into the sewer has already been found on the southwest of town and has been fixed.
Melsted also recommended the plan to decommission well No. 5 may need a revisit as its decommissioning leaves no spare well if one of the remaining two wells needs to be shut down for maintenance or repair. If well No. 5 was to be shut down, then his recommendation was to explore new sites for a third well.
Maintenance and training were areas where Melsted said improvement could be made, citing the retention chamber as one example. The retention chamber has to be cleaned every six months and the equipment physically checked. In May, a leak was found in one of the pipes resulting in water bypassing the filtration system and subsequently repaired. How long it had been leaking, no one knew. He also noted there had been an overfeed of chemicals and suggested a slightly lower rate to be applied. He also stated that there seems to be a struggle to keep chlorine levels maintained because the staff are not confident with handling chlorine gas, and suggested a one-day training course to cure that problem. He also recommended that the system needs regular maintenance.
There was also concern about the filters when it comes to the timing of backwashes leaving filters to run longer than they should. Overall the south filter produces good water, he said, but the north filter suffers from mud balling but can produce good water if the backwash timings were changed. Filters cost approximately $45,000 and last for about ten years and were last replaced in 2011.
Melsted then mentioned the media, which need to be cleaned or replaced, and takes about two days per filter to replace. As the town reservoir has the capacity to supply the town water for three days, a two-day shutdown should cause no problems. He also noted that backwash rates were not being achieved and that some equipment may have to be replaced or calibrated. The backwash motor itself is weak, he said, and not powerful enough. He suggested that the backwash pump and motor be replaced.
Maintenance and cleaning schedules indicate the town’s reservoir and clear well are due for a clean this year and, if it that does happen, Melsted suggested to make sure this is done after the media and filters have been cleaned.
He also suggested that some infrastructure will have to be replaced as old cast iron piping is showing signs of rust, leading to a significant amount of rust in the system.
The water tower that is scheduled for some significant refurbishment this year is working well but is susceptible to freezing during the winter months, reported Melsted. He made some recommendations with one option to eliminate the tower entirely from the system and go onto variable speed operation. The life of the tower is drawing to a close with only another five to ten years of life left. However, Melsted said it could run another 20 years.
Melsted also mentioned that there were many valves in town that are not working, which made directional flushing almost impossible. He also added that flushing the system should take a period of weeks and not days.
The brown water some residents have experienced, in his opinion, was caused by iron manganese that slipped through the filters and built up over time in dead ends. That, combined with a low flow, help to develop a build-up in the service lines that if and when disturbed, causes the discoloration.
Melsted suggested that three issues need immediate attention: the amount of water going through the system need to be explored; the problems surrounding backwashing; plus the issue of the filters and media.
Melsted ended his report by saying in the fall, with all the valves working, directional flushing of the system over a period of weeks should take place.
It has also been announced that at the beginning of July Wadena will welcome a new Public Works Director, Alyshia Neuman, Class 2 Water and Treatment Distribution Operator.