Nicole Goldsworthy
Local Journalism Initiative Reporter
SaskToday.ca
HUMBOLDT — The City of Humboldt says an emergency wastewater bypass that discharged sewage-impacted water into Humboldt Lake on June 30.
According to the City of Humboldt, this was implemented only after all practical alternatives had been exhausted during a period of exceptional rainfall.
The bypass began at about 9:35 p.m. on June 30 and ended at approximately 5:13 p.m. on July 1, after flows within the city’s wastewater collection system returned to levels that could be safely managed said the City of Humboldt
According to Peter Bergquist, Director of Public Works, 164.3 millimetres of rain fell between June 22 and July 1, saturating the ground and causing large amounts of groundwater infiltration and stormwater inflow to enter the sanitary sewer system. Those additional flows pushed portions of the wastewater collection system beyond capacity.
Bergquist said that the city staff worked continuously to avoid a bypass by using septic and vacuum trucks to transport wastewater within the collection system while taking other operational measures to maximize capacity.
Despite those efforts, the city said incoming flows continued to exceed what the system could safely handle.
“The bypass was implemented only after all practical alternatives had been exhausted,” Bergquist said in its response to SaskToday. “The temporary bypass was implemented as a last-resort measure to protect public health and property.”
The City of Humboldt said the alternative was the risk of sewage backing up into homes, businesses and public infrastructure.
Based on operational data, the total bypass volume was approximately 3,704 cubic metres. Engineering analysis estimated that 180 to 235 cubic metres represented normal sanitary sewage, while 3,470 to 3,525 cubic metres consisted of groundwater infiltration, stormwater and other wet-weather inflows that had entered the sanitary sewer system.
The city said the event was reported to provincial regulators as required. It also notified residents living around Humboldt Lake directly but did not issue a public news release.
In a July 3 letter to Humboldt Lake residents, the city said approximately 94 to 95 per cent of the bypassed volume consisted of stormwater and groundwater infiltration, while five to six per cent was normal sanitary sewage.
The letter added that, although the discharged water was sewage-impacted and appropriately reported to provincial agencies, “it would not be accurate to characterize the entire bypass volume as undiluted household sewage.”
The City said temporary wastewater bypasses, while undesirable, can occur in municipalities during prolonged wet weather when groundwater infiltration and stormwater inflow overwhelm sanitary sewer systems.
Bergquist said they continue to evaluate ways to reduce groundwater infiltration through infrastructure renewal, system maintenance and public education. The City has also offered programs to help homeowners disconnect weeping tiles from the sanitary sewer system and install sump pumps that discharge to the ground surface, reducing pressure on the wastewater network during heavy rainfall.
The city said it continues to work with provincial regulatory agencies while monitoring conditions. It added that public health officials are responsible for determining whether recreational water advisories or beach closures are necessary and that, as of the July 3 resident update, the city had not been advised of any advisories or closures for Humboldt Lake.
