The District of Squamish's latest measurements estimate that about 1,587 cubic metres — 1.59 million litres — of sewage and greywater were dumped into the Bridge Pond of the Squamish Estuary over the weekend.
That's about 64% of the total volume of an Olympic swimming pool.
This represents about 11% of the total amount of wastewater generated by the community that day.
It's one part of the latest update regarding the failure of the Queens Way sewer lift station that happened on Jan. 14. During a tour that The Squamish Chief took of the site on Jan. 19, officials revealed new details about what caused the incident.
During the lift station failure, District crews were forced to use vacuum trucks to transport wastewater to other manholes leading to the wastewater treatment plant in the Public Works Yard.
Normally, sewage and greywater from downtown would be pumped to the Queens Way station, which would then funnel it further along the District's pipe network until it eventually reaches the town's wastewater treatment plant.
However, the Queens Way station manhole, about seven metres deep, gave out.
"It's not that the manhole clogged and then broke," said Devin Kiyonaga, a municipal engineer. "The problem is the manhole itself was deteriorating, and the side of it gave out. And then debris entered the manhole and clogged the pipe at that point."
Sand, gravel, and other outside materials started flooding the pipe.
While more effluent was going through the pipes due to the wet weather, staff said it was not a problem of too much volume.
"So, normally, we're kind of between 8 million and 9 million litres a day," said Benjamin Kineshanko, the District's public works technical operations manager.
"Last week, we were running 13 million, 14 million, 15 million litres a day because of rain, king tides, high river levels and a generally high groundwater table that occurs naturally in the winter months ... it's very average."
The figures he listed represent the amount of water flowing through the system and being treated at the wastewater treatment plant.
"The rain events we've experienced in the last week or two are pretty typical to Squamish," Kineshanko said.
He said the amount of volume flowing through the system that day was well within the District's capacity.
"So our permit with the Ministry of Environment that we're allowed to discharge is 17.85 million litres a day [from the wastewater treatment plant]," said Kineshanko. "And we've treated up to and in excess of that in the past without issue, while still meeting our analytical parameters."
Officials say the main reason for the failure was the result of degradation of that lift station's manhole. The wet weather, which created high groundwater levels and malleable soil, was a contributing factor.
With respect to degradation, this lift station was in worse shape than others, due to the particularities of its location, officials said. It's very unlikely this situation would occur again in other parts of the municipality, they said.
"This is the worst location in town," Kineshanko said.
In this location, the sewage has less access to oxygen, staff said. As a result, bacterial reactions in the wastewater contribute to more degradation in comparison with other areas around town.
"In the absence of oxygen, [bacteria] will then use sulphur instead of oxygen for cellular respiration," said Kineshanko. "And the byproduct of that is hydrogen sulphide gas. And when that hydrogen sulphide gas comes into water on the exterior of a concrete manhole, that is a moist environment. It becomes sulphuric acid. Sulfuric acid degrades concrete."
When the municipality rebuilds this manhole, it's going to have a liner of some sort that is inert to the effects of hydrogen sulphide, he said.
The role of weather
Kiyonaga said the weather had a role to play in the failure, though it's hard to say to what extent.
"If it was high and dry right now, and the groundwater level was a lot lower, maybe the manhole wouldn't have failed the way it did or when it did," said Kiyonaga. "But, yeah, it's hard to quantify for sure."
Rainwater entering the system through storm drains was not a factor though, because those systems are separated from the sewer pipelines, staff said.
Before crews could set up a bypass line that would take the flow directly from downtown to the wastewater treatment plant, officials asked residents south of the Mamquam River to reduce their water use.
While the municipality announced the bypass operation was ultimately successful, crews had to discharge wastewater into the estuary.
"[The discharge] was continuous for five hours, meaning the rate fluctuates slightly, but it was five hours," said Kineshanko.
It was done as a last resort, and in this case, public health took first priority, he said.
The District said this was done as a last resort to keep wastewater from backing up into people's homes and businesses.
Kineshanko said that, as of now, most of the effluent has likely dispersed from the pond.
"The Bridge Pond fills and empties twice a day, tidally," said Kineshanko. "We have tide gates that control the volume of water in and out of Bridge Pond at Third Avenue. They're automated [to open twice a day], but that day we controlled them in hand and allowed additional seawater into Bridge Pond to…flush [the pond.]"
Environmental consultants will be monitoring the situation to see the impacts.
The federal government is monitoring the situation.
Environment and Climate Change Canada issued a written statement to The Squamish Chief saying it was aware of the discharge and is reviewing the situation.
"Enforcement officers are attending the site of the spill," wrote spokesperson Nicole Allen.
"ECCC is responsible for administering and enforcing the pollution prevention provisions of the Fisheries Act, which prohibit the deposit of deleterious substances into water frequented by fish. If ECCC enforcement officers become aware of information regarding alleged violations of the Fisheries Act, they may conduct inspections in order to assess compliance. When there is sufficient evidence of an alleged violation, enforcement officers may take appropriate action in accordance with the Compliance and Enforcement Policy for the Habitat Protection and Pollution Prevention Provisions of the Fisheries Act."
The provincial Ministry of Environment had a similar but much sparser comment.
It issued a statement saying its compliance and enforcement staff are aware of the discharge and are reviewing the information. At this time, no compliance and enforcement actions have been taken.
In the late afternoon of Jan. 24, the ministry provided an update, stating that, "The Environmental Emergencies Program has engaged with both the District of Squamish and a qualified professional retained by the District. The ministry is reviewing the District’s sampling plan and will make recommendations to assist in determining impacts and a path forward."
Impact on fish?
On a more local level, the Squamish River Watershed Society noted the possible effects that a sewage dump could have on fish.
While she didn't have information on how much damage may have been done, Francesca Knight, president of the association, described in general terms how this could affect fish.
"Short-term exposure to a small quantity of raw sewage would not likely be harmful to fish in the Bridge Pond, depending on how the material was diluted through Bridge Pond," Knight wrote to The Squamish Chief.
"Longer exposure, however, would be a problem, as the oxygen required to break down components of the sewage would reduce/deplete the oxygen available to the fish. This is due to biological oxygen demand (BOD), a water quality parameter that gives scientists an idea of how much organic material is in a waterbody. The greater the concentration of organic matter (like raw sewage), the higher the BOD, which means less oxygen for aquatic life in the water column or benthic habitats (sediments on the seabed). In a longer exposure period, or a higher concentration, fish can definitely be killed, and certainly have been, by exposure to raw sewage. Were any fish killed as a result of the DOS' recent sewage dump, we just don't know."
Fisheries and Oceans Canada declined to comment, saying it did not have specific details of the discharge.
The Sḵwx̱wú7mesh Úxwumixw (Squamish Nation) declined to comment for this story.
District officials say the aging lift station has been on the municipality's radar for some time. Plans had been made to upgrade the station, which is about 25 years old.
However, work was not completed this past summer because contractors were asking for double the price the District was hoping to pay, said Kiyonaga.
The District went out to tender around 2021, but the prices that came back were too high. Staff said supply chain shortages caused by the pandemic were a big factor.
"So we re-tendered another tender, and we reduced the scope, focusing on this manhole," said Kiyonaga. "And then once again, the price came back double what we had budgeted that year, which was already higher than the year before."
The municipality told The Squamish Chief in a written statement that the cost estimate was approximately $500,000, and so this amount was budgeted. The lowest bid received was $1.15 million, resulting in the need to adjust the budget and the timeline for the work.
The District was still accepting bids when this manhole failed and was looking for a contractor as of press time.
What is next?
Emergency work has been done to fix the most vital parts of the lift station. In the meantime, the District is looking for contractors to upgrade other parts of the structure.
"We [are going to] take out the manhole replacement portion out of the existing tender … and we have hired a contractor on an emergency basis just to fix just to replace the manhole," said Kiyonaga. "And then we'll be adjusting the tender going forward for the remaining portion."
There were some indicators that the manhole was deteriorating, causing crews to get ready for work in the days leading up to the failure.
Staff said that they had hoped to complete some emergency work just before the event, but the weather conditions were not conducive to doing this in the safest way. As a result, the manhole failed just before the scheduled work.
Mayor Armand Hurford said that the speed with which this issue was resolved was a testament to the planning that had identified the Queens Way lift station as a facility in need of upgrades.
"Without that level of preparedness, and being ready…this crisis might still be happening as we're standing here," Hurford said.
The mayor and staff also thanked the community for its support, noting the many contractors that came to aid the municipality on short notice.
Finally, for cases where the lift station failure and effluent dump may have affected private property, the District said there is a case-by-case process for such events.
The District said property owners who believe they have a claim can submit a request to the District by emailing firstname.lastname@example.org.
***Updated on Jan. 25 to add a late updated comment from the provincial Ministry of the Environment, which was given in the late afternoon of Jan. 24.