Sewer and storm water spilled into Hamilton Harbour twice as often last year
The city says it's wetter weather, higher lake levels and a $340M upgrade to the Woodward plant
The number of times partially treated sewer and wastewater Hamilton dumped into the harbour doubled last year, and the city says it's from more rain, higher lake levels and repairs to a major water treatment plant.
The number of bypasses increased to 34 in 2019 from 17 in 2018
A local environmental organization says the increase isn't good news, but it's also expected.
A new city report also shows 3,067 million litres leaked into Hamilton Harbour in 2019 because the Woodward Wastewater Treatment Plant couldn't handle it. That's up significantly from the 1,868 million litres in 2018, and a five-year average of 1,771 million litres.
The increases aren't a surprise, says Lynda Lukasik, executive director of Environment Hamilton.
Climate change will bring more volatile weather and higher lake levels, she said. And the city warned people that the treatment plant upgrades — a $340-million project ending in 2022 — would temporarily mean more bypasses.
"Because it's happening for a limited period to get us to a better place, I guess we can live with it," she said.
The bigger question, she said, is whether higher lake levels will overwhelm the system and ultimately undo efforts made in upgrading the plant anyway.
City council's public works committee heard the report on Wednesday. Andrew Grice, head of Hamilton Water, said lake levels were the main culprit. When levels are high, he said, lake water flows into the CSO tanks that are meant to hold back surges of stormwater and reduces their effectiveness.
There have been bypasses this year too, he said, but the number is "not quite as high as we experienced in 2019."
Bypasses happen when there's heavy water flow, whether it be through rainfall, snow melt, or high lake levels.
The amount of water overwhelms the nine combined sewer overflow (CSO) tanks in Hamilton's lower city, which means more volume makes it to the Woodward plant and overwhelms the system there. To protect the plant's infrastructure, the report says, whoever is operating the plant will initiate a bypass, which means sewage and stormwater will be released into the harbour only partially treated.
That partial treatment involves removing all the solid material and applying enough chemicals to remove the phosphorus. From May to October, the city also adds chlorine.
Hamilton had fewer bypasses than Toronto, which let out 4,383 million litres of partially treated sewer and stormwater in 2019, up from 2,093 million litres in 2018. It saw more than Niagara (2,178 million litres), and far more than Sudbury (338), London (16) and Kingston (15).
Lukasik says the report shows why the city should implement a stormwater fee system that charges more to property owners with large impervious surfaces like parking lots.
It also illustrates why people should only flush urine, feces and toilet paper — no medicine, plastic tampon applicators, wipes and the like.
On that note, city staff also presented a report showing the origin of most of Hamilton's "floatables" (detritus that ends up in the water).
The city, prompted in part by Indigenous water walkers, hired Cole Engineering. The study found most of it was waste people had flushed.
The city has installed booms, signs at CSO outfall locations, and needle drop boxes at eight parks. The booms are part of a pilot project that ends in 2021.
The Own Your Throne advertising campaign telling people not to flush items like condoms and tampon applicators has helped, said Deborah Goudreau, the city's manager of water services. The city plans a kitchen-related campaign called Beware the Berg.
The city also added a boom at the Dunn CSO outfall, where Lukasik noticed a problem earlier this year.