Ottawa, Ontario's state-of-the-art combined sewage storage tunnel — costing $232 million and commissioned in 2020 — was unable to cope with a recent severe thunderstorm.The tunnel, designed to hold up to 43 million liters of contaminated rainwater for treatment prior to discharge into the Ottawa River, was overwhelmed, resulting in the release of 316 million liters of polluted water directly into the river.
Despite the tunnel's success in significantly curbing untreated effluent discharge into the Ottawa River over the past three years, the recent storm's intensity exceeded its capacity, Marilyn Journeaux, director of water services at the City of
