Instead, the plumbing at various levels of the building are often sequestered, with pressure supplied from a rooftop water tower instead of the municipal supply.
Sequestered may eventually leak up through the ground, may lead to unexpected geological instability or may cause contamination of aquifers used for drinking water supplies.
While the carbon had been sequestered naturally, some point to the event as evidence for the potentially catastrophic effects of sequestering carbon artificially.