Minnesota regulators have determined that Enbridge Inc. must pay $3.2 million in penalties and repairs after construction of the contentious Line 3 oil pipeline replacement project was found to have caused an underground aquifer to leak.

Line 3

The Minnesota Department of Natural Resources (MDNR) announced that the mistake has cost a $20,000 administrative penalty, $300,000 for water losses, $250,000 for environmental monitoring, and a $2.75-million fund for future restoration costs.

Calgary-based Enbridge pledged to cooperate with the state regulator on damage control and prevention.

The Minnesota regulators said inspections found a 24.2 million-gallon leak from an underground aquifer that was penetrated by a ditch 18 feet deep and pilings driven down to a depth of 28 feet at the...