Equinor has been ordered to carry out an assessment at one of Norway’s biggest oil refineries after an investigation uncovered “unacceptable” conditions.
The Norwegian Environment Agency (NEA) also told the energy giant to implement measures to prevent negative environmental impacts arising from potential ground pollution at the Mongstad facility.
It follows the submission of an internal investigation by Equinor earlier today into practices at the refinery, around 30 miles north of Bergen.
Earlier this year, the Stavanger-headquartered company became aware of a seepage of oily water into the ground at Mongstad, as well as further leaks into the overflow basin.
An increase in the presence of oil in the basins was picked up by a new water volume meter that was installed early last year.
The Norwegian Environment Agency was notified in February, at which time Equinor also initiated an internal investigation.
The enquiry got underway in Spring and determined that the direct cause of the leak was increased discharge of oil from already polluted ground.
Equinor said the installation of the new water flow metre led to higher groundwater levels in periods of heavy rain, causing oil to be washed into the overflow basin, where treated water is collected before being released into the Fensfjorden fjord in accordance with the refinery’s permit.
Irene Rummelhoff, executive vice president of marketing, midstream and processing at Equinor, claimed measures were implemented as soon as they became aware of the situation.
She added that oil in the ground around the overflow basin has “now been collected” and all identified sources of leakage have been fixed.
A total of 112 cubic metres of oil were collected and removed from the area.
According to Equinor, the measures have been effective and the oily water values from the overflow basin have returned to normal.
The investigation report revealed that the oil seepage cannot be tied to a particular incident, but is rather the result of leaks from the drainage system, as well as several minor, past discharges from operations and maintenance routines and incidents.
The NEA issued an order today requiring Equinor to undertake a “thorough assessment” of the pollution situation in the ground around the refinery.
Ms Rummelhoff added: “The conditions we uncovered at Mongstad are unacceptable. The investigation shows an inadequate understanding of requirements that apply for discharges to the ground.
“This has led to us developing a practice in this area that does not conform with relevant environmental requirements.
“In addition to operative measures on site, we have therefore commenced work to improve knowledge and ensure compliance with all requirements for discharges to the ground.
“As regards discharges to water, the investigation confirms that we have good routines in place to ensure that we are within the limits set by the authorities.”