DEC publishes Arctic offshore permit

On Feb. 20 the Alaska Department of Environmental Conservation published a proposed final general permit for waste discharges from geotechnical surveys in state waters of the Beaufort and Chukchi seas. Comments on the permit were required by Feb. 27 - a draft version of the permit had already been through public review. DEC has developed the new permit in coordination with a similar permit the Environmental Protection Agency issued on Jan. 29 for federal waters of the two Arctic seas.

Oil and gas companies typically conduct geotechnical surveys over offshore oil prospects and along potential subsea pipeline routes to determine the nature of the seafloor. A survey generally involves shallow rotary drilling, with the use of water-based drilling fluids. Fluid and rock cuttings from the drilling generally flow directly to the seafloor as they exit the borehole. Surveys may also be used to locate possible archaeological resources.

The permit, issued under the Alaska Pollutant Discharge Elimination System, or APDES, covers 12 types of discharge, including water-based drilling fluids and associated drill cuttings; deck drainage; domestic wastewater; uncontaminated ballast water; and bilge water. An operator can discharge effluents and minor quantities of pollutants within limits that the general permit spells out. But the operator must notify DEC in advance of the planned operation and the anticipated discharges. The operator must also monitor discharges during survey operations and must report the results of the monitoring to DEC.

The general permit also authorizes, upon request, a 100-meter cylindrically shaped mixing zone around the source of certain discharges, to enable dilution of materials in the discharges to permitted concentrations in the surrounding seawater.

- Alan Bailey