§ 217.34 Mitigation requirements. When conducting the activities identified in § 217.30(a), the mitigation measures contained in any LOA issued under § 216.106 of this chapter must be implemented. These mitigation measures shall include but are not limited to: ( a ) *General conditions.* ( 1 ) Hilcorp must renew, on an annual basis, the Plan of Cooperation (POC), throughout the life of the regulations in this subpart;
( 2 ) A copy of any issued LOA must be in the possession of Hilcorp, its designees, and work crew personnel operating under the authority of the issued LOA;
( 3 ) Hilcorp must conduct briefings for construction and ice road supervisors and crews, and the marine mammal and acoustic monitoring teams prior to the start of annual ice road or LDPI construction, and when new personnel join the work, in order to explain responsibilities, communication procedures, the marine mammal monitoring protocol, and operational procedures;
( 4 ) Hilcorp must allow subsistence hunters to use the LDPI for safe harbor during severe storms, if requested by hunters;
( 5 ) In the unanticipated event of an oil spill during LDPI operational years, Hilcorp must notify NMFS of the spill within 48 hours, regardless of size, and implement measures contained within the Liberty Oil Spill Response Plan; and
( 6 ) Hilcorp must strive to complete pile driving and pipeline installation during the ice-covered season.
( 7 ) Except during takeoff and landing and in emergency situations, aircraft must maintain an altitude of at least 457 m (1,500 ft). If a marine mammal is observed, then a horizontal distance of 305 m (100 ft) of whales or seals will be maintained between the aircraft and the observed marine mammals.
( b ) *Ice road construction, maintenance, and operation.* ( 1 ) Hilcorp must implement the NMFS-approved Ice Road and Ice Trail Best Management Practices (BMPs) and the Wildlife Action Plan. These documents may be updated as needed throughout the life of the regulations in this subpart, in consultation with NMFS.
( 2 ) Hilcorp must not approach ringed seal structures (*i.e.,* lairs or breathing holes) within 150 m or ringed seals within 50 m.
( c ) *Liberty Drilling Production Island construction.* ( 1 ) For all pile driving and construction activities involving heavy equipment, Hilcorp must implement a minimum shutdown zone of 10 meters (m) from any marine mammal in water or seals on land. If a marine mammal comes within or is about to enter the shutdown zone, such operations must cease immediately;
( 2 ) For all pile driving activity, Hilcorp shall implement shutdown zones with radial distances as identified in any LOA issued under §§ 216.106 of this chapter and 217.36. If a marine mammal comes within or is about to enter the shutdown zone, such operations must cease immediately. NMFS may adjust the shutdown zones pending review and approval of an acoustic monitoring report (see § 217.35);
( 3 ) Hilcorp must employ NMFS-approved protected species observers (PSOs) and designate monitoring zones with radial distances as identified in any LOA issued under §§ 216.106 of this chapter and 217.36. NMFS may adjust the monitoring zones pending review and approval of an acoustic monitoring report (see § 217.35);
( 4 ) If a bowhead whale or other low frequency cetacean enters the Level A harassment zone, pile or pipe driving must be shut down immediately. If a beluga whale or pinniped enters the Level A harassment zone while pile driving is ongoing, work may continue until the pile is completed (estimated to require approximately 15-20 minutes), but additional pile driving must not be initiated until the animal has left the Level A harassment zone. During this time, PSOs must monitor the animal and record behavior;
( 5 ) If a marine mammal is approaching a Level A harassment zone and pile driving has not commenced, pile driving must be delayed. Pile driving may not commence or resume until either the animal has voluntarily left and been visually confirmed beyond the shutdown zone; 15 minutes have passed without subsequent detections of small cetaceans and pinnipeds; or 30 minutes have passed without subsequent detections of large cetaceans;
( 6 ) If a species for which authorization has not been granted, or a species for which authorization has been granted but the authorized takes are met, is observed approaching or within the monitoring zone (which equates to the Level B harassment zone), pile driving and removal activities must shut down immediately using delay and shut-down procedures. Activities must not resume until the animal has been confirmed to have left the area or the observation time period, as indicated in paragraph (c)(5) of this section, has elapsed;
( 7 ) Hilcorp must use soft start techniques when impact pile driving. Soft start requires contractors to provide an initial set of strikes at reduced energy, followed by a thirty-second waiting period, then two subsequent reduced energy strike sets. A soft start must be implemented at the start of each day's impact pile driving and at any time following cessation of impact pile driving for a period of thirty minutes or longer;
( 8 ) All pipe- and pile-driving activities (impact and vibratory) and LDPI support vessel traffic outside the barrier islands must cease by August 1, annually, and not resume until the official end of the hunt or until the quota has been met, whichever occurs first. Hilcorp must coordinate annually with subsistence users on the dates of these hunts; and
( 9 ) Should an ice seal be observed on or near the LDPI by any Hilcorp personnel, during construction or operation, the sighting must be reported to Hilcorp's Environmental Specialist. No construction activity should occur within 10 m of an ice seal and any vehicles used should use precaution and not approach any ice seal within 10 m.
( d ) *Vessel restrictions.* When operating vessels, Hilcorp must: ( 1 ) Reduce vessel speed to 5 knots (kn) if a whale is observed within 500 m (1641 feet (ft)) of the vessel and is on a potential collision course with the vessel, or if a vessel is within 275 m (902 ft) of whales, regardless of course relative to the vessel;
( 2 ) Avoid multiple changes in vessel direction;
( 3 ) Not approach within 800 m (2,624 ft) of a North Pacific right whale or within 5.6 km (3 nautical miles) of Steller sea lion rookeries or major haulouts; and
( 4 ) Avoid North Pacific right whale critical habitat or, if critical habitat cannot be avoided, reduce vessel speed during transit.