Section 217.234 - [Effective 1/1/2025] [Effective until 12/31/2029] Mitigation requirements(a) When conducting the activities identified in § 217.230(a), the mitigation measures contained in this subpart and any LOA issued under §§ 216.106 of this chapter and 217.236 must be implemented by the Navy. These mitigation measures include: (1) A copy of any issued LOA must be in the possession of the Navy, supervisory construction personnel, lead protected species observers (PSO), and any other relevant designees of the Navy operating under the authority of the LOA at all times that activities subject to the LOA are being conducted;(2) The Navy must ensure that construction supervisors and crews, the monitoring team, and relevant Navy staff are trained prior to the start of activities subject to any issued LOA, so that responsibilities, communication procedures, monitoring protocols, and operational procedures are clearly understood. New personnel joining during the Project must be trained prior to commencing work;(3) The Navy, construction supervisors and crews, and relevant Navy staff must avoid direct physical interaction with marine mammals during construction activity. If a marine mammal comes within 10 meters (m) of such activity, operations must cease and vessels must reduce speed to the minimum level required to maintain steerage and safe working conditions, as necessary to avoid direct physical interaction;(4) The Navy must employ PSOs and establish monitoring locations as described in the NMFS-approved Marine Mammal Monitoring Plan. The Navy must monitor the Project area to the maximum extent possible based on the required number of PSOs, required monitoring locations, and environmental conditions;(5) For all pile driving activities, the Navy shall implement shutdown zones with radial distances as identified in a LOA issued under § 217.236. If a marine mammal is observed entering or within the shutdown zone, such operations must be delayed or halted.(6) Monitoring must take place from 30 minutes prior to initiation of a pile driving activity (i.e., pre-start clearance monitoring) through 30 minutes post-completion of a pile driving activity.(7) Pre-start clearance monitoring must be conducted during periods of visibility sufficient for the lead PSO to determine that the shutdown zones are clear of marine mammals. Pile driving may commence following 30 minutes of observation when the determination is made that the shutdown zones are clear of marine mammals.(8) If a marine mammal is observed entering or within the shutdown zones, pile driving activity must be delayed or halted.(9) If pile driving is delayed or halted due to the presence of a marine mammal, the activity may not commence or resume until either the animal has voluntarily exited and been visually confirmed beyond the shutdown zone or 15 minutes have passed without re-detection of the animal.(10) Pile driving activity must be halted upon observation of either a species for which incidental take is not authorized or a species for which incidental take has been authorized but the authorized number of takes has been met, entering or within the harassment zone.(11) The Navy 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 30-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 30 minutes or longer. 89 FR 81864 , 1/1/2025through 12/31/2029