Hudson Transmission Partners’ (HTP) requested amendment to its certificate of environmental compatibility and public need for its 345-kV submarine/underground electric transmission line between Manhattan and New Jersey are approved to allow repairs to move forward expeditiously, New York regulators said on Jan. 12.
As noted in the state Public Service Commission’s (PSC) order, HTP in September 2010 was granted a certificate of environmental compatibility and public need that authorized the construction and operation of a new 345-kV electric transmission facility between Ridgefield, N.J., and Consolidated Edison Company of New York’s West 49th Street substation in Manhattan.
The certificate was amended in 2011 and 2012, the PSC said, adding that HTP on Jan. 2 filed a petition for another amendment to its certificate to allow it to conduct necessary repairs to a fault identified in the cable buried in the river bed of the Hudson River. The certificate as currently amended does not include provisions for sediment removal in circumstances of cable repair and maintenance, the PSC said.
HTP, in its petition, sought approval to use mechanical dredging during in-river cable maintenance, repair and replacement operations in addition to its existing authority to use mechanical dredging in the installation of the temporary cofferdam related to land-to-river transition operations. Additionally, HTP sought approval to allow for reuse of dredged sediments in the excavated area, contingent upon prior approval by the U.S. Army Corps of Engineers (USACE) and New York State Department of Environmental Conservation, the PSC added.
The DEC on Jan. 10 submitted comments, saying that it does not object to the petition, provided several concerns and conditions are satisfied.
The DEC asserted that HTP’s proposed option to leave the cable exposed and allow for natural reburial is inconsistent with the existing certificate and certain water quality certification (WQC) conditions requiring a minimum burial depth of 10 feet below the existing river bottom, and alternatively, recommended that, if the excavated materials do not meet the standards for reuse as fill, clean materials be imported to restore the excavation area to pre-disturbance contours following the repair.
The PSC also said that the DEC supports a one-time waiver of the time-of-year restriction for in-river construction activities in order to achieve timely completion of the repair. The DEC also advised that HTP should maintain visual monitoring to detect and appropriately respond to any emergence of dielectric fluid on the water surface down-current of the project area during all phases of construction activities associated with the repair, and further recommended that the excavation plan be modified to specify, for instance, where excavated sediment will be stockpiled.
The PSC also noted that the City of New York on Jan. 10 submitted comments, neither supporting nor opposing the petition. The city noted that the portions of HTP’s transmission facility are located in the city’s land under water and are governed by a revocable consent issued by the city. While the portion of the cable that is subject to the repair described in the petition is not subject to the city’s revocable consent, any future maintenance, repair or replacement activities elsewhere in city land under water would be subject to the terms of the city’s revocable consent, the city said.
The PSC noted that the proposed repair work represents “required cable maintenance and repair work” indicated in the certificate, and therefore, a waiver of the time-of-year restrictions for construction of navigable waters is not required.
The DEC’s recommendation that HTP maintain visual monitoring to detect and appropriately respond to any emergence of dielectric fluid on the water surface down-current of the project area during all phases of construction activities associated with repair of the cable is reasonable, the PSC said.
The PSC said that HTP’s certificate is to be modified by amending the language in Certificate Condition 45 and §401 WQC Condition 11 to read:
- To avoid disturbance to near shore sediments, HTP is to employ horizontal direct drilling (HDD) to install the submarine cable system from the approved HDD drill pit to the exit pit in the bed of the Hudson River. The exit pit is to be installed within a dredged cofferdam, and no dredging is authorized except for dredging in connection with installation of the cofferdam and subsequent installation activities at the cofferdam location, and in connection with maintenance, repair and replacement activities under plans prepared in connection with specific maintenance, repair or replacement operations submitted for review to state Department of Public Service staff and DEC staff
HTP’s certificate is to be modified by amending the language in Certificate Condition 46 and §401 WQC Condition 12 to read:
- An environmental bucket is to be used for dredging silt or other fine-grained materials during cofferdam construction, transition operations, maintenance operations, repair operations and replacement operations undertaken under Certificate Condition 45 and WQC Condition 11. Drawings and specifications of the environmental bucket must be provided to DEC staff and DPS staff prior to the anticipated start of dredging
The PSC also said that HTP’s certificate is to be modified by amending the language in Certificate Condition 46 and §401 WQC Condition 12 to read:
- All sediments excavated during cofferdam construction, transition activities at the landfall location, maintenance activities, repair activities and replacement activities must be disposed of at a state-approved upland disposal site unless approved for reuse in the excavated area by the USACE and DEC staff. HTP is to provide the result of all dredged sediment tests to DPS staff and DEC staff prior to reuse as cable cover or disposal at an approved upland location. Dredged material is not to be sidecast, stockpiled on-site, or reintroduced into the harbor unless approved by the USACE and DEC staff
Among other things, the PSC said that HTP is to prepare, in consultation with DPS and DEC staff, a final excavation plan for submarine cable cut, cap and seal procedures prior to the start of repair activities included in the petition.