The Arkansas Public Service Commission (APSC) should find that construction of Entergy Arkansas Inc.’s (EAI) proposed electrical facilities using the existing route of the EAI Datto to EAI Jim Hill transmission line is reasonable, Clark Cotten, senior electrical engineer for the PSC general staff, said on Oct. 6.
As noted by Cotten’s direct testimony, filed with the APSC on behalf of general staff, Entergy Arkansas in July filed its application for a certificate of environmental compatibility and public need (CECPN) to rebuild and upgrade its existing EAI Datto to EAI Jim Hill 115-kV transmission line within its existing 100-foot right of way (ROW) to operate at 161-kV.
The proposed line is about 39 miles long and would include upgrades to the existing end-terminal substations, EAI Datto and EAI Jim Hill, and three intermediate substations – Arkansas Electric Cooperative Corporation (AECC) Corning North, EAI Corning, and EAI Texas Eastern switching station #8 – to operate at 161 kV.
The line would also include the rebuild of navigable water crossings of the St. Francis and Black rivers. The proposed facilities are located in Clay County, Ark., and in Dunklin County, Mo., Cotten added.
The EAI Datto substation would be expanded and upgraded to accommodate the 161-kV connections to the proposed line. Entergy Arkansas does not anticipate that additional acreage would be required for the substation expansion, but additional property for right of way (ROW) would be needed for routing the proposed line into the substation.
At the AECC Corning North substation, the existing high voltage bus conductors in the station would be upgraded to 161-kV operation and the two existing motor-operated line switches would be upgraded to 2,000 ampere capability, Cotten added.
Entergy Arkansas’ Corning substation is rated for 161-kV operation and all facilities are adequate for the proposed line, he said.
The EAI Texas Eastern switching station #8 and related facilities would be dismantled and a new 161-kV substation would be built on about 2.8 acres adjacent to the existing facility.
Cotten also noted that about two miles of the eastern portion of the proposed line and the EAI Jim Hill substation are located in Dunklin County, Mo., Cotten added, noting that the EAI Jim Hill substation 115-kV facilities would be upgraded to 161 kV with no additional property required for the planned expansion.
According to the company, contract crews are scheduled to begin ROW survey and preparation in 2Q17, continuing through 3Q17. Construction of the proposed line would begin in 4Q17, and completion of the proposed electrical facilities is projected for 2Q19, Cotten added.
Entergy Arkansas has noted that the proposed electrical facilities are estimated to cost $67.2m.
According to the company, the proposed line is needed to comply with NERC reliability standards and improve transmission reliability due to contingencies that would cause thermal overloads and low-voltage conditions in the northeast Arkansas service area. Cotten also noted that the Midcontinent ISO (MISO) found that Entergy Arkansas’ proposed electrical facilities are the preferred transmission solution over the interregional and regional alternatives that were considered for several reasons, including that the proposed facilities strengthen an existing transmission circuit.
The MISO Board approved the project for inclusion in Appendix A of MISO’s MTEP 15, Cotten said.
Discussing the project’s expected environmental impact on the area’s hydrology, he said that while the proposed route crosses the St. Francis River, Black River and numerous smaller waterways and agricultural ditches, those waterways would be spanned and structures placed in locations that would not impact water movement within the channels or the existing levee system.
An environmental impact statement (EIS) that the company filed stated that minimal disturbance and loss of vegetation would result from the construction and operation of the proposed electrical facilities along the proposed route, Cotten said. The EIS also noted that within Clay and Dunklin counties, 10 different species are listed on the federal list of threatened and endangered (T&E) species, including five species of mussels, three species of plants, and two species of bats; the bald eagle is also protected in the project area, Cotten said.
According to the EIS, construction and operation of the proposed electrical facilities would not likely have significant adverse impacts on T&E species. Cotten added that the EIS also stated that limited impacts to wildlife are expected.
Among other things, Cotten said that the company has established, and MISO has determined, that the construction of the proposed electrical facilities is needed to improve operational reliability, low-voltage conditions, and existing area transmission line overloads during certain contingencies in the northeast Arkansas service area and are in the public interest.
Noting that Entergy Arkansas has provided evidence of permissive authority from the U.S. Army Corps of Engineers (USACE) for the proposed crossing of the Black River, Cotten recommended that the petition for the navigable water crossing of that river be approved.
Cotten also said that Entergy Arkansas has not provided permissive authority from the USACE for the proposed crossing of the St. Francis River, and recommended that the petition for the navigable water crossing of that river be denied at this time. He recommended that further consideration be given to the company’s petition once it receives the approval needed from the USACE and files such proof in the docket, or in the alternative, the company’s petition be conditionally granted to become effective upon receipt of the Section 10 permit from the USACE and the subsequent filing of said permits with the APSC.