A proposal to build a floating liquefied natural gas (LNG) import terminal and associated facilities off the coast of Puerto Rico to supply gas to the island’s largest power plant would have a limited impact on the environment, and most of it would be during the construction phase, according to FERC.

On Thursday, the Federal Energy Regulatory Commission (FERC) issued a 569-page draft environmental impact statement (DEIS) on the proposal by Aguirre Offshore GasPort LLC, a subsidiary of Excelerate Energy LP, to build an LNG receiving facility about three miles off the southern coast of Puerto Rico, about one mile outside of Jobos Bay, near the towns of Salinas and Guayama [Docket Nos. CP13-193 and PF12-4].

The proposal calls for building a 4.1-mile subsea pipeline connecting the offshore LNG facility to the Aguirre Power Complex, which is operated by the Puerto Rico Electric Power Authority (PREPA). It also calls for building a floating storage and regasification unit (FSRU) that would be moored at the gas port on a semi-permanent basis.

Currently, the Aguirre plant relies exclusively on No. 2 and No. 6 fuel oil to generate its 1,492 MW of power. It contains 12 fuel combustion sources located in three plant areas — a combined-cycle power plant, a steam power plant and a simple-cycle power block. PREPA has proposed converting the plant into a dual-fuel generation facility, with the capability of using natural gas at both the combined cycle (600 MW) and steam (900 MW) power plants.

“We determined that construction and operation of the project would result in limited adverse environmental impacts that would mostly occur during construction,” FERC said. “This determination is based on our review of the information provided by Aguirre LLC and further developed from data requests; field investigations; scoping; literature research; alternatives analyses; and contacts with federal, state, and local agencies, and individual members of the public.

“We conclude that approval of the project would have moderate adverse environmental impacts, but these impacts would be reduced to less-than significant levels if mitigation measures are implemented.”

Specifically, FERC’s mitigation measures, 65 in all, include requiring Aguirre LLC to conduct various preparations before construction begins; file bi-weekly status reports until all construction and restoration activities are complete; implement final design changes, and to perform tests and issue additional reports prior to commencement of service.

According to the DEIS, Excelerate will provide one of the nine FSRUs in its fleet for the project. The vessel has an LNG storage capacity of 197,400 cubic yards, which when regasified is approximately 3.2 Bcf.

The DEIS adds that Excelerate’s FSRU will be capable of supplying up to 500 MMcf/d to the power plant, with peaking rates of up to 600 MMcf/d. But information provided by Aguirre LLC shows the power plant will only be able to utilize 225 MMcf/d.

Aguirre LLC filed an application with FERC for the floating LNG terminal in April 2013, a little more than a year after Excelerate inked a contract with PREPA to provide fuel for the utility’s power plant (see Daily GPI, April 22, 2013; Dec. 23, 2011).

FERC has scheduled public meetings for Sept. 9 and 10, in Guayama and Salinas, respectively, to discuss the proposal. The deadline for public comments on the DEIS is Sept. 29.