Gateway Generating Station

The proposal to construct the project was filed with the California Energy Commission by Mirant Delta (now GenOn Energy Holdings) in January 2000, and certified in May 2001, at which point construction began. However, by 2002, Mirant Delta was experiencing financial difficulties, and construction was suspended.[7]

In July 2005, Pacific Gas & Electric acquired the partially-constructed plant from Mirant in a settlement agreement;[3] in 2006 it was approved as a co-owner of Unit 8, and the process of filing paperwork was resumed.[7]

PG&E wanted to change the name of the project from "Contra Costa Unit 8 Power Project" to "Gateway Generating Station"; this name was chosen to show that the "plant represents the "Gateway" to the future of electric power generation" [3] and was required to file a request for this. The Energy Commission approved this request five months later. During that time, in December 2006, PG&E became the sole owner of the project.[7]

Construction finally began in February 2007; the plant construction was expected to cost about $370 million, employ as many as 400 workers at its peak, involve approximately one million worker-hours, and be providing electricity to customers by 2009.[3] It was also expected that PG&E would pay approximately $1.5 million to Contra Costa County annually in property tax.[3] It was the first new plant built by PG&E in nearly twenty years.[3] In July 2008, construction was "two-thirds" finished;[9] The gas turbines were first fired in November 2008,[7] and commercial operation began on January 4, 2009.[7]

The facility uses aqueous ammonia for both condensate hydrogen ion content (pH) control[5] and reduction of NOx emissions, through a selective catalytic reduction system.[1][5] To perform these tasks, the system has up to 18,020 gallons of aqueous ammonia solution (39,628 pounds of ammonia) in it at any given time;[5] the ammonia storage tanks are in a walled containment basin.[5]

In its first year of operation, the plant emitted 942,028 tons of CO₂, 5 tons of SO₂ and 83 tons of NO_x,[6] while consuming 17,224,258,000 cubic feet of natural gas in order to generate 2,490,205 megawatt-hours of electricity.[6]

In 2010, the Trans Bay Cable was switched on, linking San Francisco's electrical grid with distribution infrastructure in the Contra Costa County; Gateway Generating Station was one of more than ten fossil fuel plants linked to San Francisco in this project.[2]

In June 2013, the Center for Biological Diversity submitted a legal notice of their joint intent (along with Communities for a Better Environment) to sue the Environmental Protection Agency for approving the project, claiming that its nitrogen emissions harmed local communities and "transform[ed] the chemical composition" of the nearby Antioch Dunes, causing hardship for several dozen endangered Lange's metalmark butterflies.[10][11][12] The goal of the lawsuit was to cause the EPA to reject PG&E's air emissions permit for the plant.[12] In response, PG&E said that Gateway was "state-of-the-art", and that it had entered a voluntary Safe Harbor agreement for 12 acres of its property to be used as dune habitat for the butterflies and plant species. PG&E spokeswoman Tamar Sarkissian said: "To our knowledge, we are not a party to this lawsuit".[12] Laura Horton, staff attorney at the Wild Equity Institute, said that this was "PG&E's last chance to do the right thing".[10][11] This mission was not to succeed, however; U.S. District Judge Phyllis Hamilton dismissed the suit in October, pointing out numerous issues with the filing and denying Wild Equity leave to amend its complaint.[13]

In July 2017, the New York Times identified Gateway Generating Station as an "investor-owned power plant" and noted that it was represented by the Edison Electric Institute trade association.[14]

A fall 2017 audit/inspection by Contra Costa Health Services Hazardous Materials Programs (CCHSHMP), to ensure compliance with CalARP (California Accidental Release Prevention) program requirements, found 12 corrective actions for PG&E to implement, and made 18 further recommendations. There had not been an incident related to regulated CalARP materials in the five years prior to the audit.[15]

The CCHSHMP concluded that, while the facility had a management system in place to oversee CalARP requirements, some timelines had not been met due to changes in site leadership. They also found that the facility's incident investigation, maintenance program, Safety Information program, training program and self-audit programs were implemented sufficiently, but needed to be followed on schedule and kept current. Some revisions of standard operating procedures were inaccessible, but this issue was addressed during the audit.[15]

• List of power stations in California