Last legal obstacle for streetcar loop in SF’s Dogpatch falls

Passengers board an inbound N-Judah streetcar at 48th Avenue in San Francisco, Calif. on Thursday, Aug. 27, 2015. The state Supreme Court has removed the last legal barrier to a long-planned Muni streetcar loop in San Francisco’s central waterfront area, rejecting an appeal by a neighborhood group that wanted the line rerouted. less Passengers board an inbound N-Judah streetcar at 48th Avenue in San Francisco, Calif. on Thursday, Aug. 27, 2015. The state Supreme Court has removed the last legal barrier to a long-planned Muni streetcar loop ... more Photo: Paul Chinn, The Chronicle Buy photo Photo: Paul Chinn, The Chronicle Image 1 of / 1 Caption Close Last legal obstacle for streetcar loop in SF’s Dogpatch falls 1 / 1 Back to Gallery

The state Supreme Court has removed the last legal barrier to a long-planned Muni streetcar loop in San Francisco’s central waterfront area, rejecting an appeal by a neighborhood group that wanted the line rerouted.

The justices unanimously denied review Wednesday of a lower-court ruling that said the city had adequately studied the planned project in 1998 and found no harmful environmental impact.

The turnaround on the T-Third Street line in the city’s Dogpatch neighborhood is planned to run along 18th, 19th and Illinois streets just south of Mission Bay and provide a link to the Central Subway, due to open in 2019. The San Francisco Municipal Transportation Authority said construction of the loop should be completed by July.

The loop was part of a light-rail project that city transportation officials approved more than 15 years ago, but did not authorize construction until September 2014 after San Francisco obtained a $10 million federal grant.

Transit officials say the loop will make more light-rail service available for peak traffic periods and special events, including basketball games at the Warriors’ planned arena at Third and 16th streets. But a group of residents and business owners said the loop would cause noise and traffic congestion and would be less disruptive if it were rerouted about six blocks south to an existing Muni yard.

The legal dispute involved the adequacy of an environmental impact report that San Francisco had prepared in 1998, when the project was first planned.

Opponents, the Committee for Re-Evaluation of the T-Line Loop, contended the report was obsolete because of an influx of apartments, condominiums and stores in the neighborhood. But a state appeals court ruled in November that the city had analyzed the project and its impacts in 1998 and did not have to prepare a new study.

The loop the city approved in 2014 is “the same loop that was described” in the 1998 study, Justice Marla Miller said in a 3-0 ruling. That study “addressed the environmental effects of which the (lawsuit) complains: noise and vibration, dust, air quality, parking and roadway capacity” and found no significant impacts, she said.

She also said the Federal Transit Administration had conducted its own assessment in 2013 and found no harmful impact on air quality, safety, parking or existing land uses. The ruling became final Wednesday when the high court denied a hearing in the case.

David Lanferman, lawyer for the opposition committee, said the outcome was disappointing.

“Despite acknowledging lots of significant changes in Mission Bay and Dogpatch (since 1998) Muni never went back and did the (environmental) review that the law ordinarily requires,” Lanferman said.

The case is Committee for Re-Evaluation of the T-Line Loop vs. SFMTA, S239825.

Bob Egelko is a San Francisco Chronicle staff writer. Email: begelko@sfchronicle.com Twitter: @egelko