Residents of a Washington suburb and an environmentalist association filed, on 28 August 2014, a federal lawsuit to stop the Light Rail (Purple Line) PPP project.

According to the environmentalist association,  Friends of the Capital Crescent Trail (FCCT), the federal government has not adequately accounted for two species of amphipods. FCCT claim they live in the seeps along Rock Creek and Coquelin Run that would be degraded or destroyed by the construction of the new rail line.

According to Meagan Racey, spokesperson for the U.S. Fish and Wildlife Service,  there are no needs to reevaluate protections for the amphipods because there is no evidence that amphipods exist in the seeps near the Purple Line route.

In late July the Maryland Department of Transportation together with the Maryland Transit Administration launched the Request for Proposals (RFP) for the design, build, finance, operate and maintenance (DBFOM) the US$2.2 billion Light Rail project. The DBFOM rail PPP project also involves the equip and supply light rail vehicles.

In early January the following four teams were shortlisted:

• Maryland Purple Line Partners: VINCI Concessions, Walsh Investors, InfraRed Capital Partners, ALSTOM Transport and Keolis S.A.

• Maryland Transit Connectors: John Laing Investments Limited, Kiewit Development Company and Edgemoor Infrastructure & Real Estate LLC

• Purple Line Transit Partners (PLTP): Meridiam Infrastructure Purple Line, LLC, Fluor Enterprises, Inc. and Star America Fund GP LLC

• Purple Plus Alliance LLC Proposer: Macquarie Capital Group and Skanska Infrastructure Development Inc.

Shortlisted consortia must submit their proposals on or before 9 January 2015. The preferred bidder is scheduled to be announced on 12 March 2015.

The Purple Line is a 16-mile light rail line that runs east-west inside the Capital Beltway between Bethesda in Montgomery County and New Carrollton in Prince George's County with 21 stations planned that will provide direct connections to Metrorail's Orange Line, Green Line and two branches of the Red Line, and the MARC Brunswick, Camden and Penn Lines. The total project cost is US$2.2 billion, with the private sector expected to invest between US$500 and US$900 million.