The Town of Chevy Chase will contribute $25,338 for a study to detect whether seeps and wetlands in Montgomery County, near the planned route for a light-rail Purple Line, contain DNA of endangered shrimp-like creatures.

The town council voted 3 to 1 Wednesday evening to approve a grant request from the nonprofit Friends of the Capital Crescent Trail. The trail advocacy group sued four federal agencies in August, alleging that they improperly approved a Maryland Transit Administration environmental study of the Purple Line without adequately considering the project’s potential impacts on two crustaceans.

The trail group says the extremely rare Kenk’s and Hay’s Spring amphipods could be harmed by the line’s construction and additional stormwater runoff that would result from increased development after the line is built.

The Hay’s Spring amphipod has been a federally protected endangered species since 1982, and the Kenk’s amphipod is a candidate for federal listing.

Because the amphipods are so tiny and difficult to find — they live in shallow pools, often beneath leaves and rocks — the trail group has said it needs a study that would detect the amphipods’ DNA, signaling their presence.

Federal officials have said the Purple Line’s construction would have no impact on either crustacean, saying their habitat is too far away or would be unaffected by the watershed’s groundwater.

Some of the grant money also will be used to study whether increased development planned for Chevy Chase Lake and other communities along the proposed Purple Line route would increase storm water runoff and erosion, and whether construction would pollute nearby water.

The Town of Chevy Chase has fought the Purple Line’s proposed alignment for years, saying it would destroy the wooded Georgetown Branch Trail that runs along the town’s northern border and would bring train noise and vibrations to nearby homes.

In addition to funding the DNA study, the town has spent $272,000 on a Washington law firm to lobby against the project, the town manager said.

Whether the $2.45-billion Purple Line will be built anytime soon remains uncertain. Maryland Gov.-elect Larry Hogan (R) has said he believes the project is too expensive. However, Hogan has not said whether he will cancel its construction, which is now scheduled to begin next year.