Mainers will soon have a lot more fast food on their plates when three new fast casual-style restaurants open in South Portland, Westbrook and Scarborough.

Elevation Burger, a certified organic hamburger chain, announced Wednesday that it will open a restaurant at 85 Western Ave. in South Portland during the week of Jan. 16.

Red Robin Gourmet Burgers, based in Colorado, will open its new Scarborough location sometime in “early spring,” according to a spokeswoman. The restaurant, located in the Scarborough Gallery shopping complex with Lowe’s Home Improvement and a Walmart Supercenter, will be the first Red Robin in southern Maine.

Chipotle Mexican Grill, which opened its first Maine restaurant in South Portland in December 2010, will add a location in Westbrook sometime in “early spring” — perhaps late February or early March, according to a spokeswoman.

The new restaurant will be in the Westbrook Crossing plaza at Route 25 and Riverside Street.

Red Robin is known for its variety of gourmet burgers and “Bottomless Steak Fries.” Chipotle serves up burritos made with fresh, humanely raised meats, and Elevation Burger uses only 100 percent-certified organic beef that is ground fresh on site.