Two development teams have submitted bids for an MBTA-owned parcel next to its Mattapan station, and both have plans for new mixed-income residential projects with neighborhood-oriented retail.

Neither group would disclose its bid for the 2.48-acre parcel at 466 River St. A spokesman for the MBTA, which set a $1.5 million purchase price for the property, also declined to disclose bid details, saying a review of each proposal has just started.

Boston’s Trinity Financial hopes to construct three six-story buildings?totaling about 250,000 square feet, with 267 residential units, 152 parking spaces and another 50 spaces for commuters. Two buildings would house apartments and the other would contain condos with a mix of market-rate and affordable units. The project would include 4,500 square feet of retail space.

“It’s a great opportunity to bring economic development to that location,” Trinity senior project manager Mathieu Zahler said.

Renderings by Boston’s ICON Architecture show a south-facing landscaped courtyard between the buildings that opens onto River Street and a rotary with a water fountain on a newly created street.

“All of this is predicated on getting the community to weigh in,” Zahler said.

Nonprofits Preservation of Affordable Housing Inc. and Roxbury’s Nuestra Comunidad ?Development Corp. hope to build an approximately 150,000-square-foot development of two buildings with 135 residential units and 10,000 square feet of retail.

“We expect the bulk of (units) to be rental, but our plan really speaks to bringing some home-ownership down on the street level and really activating (it) … with eyes, essentially, on the street,” said Julie Creamer, POAH’s vice president of new construction.

Half of the rental units would be available to households earning ?60 percent of the area median income. The balance of residential units would be market rate/workforce housing.

Community members want a substantial amount of affordable units at the site, so low- and moderate-income residents can stay in the neighborhood and enjoy benefits of future development, according to Nuestra executive director David Price.

“Even though Mattapan is a relatively affordable neighborhood, neighbors are concerned about the prices going up,” he said. “They’re concerned about gentrification coming to Mattapan. We also heard loud and clear that the community wants a sit-down restaurant, and that’s on the top of our list.”