On the day before Russo’s closed, Nick Quaranto, a software engineer, stood in the long check-out line with blocks of Parmesan in hand. “I had a breakthrough moment,” Quaranto says. “We were all pretty sad, and I needed to channel that grief into something great.” The 100-year-old Watertown family business had customers crying when the news first broke that the market was closing. The store’s fans have even created a Life after Russo’s Facebook group to share sources for some of the foods the store sold. In the check-out line that day, Quaranto envisioned starting a food co-op. There’s one in the works in Dorchester and Maynard. “How do you get people sold on this model when there aren’t a lot of examples?” he asked himself. Since then, Quaranto has assembled a volunteer board with varied backgrounds — tech, manufacturing, medical fields, community work, and others — who are spearheading the Charles River Food Co-op. “We’re not going to re-create Russo’s, but we’re all devoted to the idea of making something in the same vein,” says Quaranto, the board’s president. Organic New England produce and many local foods, as well as bulk products to save money, will be a focus. There’s also support from the Russo family, which can help connect them to suppliers. Collaborations with a few organizations, including the Food Co-op Initiative, which helps member-owned markets get started, has offered invaluable advice. Even though the store’s location is still to be determined, either Watertown, Waltham, or Newton, there’s already 570 members. There’s a hope that residents will come from other communities as well, as they did for Russo’s. A share costs $200, and people who become members are the first fundraising sources. Getting the grocery off the ground may take at least three years, according to Quaranto. “The bigger our network gets, the quicker we will be able to do this, " he says. For more information and to become a member, visit charlesriverfood.coop.