Shanai Matteson poured three small cups of water for Mary Moxon last Friday, putting them on a wooden board, like a flight of beers at a craft brewery. “It’s very subtle, but water has different tastes, and it has to do with the mineral content of the water, the treatment of the water,” Matteson said. “Sometimes it has to do with the pipes or the container that the water comes in.” Matteson had just set up her table, called a popup Water Bar, at Project North, a music and sustainability festival