In a small saucepan combine blueberries, sugar and 2 tablespoons lemon juice. Cook over medium heat until berries begin to break down. Reduce heat to medium-low, stir and cook until stirring frequently for about 5 minutes.

Remove from heat and let cool. Using a fine mesh strainer, strain blueberries. Press berries to make sure to get all the liquid. Refrigerate until chilled. Meanwhile make sure that remaining lemon juice is chilled too. Pour into a 2 qt pitcher; add the lemon juice and water. Serve over ice in glasses. Add additional blueberries or lemon slices for garnish if desired.