Start by making the simple syrup. Combine the 2 cups of water with the one cup of sugar in a saucepan and turn to medium heat. Whisk the sugar and water combination until the sugar dissolves. Remove from heat and allow to cool.
Juice the lemons until you have one cup of lemon juice. Then mash/puree the blueberries.
Mix the lemon juice, blueberries, simple syrup, and 6 cups of water in a large pitcher or container until combined.
Notes
You can store this lemonade in the fridge in a covered container for up to five days.