Combine sugar and 1 cup of water in small saucepan. Bring to boil over medium-high heat, stirring until sugar is completely dissolved. Cool to room temperature. (You can speed up the process by putting it in the freezer for 15 minutes.)
In a large pitcher, combine fresh lemon juice, cooled simple syrup, and remaining 7 cups of water.
Serve cold over ice.
This recipe was created using FRESH lemons. If you choose to use bottled lemon juice from concentrate (i.e., Real Lemon®, etc.) instead, add 1/4 cup more sugar to the simple syrup.