Rinse the grape leaves in cold water and let them drain.
In a large bowl, combine rice, onion, dill, parsley, pine nuts, olive oil, lemon juice, salt, and pepper. Mix well.
Place a grape leaf on a flat surface, shiny side down. Place a small spoonful of the rice mixture near the stem end.
Fold the sides over the filling and roll up tightly. Repeat with remaining leaves and filling.
Layer the dolmas in a large pot, seam side down. Pour water over the dolmas until just covered.
Drizzle with additional olive oil and cover with a heat-proof plate to keep them submerged.
Bring to a boil, then reduce heat and simmer for 1.5 hours or until rice is cooked.
Serve warm or at room temperature with additional lemon wedges.