Soak clams in water for one hour with sea salt. rinse well.
bring a large pot of water to a boil.
sauté garlic over medium heat in a large skillet with olive oil. add clams, bay leaf, and wine. cover and cook until clams open. discard half of the shells. pour cooking juice in a measuring cup and let it sit until the sediment falls to the bottom. filter the juice through a cheese cloth.
sauté leeks in a separate small skillet with butter for 3-4 minutes. season with salt and freshly ground black pepper.
add leeks to skillet with clams and simmer one minute. set aside.
cook pasta two minutes less than the recommended cooking time. drain, reserving 2 cups of the pasta cooking water.
add hot pasta to clam and leek mixture, heat 1-2 minutes, adding the pasta cooking water to thin sauce if desired. finish with chopped parsley.