Soak the clams for 15 minutes in a brine solution. A brine solution is 1/3 cup of salt to 1 gallon of cold water. Repeat the 15 minute soak with a fresh brine solution. After soaking for a total of 30 minutes, scrub the clams under cold water with a stiff brush. Place 1/2 inch of water in a pot with a cover. Place the clams on a rack over top the water, not in it, and bring the water to a boil. Steam the clams in the pot for 5-10 minutes until their shells open up. Remove each clam as its shell opens and serve immediately.