Sift together flour, baking soda and salt. Set aside.
Cream butter or margarine with white and brown sugars. Blend and beat well. Add eggs and water. Stir in vanilla. Add dry ingredients and mix thoroughly.
Cover and refrigerate for 2 hours.
Preheat oven to 375 degrees F (190 degrees C).
Enclose 1 chocolate mint wafer in 1 tablespoon of chilled dough. Bake on greased cookie sheet for 10-12 minutes.
