MARINADE - Pour 1 qt water into a sauce pan over a medium heat. Add the kosher salt and brown sugar and stir until dissolved. Add Worcestershire sauce, soy sauce, black pepper and garlic and simmer for 5 minutes. Pour remaining 3 qts of water and some ice into a large enough pot to hold the brine and the meat. Pour the hot brine into the cold water and ice and stir. Allow the brine to cool to 40 degrees. Add meat and refrigerate for 24 hours.
Place meat in crock pot and cover with onion, Worcestershire sauce, garlic powder, and pepper.
Add carrots and potatoes.
In a small bowl mix Mrs. Dash seasoning, onion soup mix, cream of mushroom soup, and 1 cup of water. Pour over top of roast.
Cook on low 4-6 hours (usually the roast takes 4 hours and veggies take around 5 hours).