Place black-eyed peas in a colander and rinse under cold water.
In a large Dutch oven, cook bacon over medium heat until crisp, 8 minutes. Remove bacon with slotted spoon. Set aside.
Add onion, chopped, to drippings; cook 5 minutes or until tender.
Stir in black-eyed peas, bacon, water, diced ham,cayenne and black pepper. Bring to a boil; reduce heat. Simmer, covered, for 20 minutes.
Stir in rice. Return to boiling; reduce heat. Simmer, covered, for 15 minutes.
Remove from heat. Let mixture stand, covered, for 10 minutes. Stir in 3 chopped scallions before serving.