Wash the green beans under cool, running water. Trim the ends off if desired. You can leave the bottom on if you want but the top stems should be removed.
Add the water and salt to a large stock pot and bring to a boil.
Fill a large bowl with ice water and set it beside the stove.
Add the green beans to the boiling water, stir, and cook until slightly tender but still crisp, about 2 to 3 minutes.
Using a pair of long-handled tongs, remove the beans immediately from the pot and immerse them in the ice water.
Remove from the ice bath and gently pat the beans dry with clean towels or paper towels.
Transfer the beans to the freezer bags and line the beans up in the same direction. Label with the date. Remove as much of the air as possible, whether with a vacuum sealer or by pressing the air out of the bag gently with your hands, and seal the bag. Freeze and use within 6 months.
To defrost simply remove from the freezer, open the bag slightly, and defrost in the fridge.
Notes
You can use a vacuum sealer or simply put the beans in a freeze-safe bag and press as much air out as you can.
Make sure the beans aren't in too thick of a layer in the bag.