Dump it into Californians tap water supply apparently :)

On serious note, Chlorine is widely use chemical, used in cleaning products, bleaching paper and cloth, pesticides , rubber, and some solvents.

Chlorine has lots of industrial uses, so I imagine you sell it. If you produce enough as a by product the cost will go insanely low.

If you had to dump it, you'd probably react it with something cheap to make it inert. This would generate energy, it's akin to combustion with oxygen. You could use that energy to decrease the energy requirements of splitting the NaCl in the first step.

For example, you could use it to turn calcium carbonate AKA limestone into calcium chloride, which is rather harmless. You would get carbon dioxide out of this.

That doesn't sound like a good idea, we already have too much CO2.

Something that might work on a small scale could become an ecological threat on the scale of a billion electric cars.

Bleach. Clorox sells lots of it.

Use carbonate, which doesn't have this problem.

This would be preferred anyway: HCl is nasty, and carbon dioxide is not.