Well, you’d have a clear conscience until your pets and neighborhood animals die from ingesting the coolant. Call your local garage or repair facility and ask them what to do with it. It is hazardous waste, any advice to dump it on the lawn is bad advice.
And while dumping coolant might not be illegal in all states, cruelty to animals is, and that’s what you’d be charged with if you dump it on your lawn and animals die.