They are not legal everywhere. Check with your local inspector first. They should never, never be dumped into a private septic system without increasing the size of the septic tank by 50% and increasing the leach field size as the poo poo particulate stays suspended for long periods of time and can choke off the bacteria in the tank. Same goes for standard ejection pumps. Check the code very carefully. If these type systems are installed on a standard septic any claims made on your insurance should the tank\leachfield fail will be null and void.