Hi. I currently have a sink trap with outlets for the washing machine and dishwasher. I also have a water softener where the brine drain and overflow currently go out through the wall and into the external downpipe. I'm getting the external wall rendered and moving the downpipe and rather than drilling through again I'd rather connect the water softener drainage to the sink trap. Do they make sink traps with 4 outlets? I've looked online but can't find anything. Any advice? I know I've got to incorporate an air gap too. Thanks.