I spoke with the Raritan Tech rep regarding the Electro Scan system. It fits nicely in the cockpit locker to starboard aft of the waterheater. You insert a 'Y' valve between the head and the Electro Scan, the same type used to divert the holding tank to the macerator pump for overboard. The discharge side of the Electroscan is simply plumbed around to the discharge hose beyond the macerator pump. That way the holding tank is used if in a NDZ. Now with all that said, I determined the whole project is unnecessary since pumpout stations are available enough, and a portable waste caddy can be bought for a whole lot less and no installation needed.