The clothes washer requirement ("install drain and drain pan") in ID 2.1, part (c) can be satisfied with the use of a moisture sensor to detect leaks and an automated mechanism to control the flow of water. However, it is only acceptable if the mechanism is designed so the default setting is "off"; in other words, water is only allowed to flow when the system does not detect a leak and there is power. The moisture sensor must be located in a pan underneath the washing machine in such a way that the system will shut off if there is a leak.
Updated 10/1/13 for rating system applicability.