http://ag.ansc.purdue.edu/meat_quality/food_borne_illness.html

Don't connect a waste line into your food box. You are depending on a pump to or gasket to keep things clean?

If you want to drain the box, use an open site drain (i.e. one that isn't in direct contact with waste). Can you get the drain into a shower sump, or have a hose that you could simply put into the sink while pumping which is otherwise clean?

http://ag.ansc.purdue.edu/meat_quality/food_borne_illness.html