The grey water holding tank consists of waste from RV showers, sinks and tubs. While it isn't as dirty as the black water tank, it is important to dispose of its contents properly. Here are a few steps that you can take to make sure that your grey water tank gets emptied the right way.
Step 1 - Dump Black Water First
Make sure that you are dumping your tanks in a pre-approved area or dump station. Before you can dump your gray water tank, you will need to clear out the black water tank. To do so, hook up the hose to the dump station, and open the valve while you rinse. Once you have done this, close the valve.
Step 2 - Dump Grey Water Tank
Now that the black tank has been emptied, open the valve for the grey water tank. While the it is draining, use the hose with the spray wand on the end to hose it down. Be sure to rinse every spot and continue to spray as the water flushes out. You want to get to a point where the water draining is clean and clear. Once you are finished, close the valve and remove the hose.