Is it the tank drain, or is it coming out of the tank vent line? If it is coming out of the vent line, just find something to plug it with. Loosen the filler cap or remove the plug before using the pump. If it is coming out of the tank drain line, it needs to have a valve put on it.
Becky, Bob and Taylie & Bode
2009 Silverado 2500HD Duramax/Allison
2014 Heartland Sundance XLT 245RL