Dirty water can also get into the fuel through the fittings on the top of the fuel tank. Much has been written about that. The fittings sit in a depression on top of the tank and under slushy conditions can fill with dirty water over the fittings which are open to the interior of the tank. I ended up installing fuel line hose to the fittings and pushing the other end of the hose between the tank and the shield. At least this way if the fittings are sitting in cruddy water, it will not get into the tank. I find it disgusting that DC would allow this to happen and then blame fuel contamination on the customer.