I have attempted to blow the muck away using a homemade water jet type of apparatus with no luck. I appears that the entire inlet end is buried under mud and muck. By siphoning, all of the mud and material should be removed. I feel that the siphon that I am planing on using would do the same thing as the pump truck that you suggested without the cost. Also, would they be able to reach out 16 to 20 feet out into the water and vacuum the bottom that is 7 to 8 feet deep?