Blu Site Solutions' 250-300 gallon holding tank works well for many uses. This tank has been rotationally molded and is made from the strongest polyethylene (plastics). It is most often used under on-site office trailers, but has also been used for temporary waste storage in other locations as well. Multiple clean-out ports with uni-seal grommet are making cleaning easier and will decrease damage. A uni-sear grommet and threaded PVC connector is inserted in each port. The sturdy quality of this robust holding tank is reliable and space-saving at the same time.