Sludge roll-off containers from Bucks Fabricating are available in varying styles to suit specific needs. They can be built in a tub or rectangular style, and have splash plates and various fittings. These sludge boxes are built to haul wet loads without the danger of spilling or leaking contaminants on the way. Typically there is a side-roll tarp or throw tarp system and dewatering option available. They can also be built completely solid, without a tailgate, to serve as a mixer box. They are certified liquid-tight and tested on site. 800/233-0867; www.bucksfab.com.