There is no such thing as a small concrete washout disposal problem. Environmental regulations are becoming more stringent in describing how process water must be properly treated and disposed.
For many precast concrete producers, the costs associated with developing an efficient and economical standard operating procedure for fresh concrete clean-up are increasing. Normally, pre-cast operations don't generate great amounts of waste, so they don't require extensive recycling systems.
Producers looking for a new and efficient method to handle small cleanup jobs and reduce water usage by recycling process water should take a hard look at the EWOC concrete washout container. The system is not designed to recycle large quantities of leftover concrete. “It's the only cleaner specifically designed for the tools used in the concrete industry,” says Andy Olson, salesman for Construction Midwest Inc., the system's national distributor based in New Hope, Minn.
Producers can efficiently clean concrete truck chutes, power buggies, mortar mixers, buckets, and hand tools while complying with local water discharge regulations. The units have been in the field for about one year.
EWOC comes in two sizes. EWOC Senior is designed for outdoor or plant conditions. It features a 100-gallon water storage tank that is designed to handle about one week's worth of tool and chute washout before requiring cleaning. EWOC Junior is designed for interior projects, such as plastering, drywall installation, and small masonry projects. It has a 50-gallon tank, small enough to allow contractors to roll the unit through most standard interior doors.
How it works
EWOC operates like a parts cleaner. Workers hand-spray filtered water, pumped from its storage tank, to wash tools, truck chutes, and other items. Rocks, debris, and solids from the washing process are scalped from the cleanout by the unit's 3-inch-thick, heavy-duty, composite grid. The perforated deck's ½-inch openings retain material with a nominal size of about 1/8-inch.
The cleanout water then gravity- drains through a two-part fabric filtration system, comprised of a prefilter membrane and a top filter. The prefilter is a disposable fabric sheet designed to capture the 100-mesh material.
EWOC's manufacturer recommends replacing the prefilter daily. The soiled fabric can be safely disposed of in a trash dumpster. The top filter is a tightly woven polypropylene fabric sheet designed to capture any material passing through the prefilter, thus preventing residue build-up in the water tank.
Built for harsh conditions, the solidly welded unit is designed for forklift handling, and its heavy-duty hinged lid can be closed to prevent rainwater and unauthorized dumping. The EWOC is equipped with a trash pump and a secondary filter to assure a steady flow of pressurized wash water.
Servicing World of Concrete
EWOC was put to the test at World of Concrete in January. Before the show, World of Concrete's construction crews placed more than 30,000 square feet of flatwork for the show's exhibitors and editorial events. Three EWOCs were strategically placed to help handle the washout and tool cleaning.
According to Sue Basham, World of Concrete's outdoor exhibits manager, the EWOC units helped increase efficiency. In previous years, Basham had to pump out the show's central disposal dumpster about 20 times. “This year with the three EWOCs, I had to make only one call for the disposal pumper, even though the amount of concrete we placed increased by one-third,” says Basham.