Construction sites have long been identified as a large contributor to urban runoff pollution if the proper pollution prevention practices are not regularly performed. Materials washed into the storm drain have a direct impact on local waterways and habitat living in that environment.

The most common discharge into our storm drains from concrete construction is the residue and contaminants from washing down equipment such as concrete trucks, pumps, mixers, chutes, hand tools and wheelbarrows. It also comes from other cementitious type products such as grout, mortar and stucco. Concrete or cementitious washout wastewater is caustic and considered to be corrosive with a pH near 12, essentially the same as Liquid Drano®, Ammonia or other household cleaning detergents. The primary ingredient in ready mixed concrete is Portland Cement, which consists of Portland Cement Clinker, Calcium Sulfate, Calcium and Magnesium Oxide, metals and trace elements of potassium and sodium sulfate compounds, chromium compounds and nickel compounds.

Due to this high potential for urban runoff pollution, the United States Environmental Protection Agency (US EPA) has stepped up their efforts to keep Storm Water Pollution Prevention Plans (SWPPP’s) compliant to the National Pollution Discharge Elimination Systems (NPDES). All of these mandated criteria are part of the US Clean Water Act and mandates the utilization of Best Management Practices (BMP’s) on construction sites. Potential discharges into the storm drain systems from concrete work has become a priority of the federal and state EPA, water quality control officials, regional and local inspectors as well as a strategic target of the advocacy and environmental groups.

Concrete Washout Of Arizona (CWOfAZ) has addressed this serious challenge in keeping regulatory agencies and advocacy groups satisfied while protecting and balancing the interests of the concrete and construction industry. CWOfAZ has developed a BMP that not only meets SWPPP guidelines, but also exceeds them. In doing this, CWOfAZ is making every effort to protect the concrete and building industries and minimize regulatory fines and civil liabilities.

This Best Available Technology (BAT), is a concrete washout bin which is portable, self-contained and watertight roll-off bin that controls, captures and contains concrete washout material and runoff. This state-of-the-art, concrete washout bin includes several unique design features including, steel folding ramps to accommodate almost all concrete pump hoppers, a high-grade plastic interior lining to assist in extracting the washout material and a watertight bin and seal to eliminate any wastewater discharge. The washout bin is capable of holding approximately 5.5 yards of material, which is equivalent to washing out approximately 38 concrete trucks and 2 concrete pumps/hoppers.

This system and method allows trade personnel to easily washout concrete trucks, pumps and equipment on site and facilitates easy off site recycling of the same concrete materials and wastewater, while protecting the storm drain system from potential illegal discharges. The off site recycling component of both the concrete material and washwater decreases waste generation, increases concrete waste diversion from our shrinking landfills, ultimately creating an even more environmentally sound recycling application. This system replaces other outdated washout BMP’s, which are costly, unsightly and damaging to the environment since their containment value diminishes, do to inherently faulty material, over use and lack of maintenance.

CWOfAZ is currently being used by some of the largest residential and commercial builders in the country with tremendous success. CWOfAZ has assisted these builders in lowering their operational costs relating to concrete washout containment, overall cleanliness of jobsites, maximizing operational efficiency and keeping them in compliance, while balancing the needs of the building industry. In many state and regional SWPPP seminars and training classes, good housekeeping is listed as a key BMP. The CWOAZ offers more than good, but outstanding housekeeping.


If the definition of Best Management Practices truly means BEST in an effort to protect the environment, comply with regulatory guidelines and enable the concrete and building industries to minimize liabilities affordably… Concrete Washout OfAZ is THE BMP and the ultimate Risk Management tool for concrete washout containment!