Existing Containment

Measures that don’t add up

Although CWS stands alone as the leader and pioneer in the concrete washout containment and recycling market, there are other companies who offer what we believe are inferior services to dispose of concrete washout material. 

Washout Pits

The washout pit has been around for quite some time and allow for onsite washouts. They are generally constructed with hay bales and plastic in a 12’ X 12’ X 2’ area. Even though current BMP’s suggest making this type of washout containment area, these pits are inherently flawed as the plastic and hay bales break down and allow the hazardous wash water to escape, creating the potential for illegal discharges into waterways. 

Almost all jobsites require the use of concrete pump trucks when working with concrete. These pumps have a larger discharge than concrete trucks and are also required to washout in a contained area. They generally have to washout next to a pit, since they cannot get into the washout pit without breaking the integrity. Again, this allows the hazardous wash water to escape and leach into the soil, possibly flowing into a storm drain. The contractor then has to have the washout material broken up, excavated and removed from the jobsite. Once the material is removed, the hazardous wash water is left behind in the soil, potentially resulting in illegal discharges and/or contaminated soil that will inhibit vegetative growth.

We have scoured construction sites all across the Greater Sacramento area and have yet to find a washout pit that contains all the caustic waste water and material like the CWS does. In addition, the cost for construction, excavation and re-construction of the washout pits is cost prohibitive when compared to the CWS. (See Below) 

Sludge Boxes

Sludge boxes or small waste boxes, generally around 5 yards, have also been used in an attempt to contain washout material on construction sites. Again, as with the hay bale washout pits, this system is inherently flawed, as it is not watertight and leaks caustic wash water onto the ground and into the storm drains as well as not having the ability to washout the hopper of a concrete pump truck.

It is generally lined with plastic in an attempt to prevent it from leaking. However, in the pictures below, you can see that it does not work. Even if water remains in the box, which is unlikely, the usual practice is to still allow the hazardous wash water to escape from the box and leach

into the ground or storm drain. Again, we have to be concerned not only about the known discharges but also what is left behind for the homeowner when he/she begins working with the soil in preparation for landscaping.

Concrete Reclaimers

Concrete reclaimers have their place in the concrete washout market. These reclaimers are affixed to the truck and allow the driver to washout into a bucket that is attached to the end of their chute. The wastewater generated is then stored on the truck and the remaining material is dumped back into the drum for recycling at the batch plant.

This particular system is good for smaller or rural jobs but does not address high production jobs such as residential home building, large-scale commercial projects or washout of concrete pump trucks that require a designated concrete washout. Also, concrete suppliers generally charge an additional fee for the reclaimers above what they are charging for the ready mix itself. In addition, the reclaimers are expensive to install and require on going maintenance to keep them operational. 

It takes approximately 2-3 times longer per load to washout a chute into a reclaimer than it does using the CWS bin. The resulting delay at the jobsite increases the turn around time thereby reducing productivity and revenue and tying up precious space on the site. We estimate that the average loss per truck is near ½ load per day. Multiply that by the amount trucks in a concrete suppliers fleet and you get a staggering loss of revenue.

Washout Sacs and Bags

Washout sacs or bags are either made from ~6 Mil plastic or polypropylene material and hold anywhere from ~5 to ~400 gallons of material. The process is less than desirable and for the smaller bags requires two people, one to wash down the chute and the other to hold the bag. The bag is then either tied or taped shut. After washing out, the bag(s) are left on the ground for the builder/contractor to dispose of. 

As with hay bale washout pits and sludge boxes, this system is inherently flawed as well do to the use of plastic. The bags can be left on the jobsite up to several weeks, exposing them to the rough ground and elements. When the construction site gets around to disposing the washout bags, generally the bags have been torn open, releasing the caustic and hazardous wash water onto the ground and potentially resulting in an illegal discharge. The contractor now has to dispose of the waste and has difficulty recycling the concrete material do to the plastic.

The larger poly sacs are manufactured for concrete pump and concrete truck washout containment. The sacs are designed to allow caustic washwater to leak out and not contain it, resulting in an illegal discharge. When full, the sacs have the capacity to hold nearly 1 ton of concrete, which may pose additional problems. Once the sac is full of material the contractor is required to find a way to dispose of it, ultimately increasing the amount of time and resources they must spend on this. This requires them to use a crane or forklift to move the sac around on the jobsite. The waste will most likely have to be sent to a landfill instead of being diverted and recycled, which increases time, money and resources. 

Commonalities Among Existing Measures

As you can see the most common feature amongst the existing measures mentioned is the lack of regulatory compliance and overall risk management. Also, there will most likely be an increase in waste generation instead of reducing it by diversion and recycling. Using these systems may in fact increase your company’s risk relating to concrete washout containment.