In a typical self-serve carwash where a central basin is in the middle of the bay, it can be difficult to have a satisfactory sediment removal and odor control system. With a tunnel or rollover installation the water is returned to a reclaim vault or tank where the sediment and reclaim water can be treated properly and consistently.
Ideally, there should be some kind of system in place at a self-serve facility, because when there is no reclaim vault or tank it is not only difficult to control the sediment and odor, but can require a lot of maintenance. Keep in mind that a system that eliminates odor consistently is almost an impossibility. Controlling self-serve odors is troublesome because the amount of used water is not really controlled or consistent and that goes for the amount of chemicals used in the cleaning process as well.
The main problem with odor treatment
Typically, a self-serve facility consists of multiple bays that have a catch basin in the center of the bay where the water and sediment collectively flows and settles. From there, the used water is then sent to the sewer system with possibly an oil or water separator used prior to being disposed. The main problem when trying to treat this used water and sediment is that the water flow is not steady, and when a facility is seeing a lot of customers the used water will flow through the basin very quickly and there is not enough time to properly treat the water.
The same thing can happen when trying to treat the sediment. The odor which is discharged from the sediment is also very difficult to eliminate simply because much of the enzyme and bacteria washes away. Applying enzyme and bacteria over a period of time and maintaining (with other possible odor control products) a strict schedule will allow the enzyme and bacteria to establish a colony that is able to consume the petroleum hydrocarbons as well as other organics thereby reducing odor by a substantial amount.
If it’s a new facility, you may be in luck
However, if you’re building a new facility from the ground up you might be in luck as there is one way to better control odors. You can install a strip or trench drain and lay it throughout all of the bays and then have wastewater exit into a holding tank or vault. The catch basins are constructed in a cone shape so that the water and sediment are flushed into the strip drain and continue down to the holding tank or vault.
At this point the sediment can either be pumped out by a service company or pumps can be placed in the holding tank or vault to pump out the sediment on a preset timetable into filter bags which can then be disposed of according to local ordinances. Be sure to know your local ordinances before doing so.
Existing carwash operations can also be retrofitted whether they are self-serve, conveyorized tunnels or automatic rollovers. The construction costs will vary depending on the distance from the catch basin locations to the filter bag container.
Pumps can be installed in the catch basins and piping can be run to the filter bag container, an electrical conduit will need to be run from each pump to the programmable controller which can be located in the bay or the equipment room. The sediment and sludge that is contained in the filter bags can then be disposed of according to local ordinances. The excess water will be sent to either the oil and water separator or directly to the sewer.
It’s better than nothing
The odor emanating from the holding tank and vault can also be controlled by adding aeration on a 24/7 basin as well as enzyme and bacteria on a weekly to monthly basis. The public and your employees will not be as openly exposed to the used water or sediment odors, creating a much better environment all around.
Andy Pazz has been in the carwash industry more than 35 years, he is the owner of Laguna Ltd. www.laguna-ltd.com
and has written a book, How to build an exterior carwash, www.car-wash-business-pro.com