Reclaim Tips — In Self-Service Wash Applications
Raise the subject of reclaiming water in the car wash industry, and thoughts turn to tunnel and in-bay-automatic washes, where larger volumes of water are used. Self-service washes do not come to mind readily for one reason or another. However, reclaim can be a viable part of any self-service wash if it is properly incorporated and maintained.
For sites that provide a spot-free rinse, reclaim is as easy as saving the rejected water (concentrate) from the spot-free system and using it in lieu of the city water feed. By simply installing a tank and capturing the water that would normally go to drain from the spot-free system, one can save up to several hundred gallons of water per day.
For example, a one-membrane spot-free system is designed to produce up to four gallons of concentrate water for every one gallon of spot-free water produced. Therefore, if you use 300 gallons of spot-free water daily, you may be pouring up to 1,200 gallons of perfectly usable water down the drain every day.
Another way to incorporate the spot-free reject water would be to use it in a weep system instead of buying extra water for this purpose. These techniques can go a long way to saving water and money in a self-service setting. If the spot-free system is fed by a well, a water-quality test may be necessary in order to determine if the above-mentioned uses are viable options.
WHAT’S IN THE WATER
Remember, when installing a reverse-osmosis unit in any wash, it is a good idea to know what is in the water that you are feeding the unit. As mentioned above, a water-quality test is highly useful any time you are using a well. This will determine the proper pre-treatment of the feed water in order to prolong the life of membranes, as well as optimize the efficiency of the spot-free water production. When using municipal water, it is also good to know how the water has been treated. High levels of flocculants and different methods of disinfecting the water need to be considered and dealt with on the pre-treatment side of the RO unit. Contact your water provider to get a water-quality report and pass it on to your equipment provider to help address these issues upfront.
Another way to reduce fresh-water use is to install a water recovery system and use the reclaimed water in the wash process. This water could be used in applications aside from the final rinse of the vehicle and, most likely, mixing chemicals. The initial wet down of the vehicle and any intermediate rinse stage could be operated with reclaimed water.
Since most sites use a single wand for supplying water to the wash bay, operators are reluctant to have the reclaim water mix in the fresh water feed line. A way to get around that would be to add a reclaim water wand to the bay that is dedicated for this purpose only. I have seen this technique overseas where it seems to be a common practice. This is accomplished by installing an extra trunk line from a high-pressure reclaim pump stand. The pump stand is plumbed to the additional wand in each bay. Label this wand “Wash Water Wand” and the other wand “Rinse Water Wand.” You can have your self-service equipment provider install it in such a manner that it is only available for the selectable functions that you want to run on reclaim water. Coupled with proper wand labeling, this will make the wash experience less confusing for the customer.
As mentioned above, weep systems consume a great deal of water during the colder months of the year. Using reclaim water in this process will benefit the owner’s bottom line by reducing the amount of water that must be purchased to operate the wash. If you add the extra wash-water wand to each self-service bay, it will be easy to tap off of the trunk line to provide a port for weeping.
Weeping with the reclaim water also helps keep the water moving through the whole reclaim system. One of the main complaints about using reclaim is that the water used in the first few washes “smells” no matter what is done for the treatment of the reclaim water. Whether ozone, enzymes, or bacteria are added to the reclaim holding pits, some washes still experience this issue. The explanation is simple: Even though the underground pits are being aerated, ozonated, or treated in some fashion, the water in the pipes between the reclaim and the point of use is stagnant and not within the treated loop. Weeping with the reclaim water keeps it moving and introduces it back into the treatment stream, thus cutting down on the smell that is experienced with the first washes of the day.
YES, YOU CAN
The conventional wisdom that it is not economically feasible to reclaim water in a self-service car wash is not necessarily true. With a bit of creativity and customer education, it is quite possible with minimal upfront cost. By incorporating one or all of these water-conservation methods in the self-service operation, fresh water consumption and discharge to sewer can be reduced and operating costs can be lowered for the self-service car wash owner.
Dwight Royal is CEO/director of operations of Lakeland, FL-based Con-Serv Mfg. You can visit the company on the web at www.con-servwater.com.