How Wash Water Reclamation Works for Mobile Fleet Washing

Every mobile wash vendor in Metro Atlanta will tell you they reclaim their water. Some of them do. The phrase covers everything from a full vacuum recovery and filtration system that captures nearly all of the wash water, to a rubber mat over the nearest storm drain and a hope that the sun handles the rest. If you are the one signing the service agreement, the difference lands on you, because it is your lot the water ran across and your name on the notice from the county.

This post walks through how reclamation actually works on a mobile fleet wash, stage by stage: containment, recovery, filtration, and disposal. It ends with the questions a fleet manager should ask a vendor and, more usefully, what to ask them to show you. None of it requires you to become an environmental engineer. It requires you to know what the equipment looks like and what it is supposed to do.

Containment: Berms, Mats and Drain Covers

The first job is to keep the water from going anywhere on its own. A mobile crew arrives with three kinds of tools for this. Drain covers are heavy rubber or polyurethane mats, typically 3 by 3 feet or larger, that seal over a storm inlet by their own weight; some crews use inflatable plugs that go inside the pipe instead. Berms are flexible barriers, filled with foam or water or fitted with a weighted lip, laid in a line on the pavement to stop the sheet of water from running to the edge of the lot. Wash mats are large impermeable pads with a raised edge, from a single-vehicle 20 by 40 feet up to pads that take a tractor-trailer, and the vehicle is parked on the mat for the wash.

On a sloped lot, which describes most Atlanta yards, the crew reads the grade and berms the downhill side so the water collects in a low corner where the vacuum can reach it. On a flat lot, mats do most of the work. On gravel, only a mat works, because a berm leaks underneath.

What to look for: the drain cover should be on the inlet before the first drop of water hits the truck, and the berm should be continuous, with no gaps at the ends. A crew that starts washing and sets the containment out afterward is not containing anything.

Recovery: Getting the Water Off the Ground

Contained water still has to be picked up. The workhorse is a vacuum: a wet vacuum with a floor tool, a vacuum boom (a long perforated bar that lies along the low edge of the berm and pulls water in along its whole length), or a sump pump dropped into the low corner. The water goes into a holding tank on the truck or trailer, commonly 200 to 500 gallons on a mobile unit.

The recovery rate matters. A hot-water unit puts down 4 to 8 gallons per minute. If the vacuum cannot keep pace, water backs up over the berm. A well-run crew keeps the vacuum going through the wash rather than waiting until the end, and carries enough tank capacity for the day's schedule or a plan to empty mid-day.

Recovery is never 100 percent. Some water evaporates, some stays on the vehicle, some is held in the mat. A serious system captures the large majority of what is put down, and what remains is a thin film on the pavement rather than a stream to the drain.

Filtration: What Happens in the Tank

Recovered water is dirty. The solids are silt, clay, brake dust and grit; the liquid carries detergent, oil and grease. The first stage is screening and settling: the water sits in a tank or a series of baffled chambers while the heavy solids drop out. The second stage is oil-water separation, where oil floats and is skimmed or trapped. The third stage, on better systems, is filtration through bag or cartridge filters down to a set micron rating, and sometimes activated carbon to pull out dissolved hydrocarbons.

Some mobile systems recycle at this point: filtered water goes back into the supply tank and is reused for the pre-rinse on the next truck, with fresh water reserved for the final rinse. That cuts fresh-water use sharply and is the setup you want during a drought. Other systems collect only, filter enough for disposal, and do not reuse.

Filtration produces sludge: the settled solids and the skimmed oil. That has to leave the site as waste, not go back on the lot. Ask where it goes.

Disposal: Where the Water Ends Up

There are three legal end points for recovered wash water. It can go to the sanitary sewer with written authorization from the utility, either at the customer's site through a cleanout or at the vendor's own facility. It can be hauled to a permitted treatment or disposal facility, with a receipt or manifest for each load. Or it can be reused as wash water until it is too dirty, then sent to one of the first two.

What is not a legal end point: the storm drain at the customer's yard, a ditch, a grassy strip, or the vendor's back lot. A vendor whose tank is empty at the start of every day and who cannot say where yesterday's 400 gallons went is disposing of it somewhere, and you should assume the worst.

Heavy equipment is the hard case. An excavator or a dozer coming off a Douglas County site carries hydraulic oil, grease and a lot of clay, and the recovered water is far dirtier than a tractor-trailer's. The filtration and disposal plan has to be sized for that, which is one reason a vendor that does both fleet washing and heavy equipment cleaning should be able to describe two different handling plans, not one.

What to Ask a Vendor to Show You

Do not ask whether they reclaim. Ask them to walk you through it. Ask to see the drain covers and berms on the truck, and ask them to set up the containment on your lot before the first wash while you watch. Ask what the tank holds and how many trucks that covers before it has to be emptied. Ask to see the filter housings and the oil-water separator, and ask when the filters were last changed.

Ask where the water goes, and ask for the paper: the sewer authorization or the hauler receipts. Ask what they do differently for heavy equipment. Ask what happens if it rains during the wash, because a berm full of rain overflows. Ask for the insurance certificate and whether it covers environmental liability. Then walk the lot after the first wash and follow the water yourself. If you want the background on why any of this is required, our explainer on pressure washing water reclamation covers the rules side.

A good vendor welcomes this. The equipment is a large part of what you are paying for, and they would rather show it than explain a complaint later. A vendor who gets vague at the disposal question has answered it.

See the Equipment Before You Sign

PBD Pressure Washing brings containment, vacuum recovery and filtration to every fleet and heavy equipment job across Metro Atlanta, and we will set it up in front of you on the first visit. We can tell you what the tank holds, where the water goes, and what we do differently when a dozer is on the mat instead of a dry van. Paul Dunbar spent 25 years hauling equipment for people who expected things done right without being asked, and that is the standard the crew works to.

If you want to see how reclaim actually works on your own lot, request a quote or call (404) 933-8559. We will bring the equipment, set it up, and walk you through it before the first truck gets wet.

HOW WASH WATER RECLAMATION WORKS FOR MOBILE FLEET WASHING