blog login
| Wash Water Control Handbook |
 |
 |
 |
|
A Handbook on Wash-Water Control By Jerry McMillen President, PressureWasher.net 10821 Airport Drive El Cajon, California, USA 92020
2
A Handbook on Wash-Water Control
The information, illustrations, photographs and equipment designations in this Handbook are proprietary property of PressureWasher.net. A copyright © application has been filed. Requests for permission to use any portion of the information in this Handbook should be made to Mr. Jerry McMillen, President,
President, Cleaning System Specialists, Inc. dba PressureWasher.net.
10821 Airport Drive El Cajon, USA 92020 PressureWasher.net
3 Wash-Water Control Handbook By Jerry McMillen
Introduction The capture and control of wash-water resulting from pressure-washer operations is both an art and a science. This Handbook presents information vital to making informed decisions on acquiring, operating, and maintaining available wash-water control equipment, and also provides the background of environmental and legislative requirements which make wash-water control necessary. Established pressure-washer operators as well as new entries to the field now find that controlling the discharge of run-off from washing operations into storm sewers is an important and required addition to their capabilities. Hence this Handbook is designed to assist both owners and operators to understand the requirements for run-off control, and to help in selecting appropriate control equipment to meet these requirements. Since quality wash-water control equipment involves rather substantial capital investment and operator training, detailed information is provided on those features which contribute to good water recovery and long equipment life. Operator training in the proper use and maintenance of wash-water control gear is crucial, and the Handbook describes not only how to properly assemble and arrange equipment for various run-off situations, but also gives examples of some actual field operations.
Avoiding Environmental Pollution The rapid acceptance of high-powered pressure-washers for commercial cleaning of driveways and parking lots as well as vehicles, walls and roofs brings an environmental problem – dealing with the run-off of wash-water from these operations. If allowed to run into the storm drain, not only the water, but paint chips, oils, and worse go directly into the local sea, lake, or river environment, since storm drain flows rarely receive any further treatment whatsoever. With the concerns of residents and tourists alike at stake, cities and towns are understandably nervous at the prospect of polluted water from storm drains adversely affecting the aesthetics of their river and beach areas.
A typical storm drain on a city street. Storm water entering the drain flows to a discharge point, typically at a lake, river or ocean. A photo of a storm-water outfall into an ocean bay is shown below. Surely, preserving scenes like this for future generations is reason enough to avoid discharging runoff, containing dirt of any kind, into the environment.
4
Flow from the storm drain exits here, with other drains visible along the shoreline.
Complying with Legal Rules and Restrictions Local laws identify "Storm Water Conveyance Systems", by which it is meant the roads, streets (even the gutters), or any other means of storm-water flow into lakes, rivers, or the sea. With minor exceptions, it has become unlawful to discharge any type of non-storm water into the Storm Water Conveyance System. Storm-water drains usually flow directly into the nearby ocean, lake or river, without any treatment whatsoever. Anything other than "precipitation" water (rain or snow) might contain pollutants adversely affecting the receiving waters, and based on environmental concerns, and following Federal and State mandates, many cities and towns have enacted laws prohibiting discharge of any type of non-storm water into the storm-water system. And the "Storm Water Conveyance System", as it is typically called, includes roads, streets, and even the gutters. Usually there are minor exceptions, such as individuals washing their cars, excess landscape and lawn watering, and fire fighting, but commercial pressure-washing operations are not among the exceptions. Washing say, a grocery parking lot, requires the operator to prevent wash water from entering streets or gutters leading to storm drains. Disregarding these regulations can lead to substantial fines and legal hassles. The rules are clear: "no water down the storm drains!" Further complicating the issue, in many states the owner of the property is the legal owner of the waste-water produced at his property. So if the pressure-washer guy permits an illegal discharge to the storm sewer, it might be his customer who gets the citation and fine! (That probably means his former customer.) As an example of municipal interest in controlling possible run-off from the pressure-washing industry, the city of San Diego, California has issued a set of plastic-encased cards giving a synopsis of the regulations, and offering "Best Management Practices" which may help in carrying out the intention of the law. The cards are free to local owners and operators of commercial pressure-washing equipment. The San Diego "Best Management Practices" for prevention of storm water pollution give a capsule view of what will be required nationwide in the industry in coming years. These recommended practices can be summarized as follows: Planning for waste-water capture – Before starting washing operations, plan how the waste-water will be collected, avoiding storm drains and discharge into streets. Plan what shall be done with the collected water. Arrange water barriers and covers so as to minimize the possibility of an improper or accidental discharge into the storm drain. 5
Cleaning and washing activities -- Use dry methods to pre-clean, and remove the residue to approved containers, if deemed hazardous. Minimize amount of water used during washing. If hazardous wastes are created during washing operations, avoid mixing with non-hazardous wash water, to reduce disposal costs.
Wash water collection and disposal -- Recovered wash water may be recycled or otherwise disposed of in the proper manner. The captured wash-water (if no hazardous pollutants are present) may usually be discharged onto landscaped areas, with the owner’s permission, and as long as there is no runoff to storm drains. However, some beach communities located in regions of steep cliffs forbid this disposal method. Some desert localities prohibit ground discharge as it might harm native plants. Otherwise the property-owners sewer connection (sink, toilet, etc.) may be used if the flow rate does not exceed (typically) 20 gpm. Other fairly common restrictions include a maximum discharge (without a permit) of 2,500 gallons per day from exterior mobile power washing, and 25 gallons per day (after suitable treatment) from engine washing. Some communities require (and charge for) a discharge permit regardless of flow quantity. Many local codes are available over the internet. The regulations come with teeth. Violations of the no-discharge rules can be classed as misdemeanors and (in San Diego) are subject to fines of up to $10,000 per day per violation, up to a maximum of $100,000 for any related series of violations. Other localities may have lesser penalties, but fines approaching this magnitude are scary enough to oblige operators to train their personnel in water recovery as well as washing techniques. High pressure cold-water washing is essentially benign. It is the washed-off material which is often the problem, and preventing this from entering the storm drains is the goal of all the environmental rules and regulations.
Commercially Available Wash-Water Run-Off Control Equipment
VacuBerm A VacuBerm, or similar tool, is the primary collection tool for the recovery of wash-water runoff. Located at appropriate collection points, it functions both as a dam, preventing run-off from going any further, and as a vacuum source to suck up and remove the impinging water. The following photo shows a VacuBerm in operation, connected by hose to a vacuum source. The rather simple external appearance conceals a sophisticated design. These are clever tools in the water-collection aspect, but should be chosen wisely, as they should be able to withstand a car running over it, and not all applications are flat smooth surfaces. Vacuum Berms are available in lengths of 4, 6, 10 feet and longer. Shorter versions are intended for draining puddles. The VacuBerm is an extremely successful design; it is not unusual to have water impounded on the upstream side, with a completely dry surface on the other. Just be aware that finesse is always required when training water to "jump into a hose".
The VacuBerm in use. A flap on the back of the mesh enclosing the VacuBerm can be used to accommodate sand bags or sand-filled tubes which aid in conforming to uneven surfaces. (Patented) 6 Other Berms or Booms Berms or booms consist of plastic tubes of various diameter, filled with sand (or sometimes water) which can be laid on the ground to divert run-off to a collecting point. Occasionally they are used to form a collection area, which can then be drained using a sump pump or a short VacuBerm. Typical berms ("water booms" or "sand-snakes") are 6 inch diameter and 4 to 50 ft. long. Sometimes sand bags are used to perform similar functions. Berms are inexpensive and commercially readily available.
Vacuum Recovery Tanks
When using the VacuBerm or other wash-water recovery tools, an interceptor tank must be used to prevent water and debris from entering the vacuum pump. It is absolutely vital to protect the vacuum pump from any possibility of damage due to ingesting solids of any kind. This function is provided by the "Vacuum Recovery Tank." This tank separates the recovered water and debris from the air entering the vacuum pump. The tank is actually much more sophisticated than it appears at first glance. The Vacuum Recovery Tank consists of a rust-resistant 30-gallon drum containing a shielded inlet for the air-water-debris mixture from the VacuBerm, separated by a mesh screen from the other components. Water and air are filtered by the debris screen. The air component passes through another, finer-mesh filter and then exits to the vacuum pump. Th recovered water is picked up by a rugged sump pump, having an automatic float control, and is pumped to a disposal area. An added safety feature, included in the exit filter assembly, is a floating ball, which will shut off the exit to the vacuum pump in case of sump-pump failure.
Vacuum Pumps The heart of the wash-water recovery system is a powerful vacuum pump. For professional use, home-style "shop-vacs" are unsuitable, since they require frequent manual emptying of the captured water, and do not provide adequate vacuum. Vacuum capability, expressed in units of how high the vacuum will lift a column of water, is a critical feature, since in practice, equipment is installed on a truck or trailer, thus requiring several additional feet of lift from ground level. Professional vacuum sources provide lift capability of at least 10 feet, with more powerful units capable of lifting up to 18 feet of water. Of course there is a volume flow aspect also; typical units range in capability from moving 100 cubic feet of air per minute, to 500 or more. 7 Electric vacuum sources, consisting of an enclosure housing one or more 3-stage fans, are quite capable and are the usual choice for smaller jobs requiring only one operator. Units operating on 120 or 220 volts provide over 10 feet of water lift, at flow rates up to 200 cu.ft/min. A minor drawback is that they draw rather substantial amperage, usually requiring a separate circuit. A typical electric vacuum source, having two 3-stage fans, and capable of 200 cu. ft./min capacity, with a water lift of over 10 feet. The inlets to the two fans are shown, and the exhaust is to the side.
The vacuum source and the vacuum recovery tank can be mounted together to form a compact unit as shown below, with cart frame, hose and "VacuBerm." Auto-pump-out is rated to 35 gpm.
8 More powerful units comprise a gasoline or diesel engine with belt drive to a positive-displacement blower style air mover. Typical units range from 6½ to 35 horsepower, providing water lifts from 14 to 18 feet, and airflow rates from 200 to 650 cu.ft./min. The greater power capability allows multiple operators to use the system simultaneously. These units are typically mounted on a frame as shown, with modular options, and installed on truck or trailer. Belt-drive positive-displacement blower vacuum source; 16 horsepower, 16 ft water lift, at 350 cu.ft./min, shown with dual tanks to total 30gpm auto-pump-out, vacuum berm and vacuuming surface cleaner.
Vacuuming Surface Cleaners The vacuuming surface cleaner is an important tool when cleaning sidewalks, driveways or parking lots, where runoff to storm drains must be avoided. They are also useful indoors, avoiding the extra step of mopping up the used wash-water. Attached to the vacuum system in place of, or in addition to, the VacuBerm, they provide a valuable time-saving, surface cleaning capability. There are many rotating–bar surface cleaners on the market, from 8 to 36 inches in diameter, all having basically the same general design, i.e. a round housing enclosing a rotating bar, driven by water jets inclined at a slight angle to the surface to be cleaned. The reaction from the water jets spins the rotating bar at up to 2000 rpm, while at the same time, a powerful cleaning action is exerted on the surface being washed. The entire assembly, mounted on wheels, is pushed around like a lawnmower. These are very efficient cleaners, however, the wash water left behind, typically about 4 gpm, means run-off to storm drains must be controlled, and when used indoors, some sort of vacuuming or mopping operation must follow. The vacuuming surface cleaner solves these problems. The rotating bar of a standard surface cleaner is surrounded by an annular vacuum chamber, which is connected to a vacuum system. The result is a surface-cleaner which not only cleans, but leaves behind a surface which is only moist, not wet. Not having to go back and rinse, because it all got sucked up, means a great saving in time and labor. This added efficiency pays for becoming environmentally friendly very quickly. The complete vacuuming surface cleaner equipment system comprises a pressure washer (typically 4 gpm at 4000 psi) to feed the surface cleaner, a vacuum source together with vacuum recovery tank, automatic pump-out and all connecting hoses. Total investment approx. $10,000. 9
Vacuuming surface cleaner equipment: surface cleaner, vacuum system, and pressure washer
Hand-Held Vacuum Devices Hand-held vacuum wands comprise one or more high-pressure water jets, usually mounted in a roughly oblong enclosure which has a vacuum chamber arranged around all edges. Short-handled versions are used for clean-up of low walls, etc. while longer-handled types are used to scrub corners where the rotary surface cleaner cannot reach. Other long-handled versions are used to clean outside walls. One interesting application of the vacuuming wand is to clean decks and balconies, where drips and run-off must be eliminated to avoid unsightly stains on the building exterior. These devices may require the usual pressure washer, as does a vacuuming surface cleaner, or pressure regulated supply, as the upholstery tool shown below. With a vacuum pump, vacuum recovery tank, hoses, etc, they are modular, and greatly enhance cleaning options.
Detailer Upholstery tool 10
Hand-held wash wand. High pressure spray from 4 nozzles is directed at the surface, and is removed by a surrounding vacuum chamber. This wand is designed for cleaning restrooms, kitchens, decks and balconies.
Oil-Water Separators
Oily surfaces are often encountered when cleaning driveways and parking lots, and also automobile detailing often produces significant amounts of grease and similar grime. This can usually be captured by the VacuBerm or vacuuming surface cleaner, but disposal of the recovered oily water becomes a problem. Landscape disposal is undesirable, due to possible plant damage. City regulations regarding sanitary sewers often have quite low permissible volumes of oily waste which can be accepted. The answer to the disposal problem is the oil-water separator.
There are many devices for separating small quantities of oil from water, however, most are complex and unsuitable for installation on a truck or trailer. Separators based on an oil-phillic filter can remove the oil from captured wash water at a rate of up to 10 gpm, with a final discharge no greater than 200 oil/water parts-per-million. This is adequate and acceptable for disposal into most city sanitary sewers. These very simple separators consist of a large tank filled with oil-attracting filter material, arranged so that the oily water from the vacuum recovery tank makes multiple passes through the filter. After a period of use, the oil-attracting filter material is easily replaced. Auxiliary filters can be arranged to remove particulate material down to 50 microns or so. Oil separation rates up to 1½ gallons per hour can be achieved. One of the attractive features of this type of separator is that there are no moving parts and no electrical connections are required. Hence these separators are especially suitable for installation on trucks or trailers, and are easily brought to the work site. 11
Oil-water separator (66 gallon) with associated cleanable cartridge filters ready for install.
A typical parking garage cleaning system should include 35hp Hot pressure washer, Vacuum wash water control, Oil Water Separator with filtration for re-use, with generator, and on-board water supply. This will keep 2 people profitably productive AND enviro-friendly production style. 12
The assembly of all the equipment items mentioned above is really quite simple and easy to understand. The main concern is properly connecting the vacuum hoses. The VacuBerm, vacuuming surface cleaner, and other tools "slip-fit" into the vacuum hose, while a positive connection to the vacuum tank is achieved using a "cam-lock" coupling. A short "connect hose" between the vacuum tank and the vacuum pump is hot air rated. The automatic pump-out discharges through a garden hose fitting, or for higher flow rates, a 1¼ to 2" discharge hose.
Complete assembly of typical VacuBerm wash-water recovery system. If using an electric fan-type vacuum pump, care must be taken to select an electrical outlet capable of supplying up to 20+ amperes. A separate outlet (on a different breaker) is required for the automatic pump-out. For remote locations, a portable generator will be needed. When you require big vacuum from electric power, you will need big power to run it… For 3000 watts of vacuum, plus 1500 watts of pump-out, add start-up current, and you need a 6500 watt generator to run the 115 volt system with reliability,
As shown above, the VacuBerm or other tool connects through the vacuum hose to suck water and debris into the vacuum tank. A filter screen inside the vacuum tank prevents objects larger than sand from entering the automatic "pump-out" pump. When the water in the tank reaches mid-level, a float switch on the automatic pump-out energizes the pump. Water from the vacuum tank can then be diverted to a sanitary sewer, filtered for re-use, or (with the permission of the owner) used to water the landscape. 13
Best Practices in Using the Equipment – Operator Training
Best Management Practices (BMP’s) for run-off control are really just common sense, but the on-the-job equipment operator must be trained to use his/her common sense! Here are some suggestions...
Start by emphasizing the legal responsibilities and the environmental consequences involved in allowing wash-water to enter the storm-sewer system. Disregarding these fundamental issues might subject the company owner to legal harassment as well as fines. Emphasize the on-the-job responsibility to survey the wash-water run-off possibilities before starting cleaning work. Place SandSnakes and VacuBerm in proper position to intercept run-off to streets and storm drains. Locate a suitable disposal place for the recovered wash-water, such as sanitary sewer (sewer clean-out, sink, etc.), or with the owners permission, landscape areas. If the run-off is likely to be oily, use oil-attracting fiber pad ahead of VacuBerm, or engage the oil-water separator.
If surfaces are dirty and dusty, do a preliminary brush-sweep and dispose of the trash before you begin power washing.
Lay out and connect all vacuum hoses, as well as the disposal hose. If using an electric vacuum pump, locate suitable outlets for vacuum fans and pump-out in vacuum tank.
Start the vacuum system, and check to make sure it is functioning properly.
Put on face shield and ear protection, start pressure washer, and begin washing.
Every few minutes, check to make sure run-off is being properly captured, and there is no leakage to storm drains.
After washing complete, continue vacuum operation, until all run-off has been captured.
Drain vacuum tank appropriately (to landscape or sanitary sewer) and legally.
14
Some Complete Truck or Trailer Mounted Units
In this section we show examples of complete pressure-washer and wash-water recovery units, mounted on trucks or trailers, ready to go to work.
System mounted in a van. Convenient, accessible, and serviceable.
Truck mounted system with reclaim for re-use and 4 gpm to 4000 psi, is perfect for small jobs and spot cleaning with wash water re-use, as in graffiti or bus stop cleaning applications.
15
Heavy-duty trailer-mounted system, has engine-driven vacuum and two vacuum waste tanks with dual inlets on each, for multiple wand operations, like parking garages, or shopping centers.
Using the Equipment in the Field Here we show some typical examples of the recovery equipment in actual field use.
Here we see the VacuBerm (held to the contour of the surface by a sand-filled boom) intercepting water before it gets to a storm drain, which is also protected by an oil-absorbent pad weighted down by a sand-bag.
16
Using a vacuuming surface cleaner can avoid any possible discharge into the bay.
Equipment Maintenance and Upkeep Daily (end of job) maintenance chores Flush and vacuum the outer surfaces of the VacuBerm and other tools to remove any attached debris. If OilPhyllic filter pad used, flush debris away.
Lift off lid and dump out Vacuum Tank (avoiding any run-off problems)…
Rinse tank and screen. Check air filter for debris. Rinse sump-pump screen.
Vacuum perimeter of vacuuming surface cleaner to remove debris, especially cigarette butts, which are frequently trapped in the outside brush assembly.
Spray silicone aerosol lubricant into engine-driven blower (for 5-10 seconds) to lubricate and avoid corrosion. Maintain blower oil level and check grease supply. EVERY DAY!
Bi-Weekly (or more often) maintenance chores Change engine oil every 50-75 hours of engine operation. Don’t wait until it turns black! Remove and clean check-valve at outlet of pump-out pump. It must seal to allow the sump pump to prime itself. 17
Trouble shooting Vacuum Reclaim systems are designed for lifting water up to a total of 10 to 16 feet vertically, including the lift up into the waste tank, onto the truck-bed or trailer, where the auto-pump-out could still overcome the vacuum working at "full tilt" with a long hose attached to a surface cleaner from hundreds of feet away. As amazing as it is, in performance, the engine driven systems are still limited by the distance the vac has to suck up the water, and how easy you have planned for the auto-pump-out to push water out of the waste tank "against the vacuum". Connecting it correctly is "key". IF you are using the vac at max hose length, max vacuum against a vacuuming surface cleaner, to expect the pump-out to discharge full flow, don’t constrict it with a 5/8" garden hose. You’ll need a 1½" discharge hose to accommodate the needs of the pump-out for max performance. If it still isn’t working, maybe the check valve at the auto-pump-out is dirty… loosen a hose clamp, and rinse it with a garden hose… quick, easy, and with minimal downtime. If the pump-out doesn't kick on at all, maybe the float-switch is handing-up on the slide-in-filter, or the float-switch-lever-arm is dirty.
Here are a few more tips.
VacuBerm or vacuuming surface cleaner not working well… Check for debris build-up as outlined above. Electric-driven fan not working… Check fuse and it’s contacts. Check the GFCI (ground fault circuit interrupter) on the power cord… was it dropped ?? does it light up ? Vacuum not providing much vacuum. Check for debris on fan inlet screen (at fan’s face.) Check for clogged air filter inside vacuum tank. Check tank lid for a good seal. Fan makes unusual sound. Check motor brushes for wear. Engine-driven blower makes unusual sound, or reduced vacuum... Check for clogged air filter and leaks in vacuum tank lid. Pump-out not working… Check electric circuit. If OK, then inspect arrangement inside vacuum tank – float switch may be blocked somehow, or be clogged with debris. Check valve must seal, and the pump must be able to prime itself. Vacuuming surface cleaner bar not rotating... Check water filter and/or nozzles for debris.
18
ABOUT THE AUTHOR Jerry McMillen started the forerunner of his present Company, Cleaning System Specialists Inc. (dba PressureWasher.net), in his garage in 1986, and was manufacturing custom systems within a year. Vacuum and Reclaim equipment development began in 1989. All the pressure-washers and wash-water control units that he presently manufactures contain his personal inventions and designs. Jerry is also a member of the Technical-Standards Committee of the Cleaning Equipment Trade Assoc., and the Enviro Compliance Council of The National. Assoc. for Professional Detailing and Reconditioning He has shared his knowledge by contributing significant articles to professional trade journals, and lectured on Wash-Water Control. Jerry’s wife, Doris, is Vice President of the Company. Jerry and his family live in San Diego, California. Offices are located in El Cajon, CA
|
