PORTABLE PRESSURE WASHER FOR CLEANING RECREATIONAL SITES

Dave Erlenbach, Mechanical Engineering Technician

Brenda Land, Sanitary Engineer

• BACKGROUND
• HEALTH AND SAFETY
• AVAILABLE PRESSURE WASHERS
• CONCLUSION

BACKGROUND
Cleaning toilet buildings with brooms, mops, and brushes is time consuming. With reduced staff and increased workloads, toilets and other recreational structures may not be cleaned to an appropriate standard. Using a fire engine to clean toilets and recreational structures is inefficient and the engine may be unavailable during the fire season. The use of a high-pressure, low-volume portable pressure washer is more effective and less time consuming. The procedures for cleaning recreation sites with a pressure washer are contained in the U.S. Department of Agriculture (USDA) Forest Service San Dimas Technology and Development Center (SDTDC) publication Cleaning Recreation Sites, 9523 1206-SDTDC. (See figures 1 and 2.)

Figure 1—Cleaning the toilet interior using a pressure washer.	Figure 2—Cleaning the building exterior with a pressure washer.

Health and Safety
All sanitation workers must be trained in good hygiene and safety practices and follow Sections 22.3, 52.3, and 27.31 of the Health and Safety Code Handbook, FSH 6709.11. Human waste can contain a large number of pathogens and should always be treated as contaminated material. Always wear rubber gloves, boots, and face protection when cleaning toilet facilities.

Available Pressure Washers
SDTDC’s literature search of available pressure washers found several brands and models costing between $400 and $10,000. Many of these units were unsuitable because of weight, pressure, or discharge. Most were also incomplete and required a water tank, a hose reel, or a hand-washing station. Some washers required the unit to be skid mounted.

As a result of the literature search, the SDTDC project leader decided to design and build a complete skid-mounted system that best met the needs of the USDA Forest Service. The design criteria included:
    •  Skid-mounted slip-on features for a light truck bed
    •  100 feet of hose
    •  200-gallon water tank
    •  Variable pressure wand
    •  5.5 horsepower, belt-driven, gasoline engine (minimum)
    •  3 gallons per minute minimum discharge
    •  2-year warranty

The contract to build the portable washer was awarded to Marsh Industries. The prototype unit was delivered to the Tonto National Forest in Region 3 for evaluation. (See figure 3.)

Figure 3—Marsh Industries skid mounted slip-on pressure washer.

Paul (Pete) Libby of the Recreation and Lands Staff on the Tonto National Forest (Region 3) evaluated the unit and was pleased with the quality of construction. However, he suggested the following modifications to ensure a safer and more efficient system.

• Replace the 200-gallon tank with a 100-gallon baffled tank. The 200-gallon tank exceeded the payload rating for a ½-ton truck. The tank was not baffled and caused water movement in the tank when stopping, starting, or cornering.
  
• Add a USDA Forest Service-approved spark arrester.
  
• Modify the heat shield over the engine. Several people received minor burns when reaching around the engine.
  
• Use a hose reel instead of a hose rack. A hose reel is easier and quicker for deploying and retrieving hose than a hose rack.
  
• Add a rack to hold a cooler, a 5-gallon hand-washing station, and a hose reel.

The Tonto National Forest made these pressure washer modifications. The modified unit decreased the time needed to thoroughly clean a toilet building, excelled at cleaning the toilet riser without brushes, and removed most graffiti from the walls.

The pressure washer worked so well for cleaning recreational sites that the forest wanted another unit. They requested quotes, using the modified criteria, and the contract for the new pressure washer was awarded to Hotsy Corp. (See figure 4.)

Figure 4—Hotsy skid-mounted slip-on pressure washer system.

Landa also manufactures a slip-on pressure washer that meets the original contract specifications. (See figure 5.) This unit is available from the General Services Administration contract. A comparison of the three pressure washers is shown in table 1.

Figure 5—Landa skid-mounted slip-on pressure washer system with trailer.

Table 1—Pressure washer comparison.

¹off highway vehicle
²General Services Administration

Conclusion
A pressure washer decreases the time and increases the thoroughness of cleaning recreational facilities. It uses less water than a fire engine and is available during fire season. It is also safer because employee-contact with hazardous chemicals is reduced. A complete slip-on pressure washer is easily removed from the pickup truck without having to disconnect the tank or hose. The unit can be stored when not in use.

For further information, contact Dave Erlenbach, project leader, by phone at 909–599–1267 ext 264 or by e-mail at derlenbach@fs.fed.us