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Safe sewer cleaning

High-pressure sewer cleaners require extra care.


April 3, 2020
By William Bernhard, technical and safety services manager, Association of Equipment Manufacturers

Topics
Accidents with high-pressure cleaning equipment can inject fluids into the body causing potentially fatal injuries. Gas and exhaust buildup are also risks. Photo courtesy of RamVac by Sewer Equipment.

In our quest to continue to improve safety for everyone using off-highway equipment, the Association of Equipment Manufacturers has teamed up with the manufacturers on our Underground Equipment Manufacturers Council to assemble a comprehensive safety manual for high-pressure sewer cleaning equipment.

“One of the biggest cost centers for companies operating in the construction industry is worker safety incidents, and they’re almost all preventable costs,” says Curt Blades, senior vice-president of Agricultural Services at AEM. “Violation fees themselves can go as high as $70,000 per incident, and that doesn’t consider worker’s compensation claims, legal bills, lost productivity, or even staff turnover. Simply said, talented staff stay where they know it’s safe.”

For rental companies, end-user safety is also a critical consideration. If for no other reason, user safety increases the likelihood of a successful job, a happy customer, a job well done with your equipment, and your equipment returned in good condition on time and ready for the next job.

What are High-Pressure Sewer Cleaners?
High-pressure sewer cleaners use any combination of high-pressure water discharge and vacuum suction to clean sewer lines and other drainage systems. The nature of the business means these are mobile units, and come in three different styles: trailer-mounted water-jetting units; truck-mounted units that can both jet water and have vacuum suction; and skid-mounted units with both water jetting and vacuum suction.

The First Step in Safety is Often a Documented Safety Program
Depending on the laws, rules and regulations in the area your company operates, a documented safety regimen for your equipment may already be required. However, if it isn’t, it’s still a best practice, especially for rental companies. With a documented safety program, your company has consistent and quality information to relay to your customers so ensure safe operation of this dangerous gear.

That safety program should include instructions that apply to all sorts of equipment use (“Don’t use while impaired by the use of alcohol or drugs.”); proactive and reactive safety tips to know before using the equipment (“Know your emergency response numbers, hospital locations and how to identify your location to first responders before traveling to your job site.”); and other general safety tips (“Perform a walk-around inspection prior to accepting a rental piece of equipment.”).

That safety program should also document the correct set of Personal Protective Equipment (PPE) that should be worn by all equipment operators and assistants on site. For high-pressure sewer cleaners, that should include a hard hat; waterproof, steel-toed boots; safety glasses, goggles or a face shield; waterproof, electrically insulating gloves as required; hearing protection; reflective clothing; wet weather protective gear as required; a respirator or filter mask as required; and metatarsal guards (including those that provide shin protection).

The Pressure is on Preparation
Knowing the hazard points of any piece of equipment before operating it goes a long way toward preventing costly accidents. High-pressure sewer cleaning equipment presents hazards including pressurized fluid injection into the body, especially from the hydraulic lines, and these can be fatal. With many of these units running on ultra-low sulfur diesel fuel (ULSD), static discharge during refueling presents a hazard. So does the atmosphere where it’s being used.

The nature of sewer lines is they are enclosed with the idea of keeping its contents (both liquid and gaseous) contained inside. If you are operating a high-pressure sewer cleaner with the engine in the enclosed space, the exhaust gases can concentrate and disable, or even kill, the people in the pipe. Additionally, if the sewer line already has a high concentration of flammable gases, using a sewer cleaner in such an environment can trigger a fire or detonation.

A Safe Start is a Good Start
Sewer cleaners should always be started from the operator’s point, whether that’s the seat or another position designated by the manufacturer. Every piece of equipment is different, so it’s important to review the machine’s starting procedure in the operating manual, before startup. This would include information on what steps to take before operating the equipment and what to look for after the machine has started.

Three Simple Rules to Aid in Safe Operation

  • Understand the machine’s limitations. Be in control of the machine at all times.
  • Be sure that the work area is clear of all persons.
  • Look and listen for malfunctions. Stop if a malfunction or erratic operation is detected. Correct or report trouble immediately.

Customers need to remember they are operating a machine that combines the hazards of high-pressure water discharge with the hazards of high-pressure hydraulic operation all in an enclosed space. This equipment can also bring hazards from boom operation (especially near power lines) and high-suction vacuum operation, which are doubly-concerning when combined with the hazards around sewer gas and the potential of chemical waste.

Shut Down Safely for a Successful Day
Once an operator gets through the job safely, there’s no worse way to end the day than to have a safety incident on shut down. They should make sure the position controls are either in a neutral or locked position, the parking brake is engaged, all the hydraulic pumps and pneumatic compressors are shut off and give the engine a chance to idle and cool down for a few moments. Once the engine is shut down, the operatgor should make sure all the water, air, and hydraulic lines are depressurized, everything with a lock is locked and maintain three-point contact with the machine while exiting.

Rental Companies Need to Practice Safe Maintenance as Well
Typically, responsibility for maintenance of rented equipment falls on the rental company. While most of the hazards for a high-pressure sewer cleaner reside at the job site, not all of them do.

The first and best line of safety defense for any equipment owned, operated and maintained by a rental company is a checklist that includes boththe tasks to perform and how to perform them safely. That way, the equipment can be maintained safely (protecting maintenance workers), successfully (protecting your customers) and consistently (building trust with customers).

Following the equipment manufacturer’s maintenance instructions and schedule is the best way to keep equipment running properly. Those maintenance instructions from the manufacturer are going to contain information like the machine’s lubrication charts.

Making sure maintenance technicians are qualified to maintain the equipment is the best way to do it safely. Keeping track of who is qualified and authorized helps make sure proper, safe maintenance happens consistently.

Personal Protective Equipment (PPE) is also critical here. Maintenance shops need to keep hard hats, safety shoes, face and eye and hearing protection, and apparel and equipment to protect against exposure to corrosive chemicals that are common in the operation of these machines. Shop managers should also make sure all technicians are aware there are rotating parts in these machines, so loose clothing should not be allowed while operating or performing maintenance.

In addition to rotating parts, maintenance technicians need to be just as cautious of high-pressure issues as well, including hot radiators, hydraulic hoses (including injection of hydraulic fluid into the body), and damaged tires.

Why does AEM create these safety manuals?
The Association of Equipment Manufacturers (AEM) works with all member manufacturers of certain types of equipment to create safety manuals for two reasons: to help manufacturers collaborate on best practices in safe equipment creation and to create comprehensive guides for owners and operators to minimize costly workplace injuries.

High-pressure sewer cleaners present a unique set of safety concerns. In these machines, just about everything inside is either under dangerous levels of pressure, or are designed to create dangerous levels of pressure. This is necessary for these machines to adequately perform the task they were designed for. However, they also create other dangers, including dangers for explosion, due to the environment they have to work in.

AEM encourages organizations that own these machines, or any other piece of off-highway equipment, to keep these manuals on hand and as part of their qualification process for operators and technicians.