Follow these guidelines for locating buried utilities
Successfully locating and identifying buried utilities is a process of elimination of mistakes. Thorough understanding of the survey area and the equipment’s correct operating procedures can help you help your customers save a great deal of time and money. No matter what locating equipment is used, these guidelines will help drilling or excavating crews understand precisely where they can operate safely.
Job-site awareness is critical. Your customers should gain as much knowledge about the location of the facilities before pulling out pipe and cable locators. There are three essential steps:
- Call 811. Smart digging always requires a call to 811. This cannot be overemphasized. Calling 811 is important whether you are planting a tree in your backyard or installing new utilities. Calls to 811 are routed to your local One Call Center, where an operator will ask details about your project. With this information, the operator will notify the local utility companies that subscribe to their service. Within a few days, the companies will send a professional locator to mark the approximate location of your underground lines, pipes and cables.
Some important things to remember about calling 811:
- Call a minimum of 48 hours before you plan to dig. Some states require a 72-hour notice.
- Only call if you intend to dig. You should not call 811 simply to acquire a map of the utilities in your area.
- One Call contractors mark utilities for free, so take advantage of the 811 service. It can help you avoid utility damage, power outages, fines and worse.
- Not all utility companies subscribe to 811, so know which utilities may not be located.
- Utility companies will locate the lines they own. Private lines from the meter to the house may not be marked. Also, private lines owned by schools, churches, hospitals and military bases may not be marked.
- For more information, visit the 811 website at call811.com.
- Use available facility records. Facility records indicate approximate location, number of facilities and access points for buried facilities within the job-site area. Records are usually available from the facility owner.
- Visually inspect the job site. Visual inspection is necessary to determine if there are facilities not on record. Evidence of a facility includes poles, dips enclosures, pedestals, valves, meters, risers and manholes.
Pipe and cable line locators actually can locate the electromagnetic (EM) field produced by the AC current flowing on the line, not the pipe or cable itself. Many non-metallic pipes and cables have tracer wires buried next to them that can conduct electricity.
EM pipe- and cable-locator equipment systems consist of a transmitter and a receiver that are portable and, when properly used, very accurate. After identifying the best access point to the target line, the operator can place a signal on the line either by direct connection, clamp induction or broadcast induction. The most accurate method is direct connection, which involves the signal traveling from the transmitter, through the target line, and returning through the ground stake.
Here are some recommended procedures for direct connection:
- Setup. Remove common grounds and connections to other utility lines to prevent the signal from being placed on untargeted lines. Insert the ground stake to the left or right of the target line’s suspected path. The transmitter’s black ground wire should not cross other lines. Connect the black transmitter wire to the stake and the red transmitter wire to the target line. Remove any paint, dirt or corrosion from the target line.
- Power and frequency selection. On the transmitter, select the appropriate settings to match the conditions of the particular locate. Use the minimum power level and the lowest frequency required to locate the target line. Remember, the higher the frequency, the easier to couple to adjacent lines and the shorter distance the signal travels.
- Sweep. Set the receiver frequency to match the transmitter frequency. Conduct a 360-degree sweep around the access point where the transmitter is connected to the target line. This helps locate the direction of the target line.
- Tracing the target line. The target line can be identified by finding the location with the strongest signal response. Sweep the receiver perpendicular to the target line and walk along its path. Retrace the path and mark with the proper color paint or flags.
- Know your limits. A tolerance zone of 18 to 24 in. should be observed around all located utilities until the exact location is verified. The only way to verify the exact depth and location of a target line is to expose it. First, select the critical areas along the marked path of the target line, and then hand dig or vacuum excavate to the target line. Exposing target lines can be safely accomplished using equipment such as a Ditch Witch FX20, FX25, FX30 or FX60 vacuum excavation system.
These locating procedures are general guidelines and are not intended to be a comprehensive guide to operating an electronic locating system. The operator’s manual contains complete recommendations and instructions for correct operation and maintenance. When excavating around underground utilities, your customers always should be prepared in case of an emergency and know how to react in the event of a damaged utility.
Matt Lumbers is electronics product manager for Ditch Witch, Perry, Okla. The Charles Machine Works (CMW®), Perry, Okla., manufactures Ditch Witch® underground construction equipment. For more information on Ditch Witch equipment, go to ditchwitch.com. For additional general tips on job-site safety, visit Ditch Witch’s safety page at ditchwitch.com/resources/safety.
Researching your market
Researching your market for utilities
By studying the needs in your marketplace, you can better understand the equipment rental opportunities and the types of inventory you can provide to municipalities and other potential customers with utilities, underground and other trenching jobs.
“If you are dealing with municipalities, get an idea of what work they actually do. You can have a water department that may need to put in service lines, and they may have their own crew, or they may subcontract that out and have a contractor do it. Get an understanding of who is doing the work,” says Todd Roorda, tree care/rental sales manager, Vermeer, Pella, Iowa.
“The size of trencher you will need will depend on the work they are doing. For instance, if you’re putting in a water line, you’ll want to get below the frost line in the northern part of the U.S. In the southern part of the U.S., they go a bit shallower. Any time you have a tracked machine versus rubber tire, you’ll have less ground disturbance and more flotation. That’s going to be a definite advantage,” he says.
Anna Foster, rental product marketing manager for Sitework Systems, The Toro Co., Bloomington, Minn., agrees and says both walk-behind and ride-on trenchers can be used for utility work.
“Walk-behind tracked trenchers offer the power and maneuverability needed for small to medium trenching jobs while going easy on grass surfaces. For larger work, municipalities more commonly use a ride-on product, like our new vibratory plow, which combines trenching and plowing capabilities to complete drip line, cable and other utility installations,” Foster says.
Natural disasters bring their own challenges for utility work. “For natural disasters, think about different sizes of machines. For storms like Hurricane Sandy, we see municipalities and rental stores gearing up for those storms before and right after. They may add one or two chippers, or if they own 12-in. chippers, they may get 15-in. chippers. Usually after that type of storm, you’ll have larger material to handle,” Roorda says.
Foster says disaster situations often require the need to clean up debris and downed trees before utilities can be repaired. “Large stump grinders are a great rental item in these scenarios and provide the ground speed, maneuverability and cutting head power needed to help large-scale cleanup. Compact utility loaders with attachments like the Toro Dingo® grapple fork can help pick up and move debris, while fitting through smaller areas or around debris obstacles that skid -teer loaders may be too large for,” she says.
Also, “ensure customers know how to safely operate, load, and strap down equipment before they leave the store,” Foster adds. “Point out important safety and operational decals on the machine and direct customers to operator’s manuals and videos online for further training. In disaster situations, additional safety risks are present, such as debris obstacles and downed power lines, so remind users to be alert to their environment and non-equipment related safety as well.”
Roorda says every rental store should have training on each machine that goes out the door.
“Every rental store should have training on each machine that goes out the door from an operational standpoint and also preventative maintenance, depending on how long the unit will be on rent. For a month’s rent on a stump cutter, you may want to send out some stump cutter teeth along with the knowledge on how to change some of those things. For trenchers, it’s going to be additional cup cutters or digging chains. You want to point out additional grease points. The maintenance will help keep the equipment in optimal conditions. Some rental stores ask that the machines come back in for that maintenance or send someone out to the job site for that. Either way, there should be more training than the basic items for long-term rentals,” Roorda says.
Call before you dig, trench or drill
It is easy to avoid accidents by simply requesting to have the ground marked for underground utilities, but too often this request is never made. Oversights can lead to expensive and time consuming claims. Gas, phone/cable, electric, and water lines can be damaged by a tent stake driven into the ground, or trenching and digging in a spot where the utilities have not been marked.
Make sure you and your customers place a call before digging or staking on a job site and have the ground clearly marked for underground utilities. This will help protect the utilities on the property as well as keep everyone safe from injury. The national “Call Before You Dig” phone number is “811” and will assist in getting utilities marked before you dig or place stakes. You can also contact the service via the Internet at call811.com.