By George KennedyAnyone who drives a local road after a hard winter thinks he knows what a pothole is. If you are a utility contractor, however, you know what a real pothole is. Potholing is the practice of digging a test hole. It is defined in the Common Ground Alliance’s Best Practices as “exposure of a facility by safe excavation practices used to ascertain the precise horizontal and vertical position of underground lines or facilities.” Test holes are more than just a mark on the ground. When a pothole is used to locate a facility, workers can actually see where and how deep it is.Excavators hope the facility is right under the marks placed on the ground by the facility locator sent by the One Call/Dig Safe system or the facility owner/operator. However, the line is not always found beneath the mark. Therefore, state laws prohibit or limit the use of mechanical equipment to excavate within the facility tolerance zone. The tolerance zone is the space in which a line or facility is located, generally 18 to 24 in. on both sides of the facility. Special care must be taken when excavating in the tolerance zone.Utility contractors across the nation will tell you that utilities are often mismarked and you cannot rely on the marks placed on the ground. The only way to know exactly what is below the surface is to see it, and the only way to do that is to dig a pothole. Excavators should hand dig or vacuum excavate potholes to find the actual location of existing underground utilities. Some states require potholing before digging a trench or horizontal drilling and some do not. However, potholing before proceeding with the actual task of installing or replacing a utility is a very good practice — some would call it essential. Hand Digging Hand digging test holes is accomplished with blunt tip shovels (sometimes referred to as shooters), picks and digging bars which are carefully used to find and uncover utility lines. Although the hand digging method of potholing has been used successfully for a long time, it has its limitations. The cutting edge of these tools can also damage utility lines. It does not take much force to damage a fiber-optic, telephone or electric cable, a cathodic protection on gas lines or to nick and weaken plastic water lines. Care should also be taken when electrical lines are present. In addition, potholes can only be dug about 4 ft deep before they have to be opened up enough to accommodate a worker and digging holes. More than 5 ft deep creates the need for a cave-in protective system (sloping, shoring or shielding). Vacuum Excavation Vacuum excavation, although not always feasible, is becoming the most popular and efficient method for locating utilities. Trailer- and truck-mounted vacuum excavators use air or water pressure to quickly dig small, precisely controlled potholes to uncover utilities. Both air and water excavation methods have advantages and disadvantages, which should be considered before purchasing a vacuum excavation system. An important consideration is that vacuum excavators can dig deeper than is possible with a shovel. Controlled by an experienced operator, they can also uncover buried utilities without the risk of damage to them. Backfill and Restoration Some state jurisdictions and local communities frown on or even prohibit potholing when it means cutting through the surface of paved streets. If this is the case, it may be necessary to explain to officials the importance of potholing and what you’re trying to prevent. After the work is complete, the potholes must be filled and compacted to ensure that patches do not sink with time. The pothole should be clean and dry before backfilling and the pavement or surface must be replaced in accordance with local standards and specifications. Make sure you know the local restrictions and requirements before potholing. Mismarks Even with potholing, utilities will not always be found where the locator placed the marks. When this happens, mismarks and unmarked utilities should be reported to the facility owner and/or the One-Call/Dig Safe center. NUCA encourages contractors to also file a DIRT (Damage Information Reporting Tool) report with the Common Ground Alliance at www.cga-dirt.com. Reporting mismarks helps the utility owner update its maps and identify locators who may need additional training. It also helps the industry address the issue of contractors being blamed for damages that are caused by mismarks and unmarked utilities. Safety Procedures Safety is always a consideration. Contractors must ensure that vacuum crews know and follow the necessary safety precautions. In many situations, crews will be working outside the barricaded work zone where they could be exposed to traffic. They should be instructed on how to set up a temporary work zone and provided with the cones, barricades and/or signs needed to safely redirect traffic around the potholing operation. All workers should be provided with high visibility vests or clothing to be worn at all times. In addition, safety glasses — and sometimes hearing protection — must be used. Hand digging requires non-conductive or insulated tools. Companies need to provide dielectric boots and gloves and require their employees to wear them to reduce the possibility of being shocked if an electric line is damaged. Ten-Step Procedure for Damage Prevention Start your jobs off right by following this simple 10-step procedure to prevent damage to underground utilities: Plan the job. White-line or mark the area to be located. Meet the locator at the jobsite, if necessary. Call the One-Call/Dig Safe center to request a mark-out and wait the required time before proceeding. Verify that all utilities have been marked and notify the One-Call/Dig Safe center if all utilities are not marked. Pothole to find utility lines and determine the exact location and depth. Report mismarked facilities, inaccurate marks and unmarked utilities to the One-Call/Dig Safe center. Respect the tolerance zone. Support and protect exposed utilities from damage. Report damages immediately to the facility operator and investigate the cause of any damages. Backfill carefully and fill in potholes properly in accordance with standards and specifications. Conclusion Utility hits are dangerous and costly. They can only be prevented when companies commit to damage prevention. Contractors have a responsibility to their companies, employees and the general public to do all they can to prevent damage to underground utilities. That prevention comes from knowing exactly where utilities are located, and the best way to accomplish that is to both call before you dig and pothole before digging. Make a difference: Establish a damage prevention procedure, include potholing and dig responsibly. The Mid-America Regional Council (MARC) has prepared a useful Potholing Practice which includes additional information that can be downloaded from its website (www.marc.org/gif/potholing.pdf). Additional information is also available from the manufacturers of vacuum excavation equipment. George Kennedy is NUCA Vice President of Safety.
There were 2 incidents yesterday regarding construction excavating crews hitting gas lines in Broward County . If you are doing any excavations near or around Gas Lines, Fiber Optics Electrical or any other Underground Utilities you may want to call US Utility Potholing & Air Excavation to avoid these types of situations. Digging with Air is the safest way to excavate for the Utilities and Operators. If you want to avoid these situations call us at 954-937-1488. US Utility Potholing & Air Excavation is South Florida's Soft Dig Specialists A Fort Lauderdale Fire Rescue Hazmat crew works on capping off a gas leak near NE 17 Way and NE 9th St., in Fort Lauderdale. Several homes were evacuated, Thursday, July 16, 2015. (Michael Laughlin / Sun Sentinel) By Emily MillerSun Sentinel contact the reporter Fort Lauderdale homes were evacuated after construction crews punctured a 1-inch gas line with a backhoe About 50 Fort Lauderdale residents were evacuated from their homes Thursday after construction crews punctured a gas line with a backhoe, a Fort Lauderdale Fire Rescue spokesman said. A hazardous materials team worked to clamp the 1-inch gas line at Northeast 17th Way and Northeast Ninth Street as foul-smelling natural gas escaped into the air, spokesman Capt. Greg May said. Because natural gas is highly combustible, Northeast 17th Way and Northeast 17th Terrace were closed to the public, and residences in the area were evacuated. Construction crews working in the area of Northeast 17 Way and Northeast Ninth Street punctured a 1-inch gas line with a backhoe about 2:50 p.m. July 16, 2015, said Capt. Greg May, Fort Lauderdale Fire Rescue spokesman. (Fort Lauderdale Fire Rescue/Courtesy) It took crews about an hour to cap the line, which began leaking at 2:50 p.m. firstname.lastname@example.org, 954-356-4544 or Twitter @EmilyBethMiller Copyright © 2015, Sun Sentinel
Hazmat Team Responds to Gas Leak
Authorities say work crew accidentally hit gas line Author: Amanda Batchelor, Senior Digital Editor, email@example.com A Miami Department of Fire-Rescue hazardous materials team was called to a gas leak Tuesday morning. The leak was reported just before 9:30 a.m. in the area of Southwest 17th Avenue and Fourth Street. Capt. Ignatius Carroll said the surrounding area was evacuated as a precaution until the leak could be addressed by the gas company. The leak has since been capped, and residents were allowed to return to their homes and businesses a few hours after the leak was reported. Authorities said a work crew accidentally struck the gas line earlier in the morning.
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