Monthly Archives: July 2015
If you suddenly find yourself without an Internet connection, there’s a good chance that somewhere a team of construction workers just uttered a collective “uh-oh” because their backhoe dug up a telecom cable. Oops. It turns out that this problem is so common that it is costing millions upon millions of dollars in repairs every year. Backhoes, drilling and digging are serious cable killers. A SMALL EXAMPLE TO START: SWEDEN In Sweden, admittedly quite a small country, around 8,000 telecom cables are cut off by backhoes every year. In fact, a construction crew managed to do this very thing not far from the Pingdom office a few months ago. The repair costs alone for these accidents are roughly $30 or so million per year in Sweden (an estimate from a recent Computer Sweden article). If we have that many incidents in a small country like Sweden, how common are they in a big country like the United States? Let’s have a look. THE US BILLION-DOLLAR FAIL Finding recent exact data for the US proved to be tricky. A Wired article from 2006 gave us some numbers to start with. In 2004, there were 675,000 excavation incidents where cables and pipes of various kinds were damaged in the US (often referred to as “underground utility damages”). More than a quarter of those, 27.5%, were telecom-related. That would mean 185,625 cases where US telecom cables were damaged in 2004. If the cost of repairing a cable is similar in Sweden and the US, telecom cable repairs may have been around $700 million in 2004. However, there are reports that things have improved. In 2007 there were an estimated 256,000 underground utility damages in the US, a lot less than in 2004. If a quarter of those were telecom-related, that leaves us with around 64,000 incidents where underground telecom cables were damaged. Even after such a big improvement, the yearly repair costs still end up in the hundreds of millions of dollars. Over a longer period of time, say 5-10 years, the repair costs will count in the billions. AND WHAT ABOUT WORLDWIDE? We have just looked at Sweden and the US here. Now imagine the costs worldwide. Those will easily amount to several billions of dollars and hundreds of thousands of telecom cable breaks due to our careless digging. Every year. And a ton of downtime for various networks, we suspect. PREVENTIVE MEASURES In the US there is a project called One Call where both companies and individuals can call in to find out what cabling exists where they are planning to dig. An interesting option has been explored in Denmark, where a central, nationwide website provides information about the underground cabling that exists in various areas. This website can be consulted by people and companies preparing an excavation. This has cut (no pun intended) the number of accidents by 70% which is a huge improvement. Sweden has just launched a similar initiative, so we’ll see if it works as well here. Now we just hope that that the operator of that huge backhoe that recently drove by doesn’t get any funny ideas… this is article is from http://royal.pingdom.com/
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.
Utility Locating and Marking Best Practices
2.14 Sub Surface Utility Engineering Best Practice Statement: When applied properly during the design phase, Subsurface Utility Engineering (SUE) provides significant cost and damage-avoidance benefits and the opportunity to correct inaccuracies in existing facility records.1 - See more at: http://commongroundalliance.com/best-practices/best-practices-guide/214-subsurface-utility-engineering-sue#sthash.pHrgTCys.dpuf Practice Description: In certain cases and environments, it may be difficult or impossible to determine the locations of all utilities and/or impediments with sufficient accuracy to avoid damage or delay during construction. In these cases, SUE is applied during the design phase to locate, identify, and characterize all existing utility infrastructure (and other relevant nonutility features) found within a given project/area. SUE is applied in a structured manner in accordance with practices and quality levels found in ASCE 38-02 “Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data.” The project owner dictates the required quality levels as well as the amount of effort expended by the SUE provider on each. Although the standard is more detailed and comprehensive, the following is a brief summary of the quality levels defined therein: QL-D involves utility records research and interviews with knowledgeable utility personnel. QL-C involves surface survey and identifying and recording aboveground features of subsurface utilities, such as manholes, valves, and hydrants. QL-B involves application of “surface geophysical methods,” such as EM-based locating instruments, GPR, radar tomography, metal detectors, and optical instruments, to gather and record approximate horizontal (and, in some cases, vertical) positional data. QL-A involves physical exposure via “SOFT-DIGGING” (VACUUM EXCAVATION or hand-digging) and provides precise horizontal and vertical positional data. SUE results are integrated into the design process, in which design engineers use the information to create construction plans that accommodate existing infrastructure, thereby reducing the overall risk of conflicts and/or damage.2 - See more at: http://commongroundalliance.com/best-practices/best-practices-guide/214-subsurface-utility-engineering-sue#sthash.pHrgTCys.dpuf References: U.S. Department of Transportation—FHWA (12/1999). Cost Savings on rojects Utilizing Subsurface Utility Engineering. Pub. No. FHWA-IF-00-014 U.S. Department of Transportation—FHWA (3/2001). Subsurface Utility Engineering: Enhancing Construction Activities. Pub. No. FHWA-IF-01-011 ASCE 38-02 Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data Pennsylvania state law - See more at: http://commongroundalliance.com/best-practices/best-practices-guide/214-subsurface-utility-engineering-sue#sthash.pHrgTCys.dpuf 1. TR-2007-02: Modification to statement approved by the CGA Board on August 24, 2007 2. TR-2004-03: Amendment approved by the CGA Board on March 4, 2005 - See more at: http://commongroundalliance.com/best-practices/best-practices-guide/214-subsurface-utility-engineering-sue#sthash.pHrgTCys.dpuf US Utility Potholing & Air Excavation uses provides quality level A and quality level B Sub Surface Utility Data.
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.
Potholing saves time and money.
Portable vacuum excavators have been a regular sight on job sites for years. These unique units were originally used to clean septic tanks and car wash pits and to remove slurry from horizontal directional drilling projects. Now contractors are discovering that these machines have a wide range of uses on the job site, from potholing for utilities to cleaning valve boxes. By Greg Ehm Construction Equipment News Letter http://www.constructionequipment.com/potholing-utilities-saves-time-and-money July 28, 2008 Portable vacuum excavators have been a regular sight on job sites for years. These unique units were originally used to clean septic tanks and car wash pits and to remove slurry from horizontal directional drilling projects. Now contractors are discovering that these machines have a wide range of uses on the job site, from potholing for utilities to cleaning valve boxes. Vacuum excavators are self-contained units that use pressurized air or water to displace soil and create a dry or wet spoil. The displaced dry or wet spoil is removed from the area through a hose using high-velocity suction and stored in a holding tank on the vacuum. Vacuum excavators can be mounted to a trailer or the back of a truck and range in size from 100 to 1,200 gallons of capacity. Since vacuum excavators use low-pressure air or water to remove spoil, they are perfect for potholing or identifying existing utilities during underground construction projects. "Damaging existing utilities can be costly in terms of project downtime and potential contractor fines," says Dave Gasmovic, president of McLaughlin Boring Systems in Greenville, S.C. "The low-pressure water and air will not damage existing utilities like a backhoe, compact excavator or shovel. In fact, the air and water move around the existing utilities, giving the operator a clear view." Operators can select the amount of air or water pressure appropriate for the utility. A lower pressure of 1,500 psi should be used for gas and fiber lines in order to not damage the line coating. A higher pressure can be used for water lines. Line Exposure While locators are becoming more accurate, it's still important to see exactly where the line or pipe is located. Contractors are not allowed to dig in the safe zone, which may be from 18 inches up to 3 feet from either side of the marked line. The required distance varies by state. Contractors are only allowed to dig by hand or use a non-destructive method like vacuum excavators in the safe zone. Using a vacuum excavator instead of a shovel has advantages. A shovel against a water pipe is non-destructive, but on a fiber optic line a shovel can be as destructive as a backhoe, especially in hard ground conditions. "A lot of cable has been installed using horizontal directional drills (HDD) rather than trenchers, so you don't have the old-fashioned ditch line like in the past," says Gasmovic. When lines are installed using a trencher or backhoe, a lighter material like sand is placed around the line. As a contractor digs, the ground gets softer. This indicates the line is in close proximity. Lines installed using HDD don't disturb the ground or leave a ditch line, so the ground is the same hardness and it is difficult to know if you are getting close to the line or cable. Since the ground may be hard, you can easily cut a cable line with a shovel. Using a vacuum with air or water at a non-damaging pressure will safely expose the line. Selecting The Right Unit Vacuum excavators come in all sizes and options, so it's important to select a unit that will best fit your intended use. Water-based units typically dig faster through a wide variety of spoil types and reduce the volume of the excavated material. These units move more displaced wet spoil into a holding tank than an air system. However, the displaced spoil is wet and cannot be returned to the site immediately without drying. While spoil from air systems can be directly returned to the site, these systems do not cut as well in hard ground conditions, such as clay. "I encourage contractors to look for a unit with a good-quality vacuum blower, the heart of the vacuum," say Gasmovic. "They should also select a tank that has the capacity to hold a half-day's or day's worth of spoil. This will reduce the number of trips you need to make to dump the holding tank." If you are working in areas with cobble rock, then a unit with a 4-inch hose and 1,025-cfm blower unit will be more productive. Cobble soils will require a larger blower to effectively remove the spoil. The larger diameter of 4-inch hose will help reduce the potential for clogging. In areas without rocks, a 575-cfm system and 3-inch hose will suffice. The blower size also affects the amount of engine power required — a larger blower will increase the cost of the unit. Gasmovic recommends that contractors pay special attention to the filtration system and select a system that will filter the spoil and avoid clogging. Finally, be sure to select a strong trailer frame that will support the weight of the unit and a full tank of spoil. There are a number of options available: controls that allow the contractor to reverse the flow of the vacuum to blow the spoil back into the hole; booms that support the weight of the hose, placing less effort on the operator; combo units that include a jetter to clean sewers and remove the resulting trash; and automatic tank clean-out systems and auxiliary hydraulic systems that allow the contractor to run a concrete saw or breaker off the unit. The Payoff Taking the extra steps to pothole may seem like an added expense or more time, but Gasmovic stresses that safety is important. "Hitting a gas line with a backhoe, trencher or HDD could be catastrophic. A water line hit could put a hospital out of business," says Gasmovic. "The cost of shutting down a project for a day is sure to exceed the cost for a $3,000 locator and a little extra time." In this photo Chris is starting a Pothole to verify existing utilities with the use of air / vacuum excavation. This is an example of our employee Mario digging a utility test hole or utility pothole to collect Sub Surface Engineering Data using air vacuum excavation method. We collect SUE Data through these methods at US Utility Potholing & Air Excavation.
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