Facing Cross-bores
Unfortunately, preventive measures don’t always prevent damage. Sometimesaccidents still happen in trenchless construction no matter how much planning,locating and staying on target goes into a project.
What the industry calls cross-bores, or hits, are the result of a newlyinstalled utility that intersects an existing utility. When those instancesinvolve gas lines, the result can be catastrophic and fatal. Oftentimes,trenchless installation methods, such as horizontal directional drilling (HDD)and moles, are to blame.
During the past five years, cross-bores have gradually become a major focalpoint of damage prevention and liability discussions within the industry.Cross-bores involving gas lines in sewers are considered the most dangerous typeof cross-bore because when sewer lines clog and require cleaning, the equipmentused can rupture the gas lines, allowing the gas to escape and explode.
That’s exactly what happened in Middletown, Ohio, in March. A plumber wascalled to clear a clogged sewer lateral and used a “roto-rooter”-typedrain-cleaning machine, which cut into a gas line that had been installedthrough the lateral. The plumber smelled gas leaking back through the sewer andrushed a woman and her three grandchildren out of the house seconds before thehouse exploded.
Middletown was not the first time this has happened, but it may have been themost significant. Other explosions have caused serious injuries and fatalities,but the Middletown incident in some ways served as a catalyst for industryleaders to confront cross-bores.
The trenchless industry has known about cross-bores for years, but was slowto respond to the problem. Some fear that publicizing the issue could be adetriment to the HDD industry. The Middletown explosion gained nationalattention in the media and helped force the cross-bore issue to the top of theindustry’s to-do list. Coinciding with the explosion was the formation of theNASTT Cross-Bore Committee, a move that was on the association’s agenda beforethe incident. Other organizations have answered the call as well, such as theCommon Ground Alliance (CGA), National Utility Contractors Association (NUCA)and the Associated General Contractors (AGC).
NASTT’s goal is to gather all those involved in the trenchless industry andpipeline maintenance — contractors, plumbers, engineers, facility owners,municipalities, equipment manufacturers and other industry organizations andassociations — to confront cross-bores head on.
This is not to say that there have never been successful programs toeliminate cross-bores in the past. In fact, quite the opposite. However, thoseresponsible for such programs have been reluctant to publicize their efforts,some industry leaders say, citing a negative association with cross-bores, whichhas contributed to the slow-building movement to target cross-bores.
“There haven’t been many widely dispersed articles on cross-bores,” says MarkBruce, Can Clay president and chairman of the NASTT Cross-Bore Committee.“Basically, the utilities, even the progressive ones that have done a great jobof eliminating cross-bores, have shunned any talking about it, as if it’s moreappropriate to just fix them and not talk about it.”
Talking about cross-bores might be the only way to find a resolution, saysSteve Lacy, vice president of Hydromax USA and sub-committee chairman for theNASTT Cross-Bore Committee.
“The reality is that gas companies just don’t want to talk about it,” Lacysays. “It’s a big expense. It’s a big public safety issue. They just want tosquash it.”
Hydromax was among the first sewer service companies to be contracted tospecifically search for cross-bores, Lacy says. In 2001, Hydromax was one offour contractors involved in a $17 million project that located and eliminatednearly 400 cross-bores throughout 200 miles of mainline sewer and the connectinglaterals.
“The purpose of the contract was to go out and hunt for cross-bores,” Lacysays. “They knew they had a problem; they’d been finding them. Before they hadan incident, like Middletown, [Ohio], they wanted to go out and aggressivelypursue getting these things fixed.”
Despite that project’s success, Lacy says by contract he is not allowed toname the contract owner or the city where the project took place, a “Midwestcity” in Kentucky. Hydromax wanted to publish a technical paper about theproject, but was threatened with litigation and forced to stop.
“Our approach even then was we thought it was such a fantastic thing thatthey went out and found almost 400 cross-bores in 200 miles of sewer line,” Lacysays. “We thought they were doing a noble thing. They didn’t see it that way.”
Hydromax experienced the same attitude in what Lacy calls “a second Midwestcity” in Indiana, where Hydromax located 26 cross-bores in 13 miles of sewerline as part of a pilot program to improve the sewer system.
Although both projects Hydromax was involved with found cross-bores at a rateof two per mile of sewer mainline, Bruce says it’s important to realize thatthose areas were deemed “high-risk” areas before the projects started. However,that does not discount the fact that these projects could serve as excellentexamples for eliminating cross-bores and help educate the industry about aserious issue in trenchless construction across the United States.
“The industry needs to get ahead of the curve on this,” says Bruce, whoenvisions a comprehensive and cooperative effort to prevent cross-bores infuture installations and eliminate legacy cross-bores that may have occurred inthe past 25 years of trenchless installation.
Getting the Point Across
Trenchless leaders are beginning to get vocal about cross-bores. All agreethat they need to develop a plan, but not all agree on what that plan should be.Some feel prevention is the end-all, while others think any construction shouldinvolve post-inspections. One argument trumpets government legislation as theanswer, yet another says internal good-practice regulations can solve theproblem.
Whatever the plan, the industry needs a proactive approach to cross-bores,Bruce says.
A primary roadblock to addressing cross-bores is knowledge, Bruce says. Theissue has lain dormant because of a lack of awareness and, in some casessensitivity, to how it could affect the trenchless industry.
Sensitivity and the image of the industry is unimportant, says Walt Kelly, anunderground facility damage prevention consultant who has served as an expertwitness in court cases involving cross-bores and other damages related tounderground construction.
“The question really is public safety,” Kelly says. “That includes the safetyof the driller, the utility, the nearby homeowner and anybody who pays insurancepremiums. Image is secondary. But the problem is very, very real.”
Cooperation and communication between all parties involved in undergroundutility installation, proper facility location techniques and enforcement ofprocedures, regulations and legislation are important aspects of damageprevention, Kelly says.
However, damage prevention is not 100 percent effective, says Lacy, whosuggests post-inspections are a better solution because existing maps andlocating are not failsafe. With post-inspection, he says the utility owner canbe sure that a cross-bore did not occur.
So far, NASTT is taking a two-pronged approach to cross-bores, stressingprevention and post-inspection in a comprehensive quality assurance and qualitycontrol (QA/QC) program, Bruce says. By the end of the year, the Cross-BoreCommittee hopes to present a set of guidelines for preventing and eliminatingcross-bores in the industry.
“I think it’s important that we educate the industry that there aresolutions,” Bruce says. “The solutions are very comprehensive. We hope in thefuture that there will be new techniques that are faster, slicker, better andlower cost. The cost of the solutions is palatable.”
In addition to the methods of eliminating cross-bores, the cost ofimplementing those methods also is a concern. In legal cases, where damages wereawarded, contractors and the utilities that hire the contractors have been foundto be financially responsible, Kelly says. However, if a successful cross-boreelimination program is going to work, those groups can’t be forced to bear allthe costs, Bruce says.
One solution is to include cross-bore elimination with rate-increase measuresand pass on some of the cost burden to those who use the utilities, Bruce says.Although no one likes rate increases, no one likes the possible damages —personal or otherwise — a cross-bore can cause, he says.
Cost management is one area where cooperation between groups is vital, Brucesays. Information saving and sharing plus combined efforts and inspections willhelp the rate-payer, who has the most at stake.
“There is a logical and moral purpose for us to bring all sides of theutility segment together, so the data that is gained incidentally throughlooking at cross-bores can also be used for other purposes,” Bruce says. “Whywould you not want them to work together to find problems and share costs or atleast allow the utilities to get to the problem?”
Cooperation also helps with planning and prevention, Kelly says. One areaKelly cites specifically as a problem is location of existing utilities doneprior to construction
“If excavators and facility operators, especially municipal sewer operatorsand their locaters would talk — communicate more, meet and discuss — and iflocaters would be more inclined to share with excavators their feelings whentheir locates are less accurate than they ought to be,” Kelly says, “that wouldreduce incidents.”
Improper or faulty locating often leads to damaged facilities, Kelly says.Poor facility mapping, improper marking, multiple facilities marked with onlyone set of marks and technology drawbacks all lead to locating problems. Whilemost states mandate that utilities must locate their facilities prior toconstruction, the problem is that only a few states have an enforcementmechanism in place to ensure those locates are done properly.
Legislation that specifically requires cities to locate sewer laterals andGASB-34, which mandates that municipalities must inventory their assets if theywant federal money, helps improve locating practices, Kelly says. Because ofthis legislation, many municipalities have begun to re-map their undergroundinfrastructure and keep better records.
Legislation or No Legislation?
Proper construction procedures can be instituted in one of two ways: bychoice or by force. Legislation could be passed to mandate that utilities andcontractors install facilities using a so-called “accepted way.” However,according to Bruce, such legislation would effectively handcuff the trenchlessindustry.
“Legislation needs not to be technique specific,” he says. “We need to havebroad solutions and broad statements.”
Instead, Bruce would rather the industry take the proper steps to implementits own set of guidelines.
“The industry will be better served if the gas utility industry has theability to self regulate,” Bruce says. “Legislation should not be necessary.Following good practices and standards voluntarily by the utility thatsubsequently requires the contractors to follow those good standards andprocedures is the best solution.”
Legislation that prompts the industry to change is not the best solution,Bruce says, but where it can help is by leveling the playing field and makingall groups follow the accepted guidelines.
“My concern is if the industry doesn’t take a proactive approach and takecare of cross-bores, it will be taken out of our hands and will be done lesspalatably by regulation,” says Bruce, who insists the industry must actproactively to solve its own problems.
The failure to address cross-bores with a widely accepted, comprehensiveprogram will negatively impact the continued acceptance and growth of thetrenchless industry, Bruce says. The success of such a program must includeevery entity involved with trenchless construction — the owners, engineerscontractors, manufacturers, locaters and municipalities — because, as he says,“We all work in the same underground.
“Our industry is full of thoughtful, knowledgeable people,” Bruce says. “Thebenefit to being proactive is reduced liability, reduced cost of liabilityinsurance and we maintain goodwill with the public, which is a net positive forall companies. That canbe done without the contractors and without the utilitiesto drive it.”
Bradley Kramer is assistant editor of Trenchless Technology.