SEWER LATERALS AND HDD ISSUES

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SEWER LATERALS AND HDD ISSUES
2005 Western Regional Gas Conference August
23-24, 2005 ? Tempe Mission Palms, Tempe, AZ

• Dr. Samuel T. Ariaratnam
• Arizona State University

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Buried Infrastructure Problems A World-Wide
Dilemma

• Existing infrastructure has become very congested
• We continue to add and change utilities because
  of expansion, modernization, and changing
  missions
• Overall, we do not have adequate records to tell
  us where all of our utilities are located

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UNDERGROUND INFRASTRUCTURETHE OFTEN FORGOTTEN
WORLD
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A January 2000 FHWA / Purdue University study
states the following A savings of 4.62 for
every 1.00 spent on SUE was quantified from a
total of 71 projects. These projects had a
combined construction value in excess of 1
billion. To summarize, this report concludes
that you can save almost 5 in future engineering
expenses for every 1 spent on identifying and
locating underground conduit today.
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More and more utility installations are being
completed by HDD
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Smaller utilities

• telephone
• fiber optic
• services
• cable TV
• electrical
• gas

Larger utilities

• sewer
• water

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Possible Scenario?
What could happen?
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GAS LINE IN A 6 SEWER
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Protecting Public Safety Through Excavation
Damage Prevention National Transportation Safety
Board, Washington, DC, Report NTSB/SS-97/01, Dec
1997

• Expose all facilities that you will be crossing.
  All major facilities (i.e. high pressure gas,
  fiber optics, high voltage electric, major pipe
  and water lines, etc.) should be exposed every
  100 feet if parallel within 5 feet of excavation
  area when possible
• If you are paralleling a line, you should expose
  every 100 feet to verify the location and depth
  of the line. If the locate is not accurate, the
  facility owner must be contacted immediately.
• If using a boring machine, you should bore away
  from all facilities. If you must cross a
  facility, expose the line to verify location and
  depth. This may require changing the bore route
  or depth to avoid the facility.

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How often does this happen?
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What are the odds?
11,000 laterals were inspected.
250 hits identified and repaired.
2 of sewer laterals were hit.

• How many might have led to a major incident?

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MAJOR CONCERN

• CATASTROPHIC LOSSES RESULTING FROM UTILITY LINES
  THAT ARE EXEMPT
• FROM LOCATING LAWS

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What happens when laterals are hit during
drilling operations?
What happens when a plumber is called?
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Gas line Sewer Roto-rooter Disaster
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Even in nice, quiet neighborhoods?
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Officials seek answers in gas explosion Friday,
February 15, 2002 By Lanier Holt The
Post-Bulletin
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From the Post-Bulletin

• A natural gas line bisecting a clay sewer pipe
  caused an explosive surprise Wednesday.

• A plumbing contractor was removing tree roots
  from a sanitary sewer line in the 127 unit mobile
  home park when the gas line was struck.

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From the Post-Bulletin
How can this be avoided ?

• The natural gas explosion that rocked a mobile
  home park in Rochester on Wednesday shocked
  officials who say they never knew their line
  bisected a sewer pipe.

• About the only time we know about sewer lines is
  when people call because they get backed up and
  have to call someone in to clean them, said the
  Operations Manager with the local gas company.

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THE ROOT CAUSEA CATCH 22

• The laws in some States do not require all
  privately-owned some publicly-owned facilities
  in the historic corridor to be marked
• Contractors have no practical way of finding
  these are often even prohibited from check for
  them due to governmental no-cut policies

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School
Commercial Building
House
Apartment Complex
Mobile home park
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THE PROBLEM

• CONTRACTORS ARE OFTEN HELD RESPONSIBLE FOR
  HITTING THESE UNMARKED, UNKNOWN LINES
• CONTRACTORS INSURANCE RATES ARE ON THE RISE
• AS THE INSURANCE INDUSTRY IS RAPIDLY BECOMING
  AWARE OF THIS EXPOSURE, THE ABILITY OF
  CONTRACTORS TO SECURE INSURANCE FOR TRENCHLESS
  TECHNOLOGY IS IN JEOPARDY

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STATE REGULATIONS

• What do regulations say in 40 States?
• Owner or operator of an underground facility is
  responsible to locate the approximate horizontal
  location of that facility
• Is that the home/building owner or municipality?
• Does the State require them to join the One-Call
  system?
• Courts have ruled that home/building owner does
  not have expertise to be responsible for location
  of sewer laterals.

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WHAT ARE THE OTHER TEN STATES?

• New Jersey
• New Mexico
• Oklahoma
• Rhode Island
• Texas
• Virginia
• Missouri
• California
• Kansas
• Vermont

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Interesting Interpretations?

• In Kansas and Vermont
• Sewer is not designated as a facility
• In California
• exempts non-pressurized lines
• In Missouri
• exempts privately owned sewer and water lines

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THE CHALLENGE

• This exposure is escalating as more trenchless
  installations are done each year
• Action must be taken immediately
• There is little awareness of this issue outside
  of the contracting and insurance industries

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Protecting all Parties

• Public

• Gas Company

• Contractor

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THE SOLUTION

• All future sewers should be installed with a
  location device (i.e. tracer wire, marker balls,
  etc)
• All underground facilities, including sewer
  lines, should be marked by the entity that
  receives revenue from the facility
• Accurate maps should be required and available to
  contractors

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Sewer laterals need to be located, just like all
the other utilities
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Surface Ground Penetrating Radar
GPR OUTPUT
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Soft-Dig Technology
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Exact location and depth
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Laterals located along drill path
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Fish tape and beacon
Investment - 3000
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Video inspection with See-Snake
Investment - 7500
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ProScout Lateral Inspection System
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Cameras Mainline and Lateral
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MOBILE LATERAL INSPECTION
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Sewer camera unit utilized
Investment - 70,000
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when lateral clean-outs cant be found
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Lowering into manhole
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Extension tools used for entry
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Camera starting into sewer main
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What about the costs?
75 - 175 per lateral locate depending on
variables.

• Diameter of sewer main

• How much cleaning required

• How many locates per set-up

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Recognize the risk

• Require company and contract crews to locate
  laterals when drilling

• Utilize dependable, accurate methods

• Budget additional expense into projects
• and add pay units to contracts

• Design projects to reduce conflicts

• Educate local plumbers and rental stores

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Notify Your Customers
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CALL TO ACTION

• INITIATE SUPPORT LEGISLATION
• ELEVATE GENERAL AWARENESS OF OUR ISSUE

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CONCLUSIONS

• Care must be taken when boring near sewer service
  laterals
• Need for assigning responsibility for locating
  and marking these laterals
• Boring contractors need to follow good practices
  during installation of all utilities
• If a blockage occurs, must investigate possible
  causes prior to using mechanical means to
  unblock the lateral

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THIS IS A VERY IMPORTANT ISSUE!
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QUESTIONS?