Company Information of Contruction by chm36503


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									The excavator’s push for damage prevention


     Mike Kemper,
     NPL Construction Company
     December 9, 2008
The Often Forgotten Underground World
Who is NPL?

                       The safe installation & maintenance of
                       reliable energy distribution systems

• 2500 employees
• 5.7M work hours
• 16.5M feet installed/replaced
• Fleet of over 3000 units ranked in Top 20 in
  construction industry
• Heavy One-Call user
What is trenchless technology?
How about these?
  Do we have a problem?
                  Who’s responsible
                  for marking?
                     What could
  Lateral to


Old Gas Service Line    Sewer Lateral

             New Gas Main
     Madill, OK 1992

Some hits are a time bomb!

     Madill, OK 2007
How often does this happen?
Odds of getting a hole in one

1 in 12,000

Montana Gimmie
CGA Conference
March 2008


“How many of you have experienced Crossbores?”

•   2/3 of attendees raised their hands
• Result: Best Practices Task Group
 What we know:

• Minnesota Public Utilities Commission
   – 27 cross bores reported in a 6 month period
• Palo Alto, CA
   – 4 blocks inspected. 24 cross bores found
• City A
   – 2 cross bores per mile in 200 miles of sewer main
   – One cross bore at a school
• City B
   – 3 cross bores per mile of sewer main
   – One cross bore at a hospital
• City C
   – 2% cross bores out of 11,000 sewer laterals inspected
    How often do explosions happen?
    Known explosions in past 10 years

•   Austell, GA                        •   Massena, NY
•   Bellwood, IL                       •   Merriam, KS
•   Burlington, VT                     •   Middletown, OH
•   Cincinnati, OH                     •   Mobile, AL
•   Clayton County, GA                 •   Phoenix, AZ
•   Fairfax, OK                        •   Rochester, MN
•   Gilbert, AZ                        •   St. Paul, MN
•   McKinney, TX                       •   Tucson, AZ
•   Madill, OK                         •   White Bear Lake, MN

    *Based on preliminary investigations in 16 states
“Houston, we have a problem”

                      - Captain James Lovell,
                        Spacecraft Commander of Apollo 13, 1970
The exposure is:

• Low Frequency - High Severity
• Short Term vs. Long Term
• A “predictable surprise”
Unmarked sewer lines are risky business
One bad move…
Even when it seems as
though you were born to do
the job, things can go wrong.
So what should we do?

• Plumbers

• Academia

• Legislators

• Regulators

• Contractors

• Manufacturers

• Owner/Operators
Headline: March 13, 2006
“ Woman, Granddaughters Barely
Escape Explosion ”
Story: March 16, 2006

After seeing bubbles in the water
and smelling the natural gas, the
plumber told the grandmother
and her three grandchildren to
get out of the home

• Middletown, Ohio building inspector:

"The plumber did absolutely nothing wrong. He had
no way of knowing the gas line had been breached.”
Duke’s Verification Process

• Plumber or Customer calls re: sewer blockage

• Duke sends 1st responder to locate
   – No conflict – Plumber cleans sewer line
   – Potential conflict – Dispatch C&M crew to:
      • disconnect gas service and let plumber clean line
      • test and reconnect service

  The Use of Trenchless Excavation Equipment
   in Relation to the Marking of Underground
“How important is the issue of unmarked sewer
 lines to your business?”

• 40 responses from major trenchless
  contractors in the US

• Average Importance: 9.26 (10= high, 1= low)
“Are owner / operators you work for required to
 mark their facilities?”

• 40+ states already require some level of
  locating by the sewer owner/operator
  – Is that the home/building owner or
     • Courts have ruled that home/building owner
       does not have expertise to be responsible for
       location of sewer laterals.
  – Does the State require them to join the
    One-Call system?

• Recent progress in AL, AZ, GA, KS,
  MN, NM, NV, SD, TN, VA, WI …
• More can be done in most states
  – New installations
  – Replacement installations
• Who is responsible for enforcement?
Does there need to be better
enforcement of violators?
Need for better enforcement of violators



• 2005: 258 (5 per week) HDD hits in US
• Potentially affecting HDD use
9th Annual HDD Survey
Growing Pains
Underground Construction, June 2007
 Industry standards
• HDD Consortium, Horizontal Directional Drilling - Good
  Practices Guidelines

• EMI, Safety Manual: Directional Drilling Tracking Equipment

• DCCA, Horizontal Drilling: Safe Operations Guidelines

• NULCA, Excavation Practices & Procedures for Damage
  Prevention: A Guide For Protection of Underground Facilities

• CNA, Minimum Damage Prevention Guidelines: Excavation
  Practices For Underground Facilities

• Manufacturer’s Manuals

• State One-Call Manuals
                       CONFIDENTIAL & PROPRIETARY
                         TRENCHLESS TECH UTILIZED
                           GAS LINE INSTALLATIONS
              (Bore Card Required by Each Crew at Each Address)
Conflict is defined as either crossing a sewer line within 4’ or paralleling one within 4’.

                               Sewer Line Conflict?
                               Yes / No, proceed

                         Daylighted?                  Privately-Owned Sewer
                      No / Yes, proceed               Systems (trailer park, school,
                                                      etc.) require 100% daylight.

       Sewer Main                       Sewer Laterals

    NPL Policy #22, Process 2                             NPL Policy #22, Process 3
  Visually Verify Bore Clearance                            Spaced Verification
       No / Yes, proceed                                    No / Yes, proceed

                                    Call Area Manager

Reduction of risk can be achieved:
  • Formal program to address?
      AGA Survey of 60 LDC’s: 26% have
  • Better policies
  • Relatively new technology for both new
    and legacy installations
 Do you want your contractor gambling?

                         Unmarked Sewer

Contingency Plan
One LDC’s standard

• Verification is required using any or all:
   – Check manholes for depth and direction
   – Fish tape with Sonde transmitter
   – Excavate 1’ > depth of lateral near start and end of
   – GPR, if it works
   – Camera before/after bore
• Pre and post construction door hangers
Duke Energy’s sewer locate
& inspection process

New installations:
• All sewer mains and laterals must be pre-
  located to the sidewalks
• Curb-to-meter services are completed with
  open trench
• Post Camera required before ANY GAS UP
• All recordings are copied and sent to the local
  sewer district
• Sewer Tag is attached to sewer cleanout
Duke Energy’s sewer locate
& inspection process

Replacement installations:
•   Site visit all projects
•   Determine if sewer is in the front
•   Determine depth of sewers and
•   Document elevation of first floor vs. street grade
•   Pre-locate sewer mains & laterals
•   Post-camera required before ANY GAS UP
    – 8 cross bores found out of 8000 pre-camera’d services
    – .1% vs .01% for a hole-in-one

• Less than 5% more

• How do we justify not spending the $?

• Is it worth one life?
Legacy solutions

• Educate local plumbers, rental
  stores, mobile home park owners
  … to look before they root;
• Find installed problems …before
  they find us.
Case study

Case study of an inspection program to inspect
sewer mains and laterals for possible cross bores

4 priorities identified:
–   Schools
–   Hospitals
–   Multi-Family
–   Mobile Home Parks
Susceptibility factors

 • Low depth of cover of the sewer lateral:
    • Privately-owned sewer systems
    • Areas with shallow sewer mains
       • Terraced homes
       • High water tables
       • Shallow or no basements
 • Areas where the gas line is buried deep
4 Methods used

 • Maps and Records for elimination
    – Wherever evidence of open trench installation
    – Facilities installed after “no blind bore” policy began in
      March, 2002
 • Electronic separation
    – Electronically locate depth and run of sewer lateral and gas
    – Separation greater than 18” required
 • Video past intersection point
    – Used ProPipe and Orbit to complete pilot
 • Dig and Inspect
    – As needed
Video inspection technology

• ProPipe main and lateral camera launcher
  for 8” and larger lines
   – Range 1600’ (800’ each way) of sewer main and 80’ of sewer service
• ProPipe hand-operated camera for 6” and smaller lines
   – Range 200 feet
• Audio and video capable
VIDEOinspection technology
Main & lateral camera launcher
for 8” and up

Locating underway

The Launch          There it goes …
Hand-operated camera
for 8” and up
Video recording

Pilot summary stats – 6/08

• About 300,000 investigations
• 103 cross bores found (.03%)
  – 76 found via the Program
  – 27 found by plumbers/Roto Rooter
• 22,005 single family homes inspected
  with no cross bores
What’s next?

• Proceed   company wide:
   • All plastic services installed prior to 1992
   • All replaced/relocated services installed
     between 1992-2002 when new Policy started
   • Includes single family residences
   • Estimated completion: 5 years
• Continue Public Education Program
   • Presentations to 132 residential and commercial
     plumbing contractors so far
   • Information mailed to all underground contractors

• Guidelines for locating pre-construction and
  verification post construction
• Guidelines for Identification of Legacy Cross Bores
• Sample Legacy Inspection Contract
• Equipment manufacturers – notices
• Sample ordinances
   – Requiring Drain Cleaner training
   – Requiring Accessibility to Sewer Maps
“Luck is not
 a strategy”

- Steve Ewing
 Past Chairman AGA, Vice Chair, DTE
Goal: Protect all parties


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