WRGC Pinpointing Underground Gas Leaks Ron Six, Instructor Senior Utility Consultant AEGIS Insurance Services, Inc. 201/417-2487 RonaldSix@aegislimited.com

Associated Electric Gas Insurance Services A E G I S Associated Electric Gas Insurance Services Before I begin my presentation, some of you may not be familiar with AEGIS, so let me take just a moment to tell you who AEGIS is. AEGIS is an acronym that stands for Associated Electric and Gas Insurance Services. First Response

AEGIS Background Information Utility Mutual Insurance Company (member owned) Formed in 1975 by 22 gas utilities Electric Utilities began joining in 1977 375 members – 95% utilities and related energy AEGIS is a mutual insurance company formed nearly 30 years ago. Discuss slide. First Response

Our main job is not finding & fixing leaks Our main job is public safety

Pinpointing Is not an exact science. It is a developed skill which is learned and perfected through your mistakes and your successes.

Major Causes of Leaks Corrosion Mechanical failure Improper installation Improper design Faulty materials 3rd Party Damage - “Dig-Ins”

ASH ST #682 #686 4” Plastic Main 45 PSI Water Main Dead Cast Iron Gas Main First Response

The “Find and Fix Syndrome” The cure for this is to ask yourself a question “Where is the gas”? If you can answer the question that the gas is not affecting people and it is not affecting property you are cured. You must ask yourself this question on every leak before you get into the “repair” mode.

Our main job is not finding & fixing leaks Our main job is public safety

Detect Pinpoint Repair

Evaluating The Leak Where is the gas? w h e r is the gas?

Evaluating The Leak W H E R here is the gas? ow much is there? xtent of hazard (migration) elation to other structures valuate/evacuate

Factors Affecting Gas Migration Soil type Soil moisture Surface cover Line pressure Depth of burial Leak size and age Change in elevation=slope Path of least resistance

Centering = Where is the gas? Pinpointing = Where is the leak? The leak must be centered before it is pinpointed

Be Careful – “Don’t make a leak, looking for a leak.” Centering The Leak Probe holes must be of sufficient depth Test all available openings “Zero out” N-S-E-W You must have sufficient information to make a good judgement Be Careful – “Don’t make a leak, looking for a leak.”

Recent Natural Gas Incidents Springfield, MA

Methods Of Locating The Line Maps Records System experience Electronic locators 1. Basic principles of operation 2. Inductive vs. Conductive 3. Overcoming problems

Consistency = Success Exact location of main, services etc. Size of test hole (aeration is the key) Depth of test hole (must be consistent) Location of test holes (same side of main) Instrument use (consistency in testing)

PLACEMENT OF DRILL HOLES Where and how many? What size test holes? How deep? How far apart?

Size of the Test Hole ½” Test Hole 1” Test Hole

From the 1” Test Hole vs. the ½” Test Hole Size of the Test Hole ½” Test Hole 1” Test Hole 4x’s the Aeration From the 1” Test Hole vs. the ½” Test Hole

The Size of the test hole is critical Pinpointing with a ½” test hole Pinpointing using a 1” test hole

Minnich Hornet Drill

SAVE ANOTHER MISSED EXCAVATION

OLD MAIN STREET #400 #402 #404 30% Gas @ Foundation Wall 90% Gas @ Curb Concrete Sidewalk 4” Bare Steel 45 PSI OLD MAIN STREET #400 #402 #404

Use Of Soil Purger (cont’d) The soil purger is your best friend or worst enemy, depending on where and how it is used First Response

Types of Soil Purgers

Never purge near foundation #404 #402 #400 Never purge near foundation 30% Gas @ Foundation Wall Concrete Sidewalk 90% Gas @ Curb Purge Away From Foundation This will draw the gas away from the building and block the gas from migrating to the foundation wall 8” CI UP OLD MAIN STREET

Grade 1 Leak Repairs (Did you find “a” leak or did you find “the” leak You must not leave a Grade 1 Leak indication as long as the conditions that got you there are still present. If the readings went from 30% gas to 3% gas at the foundation it is still a technical Grade 1 leak. Purge the soil, get the readings to 0%, wait and make sure that the readings do not return.

60% Gas Curb 8” Steel UP CWP Maple Street 15% Gas

Maple Street 60% Gas 15% Gas Curb Service Line 8-10’ 8” Steel UP CWP 70% 50% 75% 8-10’ Maple Street 60% Gas 15% Gas

Maple Street 60% Gas 15% Gas Curb Service Line Slope 8” Steel UP CWP 40% 35% 45% 0% 15% 50% 10% Maple Street 60% Gas 15% Gas Curb Slope

Using The Soil Purger In The Pinpointing Process Purge from a hole where you know that the leak is not Plug holes near purge point Dense soil or moisture – time the purge/purge each hole Use it only when all other methods have failed

Test Methods Combustible gas indicator Natural ventilation 1. Top & bottom of hole 2. Time the readings Natural ventilation 1. Wait…let holes vent Blow pipe – vapors/soap top of hole Odor

Never use near foundation of building Use Of Soil Purger Should not be used on every leak Operation: 1. In the pinpoint process 2. As a safety tool – Never use near foundation of building 3. Residual gas Choosing a purge point is the key Techniques

10% Gas In Sewer Manhole 6” Steel UP ASH STREET CURB LINE

Gas Readings In Manhole Is gas in the sewer or just using the manhole as a venting point? Test top and bottom Percent gas readings will generally not be sewer gas Manhole CGI Test CGI Test

“Make Your Mark” Using Your Experience Using Test Results Using System Design Remember: It is much cheaper to drill than to dig. Do you have enough holes to give you enough information about the leak?

The Dry Hole Probe along the pipe Expose all of the pipe, not just the top Learn from your mistakes Use the hole to your advantage… no one “hits” them all Is it our gas?

6” Low Pressure Cast Iron High School 4” High Pressure Steel 25% gas in sewer manhole K-Street 6” Low Pressure Cast Iron 15% gas @ curb 65 69 71 67

Checking After The Repair Did we find “the” leak? Residual gas – when will it go away? Cleanup/plugging the test holes Importance of proper documentation

Stray Gas Is it lighter or heavier than air? Is there ethane in the sample? Is it a hazard? What is sewer gas/decomposition gas? Natural gas vs. stray gas Use of charcoal filter Use of collection bottles/bags Responsibilities regarding stray gas “Reasonable person concept”

Chromatographic Analysis Comparison No Ethane CO2 Methane Sewer Gas Nitrogen Ethane Natural Gas

Remember: The Job Is Not Completed Until all paperwork/documentation is completed: Neatly Thoroughly Accurately You may do everything right, but you may be judged by what is or is not documented

Be Alert Be Prepared Be Safe

AEGIS Insurance Services, Inc. Thank You Please visit our website @ www.aegislink.com Thank you for the opportunity to speak with you today and to participate in your conference. The Loss Control Division is here to contribute to your continued success. Thank you. CLICK First Response