Tank Leak Detection

1
Tank Leak Detection

• Alaska
• Spring 2004

2
Leak Detection

• Orientation
• Basics
• Automatic Tank Gauging
• Interstitial Monitoring
• Inventory Control/TTT
• SIR
• Other methods

3
(No Transcript)
4
Good intentions
5
Orientation

• What do you have or use?
• What does your leak detection system do?
• Volumetric test
• Inventory
• Statistical
• Presence/absence of something
• Can you prove it is working properly?
• Do you check your results periodically?

6
Basics

• Must check for evidence of leaks every 30 days
• Checking/testing equipment must be maintained
• Equipment/method must be 3rd party evaluated and
  on the List of Leak Detection Evaluations for
  Storage Tank Systems by the National Work Group
  on Leak Detection Evaluations (NWGLDE)
  www.nwglde.org
• Must keep records of leak tests
• 2 months of Inconclusive/Invalid readings is a
  suspected release

7
Keep paper in the roll
8
Automatic Tank Gauge

• Most common method in Alaska
• Can run test when you want
• Daily, weekly, monthly, continuously
• Device must be 3rd party evaluated and on NWGLDE
  list.
• Console and probes must be checked
• Keep a copy of all printouts

9
ATG Common problems

• Not enough fuel in tank during test
• Test interrupted (fuel dispensed/delivered)
• Test gets disabled
• Paper/ink out
• Probes go bad
• Too much throughput, not enough quiet time
• Older models had limits

10
(No Transcript)
11
Interstitial Monitoring

• Double wall tanks
• Interstice is space between inner and outer wall
• Check the space electronically (sensor and
  console) or manually (stick and chart)
• Electronic sensors must be on the NWGLDE list
• Must check every 30 days
• Must record results MONTHLY- examples Veeder-Root
  Sensor Status Report EBW Contact Report
  Incon Line Compliance Report or hand written
  log if display only (no printer)

12
Inventory Control TTT

• Stick tank every operational day
• Reconcile daily
• Track deliveries
• Reconcile monthly
• Calculate leak rate
• Have a tank tightness test every 5 years.
• State certified tester with current vendor
  certification
• Test method on the NWGLDE list

13
Statistical Inventory Reconciliation

• Take monthly inventory and have it analyzed by
  statistical company
• A more sophisticated inventory control program
• Gives you pass, fail or inconclusive
• Statistical company method must be on the NWGLDE
  list

14
Bottom line

• An operator must be able prove every 30 days his
  or her tank (and piping) is not leaking more than
  0.2 gallons per hour (slightly less than one
  quart) of product.