Sub-Surface Systems

Many sources of risk and failure are hidden underground. In such cases, EL's Entropy Minimax technology proves especially useful in uncovering difficult-to-detect patterns.

Buried Landmines and Bomblet Detection

As part of an effort to help in their removal, EL developed statistical procedures for improved discrimination of unexploded landmines and bomblets from clutter and noise. These statistical procedures are for use in conjunction with Jentek's new electromagnetic sensing technology to measure properties of underground materials.

Underground Cable Failures and Electric Power Network Reliability

Entropy Limited has worked in conjunction with the Altran Corporation to develop a model of cable sections and joints with high risk of failure. This was done using data from on-site inspections of more than 4000 underground cables in New York City, covering environmental factors (water table, salting of the streets, rainfall, temperature, etc.) as well as cable and joint characteristics (manufacturer specifications and installation procedures) and operating history (electric power loading, inspection reports and maintenance records), analyzed to determine which cables and joints have greatest risk of causing power outages in future heavy load seasons to enable targeting of preventive maintenance actions to avoid brownouts. Upon completion of the model and analysis, EL and Altran provided recommendations to ConEd to reduce the number of recurring cable and joint failures in electric power distribution networks.

Standards for Underground Tank Regulation

As subcontractor to the Midwest Research Institute, Entropy Limited conducted the study of manual inventory data from hundreds of filling stations in 35 states for the U.S. Environmental Protection Agency, leading to the federal regulations specifying monitoring standards for inventory reconciliation. The throughput rule proposed by Entropy Limited in this study was adopted by the EPA and implemented into the federal regulations 40 CFR 280.43.

Underground Tank Statistical Inventory Reconciliation (SIR)

Entropy Limited developed and operated a statistical inventory reconciliation procedure, certified in states throughout the U.S. and now licensed to Veeder-Root Service Company.  Using this SIR procedure, EL analyzed product inventory data on gasoline, diesel fuel, oil and other petroleum products in tens of thousands of underground storage tanks to identify cases of high environmental and safety risk.  (For numerous oil companies and insurance companies.)

Technical and Economic Issues in Underground Tank Regulation

At the request of the Western Oil and Gas Association, Entropy Limited conducted a study of technical and economic issues pertaining to the underground storage of gasoline, diesel fuel, jet fuel and related petroleum products.  In this study, Entropy Limited compiled statistics on underground tanks in Santa Clara County, California and analyzed the cost-effectiveness of proposed underground tank regulations.  Data from the San Francisco Bay Air Quality Management District and the California Regional Water Quality Control Board were displayed showing the numbers, locations and types of underground tanks, products contained in the tanks, and reported leakers.  Regulatory impacts of modern tank technology and double containment in terms of compliance costs and enforcement costs were assessed.

Underground Tank Lifetime Analysis

For a number of public and private organizations EL has analyzed soil and backfill data from thousands of storage sites in the U.S. and Canada, to determine the corrosiveness of the underground environment, employing tank characteristics and usage patterns to estimate serviceable lifetimes for tank maintenance and replacement scheduling.


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