Vista Engineering Technologies has evaluated a wide variety of in-tank and ex-tank leak detection and leak location systems for bulk underground storage tanks (USTs), large aboveground storage tanks (ASTs), and bulk and hydrant pipelines. These storage tank and transfer piping systems contain radioactive waste, petroleum fuels, and other hazardous substances. Our affiliate company, Vista Leak Detection, offers leak detection products and services.

Performance Evaluation

Our staff developed the standard test procedures for “evaluating and reporting the performance” of tank and pipeline leak-detection systems for the American Society of Testing Materials (ASTM) and the U. S. Environmental Protection Agency (EPA).

Performance results are reported in terms of the probability of detection (PD) and the probability of false alarm (PFA) as a function of various target leak rates and volumes of regulatory and operational interest. Performance is determined by rigorous, repeated field tests with and without leaks under the range of environmental and operational conditions.

The performance defined in terms of PD and PFA is determined from a statistical analysis of the noise and the signal-plus-noise histograms generated from the field tests.

Performance is usually reported for a PD of 95% and PFA that is less than or equal to 5% for a tightness test and 1% or less for a monitoring system.

Vista Engineering has assisted various clients with developing and conducting RCRA/CERCLA documentation and closure programs. Most notably, Vista Engineering Technologies assisted the Umatilla Army Depot in closing a chemical weapon storage site. Other Vista Engineering Technologies services include Risk Assessment preparation, Sampling and Analysis plans, and Data Quality objectives as part of the RCRA/CERCLA process.

Vista Engineering Technologies has assisted a variety of clients with evaluating the integrity of various hazardous waste storage systems. Applications have ranged from developing unique external tank monitoring approaches for buried underground tanks to unique characterization of historical leaks from landfills and trenches. Our approach to Integrity Assessments relies upon our specialized experience in application of geophysical methods, including:

• Electrical Resistance Tomography
• Sensor Network
• Tracer Testing
• Electromagnetic Methods