FEASIBILITY OF AN INTEGRATED CONTINUOUS PROCESS USING AUTO- MATIC INSTRUMENTATION AND STATAISTICAL ANALYSES TO REDUCE COSTS AND TO INCREASE THE EFFICIENCY OF PEAK DETECTION AND POLLUTION CONTROL IN UNDERGROUND STORAGE TANKS

OVER THE LAST SEVERAL YEARS, THE EPA HAS DEVOTED MAJOR EF- FORTS TO IDENTIFY AND DOCUMENT THE MAGNITUDE OF THE RISKS OFENVIRONMENTAL POLLUTION DUE TO LEAKING UDERGROUND STORAGE TANKS (UST). IN APRIL 1987, THE EPA PUBLISHED THE PROPOSED REGULATIONS FOR THE OWNERS AND OPERATORS OF UST, WHICH ARE EXPECTED TO BE FINALIZEDD IN EARLY 1988. THESE REGULATIONS INCLUDE REQUIREMENTS FOR TANK TIGHTNESS TESTS, DAILY INVENTORY CONTROL PROCEDURES AND STRICT FINAN- CIAL RESPONSIBILITIES. THE FINANCIAL IMPLICATIONS TO SER- VICE STATION OWNERS ARE SIGNIFICANT. THE ADVANCED CONCEPT TO BE EVALUATED FOR ITS FEASIBILITY IN THIS PHASE I EFFORT IS AN INNOVATIVE, COST EFFECTIVE COMBI- NATION OF AN IMPROVED INVENTORY CONTROL SYSTEM, IMPROVED IN-STRUMENTATION FOR AUTOMATIC TANK GAGING AND A COMPREHENSIVE STATISTICAL MODEL. THE MODEL ACCOUNTS FOR ALL APPLICABLE ERROR SOURCES IN EACH TRANSACTION INTO OR OUT OF THE UNDER- GROUND TANK IN REAL-TIME, ON A CONTINUOUS BASIS. WITH THE IMPROVED SYSTEM AND INSTRUMENTATION, THE DATA FROM A NON- LEAKING TANK AND PIPING SYSTEM WILL ALWAYS FALL WITHIN A RELATIVELY NARROW STATISTICAL BAND. HOWEVER, A LEAK WILL APPEAR AS A BIAS, OVER TIME, TO THE LOWER SIDE OF THE ERROR BAND, WITH THE MAGNITUDE OF THE BIAS DIRECTLY RELATED TO THESIZE OF THE LEAK. THE PROJECT OBJECTIVES ARE DESIGNED TO DEMONSTRATE THE FEASIBILITY AND THE ACCURACY OF THE SYSTEM TO PROVIDE TANK AND PIPING LEAK DETECTION TO EPA AND NFPA STANDARDS, ON A CON- TINUOUS BASIS, WHILE PROVIDING THE ADVANTAGES OF AUTOMATIC GAUGING AND CONTINUOUS INVENTORY CONTROL. SPECIFIC TECHNI- CAL OBJECTIVES CONSIDER EACH ELEMENT OF THE SYSTEM. IF THE FEASIBILITY OF THE CONCEPT IS DEMONSTRATED, THEN THE SYSTEM WILL OFFER STATION OWNERS AN INTEGRATED SENSOR PACK- AGE WITH MICROPROCESSOR CONTROL THT MEETS THE EPA PROPOSED REGULATIONS FOR BOTH INVENTORY CONTROL, TANK TIGHTNESS TEST-ING, AND PIPING LEAK DETECTION ON A CONTINUOUS BASIS. IT REMOVES HUMAN GAUGING ERRORS, ACCURATELY ACCOUNTS FOR TANK TRUCK DELIVERIES, PROVIDES SECURITY AGAINST THEFT AND ALLOWSCENTRALIZED MONITORING, BY PHONE LINES OR RADIO, OF INDIVIDUAL SERVICE STATIONS. THE COST IMPLICATIONS ARE SO LOW THAT THE OLDER SERVICE STA-TION OWNERS COULD AMORTIZE THE COST IN APPROXIMATELY ONE AND PROVIDE COST SAVINGS THEREAFTER.