||Development and Application of Borehole Flowmeters for Environmental Assessment.
Molz, F. J. ;
Young, S. C. ;
||Auburn Univ., AL. Dept. of Civil Engineering. ;Tennessee Valley Authority, Norris. Engineering Lab.;Robert S. Kerr Environmental Research Lab., Ada, OK.
Hydraulic conductivity ;
Well logging ;
Fracture zones ;
Electromagnetic properties ;
Faraday effect ;
||Some EPA libraries have a fiche copy filed under the call number shown.
In order to understand the origin of contaminant plumes and infer their future migration, one requires a knowledge of the hydraulic conductivity (K) distribution. In many aquifers, the borehole flowmeter offers the most direct technique available for developing a log of hydraulic conductivity in the horizontal direction. A new electromagnetic flowmeter developed by the Tennessee Valley Authority (TVA) is based on Faraday's law and produces a voltage that is proportional to the velocity of the water passing through the central cylindrical channel of the meter. The threshold velocity of a prototype instrument is less than 8.8 + or - 0.9 cm/min. Calculation of a K distribution (granular aquifer) or flowpath distribution (fracture flow) based on flowmeter data is a straightforward process as described herein. Applications of both spinner and electromagnetic flowmeters to granular and fractured-rock aquifers are described.