Vadose zone monitoring system having wick layer enhancement

US5272910A · kind A · utility

Assignee

• The Regents of the University of California · US

Inventors

• Lorne G. Everett · Lompoc, US
• John H. Kramer · Chesterfield, US
• Stephen J. Cullen · Santa Ynez, US

Key dates

• Filing date: May 13, 1992
• Grant date: Dec 28, 1993
• Expiry date: May 13, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G01M3/04
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A vadose zone monitoring system for detecting leaks from a contaminant storage facility or the like is disclosed in which leaks are detected in a confined radial area around at least one generally horizontal, neutron access tube disposed under the landfill. A wicking layer of material increases the leakage detection coverage area by laterally transmitting leakage to the access tube via capillary action. A clay liner may be disposed between the landfill and wicking layer for controlling the rate of leakage to prevent build-up of a pressure head large enough to force liquid through the wicking layer before it is conducted laterally to the access tube. Leak detection may be carried out by neutron moderation techniques or other moisture detection schemes for developing logs indicative of the leakage from the landfill. The wicking layer permits an entire network of access tubes or other leak detection means to be installed under substantially the entire landfill for monitoring leaks therefrom.