Tests were conducted in Wisconsin from 1994 through 1996 in several boreholes using an ultrasonic method that was developed at the University of Wisconsin-Madison to assess the integrity of annular seals. Initially, three model boreholes simulating monitoring wells were installed to evaluate the effectiveness of the ultrasonic method. Different types of seals were placed around the casings and defects were purposely introduced in the seals to test the ultrasonic method. The ultrasonic method was effective for detecting the presence of different types of seals and defects and also the changes in the condition of seals with time. Then tests were conducted in thirteen monitoring and three water supply wells to assess the condition of annular seals. The presence of different types of seals and various defects was detected. It was observed that practices used in Wisconsin for sealing monitoring wells resulted in good seals. However, the practices used for water supply wells resulted in poor seals.


Civil and Environmental Engineering


URL: http://digitalcommons.calpoly.edu/cenv_fac/214