The United States at the university of wisconsin-madison in gate tower near the lake, the elevator shaft bottom hole under the door more tower 2 meters, the lake bottom water all the year round for more than a foot deep, serious corrosion of elevator parts, although multiple governance still to no avail, 1991 EPT system installation, installation of no more than a week, the situation of seepage water of bottom hole stopped, a month after the bottom began to dry out. The school was so pleased that EPT was installed in its 15,000-square-foot basement, and Wisconsin Gov. Tommy Thompson honored the project with an "Innovative achievement Award" at the school's completion ceremony.