The ground improvement performed at the site of two 190-ft (57.9 m) diameter, 40-ft (12.2 m) high, 8 million-gallon (30,300 m3), circular steel water storage tanks consisted of installation of stone columns to mitigate liquefaction and lateral spreading potential and a surcharge program to reduce post-construction settlements. Settlement during the surcharge program ranged between 9 and 15 in. (225 and 375 mm) and post-construction settlement during the hydrotest was about 1.2 inches (305 mm)
