Seismic refraction investigations in 2 "noisy" areas differing in geologic environment and field conditions indicate the reliability of such a technique for foundation engineering problems. Shothole conditions and generating media are of great importance. Dense media, clay, and materials within the water-table are most favorable; fill debris is the least suitable. Seismic noise in the city, usually transient in character, is not an insurmountable problem; a patient instrument operator is a key to success. Several shot locations along an individual spread and a geophone spacing not to exceed 50 ft. are standard field procedure for achieving a maximum amount of data.