  The vibration stability requirements for the Next Linear Collider (NLC) are
far more stringent than for the previous generation of Colliders. To meet these
goals, it is imperative that the effects of vibration on NLC Linac components
from near-field sources (e.g. compressors, high vacuum equipment, klystrons,
modulators, pumps, fans, etc) be well understood. The civil construction
method, whether cut-and-cover or parallel bored tunnels, can determine the
proximity and possible isolation of noise sources. This paper presents a brief
summary and analysis of recently completed and planned studies for
characterization of near-field vibration sources under either construction
method. The results of in-situ vibration measurements will also be included.
