Design of 3D seismic programs must anticipate the surface sampling requirements necessary to properly record elements of the emerging wavefield that are relevant to desired target reflectors. However, parameters that are sufficient to measure desired reflection signals should not be our only consideration. In many areas, it is also important to consider the type and magnitude of noise. In particular, areas with a strong occurrence of chaotically-scattered, source-generated noise require special attention. In this study we show a clear example of an area with local occurrences of this type of noise. We show how to recognize the noise and propose a model for the cause of the noise. A conventional design for this area leads to parameters that are sufficient to produce good data where the noise is not present. However, the data quality deteriorates to an unacceptable level in the noise-prone areas. We then show a method to help evaluate to what extent parameters must be changed in order to provide confidence that useful data will result