The objective of this continuing investigation of indoor/outdoor/surface relationships has been to develop an accurate method for predicting and subsequently managing the accumulation rates and ultimately the effects of corrosive substances on electronic equipment surfaces in field and manufacturing environments. We previously reported deposition velocities for chloride, sulfate, sodium, ammonium, potassium, magnesium, and calcium associated with fine and coarse particles at telephone company switching equipment locations in Wichita (Kansas), Lubbock (Texas), and Newark (New Jersey). These results were based on comparisons of indoor concentrations, obtained using dichotomous samplers for collection and ion chromatography (IC) for analysis, with surface accumulation rates that were obtained by collecting water extracts of surfaces and then analyzing by IC. Using the results from these studies, a methodology was developed for predicting the indoor surface accumulations rates if ionic substances from their outdoor concentrations. In this paper we report new results for a site at Neenah, Wisconsin. The combination of climate and environment at this site differs appreciably from the previous sites. Wichita and Lubbock have arid climates and are subject to wind-swept dust and Newark is an urban environment with a moderate climate. Neenah is a small community in a rural farming region and has a moderate climate. In spite of the substantial differences in climate and environmental factors, the deposition velocities of the major ions in fine particles are remarkably similar at these four locations.