This data release contains files that are associated with the publication 'Understanding and predicting iron fouling associated with drainage from roadway sites constructed with rock-fill in New Hampshire, USA'. Each zipped file contains a data table or raster file and an associated metadata file. IronFoulingCutFillData.zip contains a .csv file and .xml metadata file related to the roadcut and rock-fill locations used to develop a statistical model to predict the probability of iron fouling at roadway sites constructed with rock-fill in New Hampshire. Water_Quality_Measurements.zip contains a .csv file and .xml metadata file for water quality field measurements made at drainage areas from a subset of the rock-fill locations in the IronFoulingCutFillData files. The NHIronFoulingProb.zip file contains a geotiff raster of the predicted probability of iron fouling occurring at any location within New Hampshire where rock-fill from that location is used and contacts drainage. This is the output from the statistical model prediction. NHIronFoulingProb.zip also contains an .xml metadata file. This data release contains a raster of the probability of obtaining 40 gallons per minute from a 400-foot-deep well in New Hampshire and is from the USGS Professional Paper 1660 (Moore and others, 2002). The raster originally released with the publication contains categorical ranges of the probability values and not the actual probability values. These probabilities are a variable in the statistical model developed to predict iron fouling associated with drainage from roadway sites constructed with rock-fill in New Hampshire.