Colorado Rivers sites have the lowest mean temperatures, which may be a result of factors such as altitude, snowmelt, etc. GLOBE sites have higher means, and have several outliers above 30. USGS sites have means approximately 3 - 5 deg C warmer than the other two data sets, which may be the result of site locations.
	GLOBE mean pH values are generally lower than the other two data sets, with Colorado Riverwatch highest. Relative means of the distributions are 7.2, 7.6, and 7.9 for GLOBE, USGS, and Colorado Riverwatch, respectively.
	There is a close correspondence between the USGS data and the Colorado Riverwatch data. Approximately 60% of the GLOBE sites have lower mean values. Some GLOBE surface water sites are ponds or irrigation ditches, which would generally have lower dissolved oxygen values than those associated with a flowing stream.
	There is much greater variability among the three data sets in respect to alkalinity. Almost 20% of the GLOBE sites have a mean alkalinity of 0 mg/L. Removing the sites with zero alkalinity makes the GLOBE data correspond much better with the other two sets. QA/QC problems related to alkalinity measurements are followed up on an individual basis.
	There is a very good correspondence between the GLOBE and USG electrical conductivity data. Colorado Riverwatch does not report electrical conductivity.