The study of natural restoration of groundwater quality in the treated-wastewater plume at the Massachusetts Military Reservation includes monitoring changes in chemical quality in the aquifer, and field and laboratory experiments to identify and quantify the physical, chemical, and microbiological restorative processes. Monitoring of water quality has included the collection and analysis of thousands of water samples from wells and multilevel samplers at least annually since 1994. The experimental work includes field groundwater tracer tests and laboratory experiments that similarly involved the collection and analysis of many samples.

The results of the monitoring and experimental work are described in journal papers and other reports. Selected data from this work are made available on this site to support the interpretive reports and share the data with others who also are interested in the fate of contaminants in groundwater.

Data Series 198
				Treated sewage-derived wastewater was discharged to rapid-infiltration beds at the MMR for nearly 60 years before the disposal site was moved to a different location in December 1995. Water-quality samples were collected periodically from monitoring wells and multilevel samplers during and after the disposal period to characterize the nature and extent of the contaminated groundwater and to observe the water-quality changes after the wastewater disposal ceased. Data are presented in this report for water samples collected from 1994 through 2004 from 16 wells (at 2 locations) and 14 multilevel samplers (at 9 locations) along a longitudinal transect that extends through one of the disposal beds. Data collected from the treated-wastewater plume are presented in tabular format. These data include: field parameters; concentrations of cations, anions, nitrate, ammonium, and organic and inorganic carbon species, and ultraviolet/visible absorbance.
	Savoie, J.G, Smith, R.L., Kent, D.B., Hess, K.M., LeBlanc, D.R., and Barber, L.B., 2006, Groundwater-Quality Data for a Treated-Wastewater Plume Undergoing Natural Restoration, Ashumet Valley, Cape Cod, Massachusetts 1994-2004: U.S. Geological Survey Data Series 198, 7 p.