• Performance Monitoring
• Natural Attenuation Evaluation

Vertical cross section through the wastewater (treated sewage) plume on Cape Cod, MA, showing the distribution of dissolved ammonium (NH4+ ) in micromoles per liter (µmol/L) during 1994. Small dots indicate data points. The cross-section shows a cloud of NH4+ in the center of the wastewater plume that is moving much slower than ground water. The cross section is a modified version of figure 3 from Böhlke and others, 2006, and is based on data from Savoie and LeBlanc, 1998. (click image for a larger version)

• Long-term monitoring of the plume – Water-quality samples are being collected from a large network of wells and multilevel samplers. Synoptic samples of the plume have been collected annually since 1994.
• Field and laboratory geochemical studies – USGS scientists are conducting field and laboratory experiments to investigate the processes that control the natural restoration of the wastewater plume. These experiments include small-scale tracer tests, laboratory microcosms, sediment-column solute-transport tests, and reactive-transport modeling. The objective of these studies is to link the observed progress of restoration with laboratory and field measurements of the geochemical processes causing the restoration. Geochemical analysis of monitoring data and related laboratory experiments indicate that it will take decades for natural restoration processes to return the wastewater-contaminated zone to pristine water-quality conditions. Geochemical modeling predicts that phosphorus from the plume will discharge into a nearby ground-water-fed pond for many years.
• Geochemical studies of the fate of nutrients in the plume – USGS scientists are conducting investigations of the transport and fate of phosphorus and the biogeochemistry of nitrate and ammonium in the plume.

Methods and approaches to measure and predict the rate of natural restoration of contaminated ground water are needed by cleanup professionals and natural-resource managers nationwide. These professionals can use the results of this information to develop sound decisions regarding the restoration of aquifers through the use of natural attenuation.

• Decades Required for the Natural Restoration of Wastewater-Contaminated Ground Water
• New Information on the Long-Term Fate of Ammonium in Ground Water
• Phosphorus Doesn't Migrate in Ground Water? Better Think Again!
• Can a Sewage-Contaminated Aquifer Naturally Clean Itself?
• Sewage-Contaminated Ground Water -- Cape Cod, Massachusetts
• Massachusetts Military Reservation Installation Restoration Program Home Page
• Partitioning of Solutes between Solid and Aqueous Phases

• Barber, L.B., and Keefe, S.H., 1999, Evolution of a ground-water sewage plume after removal of the 60-year-long source, Cape Cod, Massachusetts--Changes in the distribution of dissolved oxygen, boron, and organic carbon, in Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 3 of 3--Subsurface Contamination from Point Sources: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, p. 261-270.
• Böhlke, J.K., Smith, R.L., and Miller, D.N., 2006, Ammonium transport and reaction in contaminated groundwater–Application of isotope tracers and isotope fractionation studies: Water Resources Research, v. 42, W05411, doi: 10.1029/2005WR004349.
• Hess, K.M., LeBlanc, D.R., Kent, D.B., and Smith, R.L., 1996, Natural restoration of a sewage-contaminated aquifer, Cape Cod, Massachusetts, in Hydrology and Hydrogeology of Urban and Urbanizing Areas—Proceedings of the conference, Boston, Mass., April 21-24, 1996: American Institute of Hydrology, p. WQE13-WQE25.
• Kent, D.B., and Maeder, V., 1999, Evolution of a ground-water sewage plume after removal of the 60-year-long source, Cape Cod, Massachusetts--pH and the fate of phosphate and metals, in Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 3 of 3--Subsurface Contamination from Point Sources: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, p. 293-304.
• LeBlanc, D.R., Hess, K.M., Kent, D.B., Smith, R.L., Barber, L.B., Stollenwerk, K.G., and Campo, K.W., 1999, Natural restoration of a sewage plume in a sand and gravel aquifer, Cape Cod, Massachusetts, in Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 3 of 3--Subsurface Contamination from Point Sources: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, p. 245-259.
• Miller, D.N., Smith, R.L., and Böhlke, J.K., 1999, Nitrification in a shallow, nitrogen-contaminated aquifer, Cape Cod, Massachusetts, in Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 3 of 3--Subsurface Contamination from Point Sources: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, p. 329-335.
• Parkhurst, D.L., Stollenwerk, K.G. and Colman, J.A., 2003, Reactive-Transport Simulation of Phosphorus in the Sewage Plume at the Massachusetts Military Reservation, Cape Cod, Massachusetts: U.S. Geological Survey Water-Resources Investigations Report 03-4017, 40 p.
• Repert, D.A., Barber, L.B., Hess, K.M., Keefe, S.H., Kent, D.B., LeBlanc, D.R., and Smith, R.L., 2006, Long-term natural attenuation of carbon and nitrogen within a groundwater plume after removal of the treated wastewater source: Environmental Science and Technology, v. 40, no. 4, p. 1154-1162.
• Savoie, J., and LeBlanc, D.R., eds., 1998, Water-quality data and methods of analysis for samples collected near a plume of sewage-contaminated ground water, Ashumet Valley, Cape Cod, Massachusetts, 1993-94: U.S. Geological Survey Water-Resources Investigations Report 97-4269, 208 p.
• Smith, R.L., Baumgartner, L.K., Miller, D.N., Repert, D.A., and Böhlke, J.K., 2006, Assessment of nitrification potential in ground water using short term, single-well injection experiments: Microbial Ecology, v. 51, no. 1, p. 22-35, doi: 10.1007/s00248-004-0159-7.
• Smith, R.L., Böhlke, J.K., Revesz, K.M., Yoshinari, T.D., Hatzinger, P.B., Penarrieta, C.T., and Repert, D.A., 1999, In situ assessment of the transport and microbial consumption of oxygen in ground water, Cape Cod, Massachusetts, in Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 3 of 3--Subsurface Contamination from Point Sources: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, p. 317-322
• Smith, R.L., Rea Kumler, B.A., Peacock, T.R., and Miller, D.N., 1999, Evolution of a ground-water sewage plume after removal of the 60-year-long source, Cape Cod, Massachusetts--Inorganic nitrogen species, in Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 3 of 3--Subsurface Contamination from Point Sources: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, p. 285-291.

USGS Information on Natural Attenuation

• A Unique Approach to Evaluating Natural Attenuation is Applied Worldwide
  
• Relying on Nature to Clean Up Contaminated Ground Water
  
• Topical Information on Natural Attenuation, Toxics Program
  
• Listing of Toxics Program Projects Evaluating Natural Attenuation
  
• Listing of Other USGS Projects Evaluating Natural Attenuation
  

Other Toxics Remediation Studies on Cape Cod

• Nitrate Remediation
• Phosphorus Plume Remediation
• Subsurface Reactive Barrier