Typical Design of a Production or Monitoring Well

Response of Water Table to Pumping of a Well

“Cone of Depression”: Drawdown of Water Table Near a Well

Capture Zone of a Pumping (Extraction) Well

Source of Contaminant “Plume” of contamination What happens to water quality at the well as plume enters the well?

Breakthrough with Finite Duration

Effect of Dispersion Caused by the Porous Medium (Soil)

Behavior of Non-Aqueous Phase (Immiscible) Liquids (NAPLs)

Methods for Pumping LNAPLS (NOT DNAPLs)

Retardation of Contaminants that Adsorb (“Stick) to Soil Particles

Retardation : Friend or Foe?  Retardation slows the movement of contaminants toward a use area, such as supply well.  BUT retardation also slows down removal via pump and treat

The Massachusetts Military Reservation (MMR) Formerly: Otis Air Force Base/Camp Edwards Falmouth, Cape Cod, MA ( Officially: Joint Base Cape Cod as of 7/13) Groundwater Contamination from Fuels, Solvents, Ordnance and from Wastewater Sludge

The Massachusetts Military Reservation (MMR) CERCLA Site 22,000-acre property Has been used for military training activities since 1911 Located over a sole source aquifer Provides drinking water for 200,000 year-round and 500,000 seasonal residents of Cape Cod.

Main military activity started 1935 Primary mission: provide training and housing to Air Force and/or Army units Otis AFB closed in 1973 (Nixon): still used for National Guard Otis AFB and Camp Edwards HISTORY

Historic chemical/fuel spills Fire training activities (chlorinated suppressants) Landfills, and drainage structures. Effluent from the former sewage treatment plant was historically discharged into sand beds where it seeped into the groundwater.

: Air Force detected volatile organic compounds (VOCs) in on-site monitoring wells near the Base Landfill and a Fire Training Area. 1984, the U.S. Geological Survey (USGS) detected contaminants in monitoring wells downgradient of this former wastewater plant.

VOCs detected in several hundred private wells (all of which are now on municipal water) and in one town well (now shut down). The EPA has designated the Sagamore Lens underlying JBCC as a sole source aquifer under the Safe Drinking Water Act.

Final NPL LISTING: November 1989 Groundwater is contaminated with VOCs TCE, trichloroethene DCE, dichloroethylene PCE, tetrachloroethylene, EDB, ethylene dibromide (flame suppressant) Carbon tetrachloride(flame suppressant) EDB was found upwelling in two cranberry bogs, outside the MMR, in Mashpee and Falmouth.

Soil contaminated with Heavy metals Polycyclic aromatic hydrocarbons (PAHs) Pesticides, PCBs Petroleum hydrocarbons Contaminated soil was largely removed in cleanup actions in

Some shallow groundwater also contaminated by sewage/sludge plume Viral contamination Nitrogen wastes (NH3 and NO3) Surfactants (from detergents, personal care products)

Federal Facility Agreement (FFA) was signed in 1991 (amended in March 2000) governing the Superfund cleanup. Signatories include: National Guard Bureau, U.S. Air Force EPA. Since May 1996 Air Force Civil Engineer Center (AFCEC) Installation Restoration Program is currently the lead agent under the terms of the FFA. Five year reviews have been conducted and issued in 1999, 2004, 2008 and 2013

Some Cleanup Action Highlights: 1986: City water lines extended to residents on wells 1990: Interim removal of surface sludeges and wastes 1997: 10 extraction wells installed (pump & treat) 2000: Final ROD was signed on May 15: P&T, long term monitoring 2002:

Unexploded Ordnance - UXO

Bombs, artillery, etc. RDX is major contaminant 2005 Cleanup Actions: 2,800 cubic yards of soil, 8,500 ordnance items 27,000 pounds of munitions debris Unexploded Ordnance - UXO

Remediation of soil and groundwater implemented since the mid to late 1990's. ~100,000 tons of soil have been treated at JBCC Numerous groundwater treatment plants treat ~11.5 million gallons per day (as of 01/15) All treated groundwater is returned to the aquifer or discharged to surface water.