CHAPTER 2 - CCAMP STUDY AREA: T0V7NS OF BARNSTABLE AND EASTHAM 



Cape Cod Aquifer Management Project Page 12 



by evapotranspiration and is available to recharge the aquifer has been 

 estimated to range from 11 inches per year in Truro to 21 inches per year 

 in both Truro and Falmouth (LeBlanc, 1984; Delaney and Cotton, 1972; 

 Magnusen and Strahler, 1972; and Guswa and LeBlanc, 1985). Recharge to 

 the groundwater also includes return flow from the septic systems and the 

 leaching beds of wastewater treatment plants. 



2 .4 Groundwater Problems Facing Cape Cod: A General Overview . 



Barnstable and Eastham served as the specific study areas, 

 particularly during hydrogeological assessment and land-use inventory 

 tasks. Cape Cod as a whole, however, served as the generalized focus for 

 an evaluation of institutional responses to categories of existing sources 

 of contamination. Thus, it is appropriate to provide the following over- 

 view of Cape Cod's groundwater problems. 



Cape Cod's groundwater quality problems stem from a combination of 

 rapid growth and land-use planning that did not consider groundwater 

 protection. As a result, public and private water supplies, ponds, and 

 wetland and estuarine resources are threatened by a multitude of 

 contamination sources. These include: sanitary landfills, wastewater 

 treatment facilities, leaking underground storage tanks, septage pits and 

 lagoons, on-site wastewater disposal, fertilizers, pesticides, and 

 toxic and hazardous materials. The Cape has not escaped some of the 

 adverse situations presented by heavy industrial development, including 

 disposal of industrial wastewater and the creation of intensive 

 hazardous -waste dumps-. 



Prior to 1970, little hydrogeological information was available upon 

 which land-use decisions emphasizing wellhead protection could be based. 

 Development thus proceeded in a manner that largely did not consider water 

 quality protection needs. Across Cape Cod, the delineated zones of 

 contribution to public -supply wells unfortunately contain many of the 

 major sources of pollution (See Figure 1.1). 



2 . 5 Sources of Contamination 



2.5.1 Sanitary Landfills 



Many landfills on Cape Cod, in use or abandoned, have generated a 

 plume of groundwater contamination. Groundwater quality around two- thirds 

 of the active landfills on the Cape has been evaluated to some degree. 

 All the tests have revealed compounds typically associated with landfill 

 leachate such as volatile organics, phenols, sulfate, iron, manganese, and 

 other metals. Some towns, such as Falmouth, Orleans and Yarmouth, have 

 mapped their landfill plumes based on the chemical composition of water 

 samples collected from monitoring wells over a period of time. To a great 

 extent, landfills are often located in groundwater recharge areas. As a 

 result. Cape Cod landfills have contaminated significant portions of the 

 aquifer that otherwise would be available for water-supply development by 

 towns. In addition to the threat posed to public -supply wells, private 

 wells are also vulnerable to contamination from landfill plumes. 



