Project Summary:

In a recent study in Rockingham County, NH, by the USGS and New Hampshire Department of Environmental Services (NHDES), MTBE concentrations were above 0.2 µg/L (the laboratory reporting level) in 40 percent of public wells tested and in 21 percent of private wells. MTBE occurrence was greatest (62 percent) in public wells used for residential supply (apartments, condominiums, mobile home parks, and other residences). Four public wells and no private wells had water with MTBE that exceeded the 13 ug/L drinking water standard for New Hampshire. This study also found that MTBE contamination is related to a number of factors including land use and depth of well. For more information, see:

• Methyl tert-Butyl Ether occurrence and related factors in public and private wells in Southeast New Hampshire, ES&T Journal article abstract.
• Occurrence of Methyl tert-Butyl Ether (MTBE) in public
  and private wells, Rockingham County, New Hampshire, U.S. Geological Survey Fact Sheet 2004-3119.

Based on the Rockingham County study, the USGS and NHDES are now conducting a statewide study of MTBE in wells. The current study will measure (through random sampling) the occurrence and distribution of MTBE in ground-water sources used for drinking water throughout the State of New Hampshire, and test numerous physical, chemical, environmental, and anthropogenic factors for association with MTBE occurrence and concentrations.

This study will also examine the temporal trend in MTBE concentrations at wells where MTBE was previously found by re-sampling selected wells in Rockingham County. A report summarizing this study will be prepared in 2006.