Assessment of Groundwater Vulnerability in the Ossipee Watershed

Click HERE to read the report prepared for GMCG by Mia Akaogi Ecological Planning The Rubenstein School of Environment and Natural Resources University of Vermont.

GMCG Groundwater Study 2019

In the summer of 2019, GMCG, in association with Smith College’s Center for Aqueous Biogeochemistry Research, undertook a study of drinking water resources in the Ossipee Watershed towns of Effingham, Freedom, Madison, Ossipee, Sandwich and Tamworth. The overall objective is to examine the impact of land use on both groundwater and surface water chemistry.

The Ossipee Aquifer is the largest stratified drift (unconsolidated sand and gravel) aquifer in New Hampshire and is particularly sensitive to contamination due to the highly porous nature of its soils. The aquifer also serves as the conduit that links groundwater to surface water so impacts to one can influence the other. Recent studies have shown high concentrations of salt and nutrients in some local area wells.

Understanding groundwater quality is essential as most residents, businesses and public facilities in the area rely on groundwater for their drinking water.

Participants across the region provided well water samples and additionally, 20 wells that were sampled in previous studies during 2009 and 2016 were re-sampled in order to track change over time.

Samples were analyzed for 18 parameters, including: arsenic, sodium, lead, iron, copper, nitrate, nitrite, chloride, pH, conductivity, calcium, potassium, magnesium, alkalinity, sulfate, silica, barium and fluoride. Nitrate, arsenic, copper, lead and pH are five of the 12 drinking water contaminants that NH Department of Environmental Services (NH DES) lists in their recommendations for standard analysis.

The 2009 study was done with the help of a New Hampshire Moose Plate Grant. The 2019 study was done with the help of The Tamworth Foundation. Businesses that were drop off and pick up locations included The Other Store in Tamworth and Farm to Table in West Ossipee. We also extend our gratitude to the volunteers of the Ossipee Aquifer Advisory Committee and Dr. Robert Newton and his students and staff at Smith College.