SESSION A:

Topic: Determining Sustainable Yields for Public Supply and Bottled Water in Fryeburg, Maine

Author: Peter Garrett, PhD, Emery & Garrett Groundwater, Inc., Waterville, Maine

Fryeburg, Maine is being challenged to appropriately regulate bottled water withdrawals from its major aquifer while also protecting the resource for use by the Water Company, whose charter is to provide water to the municipal system indefinitely. Many citizens are concerned that an insatiable bottled water industry will “pump the aquifer dry”. Others are concerned that wetlands, ponds and streams will also go dry.

In order to determine sustainability, a groundwater flow model was constructed using geological logs on 60 borings, water level monitoring data on 50 wells, 12 staff gauges or stream weirs, and a long term dataset extending over a period of up to 3 years. Verification of the model was achieved by input of groundwater recharge by modifying actual monthly precipitation by calculated monthly evapotranspiration and runoff estimates, then comparing simulated against observed water levels in the aquifer and flow in the brook.

Sustainability of a resource for the bottled water industry is built into the definition of “spring water”, which requires that a pumping well must both show hydraulic impact on a nearby spring, and must also not eliminate flow from that spring. Such a founding concept will ensure that the aquifer cannot be pumped dry.

The concept of the water budget is particularly useful for public demonstration that “expenses” (= pumping from the aquifer) cannot exceed “income” (= groundwater recharge to the aquifer = precipitation minus evapotranspiration and runoff). Under such a water budget, one can define subcategories of expenses including:

• Fixed expenses (like mortgage payments) for a) the Town’s water needs, and b) minimum flow maintenance in the brook, and
• Discretionary expenses (like vacations or restaurant eating) for a) bottled water withdrawals, and b) additional flow in the brook.

These concepts are useful in demonstrating the concept of sustainability of groundwater resources to the public.

Peter Garrett is Vice President of Emery & Garrett Groundwater, Inc., which consults on groundwater issues from Maine to Georgia. Peter has a PhD in earth sciences from Johns Hopkins and has been practicing in Maine for 26 years, dealing with such issues as contaminant remediation, water supply exploration and development, and protection of groundwater resources. His recent focus has been on assessing sustainability such that all water users can depend on the supply indefinitely. Peter makes a special point in presenting complex technical concepts in easy to understand language and presentation.