A. Groundwater Management and Sustainability

Response of Groundwater/Surface Water Systems to Pumping and other Stresses
Charles R. Fitts, University of Southern Maine
Presentation available (pdf format)
 Abstract: Groundwater and surface water systems are linked and dynamic. Heads, stages, velocities, and discharges all vary through time as natural and human-induced transients have their impacts. Using example mathematical models and case studies, we will explore how a variety of these systems respond to common stresses such as pumping, leaching fields, drought, and storms, and why different settings respond in different ways and at different rates. We will examine confined, unconfined, and coastal aquifers, and impacts including drawdown, subsidence, and salt water intrusion.

Water Availability Analysis in Watersheds of Concern in Maine
Martha G.  Nielsen, Daniel B. Locke, Maine Geological Survey
Presentation available (pdf format)
Abstract: The Maine Geological Survey and U.S. Geological Survey have been collaborating since 2009 on a series of projects to better understand water availability in small Maine watersheds that have been identified by the State as being “of concern”, because of large water demand (both natural and anthropogenic) in relation to their size. The study designs include conducting an in-depth analysis of water withdrawals in the studied watersheds, streamflow monitoring, and developing a watershed-wide groundwater flow model for each project. To date, one study has been completed–in two small watersheds in Freeport–and another is underway in the Branch Brook watershed in Kennebunk, Sanford, and Wells. The Freeport study found that site-specific geologic data and streamflow measurements were critical inputs for groundwater flow modeling to develop a realistic and quantifiable analysis of streamflow depletion. Recharge areas and discharge zones for the confined aquifer used for municipal supply also were identified. The model can evaluate interactions between the aquifer, streams, and pumping wells for current conditions and potential future drought and increased withdrawal scenarios. The second study, currently in progress, will assess the impact of all local groundwater withdrawals on streamflow in Branch Brook and the nearby Merriland River. Lessons learned during the Freeport study are being used to improve data collection and groundwater model development for the Branch Brook study.

Using Groundwater Storage to Provide a Sustainable Irrigation Supply
Robert G. Gerber, P.E. & C.G., Ransom Consulting, Inc.
Presentation available (pdf format)
Abstract: This presentation explores the concept of using wells to capture groundwater at some distance from a stream and rely to a large extent on groundwater storage to produce irrigation water during the dry summer months. Many large-scale irrigation operations in Maine were historically supplied by direct withdrawal from great ponds and streams.  The DEP’s In-Stream Flow Rule has forced growers to look for other ways of supplying needed summer water. For those operations on or near to extensive and thick sand and gravel aquifers, the aquifer itself provides a large amount of natural storage. This paper will show how one large irrigation requirement on the order of 3000 gallons per minute for a 6-week summer period has been modeled and managed.  The groundwater withdrawal causes increasing streamflow reduction with time as the well begins to capture increasing portions of groundwater flow on its way to discharging to the stream.  However a pumping history spanning over ten years shows that repeated seasonal withdrawals at large sustained rates have not affected the spring and early summer groundwater levels in the aquifer nor the summer baseflow in the stream.  The effects on the water levels in nearby wetlands have also been studied and show a small and brief impact during the time of pumping.  The groundwater use at this site has been done in a sustainable manner and shows how proper planning, modeling, and monitoring can be used to provide an irrigation source that has very small impact on streamflows without the construction of large expensive holding ponds.

Dissolved Fe/Mn in Sand and Gravel Aquifers: Old Town’s Story and the Big Picture
Peter Garrett, Emery & Garrett Groundwater
Presentation not available
Abstract: In 1960 Old Town Water District switched their source of supply from the Stillwater River to wells installed in a riverside aquifer. At first water quality was excellent.  Within a few years, however, treatment was required to remove high concentrations of iron and manganese.  Detailed hydrogeological investigation of the aquifer showed that the wells induced flow from the river to provide 90% of withdrawals. River water, however, had low concentrations of iron and manganese.

The Stillwater was used in the 1800s for the lumber trade. Logs floated downstream to mills located on the waterfalls.  Waste wood was dumped into the river where it remains in a layer 4-12 feet thick overlying the aquifer through which river recharge flows to the wells.  Geochemical investigations showed that river water passing through the wood waste becomes anoxic, which dissolves iron oxide coatings on aquifer sand grains.

Iron and manganese are common geochemical components of groundwater withdrawn from sand and gravel aquifers throughout New England.  Many are likely to derive their high Fe/Mn concentrations via recharge through organic deposits, be they wood waste, wetland peat, leaf deposits on the bottom of lakes or abandoned meanders.  Engineering remedies using hydrogeological principles may be available in particular situations.

Identifying and Addressing Subsurface Hydrologic Connections in Association with Large Scale Linear Projects
Dale F. Knapp, Stantec Consulting
Presentation available (pdf format)
Abstract: This presentation will review the methods developed to identify near-surface groundwater flows in sloping landscapes to determine their location and flow direction. Anthropogenic disturbances of these areas can alter water quality and natural groundwater hydrology. These resources are often not jurisdictional under State or Federal regulations through the Natural Resources Protection Act or the Clean Water Act; however, identifying and properly managing these resources can better protect down-gradient wetlands and waterbodies. As responsible scientists and environmental managers, we should identify these features so that appropriate site design can be completed by project engineers and regulatory agencies are able to make informed decisions. Many techniques can be incorporated into the project design to maintain groundwater flows below the soil surface. This presentation will include specific field examples, representative photos, and interactive discussion to demonstrate the management of these issues.

Time for Reform of Maine’s Groundwater Law?
John  D. Echeverria, Vermont Law School
Presentation available (pdf format)
Abstract: The purpose of this talk is to examine whether Maine should consider reforming its traditional groundwater legal doctrine, and the talk will conclude that, while there are significant outstanding questions about this issue that deserve better answers than are now available, there are substantial reasons to believe that Maine’s groundwater law is ripe for reform.  Maine, along with a very small handful of other states, including Texas, still subscribes to the so-called rule of capture, or absolute dominion, to define private rights to the use of water.   Under this doctrine, a landowner may withdraw unlimited quantities of groundwater from beneath his or her property without regard to any potential adverse effects on the ability of other landowners (including individuals, private firms, and government entities) to access and make use of the groundwater beneath their lands.  While the rule of capture was once the dominant legal doctrine governing rights in groundwater across the United States, almost every other state has abandoned this doctrine in favor of some form of reasonable use principles which limit each landowner’s right to exploit groundwater to the extent its exercise harms other landowners’ rights to use groundwater.  In 1999, in the case of Maddocks v. Giles, the Maine Supreme Court declined to accept the argument that it should exercise its authority to modify Maine’s rule of capture.  One of the primary reasons the Court cited for its decision was that the parties in that case had not presented sufficient “evidence” that “the absolute dominion rule has not functioned well in Maine.”   An interesting question for the future is whether the state of knowledge about the operation of the rule of capture in Maine has evolved to the point that the issue of reforming Maine’s groundwater law has now become ripe for consideration.   If such evidence is not now presently available, is the reason that groundwater exploitation in Maine is currently imposing no material harm on other property owners or is further research required to identify and document harms that actually are occurring?  In addition, in light of evolving economic conditions and the likelihood of climate change and potential consequent declines in water supplies in Maine, New England, the rest of the country, and/or indeed the world, do the prospects for increased competition over groundwater resources in Maine over the next century help make the legal case for groundwater law reform in Maine?   All of these questions will be examined both in the context of Maine’s groundwater legal regime and the current state and direction of groundwater law across the country.

Water Use, Water Trends, and Water Policy in Maine
Robert G. Marvinney, Maine Geological Survey
Presentation available (pdf format)
Abstract: The characteristics of Maine’s water resources and the impacts of water use have been widely debated in policy and scientific arenas for the past several decades.  Early discussions of appropriate policies often ran up against a lack of information on available water resources and cumulative uses.  To address this, the Legislature first directed the Maine Geological Survey to map significant sand and gravel aquifers systematically across the state, a task completed in the late 1990s.  Mapped aquifers are protected from activities that may compromise their quality and are the water source for more than 70 community water systems, numerous agricultural irrigators and several water bottlers.   Through discussions in the early 2000s, further protections were added to the State’s water resources.  First, users of large volumes of surface water or groundwater were required to report their use, allowing state agencies to compile reasonable estimates of water use on a watershed basis.  Second, large-scale non-agricultural wells were subjected to rigorous permitting requirements aimed at limiting production to sustainable levels that minimize impacts on neighboring uses.

Through the Water Resources Planning Committee, established by the Legislature in 2007, the Maine Geological Survey first completed a statewide analysis of water supply and demand on a watershed basis, using information from the water use reporting program, and decades of stream flow and groundwater level monitoring by the U.S. Geological Survey.  This analysis identified several watersheds with high cumulative water use that have been the subject of more detailed investigations.  The intent of this effort is to identify potential conflicts before they become critical and work with stakeholders to resolve the issues.

As part of the effort, we have worked with stakeholders to support the USGS’s groundwater level monitoring network and to augment it with long-term groundwater information from other sources.  Review of these long-term records suggests that over the past several decades, groundwater levels have been increasing in almost all areas of the state.