By Willem Brutsaert, Ph.D.
The plan of an out-of-town sand-and-gravel operator, Harold MacQuinn Inc., is to remove the last remaining hill in Lamoine, located adjacent to the largest concentration of homes in Lamoine, near “Lamoine Corner,” an area generally referred to as the center of town. The incipient disaster is remarkably visible by anyone traveling to Acadia National Park along Route 3 in Trenton near the intersection of Jordan River Road and looking left (east) to the already scarred hilly horizon.
This last hill, locally referred to as Cousins’ Hill, was once part of an extensive ridge of hills, running more or less NNW-SSE, and parallel with Route 184, geologically referred to as an esker, which contains Lamoine’s sand and gravel aquifer. Unfortunately, this ridge of hills is now largely destroyed by a series of gravel pits that have already negatively affected the aquifer, severely decreasing its water storage capacity and increasing its vulnerability to pollution.
A permit application originally submitted in 2012 to remove the hill from its current elevation of over 250 feet down to about 30 to 40 feet of elevation, or about 60 to 70 feet below the adjacent road level, was denied by the Planning Board in 2014, resubmitted in February 2017, and denied again in December 2017. This decision was overturned by the Board of Appeals in June of 2018, despite a majority opposition of Lamoine residents. The Planning Board had no choice but to issue the permit to proceed. Friends of Lamoine, a group of concerned citizens with legal standing in this case, appealed the decision of the Planning Board. It is now up to a court of law to adjudicate this case, and that may happen soon.
Removal of the hill is a major disturbance of the landscape and will have serious hydrologic consequences. What is certain is that the removal will create a large pit that over a period of time will cause a profound lowering of the regional aquifer water table, creating a steep new water table gradient (slope) toward the pit pulling in water from every direction. During the operation of the project it will be necessary to get rid of the water flowing into it, gradually draining all springs that are now flowing out of the toe of the hill. The impact on one spring in particular, called “Cold Spring” flowing out of the southeast toe of the hill, is of major concern.
Cold Spring is managed by a publicly owned water company, established in the late 1800s, that provides water to more than 50 homes, to the Lamoine School, the Fire Department, the church, the Grange and an organic farmer. Cold Spring has always been reliable, flowing fairly steadily year-round, unaffected by weather conditions such as prolonged periods of drought or long periods of harsh winter conditions when frozen soils and snow cover prevent infiltration of precipitation. The only explanation for Cold Spring’s uninterrupted steady flow is that it ties in with the regional groundwater system of the hill. MacQuinn’s hydrogeologists, on the other hand, maintain that the spring is fed by locally “perched” water. This implies a shallow water table which would be vulnerable to the above described weather conditions and would cause intermittent water availability, causing Cold Spring to occasionally run dry. Water levels in observation wells just uphill from Cold Spring do indeed show water levels occasionally lower than the static water level of Cold Spring (elevation 137 feet). This means that occasionally there is no flow of perched water to Cold Spring. And yet the spring keeps flowing — thanks to its connection with the regional groundwater system. However, as the gravel pit gets deeper and deeper, all water will gradually start to drain toward it. This creates a strong likelihood that even the perched system will drain toward it despite its underlying layer of silt and clay. In heterogeneous deposits such as this hill, nothing is impervious. Unfortunately much of the analysis of MacQuinn’s hydrogeologists is based on extrapolation of a limited amount of data. Furthermore they disregard the existence of a groundwater divide just uphill from Cold Spring that effectively prevents much perched water from flowing to Cold Spring. A groundwater divide, sometimes called a hydraulic barrier, is a ridge in the water table that prevents water from crossing it.
A concluding statement by the Board of Appeals was, “There is one in a million chance that Cold Spring will ever run dry, ”( i.e. if the hill were to be removed). This supposition is absurd and misleading, reflecting ignorance of the concepts of regional groundwater flow. No one must be given a permit that would risk causing Cold Spring to stop flowing. The Board of Appeals’ decision to require the Planning Board issue a permit for removal of the rest of Cousins’ Hill poses a serious threat not only to Cold Spring but also to the town’s ground water. The town cannot afford to play a game of chance with its most vital resource. I and many residents hope the court will find the Board of Appeals has erred in its interpretation of the ordinances and of their authority.
Willem Brutsaert is an emeritus professor of civil and environmental engineering at the University of Maine. He has professional experience in North Africa, Germany, Belgium, Colorado, New Mexico and in Maine. While at UMaine he taught courses in fluid mechanics, surface water and groundwater hydrology, open channel hydraulics and groundwater systems modeling. He is a resident of Lamoine.