Development's impact on aquifers eyed
Wednesday, July 20, 2005 - Bangor Daily News
ORONO - As other regions struggle to find enough water to meet Americans' desire for washing their cars and watering their lawns, Maine has been blessed with the watery remains of glaciers that covered much of the state 10,000 years ago.
About 5 percent of Maine's land area is topped with mounds of sand and gravel deposited by the melting ice, which store and filter groundwater in aquifers.
Poland Spring's newest wells rely on aquifers, as do the municipal water supplies for towns from Augusta to Rumford to Fort Kent.
They're a critical natural resource.
"In the scale of a human lifetime, this is all we have," said John Peckenham, a water scientist at the University of Maine.
Unfortunately, they're also well-drained soils, prime for development. And aquifers have been mined for sand and gravel for centuries.
Peckenham has spent the past year looking into how communities can balance development and clean water, and questioning whether state environmental laws are up to the task.
"We were asking: Is there a relationship between gravel mining and water quality?" said Peckenham, a senior scientist at the Senator George J. Mitchell Center for Environmental and Watershed Research, who also serves as director of the Maine Water Resources Research Institute.
The Lamoine, Hancock and Ellsworth region, with more than 23 gravel pits comprising about a fifth of the 5-square-mile aquifer, and high housing values that spark rural development, was a perfect test site, he said.
"The area of Lamoine that's being hauled away every day is much more than in most Maine towns," Fred Stocking, chairman of the Lamoine Conservation Commission said Tuesday, just a few hours before Peckenham presented his findings to the community at a public forum.
The commission had approached the university in hopes that scientific data would help the local government plan for the town's future. After all, what's the point of developing a community if its residents won't be able to count in clean water, they asked.
"We've got this wonderful aquifer, and we've also got occasionally exploding development and gravel mining all up and down the aquifer," Stocking said.
Peckenham and a graduate student, Teresa Thornton, tested the water from nine springs, two ponds and 55 private household wells, as well as four test wells at the Cold Spring Water Co., a local bottler - all located within a quarter-mile of the aquifer.
The groundwater was far from polluted, but it did show subtle signs of strain, Peckenham said this week.
Levels of salt were rather high, perhaps indicating that road runoff was making its way through the aquifer. Nitrate levels, a frequent indication of development pressure, were slightly elevated.
And concentrations of dissolved organic carbon were also unusually high, which too suggests that aquifer isn't providing as good a filter as it used to. As dead plants and animals decay, this particular type of carbon leaches down through the ground.
In a very effective aquifer, the water beneath the sand and gravel filter is absolutely pure because bacteria have eaten away all the carbon before the rain reaches the water table.
"It's definitely telling us that some human contamination is getting into the groundwater," Peckenham said.
The researcher hopes to continue his study, perhaps comparing the Lamoine data with research in very polluted aquifers elsewhere, to understand the warning signs a town could heed before overdeveloping and losing its fresh water.
He also hopes to analyze samples from the monitoring wells that the state requires at each gravel pit, to better understand where problems could arise.
Likely, it's a matter of cumulative development - commercial and residential - rather than any one gravel pit, he said.
"We're not out to do any kind of finger-pointing," Peckenham said. "[The gravel pits are] all doing exactly what they're permitted to do by the state and towns."
For the Lamoine region, and for the 40 percent of Maine municipalities and thousands of private homeowners who rely on groundwater, it's all about preventing future pollution, he said.
"We're not in bad shape right now, but we do have things that we need to be concerned about," Peckenham said. "We have this unique natural resource. We need to decide how we're going to manage it in the future."