Lake protection rules need tightening, Lowell says

By Gail Geraghty

Staff Writer

The days are long past when a simple lake clarity test using a secci disk would suffice in determining the health of a lake, Lakes Environmental Association Executive Director Peter Lowell told the Bridgton Planning Board Tuesday.

Besides, lake clarity isn’t in and of itself an indicator of better water quality. Before one can really draw any conclusions, many other factors have to be tested as well, such as phosphorus, oxygen, algae, temperature, aluminum and something called gleotricia, which looks a little like cream of wheat, he said.

Now that the new Maine Lake Science Center is up and running, LEA has benefitted greatly from its collaboration with the several university scientists and researchers who set up residence this summer to study lake quality.

“This whole thing is a puzzle,” Lowell said. When it comes to the many potential lake threats, “What we’re really seeing here is death by a thousand cuts.”

Lowell said for much of its 40-year history, LEA has used Highland Lake in Bridgton as its “guinea pig,” in part because it’s local and quite accessible. The lake, with an average depth of 20 feet, is one of the most fragile of the 40 lakes LEA monitors, and their latest studies, from a monitoring buoy and other testing equipment, have been quite troubling, he said.

“Highland Lake looks really good until you get down in the thermocline,” which is a midway point of depth where warmer surface water mixes with cooler water below, said Lowell. While its clarity is holding steady, the oxygen levels at the bottom are basically at zero during certain times of the year, he said.

With the scientists’ help, LEA was able to track how often the zero levels occurred over time, and found a 20-fold decrease in oxygen levels in Highland Lake since 1977.

“A lot of lakes around here are basically anorexic, and are close to a tipping point,” said Lowell. Beside zero oxygen levels, “There’s all kinds of indications here of potential problems. We’re trying to figure out what rings that bell — not just Highland Lake, but Moose Pond, Woods Pond and others.”

Lowell’s tutorial on lake testing was a preamble to his main message to the board: it’s time to consider ratcheting up Shoreland Zoning and other land use standards.

“In the 1970s, they treated all lakes the same,” said Lowell. What LEA now knows is that lakes need to be treated individually, and land use standards need to reflect that, he said. “We need to protect the sensitive lakes more strongly.”

Lowell said he approves of the Department of Environmental Protection’s policy of allowing developers to “buy” phosphorus counts for a project by mitigation efforts at another location within the same watershed. Such a policy was used when McDonald’s restaurant was built on Portland Road, Planning Board Chairman Steve Collins noted.

Lowell said he hopes the board will “institutionalize your third party review” by requiring an independent engineer or surveyor to monitor plans and implementation of buffer zones and other environmental protections put forward by developers. Over the past 10 years, LEA found that up to 40% of subdivision projects built were deficient in keeping their promises on phosphorus control standards, Lowell said. “that was a pretty shocking discovery.”

Independent engineers may also need to be hired by the developer to determine how much impervious surface area will be affected by a project, said Lowell, since local code enforcement officers don’t have the time to double-check the estimated amount. More formal erosion control plans are also needed, he added.

The Planning Board also needs to realize the impact of climate change, Lowell said. “The fact is that a 50- year storm event is actually occurring every 12 years” because of the warming effects of climate change, he said. “This blows out all your culverts, ditches, retention ponds. It’s going to potentially wreak havoc. We really need to keep an eye on that ball.”

Lowell also emphasized the need for the board to require a full infiltration review for certain projects, especially those close to water bodies. He told of a recent cottage expansion on Highland Lake where the owner took to heart his suggestion of building a French drain system around the cottage. “He’s intercepting all the runoff, and it’s that kind of thing that will really make a difference.”

LEA receives stormwater conservation funds from the state that it uses to provide extra protections for some developments, like the new parking lot built behind the Bridgton Library. There, a “rain garden” was built using carefully-layered soil and gravel, as an alternative to releasing all that runoff into the sewer system.

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