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Ideas for Filtering Runoff into Sebago Lake are Put Into Action

May 14, 2008 - STANDISH — The patch of freshly seeded lawn behind the Portland Water District's ecology center is actually one of the newest weapons in the effort to protect Maine's largest source of drinking water.

The new lawn will serve as a parking area, supported by a buried plastic framework that can hold up cars and trucks while allowing rainwater to soak into the ground so it doesn't run downhill and wash pollutants into Sebago Lake.

"You can drive on this and it won't become a muddy mess," said Lynne Richard, environmental education coordinator for the water district.

Storm water flowing off rooftops, driveways, roads and chemically fertilized lawns is a growing threat to Sebago and lakes around the state, many of which now bloom with green algae because of the infusion of nutrients.

It's a problem that can spoil water quality and ruin the experience for swimmers, anglers and lakefront residents. It also could eventually cost water district customers throughout the Portland region more than $50 million in additional filtration equipment.

"For a long time, factories and municipal treatment plants were the largest polluters to surface waters, but we're finding that now the biggest pollution is our own backyards," said Barbara Welch, a biologist and lakes education coordinator for the Maine Department of Environmental Protection.

As the threat and the awareness grow, so do efforts to keep polluted storm water out of Maine lakes.

A new state law requires retailers to notify customers that fertilizer containing phosphorous -- the primary threat to lakes --should not be spread on lawns without first having the soil tested to find out if it is needed. The vast majority of Maine lawns have plenty of phosphorous in the soil already, so any more will just wash off in a heavy rain, according to soil scientists.

The Maine Board of Pesticides Control and other agencies are working on a demonstration project next to Back Cove in Portland and hope to plant a variety of earth-friendly gardens this summer. The idea of yardscaping -- moving away from large, chemically fertilized lawns -- is catching on, said Gary Fish, environmental specialist for the board.

"In the last year, things have really changed. Interest has really grown," he said. "It has been, in my mind, a drastic reversal."

The grass parking area at the Portland Water District's Sebago Lake Ecology Center is part of a new demonstration project that officially opens with a public tour this morning. Called the "Pervious Pathway," the project displays more than 12 steps that property owners can take to make sure they don't contribute to the runoff problem.

The grass pavers are one of the newest technologies and essentially reinforce a part of the lawn so cars and trucks won't make muddy ruts or crush the lawn's roots. More traditional strategies include rain barrels to collect water from roof drains, gardens that capture and absorb storm water and landscape steps made out of wood and crushed stone.

"That really keeps the water from shooting right down into the lake," Richard said. "We want to encourage people to keep their rainwater to themselves."

Erosion from lake-front properties is an obvious concern, but dirty storm water also can reach the lake from miles away. Runoff that starts as far west as Bethel will eventually find its way into Sebago Lake, and potentially into the drinking water that comes out of a tap in Scarborough, Richard said.

The demonstration project will supplement the district's education programs, which include free property inspections and advice about reducing runoff and grants to help pay for improvements, Richard said. "There's nothing like being able to show a person."

Those efforts, and the fact that Sebago water remains relatively clean and algae-free, has so far allowed the water district to avoid adding special filtration equipment that's required in most reservoirs and could cost $50 million, Richard said. "It's a huge deal for our ratepayers."

The risk of storm water pollution accumulating in the lake is mounting as development pressure brings more rooftops, roads and lawns to southern and western Maine. But Sebago has so far avoided problems with phosphorous that have turned other lakes green.

"I think it's within each of our control to keep it that way," Richard said.

STOPPING THE FLOW
Here are some tips for preventing pollution from running off lawns.

Reduce lawn area and plant native shrubs and trees. The deeper roots absorb more water, plus there will be less mowing.

Avoid lawn fertilizer with phosphorous unless a soil test indicates it's needed. (The second of the three numbers on fertilizer labels refers to phosphorous. The first number stands for nitrogen and the third for potash.)

Test soil using kits available at garden stores, the University of Maine Cooperative Extension Offices, Soil and Water Conservation Districts or by calling the state soil lab at 581-3591.

Leave grass clippings to feed lawns. Lawns older than 10 years need no additional fertilizer. Younger lawns need nitrogen.

Use a rain barrel to collect water from roof downspouts. The Portland Water District is offering barrels for $65 by calling 774-5961. Orders are due by May 15.

Sources: Maine Department of Environmental Protection, Portland Water District and www.yardscaping.org.

By Staff Writer John Richardson, Portland Press Herald, May 8, 2008

Lakes: Sebago Lake
Regions: Sebago


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