Blog

With Spring Comes Sprawl’s Toxic Runoff

By ERIC HAMMERLING

May 14 2006

The pejorative term “sprawl” conjures up an image of cookie-cutter subdivisions marching inexorably over gentle hills that were once farms or forests. Many of us bemoan the changes that sprawl has wrought on our neighborhoods and towns – more paved areas, more traffic, more look-alike strip malls.

We rarely speak of what may be the most harmful aspect of sprawl, and that is how it affects our water supply.

What is happening isn’t hard to explain. Sprawling development is accompanied by an explosion of paved areas, which scientists call “impervious surfaces.” When rain falls or snow melts, the water runs off these impervious surfaces into storm drains and is conveyed directly into the nearest river, stream or lake.

Storm water, as this runoff is known, carries along whatever is in its path. That too often includes pet wastes; road sand and salt; oil, gas, heavy metals and other car-related pollutants; pesticides and fertilizers; and sediment from poorly controlled construction sites. These pollutants, especially when combined with low water and warm temperatures, can spell serious trouble for the river or lake and the fish and the wildlife who depend upon it.

Because of this, storm water is the largest unregulated threat to the quality of our rivers and streams, by consensus of the U.S. Environmental Protection Agency, the state Department of Environmental Protection, and local water quality advocates such as the Farmington River Watershed Association and Rivers Alliance of Connecticut. Nationally, 40 percent of our rivers, streams and lakes are not meeting requirements for swimming, fishing or drinking because of storm water pollution.

Because of storm water pollution and other problems, the Connecticut Council on Environmental Quality has called sprawl the most serious environmental threat facing the state.

The amount of impervious surface in an area is linked to the ecological health of the surrounding watershed, according to the DEP’s Stormwater Quality Manual. Research has shown that when impervious cover in a watershed reaches between 10 and 25 percent, ecological stress becomes apparent. Beyond 25 percent, stream stability is reduced, habitat is lost, water quality becomes degraded and biological diversity decreases. It is unknown whether the health of rivers in areas that surpass 25 percent imperviousness can ever be restored.

Impervious surfaces also affect water resources in other ways.

More impervious surfaces mean that less water can sink into the ground to recharge groundwater aquifers. Groundwater aquifers are the primary source of drinking water for approximately a third of Connecticut’s residents and provide base flow to local rivers and streams during dry times of the year. Also, when it rains or snow melts in an impervious area, there is more runoff, which moves faster and increases the incidence of local flash flooding.

Rivers, streams, lakes and estuaries are being affected by storm water resulting from sprawl. If we don’t halt this pernicious trend, we risk compromising our drinking and recreational water resources.

If that isn’t a serious threat, I’m not sure I know what is. Correcting the problem will take both global and local action.

Sprawl continues, despite what seems to be near-universal opposition to it, for a number of reasons: Heavy reliance by towns on property taxes, underperforming big-city schools, government subsidies for road-building, outdated local zoning and the simple resistance to change in our “Land of Steady Habits.” It’s imperative that citizen action be focused on these problems, and in many towns it is.

There are also ways to reduce the effects of storm water in your yard or neighborhood. Just picking one or two of the following recommendations by the EPA’s Office on Wetlands, Oceans, and Watersheds could make a difference in your community:

Keep litter, pet wastes, leaves and debris out of street gutters and storm drains – these outlets drain directly to lakes, streams, rivers and wetlands.

Apply lawn and garden chemicals sparingly and according to directions.

Dispose of used oil, antifreeze, paints and other household chemicals properly, not in storm sewers or drains. If your community does not already have a program for collecting household hazardous wastes, ask your local government to establish one.

Clean up spilled brake fluid, oil, grease and antifreeze. Do not hose them into the street where they can eventually reach local streams and lakes.

Control soil erosion on your property by planting ground cover and stabilizing erosion-prone areas.

Encourage local government officials to develop construction erosion/sediment control ordinances in your community.

Have your septic system inspected and pumped every three to five years so that it operates properly.

Purchase household detergents and cleaners that are low in phosphorous to reduce the amount of nutrients discharged into lakes, streams and coastal waters.

With a grant from the Hartford Foundation for Public Giving, the Farmington River Watershed Association will work with University of Connecticut scientists and officials from 11 towns in the Farmington Valley to reduce the problems associated with storm water. The first workshop is from 7 to 9 p.m. May 23 at the Farmington Public Library.

Eric Hammerling is executive director of the Farmington River Watershed Association. His office is in Simsbury.

Copyright 2006, Hartford Courant