For a related presentation on "Air Quality and Sprawl" by DNREC's Air Quality Management Section, click here.
Delawareans concerned about residential development often think first about traffic. They also worry about water quality, since most of our watersheds already are impaired by pollution. They may express concern about loss of trees and habitat for wildlife, as well as drainage and flooding problems if stormwater is not managed effectively.
They probably aren't as aware of the impact on our air quality. For every residential Preliminary Land Use Service (PLUS) project reviewed by the state, DNREC models the potential emissions for a range of pollutants – including toxic substances, compounds that form smog and acid rain, carbon dioxide, and very fine dust particles called particulates that can lodge in the lungs.
All three Delaware counties fail to meet federal air quality standards for ozone, which creates respiratory and other health problems. New Castle County violates the federal standard for particulates.
Air emissions generated from housing developments include emissions from:
Area sources such as painting, lawn and garden equipment and the use of consumer products such as roof coating and roof primers;
The generation of electricity needed to support the homes in the development; and
Car and truck activity associated with the homes in the new development.
DNREC's calculation does not include additional emissions during construction from truck traffic, earth-moving and road paving. But most of the residential developments the state reviews generate enough emissions that they would require air permits if they were manufacturing plants or other business facilities.
If a development is the result of unplanned, inefficient development (sprawl) well outside designated growth zones, the impact is greater mostly because of the increase in vehicle miles getting to and from the development. In fact, the average Delawarean logs more vehicle miles traveled than in any state in the region; we are more comparable to a large, western state than a small, mid-Atlantic state.
For each of these residential development reviews, DNREC makes several suggestions for reducing the impact on air quality, including construction of Energy Star homes, providing renewable energy sources, retaining or planting trees, and providing bike and walking trails. In other states, local governments have provided incentives for or required new development to make some of these pollution-reducing improvements.