Restoring the Hudson from your own backyard

Sustainable Riverdale

By Mary Bandziukas
info@riverdalenature.org

When Congress passed the Clean Water Act in 1972, many of America’s rivers were so polluted that they had turned colors from the different wastes poured into them. Some occasionally caught fire. That kind of heavy pollution, caused by industrial effluents and inefficient sewage treatment plants, is now almost a thing of the past.

Yet today, the Hudson River still does not meet federal and state clean water goals.

According to the Environmental Protection Agency, the major source of water pollution here and throughout the United States today is surface water runoff.

Surface water runoff occurs when rainwater, usually called storm water, flows across the landscape instead of filtering into the soil. Pavement, bedrock and compacted soils all cause runoff.

Most of Riverdale uses sewers that transport both sanitary waste — the waste that is produced in homes and other buildings — and storm water in the same pipes. When the weather is dry, sanitary waste moves to a sewage treatment plant, which is in Riverdale’s case the Ward’s Island plant. When it rains, storm water enters these pipes through drains in the streets, and combines with the wastewater.

If there is too much storm water, the combined system is equipped with release valves that send the overflow directly to the Hudson and Harlem rivers, without being treated. These overflow events are called Combined Sewer Overflows, or CSOs. Depending on how much rain fell previously and the quality and depth of local soils, even rainfalls as small as one-tenth of an inch can result in a CSO.

In parts of Riverdale, storm water does not enter the sanitary system. In those cases, rainwater often flows along streets and across yards, eventually finding its way to the river.

So what contaminants does storm water carry?

• Sediment from steep slopes and bare parts of gardens, which becomes a pollutant when it disrupts normal water flow or buries marine habitats;
• Paper, plastic bags, bottles, cigarette butts and other “floatables” that entangle or are eaten by marine life;
• Pet waste, which contains pathogens and excess nutrients;
• Auto fluids, pesticides from lawns and gardens, and cleaning products that are used to wash cars and other outdoor items, which all contain toxins;
• And fertilizers, which add an excess of nutrients to bodies of water, causing algae to grow uncontrolled, and eventually leading to low oxygen levels in the water.

New York City is tackling this next frontier of water quality in several ways. These include reducing the number of CSO events by collecting storm water runoff and releasing it gradually to wastewater treatment plants after storms are over, and reducing runoff by providing more ways for it to infiltrate into local soils.

Over the next few years, new building codes, zoning regulations and street designs will attempt to reduce pollution from surface water runoff in New York City. You can get a preview of the pilot projects that are now underway by reading the mayor’s Sustainable Stormwater Management Plan at: www.nyc.gov/html/ planyc2030/html/stormwater/ stormwater.shtml.

Mary Bandziukas, a Queens resident, has worked for more than 15 years as an urban planner and environmental program manager. She has been a consultant with the Riverdale Nature Preservancy for the past decade.

Sustainable Riverdale appears in the third issue of the month. It is the work of the Riverdale Nature Preservancy, done in conjunction with The Riverdale Press and the Natural Resources Defense Council. Have an issue you’d like to see addressed? E-mail newsroom@ riverdalepress.com, and put Sustainable Riverdale in the subject line, or write to The Riverdale Press, 6155 Broadway, Bronx, NY 10471.

This is part of the January 15, 2009 online edition of The Riverdale Press.

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