The Conservation Conversation: Cleaning Up the Mess We've Made, Part III

In my previous post, I explained how coal was used during the 19th century not only to heat houses and run machinery, but also to make gas used for lighting.

Coal tar, the waste residue from that process, became the basis of a burgeoning chemical industry that was later supplanted by oil in what we know as the petro-chemical industry. This industry has left its own legacy of pollution and toxic wastes to rival that of its coal-based predecessor. 

There are thousands of spills each year from the extraction and transport of oil. Only the worst make the headlines, such as the BP disaster in the Gulf of Mexico or the Exxon Valdez spill in the Gulf of Alaska.

Of course, burning oil for energy causes air pollution, but that's a different sort of mess than the kind I've been talking about in this series. Moreover, we make a vast amount of stuff from oil, both important and trivial, and the industries that make that stuff also leave behind a witches' brew of wastes. 

We can start with the plastics industry, which traces its roots to 1868 with the invention of celluloid by the American printer John Wesley Hyatt. Three decades later Dr. Lee Baekeland introduced phenolics, a more versatile class of plastics, made from coal tar or petroleum, which could be liquefied and formed into myriad shapes. The familiar trade name of his invention was Bakelite.

Today, more than 100 billion pounds of a dizzying array of different types of plastic are produced each year in North America alone, primarily from petroleum. Not only do the manufacturing processes that make these plastics generate plenty of waste, but most of the items they produce also end up as waste. When the Udalls Cove Preservation Committee conducts its annual cleanup along the shoreline of Douglaston and Little Neck, the vast majority of garbage we collect is comprised of soda and water bottles and plastic bags. Take a boat ride around the Douglaston peninsula and look closely at the shore - you'll see plastic everywhere.

Chemistry has also come to agriculture and in a big way. Since the dawn of agriculture, humans have fertilized their farms. For most of the past 10,000 years this was done through application of animal wastes – urea and manure. In the early 1800s, we learned how to extract a new class of phosphate fertilizers from certain rocks, which had to be mined and processed leaving behind huge and dangerous waste piles.

A century later German chemist Fritz Haber discovered a way to extract ammonia from atmospheric nitrogen for subsequent transformation into synthetic fertilizers. This chemical process, which revolutionized agriculture and a number of other industries as well, made possible an enormous increase in agricultural productivity which, in turn, made possible the enormous increase in human population over the past 100 years. The process also generates environmentally dangerous wastes that must be disposed of. 

Excessive use of synthetic fertilizers also poses serious environmental threats. Excess fertilizer runs off from our farms and our suburban lawns and ends up in our lakes, bays and larger water bodies, such as the Long Island Sound. In the water, fertilizer does the same as on land-- it makes plants grow. Algae responds quickly to an influx of fertilizer, causing an algal bloom. The scummy stuff you'll see in the summer on Aurora Pond - in the heart of Udalls Cove Park - is algae responding to excess fertilizer.

As the algae die, they float down through the water column where, like all other dead organic material, they decay. Decay requires oxygen. The water has oxygen dissolved in it - that's what the fish and other aquatic animals use to live. In the summer, there is less oxygen anyhow because warm water holds less oxygen than cold water. Think of the carbonated fizz of a cold soda compared to a warm one. But large amounts of decaying algae use up all the available oxygen, causing a "dead zone" where animals become stressed or die.  

Serious oxygen depletion afflicts Aurora Pond several times every summer. It also affects the western part of Long Island Sound, including Little Neck Bay. And over-use of fertilizer in our suburban gardens is a significant part of the problem. But it isn't the major cause - that honor belongs to nitrogen from human bodily wastes.

Until the 1990s, nitrogen wasn't really considered a pollutant because its role as a fertilizer for algae and algae's role in aquatic oxygen depletion weren't well understood. Only in the past decade have we started to re-tool our sewage treatment plants to remove nitrogen so it doesn't reach the Long Island Sound.  Required by federal and state clean water laws, this multi-billion dollar effort is currently taking place in both New York and Connecticut. 

The Belgrave Sewage Treament Plant, which serves much of Great Neck, discharges directly into Udalls Cove. The discharge pipe passes across the salt marsh between Douglaston and Great Neck, then enters the concrete block house decorated with a large sunflower painting that is visible from Memorial Field and continues for several hundred yards along the bottom of the cove. The Belgrave plant installed expensive nitrogen controls a few years ago as scores of other sewage treatment plants around Long Island Sound have also been doing.

Next time I'll write more about coping with our chemical legacy, from pesticides to dry cleaners.