It was midevening in January 2010 when a light snow turned to rain over Manhattan at just the moment when people began to wash their dinner dishes, do laundry, take showers, and flush toilets in earnest. Within minutes, thousands of gallons of storm-water was rushing off the city’s non-absorbent sidewalks, parking lots, and buildings and cascading into the sewer system. Sweeping along whatever was in its path—salty grit, candy wrappers, paint, antifreeze, leaves, abandoned toys, styrofoam cups, drug paraphernalia—the storm water dropped into a matrix of 550 pipes running beneath the streets, where it mixed with untreated feces and industrial wastes and swooshed south with gathering momentum.
As the slurry of waste rose and rose, its flow accelerated from a gentle 2.5 feet per second to a raging 9.5 feet per second, scouring sediment out of the pipes and straining the venerable system. It moved from small waste pipes eight inches in diameter, into progressively larger pipes, and then into a main seventeen feet in diameter, which channeled the water downtown to a large pumping station on East Thirteenth Street at Avenue D. There, giant pumps whirred and the sewage and storm-water mix was sent beneath the East River to Brooklyn, where it was captured by the city’s newest and biggest sewage treatment plant, the Newtown Creek Waste-water Treatment Plant (NCWWTP).
This is no ordinary sewage plant. A futuristic collection of sleek gray buildings, green towers, and giant silver egg-shaped digester tanks, the NCWWTP rises incongruously from the brown-gray industrial tangle along the same waterway poisoned by the black mayonnaise of industrial pollutants. The Newtown Creek plant is a dramatic sight. Designed by the Polshek Partnership, the white-shoe architectural firm responsible for the Clinton Library and other notable buildings, it is often wreathed in steam and occasionally erupts as methane gas is flared off. At night, the treatment plant and its giant silver “eggs” are bathed in a fantastical blue glow, from a lighting scheme designed by Hervé Descottes of L’Observatoire International, in Paris. One Greenpoint resident aptly described the plant as looking like a gleaming hunk of twenty-first-century space station that crash-landed onto Brooklyn’s nineteenth-century waterfront.
The Newtown Creek plant services a large J-shaped drainage area that starts below Seventy-Fourth Street on Manhattan’s Upper East Side, flows south through Chinatown, past Wall Street, and bends east under the river to encompass North Brooklyn. The drainage includes 1.33 million people spread over twenty-five square miles. Because it collects water from such a wide area, a mere one-eighth of an inch of rain translates into 63 million gallons of excess water flowing into the system, while an inch of precipitation results in 504 million extra gallons of storm water.
“That’s a lot of water,” said Jim Pynn, the plant’s lean and garrulous superintendent. “A slow, steady rain is easier for the system to absorb than an intense storm. It only needs to be rainin’ hard for twenty or thirty minutes before we have to use the throttles”—meaning the system has reached capacity.
New York’s “combined” sewer system—considered state-of-the-art when it was built in the mid-nineteenth century—collects both runoff and sewage in one set of pipes. (There were no wastewater treatment plants at the time, and there was no reason to use separate sewage and storm-water pipes, as modern systems do.) To avoid massive backups during storms, which could flood streets and basements with toxic sewage, relief valves, called outfalls, allow the excess sewage to flow into local waters.
By the time the sewer pipes reach the Newtown plant, they are buried forty-five feet beneath the surface. On a “dry weather day,” when the skies are clear, it requires only four pumps to lift an average of 310 million gallons of wastewater per day from the pipes. But during a heavy rainstorm—when five inches of water falls in thirty minutes, say—all ten of the plant’s giant pumps are put to work and can lift up to 700 million gallons of water (usually composed of 450 million gallons of storm water and 250 million gallons of sewage) in twenty-four hours, treat it, and release it into New York Harbor.
As the wastewater pouring into the plant reached 700 million gallons that January night, Pynn grew concerned that the heavy flow was becoming dangerous: at that velocity, he said, “the water can literally erode away the sewer pipe.” He ordered the throttling of eight gigantic gates—four at the Thirteenth Street pump house in Manhattan, four at the NCWWTP in Brooklyn—which diverted, or “tipped,” the wastewater into outfalls around the city: raw sewage began to spew into New York Bay.
Such an event, known as a combined sewer overflow (CSO), is distressingly common. As little as one-twentieth of an inch of rain can be enough to cause the sewers to overflow, according to Riverkeeper. The city reports that 460 CSOs discharge more than 27 billion gallons of untreated waste-water into New York Harbor every year.
The effluent from CSOs has been found to contain human feces, high levels of coliform bacteria, forty types of disease-causing pathogens, viruses, industrial solvents, debris, metals, nuisance levels of “floatables,” pesticides (such as malathion, an insecticide used to combat West Nile virus and the suspected cause of massive lobster die-offs in Long Island Sound), and the like. CSOs can result in water quality problems, low levels of dissolved oxygen, and nose-wrinkling odors. They have closed beaches, polluted drinking water, hindered navigation, and damaged aquatic habitats.
There are 490 outfall pipes spread around the city’s five boroughs, and the Newtown plant has access to 55 of them. Pynn tries to keep untreated sewage away from already severely polluted waterways—such as New-town Creek, the Gowanus Canal, and Jamaica Bay—reasoning that “a healthy body of water, like the Hudson, East River, or New York Bay can handle the overflows. The water is cleaner to begin with, with more dissolved oxygen in it, which helps to break down the raw sewage in twenty-one days just as well as this plant does in six hours.”
By that night in January 2010, New York had 8.3 million documented residents, making it the nation’s largest city, and, with twenty-seven thousand people per square mile, by far its most densely populated. Such an “ultra-urban” setting has little space for artificial runoff controls, such as catch basins and canals. Nor is there much room to collect storm water underground, as the city’s subsurface is honeycombed with tunnels, ducts, and pipes that convey subways, electricity, natural gas, phone lines, television cables, steam, and water. New York’s main line of defense against storm-water runoff remains its aging sewer system.
New York was one of the first major American cities to build a sewer system. Construction began in 1849, when the city had about half a million residents. Water and sewage conduits were made of hand-laid ceramic tile and brick, some of which remain in use. As they age, the oldest pipes are insufficient to keep up with the city’s rising demand, and some of them are leaking. In 1856, the city’s new pipes began to dump raw sewage directly into local waterways, including Newtown Creek. It took decades, and millions of dollars, for New York to build its current fleet of fourteen sewage plants, but the system’s Achilles’ heel is the “combined” pipework.
New York is not alone with this dilemma. An estimated 4 percent of the nation’s twenty-five thousand municipal sewer systems use combined systems like those in New York. These are mostly in older cities in the Northeast, the Great Lakes, and in the Pacific Northwest. Newer cities equip themselves with separate pipe systems to capture and transport storm water and sewage water, to avoid CSOs.
Despite stricter laws and advances in water treatment in the 1990s, biological outbreaks have occasionally flared up, at least in part due to sewage infiltrating drinking supplies. In 1993, for example, both Washington, DC, and New York City were forced to issue temporary “boil orders” for tap water, in order to kill E. coli and Cryptosporidium (a parasitic microorganism), respectively. That same year 69 people died and an estimated 403,000 were sickened by a Cryptosporidium outbreak in Milwaukee tap water, in the largest recorded outbreak of waterborne disease in US history. A year later, Las Vegas suffered the nation’s second-largest outbreak of Cryptosporidium, which killed 43 people and sickened 132 more. Between 2001 and 2006, another eighty-five minor outbreaks of waterborne illness may have been partly the result of sewage contamination.
It rains or snows in New York City every three and a half days on average, providing forty-four inches of precipitation a year. Before the city’s surfaces were sealed by concrete and tarmac (which began two centuries ago), rain filtered into the soil and wetlands and was sucked up by vegetation. But as New York City expanded, impermeable streets and buildings increasingly covered absorbent earth. Between 1970 and 2000, more than nine thousand acres of land were paved over. Even the soil in some city parks and athletic fields has become so tightly compacted by heavy use that it is nearly impermeable. And in the twentieth century, 90 percent of New York’s spongy wetlands were destroyed to make room for development. As a result, most of the city’s precipitation washes directly into the sewers.
On an average sunny day, New York City residents discharge about 1.4 billion gallons of sewage, made up of household waste, street runoff, and industrial effluent, into more than seven thousand miles of sewer pipe. The system was carefully designed so that most of this wastewater flows by gravity alone. After being processed at one of fourteen pollution control plants, the treated effluent is flushed back into local rivers and the harbor. In a downpour, New York’s sewage system can absorb the crucial first five minutes of sustained rain—the “five-minute flush”—when storm water surges through the pipes and rushes into treatment plants. But if the rainfall is sustained or arrives in an intense burst, trouble can quickly build up in the system.
A drought in 2002 kept CSOs to a minimum and local waters were relatively clean. But the rainy summers of 2003 and 2004 caused so many CSOs that New York waters were declared unhealthy, and beaches were repeatedly closed. The swimming leg of a triathlon was canceled due to the pollution from CSOs.
Most notorious was the sultry afternoon of August 14, 2003, when a massive power outage—caused by surging electricity demand, computer malfunctions, and power lines snagged in trees in Ohio—led to a rolling blackout that knocked out electricity to roughly 45 million people in the Northeastern and Midwestern United States, and another 10 million in Canada. In New York, most of the city’s wastewater treatment plants used backup generators to keep functioning. But at two plants, the generators did not work, and 30 million gallons of untreated human waste was illegally discharged into the city’s waters. This led to a massive increase of fecal coliform in New York Harbor and Long Island Sound and forced the closing of most city beaches. The lack of functioning generators and the discharge of sewage violated both federal and state laws. To avoid prosecution, the city had to admit it erred and was put under court supervision. City officials said that workers had repeatedly tried to have the generators repaired, but the job was never accomplished.
New Yorkers questioned whether they had been unfairly singled out, noting that a plant in Cleveland discharged at least 60 million gallons of raw sewage into the Cuyahoga River, Lake Erie, and other waterways during the blackout, while in Detroit, citizens were advised to boil their water after the city’s sewer plants lost power. Neither of those cities faced prosecution. (Regulators ignored the protest.)
New York’s sewer system is designed to accommodate a so-called five-year storm—a rainstorm so severe that it is predicted to fall only twice a decade. But lately weather patterns have been shifting. In 2007 alone, the city experienced three intense twenty-five-year rainstorms—storms so extreme they are predicted to occur only four times per century—which flooded subways and highways and threatened to shut down the city.
At a time when national attention was beginning to focus on the long-term effects of climate change—greater heat, more frequent and intense hurricanes, rising seas—sewage experts viewed the storms of 2007 as a wake-up call.
Sewage treatment is the generic term for the removal of contaminants from runoff and domestic wastewater via chemical, biological, and physical processes. The result is a waste stream of treated effluent and solid waste, or sludge, which is often filled with contaminants and toxic compounds of an almost unimaginable variety. The main objective of sewage treatment is to clean water to the point that it can be discharged back into the environment. Americans produce about 18 million tons of feces a year, and treatment plants process about 34 billion gallons of wastewater per day, according to the EPA.
Treatment in sewage plants mimics natural cleansing processes: typically, bacteria consume organic contaminants, and sunlight helps break down pollutants; when wastewater is mixed with large volumes of freshwater, it is diluted. Similarly, most pollution control plants in the United States use three stages of treatment: primary (sewage is held in tanks, where heavy solids settle to the bottom while lighter solids and oil float to the surface and are removed), secondary (the removal of dissolved or suspended biological matter, a job often performed by microorganisms), and tertiary (the disinfection of treated water by chemicals such as chlorine by ultraviolet light, or by microfiltration). By the end of this “treatment train,” water is usually clean enough to be discharged back into a river, bay, or wetland, where it mixes with freshwater. Or it can be used as nonpotable gray water to irrigate parks or golf courses. If it is cleaned thoroughly enough, treated effluent is sometimes injected underground, to recharge groundwater stores that are eventually used to supply drinking water (as I will discuss later).
A sewage treatment plant was first built on the edge of Newtown Creek in 1967, to the standard of the day. This meant it used a two-step treatment process to remove 65 percent of the waste from the water passing through its system before flushing it into New York Harbor. In 1972, the federal Clean Water Act was passed, which required the removal of 85 percent of waste from treated water. The new standard rendered the plant out of compliance and set the stage for its reinvention. The Newtown plant’s reconstruction began in 1998 and was supposed to be completed by 2007 but was delayed; it is now scheduled to be finished by 2015, at a cost of some $5.2 billion. At peak times, a thousand workers from twenty-five prime contractors and hundreds of subcontractors try to push the project ahead as fast as possible.
On the cold day in February 2008 that I toured the plant with Jim Pynn, the Newtown Creek Wastewater Treatment Plant was still a dusty construction site. The property was originally owned by ExxonMobil, and the first priority was to excavate 750,000 cubic yards of oil-contaminated soil and replace it with clean fill. When it is fully operational, the plant’s digesters will hold 3 million gallons of sewage and process some 1.5 million gallons of sludge a day.
As Pynn weaved through a maze of silver and yellow ductwork, past settling tanks, blowers, methane-gas extractors, control rooms full of gauges and flashing computer screens, and tanks of chemicals labeled HAZARDOUS, he regaled me with tales of the things he has raked out of the sewers: turtles, fish, eels, and all manner of aquatic life. “I never found an alligator—it’s an urban legend that they live in New York’s sewers,” he said, though he and his colleagues have recovered a working camera (which took photos as it bounced around inside sewer pipes), thousands of counterfeit dollars bundled together, drug and sex paraphernalia, teddy bears, and “basically anything you could imagine that anyone would chuck into a toilet or a sewer grate.”
The primary design and cleansing feature of the plant is eight huge egg-shaped stainless steel sewage “digesters.” The digesters soar 145 feet high and bulge 80 feet wide. They were based on a German design, fabricated in pieces in Texas, transported across country by rail and truck, and welded together onsite in Brooklyn. Each egg required four and a half months of welding to assemble. When empty, an egg weighs 2 million pounds; when full of sludge, each can weigh as much as 33 million pounds; they rest on a slab of concrete nine feet thick. The NCWWTP uses an “activated sludge process” that is popular in Europe but is used in only a few US cities. It works like this: raw sewage is piped into the plant, passes through screens into grit chambers (these remove silt, gravel, coffee grounds, and eggshells, which cause wear and tear on pumps), then on to aeration (where microbes eat the “solids,” aka feces), and settling tanks (where fine air bubbles mix the microorganisms, causing the oxidation of organic matter); finally, the effluent is disinfected with sodium chloride and discharged.
The Newtown plant releases its effluent into a twelve-foot-wide, forty-eight-hundred-foot-long outflow pipe that drops steeply underground and emerges under the shipping channel in the East River. Out there, the current is fast; the treated sewage effluent passes through diffusers to spread the muck out, so no visible boils or slicks occur on the surface. The Hudson River and East River flow into New York Harbor, which opens up to the Atlantic Ocean.
In the meantime, sludge (organic material) is skimmed away from the effluent and “digested” inside the plant’s giant eggs. Inside the digesters, bacteria, heat, and a lack of oxygen break down the sludge; after fifteen days, what remains is water, carbon dioxide, methane gas (which is burned off), and digested sludge. The eggs’ oval shape helps to concentrate grit at the bottom of the tank, aids in mixing the sludge for improved “digestion,” and helps to concentrate methane gas at the top of the tank. By using this process, which avoids the traditional primary settling tanks, the city figures it will save taxpayers about $2.5 billion.
Effluent from sewage plants is a big contributor of nitrogen to New York’s waters, as is the case with treatment plants across the country. A heavy nitrogen load leads to hypoxia—a lack of dissolved oxygen—the death of fish, and the growth of algae. Nitrogen is a growing threat to major bodies of water, such as Chesapeake Bay and the Gulf of Mexico, and the EPA has placed New York under a nitrogen-reduction order.
The four wastewater treatment plants that sit along the East River, including the one on Newtown Creek, discharge 482 million gallons of treated water into the river every day; this water is 85 percent clean and accounts for about 50 percent of the nitrogen load in Long Island Sound, according to the DEP.
The Clean Water Act of 1972 was designed in part to improve the nation’s sewer controls and protect human and environmental health. Yet, despite $60 billion in upgrades to sewer systems in the 1970s and 1980s, CSOs continue to pose a major water pollution concern for 40 million people in thirty-two states.
In 1994 the EPA established a national framework to lessen the effects of CSOs. It recommended that the public be given ample warning when overflows occur, and that sewer pipes be designed in such a way that they do not become blocked. In 1996, EPA budgeted $44.7 billion to implement a nationwide CSO Control Policy, a comprehensive set of water quality standards, and in 2000 the Clean Water Act was amended by Congress to reduce sewage overflows. Some cities made great progress. San Francisco eliminated seven outfalls and reduced overflows into San Francisco Bay and the Pacific Ocean by roughly 88 percent. Saginaw, Michigan, spent $100 million to eliminate twenty of its thirty-six outfalls and reaped a 75 percent reduction in annual CSO discharge. Portland, Maine, eliminated twenty-five of thirty-five outfalls, and saw an 80 percent reduction in CSOs.
But fixing large infrastructure is physically daunting, politically challenging, and extremely expensive. A decade after Congress amended the Clean Water Act, hundreds of sewer systems remained out of compliance.
No national records document how many people have been sickened by CSOs, but there is anecdotal evidence. When local sewers overflowed in Milwaukee, the journal Pediatrics reported in 2007, the number of children suffering from diarrhea rose. In 2008, the Archives of Environmental and Occupational Health estimated that as many as 4 million people are sickened every year from swimming in California waters tainted by pathogens linked to sewage.
These are cautionary tales, especially given that between 2006 and 2009, a third of major US sewer systems (more than ninety-four hundred, including those in San Diego, Houston, Phoenix, San Antonio, Philadelphia, San Jose, and San Francisco) reported violating environmental laws. In addition, thousands of smaller wastewater treatment systems operated by factories, mines, towns, colleges, and even mobile-home parks have broken the law. But few of the violators—less than one in five, according to a New York Times analysis of EPA data—were sanctioned or fined.
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Since the 1970s, New York City has invested about $35 billion to maintain and improve the quality of its waterways and has focused on developing systems that capture CSO overflows before they are discharged into the harbor, store them until after a storm has passed, and only then send the excess water on to treatment plants.
Although rain causes Pynn headaches—and has turned him into a devotee of the Weather Channel—it is also his ally: rainwater is high in dissolved oxygen, which helps to break down pollutants. As a result of concerted cleanup efforts, the quality of New York Harbor and Hudson River water has improved significantly in the last two decades, he said, and “oxygen levels have returned nearly to their natural state.” Even so, parts of the New York waterfront, including Newtown Creek, remain polluted and unsafe for recreation, especially after heavy rainstorms.
John Lipscomb, a Riverkeeper boat captain, said that city studies claiming that local waterways are cleaner are flawed because they show only average water quality; what is more important, said Lipscomb, is the quality of water at specific locations. That kind of detailed analysis is becoming more important as the city opens the plant to the public, including nature trails, art installations, and a grand stairway leading from the plant down to the polluted water of Newtown Creek. “We’re going from the bad old days to a hopeful future where we’re inviting people to the water,” said Lipscomb. “But we don’t have the information that the public really needs to make an educated decision on whether they’re gonna fish there, whether they’re gonna eat that fish, whether they’re gonna climb down that ladder and get in the water.”
As of 2010, Newtown Creek is listed by the EPA as “unclassified water,” which, Pynn explained, means it is not suitable for recreational use. “We’re tryin’ to educate the public and promote the concept of fishing—as a sport,” he said. “But we don’t want people actually eating fish out of Newtown Creek.”
Even with expensive improvements to the city’s sewer system, “there’s no way to completely stop CSOs,” Pynn acknowledged. He explained that New York will have to rely on its combined sewer pipes for the foreseeable future because replacing them with a “two-pipe” system would be expensive and unpopular and would require entire neighborhoods to be excavated.
Environmental planners point to basic steps to control storm-water runoff and CSOs. New York City has allocated millions of dollars for “green” infrastructure projects, instituted new laws that give tax credits for green roofs, and required that new parking lots include landscaped areas to absorb precipitation. The next step is to plant more trees and use permeable pavement and sidewalks. These relatively cheap fixes will help recharge aquifers and enhance overall environmental quality. More ambitious plans include building large rooftop or subterranean cisterns, which collect rain and storm-water runoff and release it slowly—as has been done in the new Brooklyn Bridge Park. This takes pressure off the sewer system and cuts down on the amount of pollutants swept into waterways.
Other cities are taking similar steps. Philadelphia, for instance, has one of the nation’s oldest sewer systems, which is notorious for backing up and causing floods along the Delaware and Schuylkill Rivers. But over the next two decades, it plans to reinvent itself as a “porous city.” With a $1.6 billion investment, the city will plant thousands of trees, build rain gardens and urban farms, and create permeable basketball courts and parking lots that allow rain to slowly sink into gravel beds and eventually into the ground-water supply.
The volume of water flowing through sewers will increase this century, as more people produce more sewage and global warming causes more rainfall. But we have ignored our sewage infrastructure for decades, and now systems across the country are relying on outdated technology. It is a serious and growing problem. President Obama’s fiscal stimulus bill of 2009 set aside $6 billion to improve water systems, and legislation on Capitol Hill includes millions of dollars in water infrastructure grants. But those funds will not be sufficient. According to estimates by the EPA and the Government Accountability Office, upgrading the nation’s sewer systems will require $400 billion by 2020.
“People wonder where their water is comin’ from, but they never think about where it goes, and what it takes to clean it,” said Jim Pynn, waving at Newtown Creek plant’s giant sewage digesters. “But wastewater treatment is absolutely vital. Imagine what would happen if this place stopped working one day? Let’s just say it wouldn’t be pretty.”