Twenty-seven billion gallons of water is enough to cover the Bronx, Manhattan and Staten Island a foot deep, sufficient to flood a 10-foot wide tunnel from Times Square to Burma, and more water than you’d use for a 20,000-year-long shower. It’s also how much untreated wastewater New York City spills into bays, creeks, rivers, canals and the harbor in a typical year.

That’s right, untreated wastewater, every bit as gross as you’d imagine – flowing directly into the waters all around us that support plant and animal life, provide a playground for boaters and fishers, and form a shimmering reflector for sunset and moonrise.

A legacy of early sewage infrastructure that drains bathroom waste and rainwater in the same pipe, New York City’s 494 combined sewer overflow (CSO) pipes dump a brew of street trash, bodily fluids and dirty runoff whenever rain overwhelms the city’s 14 wastewater treatment plants. Other old cities share this problem with New York, but younger metropolises like Los Angeles and Phoenix don’t. The wastewater mix can harm aquatic life and put certain waterways off limits to any human contact. Federal and state agencies have pressed the city to reduce CSO releases for more than 15 years, and while progress has been made, the spills persist.

Now Mayor Bloomberg is targeting CSOs through his ambitious PlaNYC sustainability initiative, which seeks to make the city an ecologically healthier place by the time a million more residents live here in 2030 – all with showers to take, dishes to wash and toilets to flush. When he launched the sustainability drive last September, the mayor said the city seeks cleaner water “so that we can fish, swim, and enjoy the rivers that have always been the city’s most distinctive feature.” Announcing his 127-point plan in April, the mayor spelled out his vision of a city that “opens virtually all of our rivers and creeks and coastal waters to recreation.”

But amid the bold proposals in PlaNYC for reducing carbon emissions and using congestion pricing to ease car traffic, Bloomberg’s goals for water quality, critics say, drift in the shallow end of the pool. The summer issue of City Limits Investigates, Deep Trouble: New York City’s Silent Sewage Crisis, finds that the vast size of the sewage problem – and the limitations inherent in both traditional and “green” approaches to fixing it – seem to be constraining ambition for making the city’s waterways as clean as they could be.

PlaNYC’s goal is to capture at least 75 percent of the city’s wet-weather flow—the water that can lead to CSO discharges—over the next 23 years. That’s only marginally better than the 72 percent the city already attains, and well behind cities like Chicago and Boston that have also wrestled with CSO problems. In fact, the 75 percent goal is what the city is already required to meet under a 2004 consent order with the state—and could still result in some 24 billion gallons of releases each year. The plan holds out the possibility of doing more, but fails to define any more aggressive target.

PlaNYC also calls for opening 90 percent of New York City’s tributaries (98 percent of all its waters, when you count the Hudson River and New York Harbor) to recreation. But the mayor’s plan aims only for “secondary contact” —i.e., boating and fishing. While swimming in the East River is something most New Yorkers are bred to live without, the modest recreation target reflects limits on how clean the water will be by 2030. “We were looking for a more ambitious goal but we didn’t get it,” says Queens City Councilmember and Environmental Protection Committee chair James Gennaro.

Even as PlaNYC sets new goals for cleaning up waterways by reducing CSOs, the city’s strategy for meeting them seems to be shifting away from the type of capital projects that have normally been seen as necessary to reach those goals. The Department of Environmental Protection’s (DEP) traditional approach to controlling CSOs has been to build huge tanks to hold stormwater until the rain stops and the sewage plants can handle the volume. DEP has slashed the number of tanks it plans from eight to six to four, citing their huge cost and limited effectiveness. Those that are still to be built are years from completion.

Many environmentalists see the reduced number of tank projects as a good thing—they’ve always argued that so-called “end of pipe” solutions weren’t going to end combined sewer outflows, which should be the real goal. But it’s unclear whether the other methods DEP intends to use—like increasing capacity in the sewer pipes themselves and capturing litter that gets into the system—are any better than the tanks.

Meanwhile, DEP has sent mixed signals on how much it will embrace the “green” solutions that many environmental groups prefer, like porous pavement and rain absorbing gullies called “swales” along roadsides. PlaNYC highlights several possible green solutions to CSOs, but the administration calls for limited pilot programs—irritating advocates who say green approaches are proven technology. One exception in the mayor’s plan is a tax abatement for new green roofs, which use rainwater to irrigate plants and keep it out of the sewer pipes. Another is the goal to plant 1 million new trees.

But like the “end of pipe” solutions that environmentalists deride, green solutions face limits. One is cost: A green roof is two to three times as expensive as a traditional roof. Physical barriers also exist. Green roofs might not work on the pitched roofs that populate much of Brooklyn, the Bronx, Queens and Staten Island.

That’s why the city is treading slowly on going green, says Rohit Aggarwala, director of the mayor’s Office of Long Term Planning and Sustainability, which developed PlaNYC. “What we did in the plan—we did it throughout—is we set goals that we considered to be ambitious but achievable,” he says. He adds that pilot programs are necessary because green programs that worked elsewhere might not succeed in New York City; porous pavement, for example, absorbs rainwater successfully in milder Seattle, but can it survive a New York winter? And where uncertainty doesn’t reign, high costs do—a real worry for a city that is already raising water rates 54 percent over the next four years to cover soaring capital costs. “I think if we’re going to look to complete swimmability as our goal, we have to be ready for massive increases in the water rates,” Aggarwala says.

Marilyn Gelber, commissioner of DEP from 1994 to 1996, says the city has to weigh difficult tradeoffs when it comes to addressing large, complicated problems like CSOs. “It’s unrealistic to say that you can address everything, every possible discharge, and spend billions of dollars to do that and neglect other things,” she says. That’s especially true if the city is all on its own. “While we continue to have the mandate, there is pitifully little federal money coming into the city to address CSOs, to address treatment plants. The burden falls solely on the city. The feds—now, perhaps, with the change of leadership in Congress—need to look seriously at reinvesting in these kinds of urban environmental issues that are key.”

Other parts of PlaNYC also raise questions about costs and technology; congestion pricing is one. But the administration wholeheartedly backed that bold idea. The difference might be that while all New Yorkers witness traffic, few have ever seen a CSO discharge. Fewer still have contemplated their per capita share of the annual release: more than 3,200 gallons of rainwater and household wastewater, or enough to fill about 66 bathtubs.

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– Jarrett Murphy