Environmental Alchemy

Green solutions may lie buried in the sludge of a century-old sewer system

When it rains in Omaha, it pours raw sewage, industrial waste and toxic chemicals into nearby waterways. The city’s century-old sewer system is designed to either put it there or into your basement. Neither is an inviting option. But that design is changing thanks to a federal mandate from the Environmental Protection Agency. The oldest part of the city — nearly everything east of 72nd St. — currently works on a combined sewer system (CSS) where one pipe handles both storm water and sewage. During dry conditions it works great. Sewage is carried away from homes and businesses to one of two treatment plants where it is treated and then safely released into the Missouri River and Papillion Creek. If it rains heavily enough, however, the storm water rushing down drains in the street mixes with the raw sewage in the same pipe and frequently overwhelms the system in what the EPA calls a Combined Sewer Overflow (CSO)event. The combined runoff – typically 85 percent storm water, 15 percent sewage, according to the city – then flows directly to the Missouri River and its tributaries throughout the area. Omaha isn’t alone. Nearly 800 other communities are undergoing similarly massive sewer separation projects as part of the EPA's CSO Control Policy. Since 2002, Omaha has averaged 86 overflows a year, pumping 3.5 billion gallons of sewage and storm water annually into receiving streams. The goal is to reduce that number to about four a year by 2024. No matter where you look, it’s a big and expensive project. Atlanta is spending $3 billion to control its CSOs. Cleveland is protecting the Cuyahoga River with a $1.6 billion project. Omaha officials estimate the city will spend nearly $1.7 billion over the next 15 years to address 51 square miles of aging sewer lines in East Omaha. The Sewer Maintenance Division of the Public Works Department, with a staff of 64 employees and a $2.9 million budget in 2011, is in charge of making the change happen. “I believe it’s probably the biggest public works project we’ve ever undertaken,” says Marty Grate, the city’s environmental services manager. “This is like building the West Dodge Expressway, a $100 million project, every year for 15 years.” Just like that expressway, the sewer project will disrupt daily life. Streets will be torn up. Traffic will be diverted. But Grate says the project will ultimately improve more than just the city’s water quality. Omaha’s CSO Control Project is an opportunity for the city to get a little bit greener as well. Old Omaha There was a time in Omaha's history when raw sewage flowed through the streets — not by accident, but by design. Or, rather, lack thereof. For the first few decades of the city’s existence, Omahans simply emptied their outhouses and privies through trenches that poured directly into the street. Human waste pooled in wagon ruts during rainy weather and baked in alleyway cesspools during the hot summer months. Faced with a calamity of unsanitary conditions and citizen complaints, the City Council proposed Omaha’s first sewer system in 1878, according to city records. The city tried to do it right. The original plan called for separate sewer systems for storm water and sewage at a cost of nearly $1 million dollars, a $20 million project today. But with Omaha’s explosive growth in the early 20th Century, the plan was abandoned in favor of a much quicker and more common solution – the combined sewer system. Until the mid-1960s, all of Omaha’s wastewater emptied directly into the Missouri River without treatment. The city began to build separate sewer systems in developing West Omaha and constructed two treatment plants that sterilized all of the city’s wastewater prior to release into the waterways to service East Omaha under normal conditions. Combined sewers were the exception, and the City of Omaha, along with the other cities, operated under special permits from the EPA and state regulators due to the limitations of their antiquated system. But as concrete replaces grass and cities continue to grow, so does the amount of storm water runoff. By 1994, the EPA had developed its first control plan to address the growing dangers of combined-sewer overflow and had set a series of minimum controls for cities to meet by 1997. Omaha met that deadline, but a new one emerged in 2005. Because of increased federal requirements in the Clean Water Act, the EPA gave Omaha two years to have a draft of its longterm plan to address overflow issues in place. In 2009, the city submitted its completed plan to the Nebraska Department of Environmental Quality, the state organization charged with monitoring the project. The Health Factor Pat Nelson doesn’t look at a rainstorm the way most people do. She’s been working with storm water for more than 20 years, and as the compliance team lead with Clean Solutions Omaha, it’s her job to ensure the city meets all of its state and federal water-quality requirements. “The perfect place for storm water to go is into the surrounding natural bodies of water,” she says. “That’s just part of the natural hydrological cycle.” But when storm water and sewage mix you introduce a potentially potent cocktail of pollutants into the water system. Rain water can pick up pollutants from a variety of sources as it washes over yards and streets, gathering industrial waste particles from the air, car fluids, fertilizers, pesticides, and pet and animal waste. Raw sewage is a breeding ground for the E. coli virus, the most common pollutant found in overflow material. Combined is a filthy mix of heavy metals, chemicals and bacteria in our lakes and rivers. The National Resources Defense Council reports that combined-sewer overflows contain more than 100 times the concentration of fecal coliform colonies than treated waste water. At its worst, high fecal coliform concentrations can lead to a variety of human health risks from ear infections to food poisoning, and can endanger fish and other aquatic life. The Nebraska Department of Environmental Quality maintains a biennial list of impaired waterways that do not meet state water quality standards when tested for pollutants. In 2006 and 2008, Omaha’s segment of the Missouri River and Papillion Creek — the two major waterways receiving CSO runoff — were listed as Category 5 waterways, the EPA’s most severe pollution ranking, due to elevated levels of E. Coli. In 2010, both waterways were upgraded to Category 4 for E. Coli levels, but remained on the Impaired Waterways list because they contained other chemical pollutants. Based on those risks, the backbone of Omaha’s CSO control plan is to keep storm water and sewage separate through a variety of control mechanisms. In addition to sewer separation — approximately $700 million of the total $1.7 billion cost according to Grate — the city will also install a 5-mile long underground concrete tunnel along the Missouri River to accept CSO runoff. That’s the gray part of the equation, but Nelson says a large part of cleaning up Omaha’s waterways happens before storm water even reaches the sewer system. And that’s where Omaha becomes more environmentally sustainable. More Grass, More Green A number of institutional and individual solutions can help reduce a city’s storm water runoff, but they all primarily focus on soaking up as much water as possible before it reaches the storm drains. Few things do this better than vegetation. But that presents a challenge for city engineers facing firm regulatory requirements and deadlines. Everyone wants green solutions where possible, Grates says, but those efforts must be supported by structural controls that can deliver precise results. Like most cities, Grate says Omaha is working to the balance the gray solutions already in place with constantly evolving, and perhaps cost-cutting green solutions. Emily Holtzclaw is one of the engineers making that happen. As a water resources engineer and project manager with environmental engineering firm CH2M HILL, Holtzclaw does everything from work with computer models of the Omaha sewer system to conduct field visits as workers are lowered 50-feet underground to check the condition of century-old pipes. The solutions she comes up with might be multi-million-dollar projects or they may be as simple as making sure the city doesn’t have any manhole covers with holes in them. But the connecting thread, she says, is a devotion to become more environmentally sustainable. “We’re working to find other ways to deal with storm water. And one of our first tasks is always to identify and, if possible, use the green solution,” Holtzclaw says. “We’re always looking to save space and save cost and do something that’s more environmentally supportive.” In the first phase of the longterm control plan, the city is undertaking three major projects based on environmental sustainability. Last summer, Omaha received a $200,000 grant from the Nebraska Environmental Trust to restore ponds that were drained in 1931 at Spring Lake Park in South Omaha and to add a planned wetlands area to the site. Native plants with deep root systems are better equipped to soak up water, and Grate says the plan “lets nature reduce the runoff we have to deal with.” The city estimates the four-year, $1.5 million project could eventually save $2 million in overall CSO project costs. Nature is doing part of the work in sewer separations near Aksarben Village and Saddle Creek Road, as well. Rather than build an entirely new, separate sewer system, engineers are using the natural landscape to direct storm water to the waterways. Three dry detention areas in Elmwood Park will collect storm water, reducing peak-time runoff and safely depositing solids in the water before it reaches the Elmwood Park Creek. The city estimates the project will save $1 million. An above-ground, open channel will work similarly west of Saddle Creek Road, allowing soil and vegetation to clean the storm water naturally prior to its entry into Little Papillion Creek. The Saddle Creek extension is estimated to save $2 million in infrastructure costs. But the bill for Omaha’s CSO project is still potentially enormous and how the city will pay for it is debatable. The federal mandate to fix the system was unfunded, leaving the city and its citizens to pick up all of the cost. For now, the plan is to gradually increase the city’s sewage fees for residents. The average residential rate in Omaha in 2010 was approximately $15 per month. By 2017, the city estimates sewer fees could reach $50 per month — more than a 200 percent increase over the next seven years. Some local politicians are fighting to reduce that cost. In late March, Mayor Jim Suttle traveled to Washington D.C. to lobby for federal funding for the project. On March 22, the City Council approved a resolution asking Nebraska’s Congressional delegation to lobby for a 50-50 federal cost share for the project. Omaha State Sen. Heath Mello has a proposal before the Nebraska Legislature that would return state sales taxes associated with the increase — a windfall of about $48 million over the next 15 years — to the city of Omaha to help defray costs. But for now, the only certain cost-cutting measure is to go green whenever and wherever the city can. The key to cleaner, safer, more modern Omaha may lie in the mud and sludge of a century-old sewer system. “We’re not putting in green solutions because they’re cool but because they improve the project, they benefit the city and they’re cost effective,” Nelson says. “We’re going to see more and more of these solutions as time goes on.”

posted at 03:53 pm
on Tuesday, April 05th, 2011

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