A buried liability: Sewers pose expensive challenges

The first in a series by Cliff Lewis

In 2009, almost a billion gallons of sewage-laced storm water pumped into the Conestoga River and ultimately swam its way via the Susquehanna into the Chesapeake Bay. All of it was the product of a one-and-a-half-centuries-old dual sanitary and storm sewer system beneath the City of Lancaster. This antiquated system presents a chronic dilemma faced by hundreds of older cities within the United States: How to progress into the 21st century atop a 19th century infrastructure?

According to city wastewater manager Bryan Harner, “In the 1800s, originally, the sewage just ran in the street….So, at that time, a lot of communities in the United States built pipes to carry it to the waterways. Back in the 1850s-60s, the City built its first sewers….We were state-of-the art.”

The system initially collected both sewage and storm water runoff from each city residence into a single line. All of it went untreated, straight into the Conestoga River. Then, in the 1930s, the City began processing this combined wastewater at treatment plants.

The current plant on New Danville Pike, serving the city and nearby communities, can handle a maximum of 32 million gallons of wastewater. On an average day it treats 20 million gallons but, during a rainfall of around one-tenth of an inch, the system will reach its capacity and divert all additional flow—rain, sewage, and all—into the Conestoga.

According to Harner, the system overflowed an average of 2 million gallons per rainfall in 2009.
Within the United States, there are approximately 772 combined sewer systems, most of which face this problem of combined sewer overflow (CSO).

Following President Obama’s 2009 executive order to restore the Chesapeake Bay, the federal Environmental Protection Agency has been looking to tighten the reigns on the sources of its contamination. According to City public works director Charlotte Katzenmoyer, the state’s Department of Environment Protection (DEP) has annually corresponded with the City regarding its storm water management. So far, the state department has not mandated a schedule for particular improvements.

However, in the last year, however, the federal EPA has begun requesting data from City Hall. Katzenmoyer said that EPA interest could result in the imposition of a legally binding consent order, which would establish a timeline of system improvements under penalty of fines. “I’m very concerned,” Katzenmoyer asserted, “Usually if the EPA starts talking to you and asking for all kinds of information, they are going somewhere with it.”

Within the next several weeks, Katzenmoyer’s department will present the EPA with a hydraulic model of the entire city, which will provide a data-specific profile of Lancaster’s wastewater management and the potential impact of proposed solutions.

In addition to the serious problem of causing plant overflows, combined sewage increases quantity and thus raises the cost of treatment. The city spends about $12 million each year on its wastewater treatment operations.

“The way it is now,” Harner explained, “it costs a lot of money to run a treatment plant—electricity-wise, personnel, chemicals—and we get a lot more flow into here than we’d need to if it was a separated sewer system.”

Local officials have tossed around a number of potential long- and short-term solutions to its CSO dilemma: They could construct a 10 million gallon holding tank to “buy time” for treatment during rainfall events. They could introduce more permeable surfaces and “green infrastructure” to absorb water apart from the storm drains. They could build mini-treatment plants at some of City’s five pump stations to increase processing capacity. Or they could simply tear out the existing system and install a new, separated sewer—which would cost the city and property owners a fortune and be highly disruptive and disfiguring.

Most of the solutions proposed thus far either provide a partial “patch-up,” increase treatment costs, or come at a massive capital expense. (And the patches aren’t cheap, either.) The City has not yet locked in any formal project plans.

One idea that city officials have mulled over for the last several years is to separate the storm water collection in highly-impermeable target areas of the city, creating a pipeline toward a direct, clean discharge. Such an approach could provide some immediate relief for the treatment plant and serve as the first step toward total conversion at some point in the distant future.

Harner noted that to construct such a pipeline from downtown would be a mammoth undertaking in itself, but acknowledged that there are other parts of the city at which that project could be more reasonably undertaken. “There are some areas,” Harner said, “Where it could be possible to get something to the Little Conestoga….Anything within the CSO district is pretty much high-density.”

Next installment: A slew of pricey solutions to city sewage woes.