The Pittsburgh Water and Sewer Authority and communities surrounding Pittsburgh face a daunting and costly challenge: how to reduce the amount of untreated stormwater and sewage that's released into rivers when its outdated infrastructure is overwhelmed following a rainstorm.
But it's a challenge they'll have to answer as part of a consent agreement and order from the state's Department of Environmental Protection and the Allegheny County Health Department. The Allegheny County Sanitary Authority, also known as Alcosan, is under a consent decree from the federal Environmental Protection Agency to reduce its sewage overflows.
In addition to Pittsburgh, 82 other communities were required to submit plans and all featured a collaborative approach that will lessen the costs that will inevitably be borne by ratepayers.
But, without a collaborative approach ratepayers would face a much larger price tag, according to John Schombert, executive director of 3 Rivers Wet Weather, which has worked with the city and municipalities to facilitate a cooperative approach to solving the region's sewer overflow problems. The PWSA has been a leader among municipalities in promoting a collaborative approach to the region's sewer issues, he said.
PWSA began that lengthy process Wednesday when it submitted a feasibility study to the DEP and to the county health department, the first of many requirements of the consent decree. The Wet Weather Feasibility Study, which ran thousands of pages and weighed nearly 30 pounds, proposes conventional infrastructure upgrades, such as construction of a water tower and widening of pipes.
The submission of the feasibility plans met an end of July deadline set by the U.S. Environmental Protection Agency and are another step toward meeting a federal mandate to significantly reduce the 9 billion gallons of storm-caused sewage overflows into the region's rivers and streams.
The sewer system improvement plans are expensive. Alcosan sent a $2.8 billion package of sewer system improvements to the EPA in January and the PWSA's plan will cost $165 million to implement.
The feasibility study also commits the city to consideration of so-called "green infrastructure," such as permeable asphalt, rain gardens and landscaped swales, that retain stormwater and reduce its flow into overburdened sewers. Jim Good, executive director of PWSA, said the authority could have met the requirements solely with "grey" infrastructure including expansion of pipes. But it went above and beyond by not only considering green solutions but also making preliminary plans to actually implement and test them in the Saw Mill Run area.
Nancy Barylak, an Alcosan spokeswoman, said the authority has worked closely with the city and many municipalities to add green infrastructure components to its plans.
"We are looking for places where such infrastructure is feasible and where we can partner with the municipalities. We're not using the term green infrastructure. We're using source control but green infrastructure is included in that."
A big issue will be how all the municipal plans are integrated into Alcosan's, not just for system efficiencies but also for cost savings, Ms. Barylak said. One proposal under discussion is to have Alcosan take over the major "trunk" sewer lines that connect various municipalities and the city to the authority-owned collector system.
"They're looking at trunk lines that are 10-inches in diameter and larger that connect to Alcosan's main lines in places like Girty's Run and Sawmill Run," she said. "But it will be another month before we have any hard numbers on how many miles of those lines we're talking about."
Mr. Schombert said an advantage of Alcosan taking over the trunk lines would be to spread the high cost of repairing and maintaining those lines across the Alcosan rate base instead of burdening a few municipalities where the collection lines are located.
While meeting the requirements of dumping less untreated sewage and stormwater in the city will mean cleaner rivers, the cost of the upgrades will largely fall on ratepayers. As work begins, PWSA forecasts it will ramp up a fee that will top off at approximately $100 extra dollars per customers in 15 years.
Alcosan, which submitted its plans to federal authorities six months ago, estimates ratepayers will go from an average of $261 a year in sewage fees now to $800 in 15 years.
PWSA's plans for grey infrastructure include installing $40 million worth of high-tech filters on outfalls which can act as filtration to separate out debris and other kinds of solids from untreated stormwater and sewage. The authority also proposes building a large holding tank to hold excess stormwater after a massive rainstorm so as not to overwhelm the combined sewage system. In all, the "grey infrastructure" upgrades could total $120 million. When the plan is fully implemented, the authority estimates combined sewage overflows could be reduced by as much as 95 percent.
Mr. Good said if the green infrastructure experiment goes well, the plan could be altered to require less grey infrastructure. Green infrastructure is far cheaper and could help mitigate project costs.
"PWSA intends to provide the most environmental benefit per dollar spent," said Dan Deasy, authority chairman, in a news release. "Green Infrastructure will create jobs, clean rivers, beautify neighborhoods and increase property values."
Mr. Deasy said PWSA will continue to work with regulators, community groups, local governments and Alcosan to "reach a mutually agreeable, innovative and affordable way to improve and protect our region's water and quality of life."
The Allegheny County Health Department is tasked with reviewing the feasibility plans for 56 municipalities with sanitary sewer overflows, which are illegal and must be eliminated. Combined sewer overflows are not illegal but must be significantly reduced.
Geoff Butia, chief of the county's public drinking water and waste management program, said the municipal plans have been streaming in to beat the end of July deadline.
"The plans present a feasibility study that evaluates a range of options in costs and time for stopping the sanitary sewer overflows," Mr. Butia said. "Some of the municipalities have presented consolidated plans. We've got the majority in already. The technical reviews will take about a year."
The EPA has a year to review the $2.8 billion package of sewer system improvements Alcosan submitted at the end of January.