At a press conference in September, Arletta Scott Williams, the executive director of the Allegheny County Sanitary Authority [ALCOSAN], led the crowd in a chant.

“Say it with me: Green! green!” Then she asked the ALCOSAN staff, board members and media to join her. 

“I say, ‘Green,’ you say, ‘Green,” she repeated as a handful of voices echoed back. “Green! Green!” 

Williams was underlining ALCOSAN’s commitment to green infrastructure — a way of storing or transporting rainfall with landscaping and plants rather than pipes. 

After years of pressure from advocates such as the Clean Rivers Campaign, this was a significant shift in rhetoric for ALCOSAN leadership. Williams admitted that she was late to embracing green solutions and did so largely because of public pressure. 

“Sometimes it is the public outcry that gets you there,” she said. “So be it. Whatever it takes.”

But it isn’t yet clear how fully ALCOSAN is able or willing to embrace its leader’s new rhetoric.

A consent decree with the Environmental Protection Agency [EPA] mandates ALCOSAN to complete $2 billion in upgrades to prevent sewage overflows from entering the rivers. 

As part of the $2 billion plan, ALCOSAN officials have touted its $100 million Green Revitalization of our Waterways [GROW] program as one of the most ambitious green programs in the country. ALCOSAN has spent $29 million in GROW funds since 2017, of which $11.3 million has been allocated for green infrastructure. Most of the money has been spent on preventing water from entering the sewers by repairing, separating and lining old and damaged pipes. 

At a sewer conference in November, an ALCOSAN study hinted at how it may be able to spend the remaining $1.9 billion. The preliminary results of the study indicates that out of all of the remaining investment, an estimated $29 million in planned pipes could be converted to green infrastructure for about the same cost or cheaper. 

While ALCOSAN is looking into green options, it’s also required by the EPA to hold down costs for its ratepayers. Tim Prevost, the manager of ALCOSAN’s wet weather programs, told attendees at the conference that ALCOSAN had narrowed its focus to 12 sites where green infrastructure could be cheaper than gray. But even in those locations, he said he wasn’t sure if green infrastructure would be cheap enough.

Tim Prevost, the manager of the wet weather programs at ALCOSAN, describes a new study where ALCOSAN tried to locate the very best spots for using green infrastructure to reduce sewage overflows. (Photo by Oliver Morrison/PublicSource)
Tim Prevost, the manager of the wet weather programs at ALCOSAN, describes a new study where ALCOSAN tried to locate the very best spots for using green infrastructure to reduce sewage overflows at a November conference. (Photo by Oliver Morrison/PublicSource)

Advocates for green infrastructure say it’s a missed opportunity to spend money on pipes when green infrastructure can provide additional benefits, including added greenspace and stormwater mitigation that can prevent flooding. 

But ALCOSAN says it’s focused narrowly on preventing sewage overflows. According to its study, pipes are a cheaper option than green infrastructure for this purpose in most of its service area.

Thomas Hoffman, a clean water organizer for the Sierra Club who saw the presentation, said ALCOSAN’s new study suggested that, while it is espousing support, it isn’t actually pursuing green infrastructure seriously. “It’s an afterthought,” he said. He said he doesn’t understand why ALCOSAN can’t invest in as much green infrastructure as the Pittsburgh Water and Sewer Authority [PWSA].  

PWSA is moving ahead with more than $130 million of green infrastructure over the next five years and has plans to continue this level of investment for the foreseeable future. While ALCOSAN is focused on reducing sewage overflows, PWSA says its green infrastructure projects can help improve other issues like flooding in the streets, basements overflowing with sewage and streams too dirty to support fish. 

ALCOSAN officials don’t think it’s fair to compare their spending with PWSA. ALCOSAN doesn’t build its own green infrastructure; it reimburses its customer municipalities if they want to build green infrastructure, said Joey Vallarian, the director of communications. “Comparing us with PWSA would be like comparing us to Monroeville or Hampton Township,” he said. “They are apples and oranges completely.”

Bob Weimar, the PWSA executive director, said he thinks Pittsburgh ratepayers should be reimbursed by ALCOSAN because its projects will reduce the levels of stormwater that ALCOSAN has to treat in the sewer system. 

“We will continue to press the county and ALCOSAN to fund additional green projects beyond the $100 million [GROW program],” he said.

Julia Spicher, an engineer on the GROW program, said she looked at six other large green infrastructure programs run by municipalities and authorities, and GROW was the largest public grant program for preventing stormwater from entering the sewer system. Philadelphia has spent more, but the program includes funding for non-public entities, and ALCOSAN is only able to fund public projects. 

Where it can matter

The “predicament” over the past two decades, Williams said, is that ALCOSAN was not meeting the requirements of the Clean Water Act, even though most people didn’t realize sewage overflow was a problem.

“To the average person looking at the rivers, streams and creeks, [the water] was pristine,” she said. “To the naked eye, nobody thought there was a need for additional investment.”

ALCOSAN's consent decree with the EPA requires it to spend $2 billion to reduce the amount of sewage that flows into the rivers near Pittsburgh, including the Allegheny River. (Photo by Jay Manning/PublicSource)
ALCOSAN’s consent decree with the EPA requires it to spend $2 billion to reduce the amount of sewage that flows into the rivers near Pittsburgh, including the Allegheny River. (Photo by Jay Manning/PublicSource)
ALCOSAN’s consent decree with the EPA requires it to spend $2 billion to reduce the amount of sewage that flows into the rivers near Pittsburgh, including the Allegheny River. (Photo by Jay Manning/PublicSource)

In Pittsburgh in particular, the problem is that sewage from people’s homes is flushing into the same pipes that collect rain during storms. So nearly every time it rains, the pipes get too full and the overflow sewage pours into the Allegheny, Monongahela and Ohio rivers. Between May and July this year, there were more days when sewage poured into the rivers than days when it didn’t. ALCOSAN estimates that about 9 billion gallons of its sewer water end up in the rivers in an average year. 

The original consent decree plan signed in 2008 would have cost $3.6 billion to remove all of the sewage by 2026, but it was deemed too onerous for ratepayers. A modification of the plan submitted in 2013 would have reduced that cost to $2.8 billion to be spent on upgrades of its treatment plant and underground pipes. Another revision of the consent decree signed in September requires ALCOSAN to reduce the amount of sewage overflows into the rivers from 9 billion gallons to 2 billion gallons by 2036 and offers flexibility to include green infrastructure. The overall cost has dropped to $2 billion.

In theory, the new consent decree with the EPA gives ALCOSAN an extra decade to see how well green infrastructure could work. But in practice, a decision about how to spend its money will have to come much sooner because it takes years to design and build such projects.

During Prevost’s presentation at the Three Rivers Wet Weather Sewer Conference, he showed a map that identified a handful of green areas, overwhelmed by other colors that represent areas ALCOSAN found unpromising or completely unsuitable for anything other than gray infrastructure.

Prevost highlighted three of the main areas where green infrastructure may be cheap enough to replace gray infrastructure: on the North Side by the Carnegie Science Center, by the Birmingham Bridge on the South Side and along a stream in Aspinwall. These results are preliminary, he said. The full study won’t be published until April. 

He didn’t know how much the green infrastructure would cost in the 12 most promising spots, except that early estimates suggest it may be cheaper than the $29 million estimated costs of pipes. But whether or not it will actually be cheap enough, Prevost said, will require further analysis. “Those were the few areas where [the costs] were close,” he said. “Most times they weren’t close.” 

ALCOSAN eliminated areas that are virtually impossible to build in, such as streams, wetlands and on railroads, Prevost said. Then they eliminated buildings, which cover more than a quarter of their service area, because it’s expensive to build green infrastructure on buildings. 

It’s also expensive when there are significant underground utilities, steep slopes, shallow groundwater, unsuitable soils or streets that would have to be dug up. Trying to add green infrastructure on hillsides can lead to landslides; adding it near buildings can lead to basement flooding.

Through this process, ALCOSAN identified 59 sites where it could be cost-effective to use green infrastructure. At those 59 sites, it would cost $48 million to build 203 acres of green infrastructure and remove about 149 million gallons per year from the sewer system, according to the study. 

But while there are a number of locations to build green infrastructure in a cost-effective way, most of the projects would not be as effective in removing rainwater as the three large underground tunnels that ALCOSAN is planning to build or any of the additional pipes needed to feed those tunnels, the analysis showed. There are only 12 sites that appear both cost effective and may eliminate the need for some pipes, totaling around $29 million.

The Liberty Green park in Larimer will serve as the winding symbolic head of the Little Negley Run stream. In addition to a community plaza and picnic areas, it will include a public art installation that mimics the top of the stream.
The Liberty Green Park in Larimer will serve as the symbolic head of a massive green infrastructure project that is being designed by the Army Corps of Engineers and Pittsburgh Water and Sewer Authority, pictured here in 2018. (Photo by Terry Clark/PublicSource)

For example, Prevost said, Negley Run is one of the sites that looks most promising and has community support. PublicSource wrote about the community’s efforts to take an underground stream and bring it back above ground to ferry stormwater back to the Allegheny River. But Prevost doesn’t think that site is likely to eliminate the need for gray infrastructure. 

“We’re cursed with engineering knowledge,” he said. “…So I see the gray facilities as being necessary.”

Green without green

Hoffman said that watching ALCOSAN’s presentation made him feel like they were working hard to eliminate places where green could work.

By contrast, he said, PWSA is spending tens of millions of dollars building large green infrastructure projects. “So you sort of wonder, ‘What is the difference?’ You know?” Hoffman said.

One of the differences is that PWSA’s board has taken responsibility for improving the water quality of local streams, reducing basement backups and is in discussions with the city to take over responsibility to reduce some flooding problems. For PWSA, the benefit of getting sewage out of the rivers is only one aspect of what green infrastructure can do.

Ian Lipsky (center) talked to ALCOSAN board members and officials about the permeable sidewalk at a small green infrastructure project. (Photo by Oliver Morrison/PublicSource)
Ian Lipsky (center) talked to ALCOSAN board members and officials in fall 2018 about the permeable sidewalk at a small green infrastructure project. (Photo by Oliver Morrison/PublicSource)

ALCOSAN’s analysis is focused strictly on the cost of removing sewage from the rivers. “My engineers, my project managers, some of them are referred to as scrooges because we are always trying to ratchet down to make sure we are protecting the ratepayers’ investment,” Williams said at the press conference in September.

PWSA is planning to spend $19.7 million on green infrastructure in the city in 2020 and Weimar said he expects to spend more than $130 million over the next five years. The agency spent $13.8 million on green infrastructure over the past four years. PWSA has been ramping up its spending, in part to show the EPA that some of the tunneling ALCOSAN is planning to build can be replaced by green infrastructure, Weimar said. 

PWSA has been funding this work on the backs of its ratepayers, Weimar said, and ALCOSAN hasn’t spent as much as he’d like to support its large-scale projects. “We’ve gone to them and said we could use several hundred million dollars if you’re willing to give it to us and their response is, ‘We have to make sure everyone gets their fair share,’” Weimar said.

So far, PWSA has received about $9.4 million from ALCOSAN’s GROW fund to support 17 projects. It’s about a third of the total money awarded, the most of any recipient and proportionate to the size of PWSA’s customer base, according to ALCOSAN.  

It’s a small portion of the amount PWSA plans to spend on green infrastructure. Many of the best green infrastructure sites ALCOSAN has identified are in Pittsburgh because that’s where most of the combined sewer and stormwater systems are: most of ALCOSAN’s other areas keep their stormwater and sewage separate. ALCOSAN recently raised the limit that it can spend to support larger projects like the ones PWSA is undertaking, from $2 million to $10 million.

“The GROW program is not the type of green infrastructure that we think about that is benefiting communities by providing a more ecological and green neighborhood,” said John Stephen, an advocate for green infrastructure with the Negley Run Task Force. “It’s really whatever it takes to keep stormwater out of the ALCOSAN system.”

Aly Shaw, an environmental justice organizer for Pittsburgh United, said ALCOSAN’s new emphasis on green infrastructure appears to be cosmetic, an attempt to placate, “rather than putting money behind it.” 

A couple of PWSA’s largest projects could cost around $50 million each, she said. “ALCOSAN is committing a couple of million dollars here and there, not at the scale PWSA would need to implement those projects quickly, instead putting the burden on Pittsburgh residents.”

Vallarian, the director of communications for ALCOSAN, said it’s fair to call the GROW program a green program and that there isn’t widespread agreement by the public about what should count as green infrastructure. He said ALCOSAN’s daily work treating sewer water should count as green. “It’s all well and good to talk about building rain gardens in neighborhoods and all of that stuff,” he said. “But you have to think about ALCOSAN as a whole. ALCOSAN, as a whole, is a green organization … We do green revitalization of the waterway every damned day of the week.”

About $11 billion of the $29 billion spent on ALCOSAN's Green Revitalization of our waterways program has been spent on green stormwater infrastructure (GSI). (Image courtesy of ALCOSAN)
About $11.3 million of the $29 million ALCOSAN has spent on its Green Revitalization of Our Waterways [GROW] program has been spent on green stormwater infrastructure [GSI]. (Image courtesy of ALCOSAN)

Jan Oliver, the director of regional conveyance at ALCOSAN, said the authority is focused on achieving compliance with the EPA, so it’s appropriate to consider funding all methods of reducing stormwater, not just green infrastructure. “And if you are not talking about that, you are talking about green infrastructure as a method of [economic] development,” she said, “and that is not the type of authority that we are.”

The other $20 million of GROW funding already distributed has gone to more than 40 of ALCOSAN’s other municipal customers, only about $3 million of which has been spent on green infrastructure. ALCOSAN serves 83 agencies overall and wants to help smaller municipalities in the county with fewer resources.

“We’ve got a set amount of money and once that money is gone, the GROW program is over,” Prevost said. “There is no extra money coming from anywhere.”

Compensating for the future

Climate change could throw a wrench into ALCOSAN’s projections for how much sewage overflow will reach the rivers. According to a 2017 RAND study, the amount of rainfall in the region may be increasing and even after the $2 billion is spent, the rivers could still take in an annual average of 4 billion gallons of sewage in 2036.

The green infrastructure PWSA and ALCOSAN are investing in could eventually compensate for the additional rain climate change could bring. ALCOSAN has been trying to send the message, Prevost said, that green and gray infrastructure support each other’s reliability and performance.

ALCOSAN hasn’t changed its models to account for climate change, Williams said, and Prevost isn’t convinced that ALCOSAN should.

“It’s to be determined,” Prevost said. “I’ve been through droughts around here. Everything goes up, everything goes down. It’s cyclical. We’ll just see. That’s the whole part of adaptive management.”

Adaptive management is the term in ALCOSAN’s consent decree that gives it the flexibility to change course, particularly if the kinds of green infrastructure projects PWSA is investing in prove to be more successful than ALCOSAN is predicting.

“These things are going to be fluid,” Williams said at the press conference in September. “That’s no pun on the issue but yes, they have to be fluid.”

Oliver Morrison is PublicSource’s environment and health reporter. He can be reached at or on Twitter @ORMorrison.

This story was fact-checked by Remy Davison and Juliette Rihl.

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Oliver Morrison is a general assignment reporter at WESA. He previously covered education, environment and health for PublicSource in Pittsburgh and, before that, breaking news and weekend features for...