The 3RiversProud Clean Water Plan: A Green-First Proposal for Pittsburgh

Every year, nine billion gallons of diluted sewage — rain and snowmelt mixed with raw wastewater — overflow into Pittsburgh's three rivers. The Allegheny County Sanitary Authority, ALCOSAN, is under a federal consent decree to stop it. The agency has a plan, and it includes green infrastructure. But green is not the priority. We believe it should be.

This proposal lays out a different vision: one where green infrastructure comes first, where neighborhoods most affected by sewer overflows see investment first, and where the proven success of Philadelphia's green-first approach becomes the model for Pittsburgh.

Background: How We Got Here

ALCOSAN treats wastewater for 83 of Allegheny County's 130 municipalities. Its treatment plant, located on Pittsburgh's North Side beneath the McKees Rocks Bridge, currently handles 250 million gallons per day. Under the Clean Water Plan, the plant will be retrofitted to manage 600 million gallons per day by 2027 — more than doubling its capacity.

A 2008 consent decree from the Pennsylvania Department of Environmental Protection and the Allegheny County Health Department requires ALCOSAN to eliminate sanitary sewer overflows and reduce combined sewer overflows to comply with the federal Clean Water Act. The original compliance deadline was September 2026. ALCOSAN's Executive Director, Arletta Scott Williams, acknowledged in 2018 that the deadline would likely be extended to 2032 or 2036.

"We got to a point where we and the regulators recognized, 'You're not going to be able to accomplish this in the time period that we wanted you to.' I like to say you can't get blood from a turnip. There's only so much money and resource available." — Arletta Scott Williams, ALCOSAN Executive Director, January 2018

The authority expects to invest roughly $2 billion in infrastructure upgrades under the Clean Water Plan. That investment includes prioritizing green infrastructure projects to divert water before it ever reaches the conveyance and treatment system. But the scale of green investment remains the central question.

The Core Problem: Gray Dominates, Green Is an Afterthought

ALCOSAN's Wet Weather Plan, as presented in 2019, includes green infrastructure — but it also contains timelines for massive gray infrastructure projects: deep tunnels, expanded treatment capacity, and human-engineered conveyance systems. Green is included; it is not prioritized.

Currently, $100 million is allocated for green infrastructure through ALCOSAN's Green Revitalization of Our Waterways (GROW) program. ALCOSAN's communications director, Joey Vallarian, has stated that this figure is not a hard limit and that the plan is adaptable. But adaptability only matters if there is pressure to adapt. Without a committed, binding allocation, green infrastructure will remain a supplement to gray, not a replacement for it.

"We just have to get ALCOSAN to invest, quickly, large-scale, in green." — Lois Campbell, Sierra Club, October 2019

The window to prove that green infrastructure works is narrow. Design for the first tunnel section is expected to begin within a few years. Once tunnel contracts are signed and construction is underway, the financial and political momentum shifts decisively toward gray. As Brenda Smith, head of the Nine Mile Run Watershed Association and an ALCOSAN board member, explained:

"It's really incumbent on those of us who favor green solutions to, as quickly as possible, get the evidence that they will perform." — Brenda Smith, Nine Mile Run Watershed Association, October 2019

Philadelphia Proved It Works

In 2011, the Philadelphia Water Department reached its own agreement with federal authorities and won approval for a green-first approach to managing stormwater. Eight years into a 25-year plan, independent analysis confirmed that tools such as tree trenches and rain gardens are reducing overflows — exactly the outcome Pittsburgh needs.

The analysis, conducted by Econsult Solutions for the Sustainable Business Network of Greater Philadelphia, found that green infrastructure delivers benefits far beyond clean water:

• Equitable distribution: Green projects were disproportionately located in low- to moderate-income neighborhoods, meaning the benefits flowed to communities that needed them most.
• Economic development: Because green projects tend to be smaller and more dispersed, local businesses could be contracted as vendors — spreading economic impact across the community rather than concentrating it in a few large construction firms.
• Community amenities: Green infrastructure creates open space, tree canopy, and recreational assets that improve quality of life and property values.
• Climate resilience: Green systems absorb rainfall naturally, reducing flash flooding and easing the burden on the combined sewer system during increasingly intense storm events.

"They were disproportionately located in low- to moderate-income neighborhoods, and seeing that we consider them as beneficial we think that that's a good thing." — Lee Huang, Vice President of Econsult Solutions, October 2019

The 3RiversProud Proposal

We are not asking ALCOSAN to abandon gray infrastructure. The treatment plant expansion and conveyance upgrades are necessary. We are asking that green infrastructure be given a real, binding priority — not as a supplement, but as the first line of defense.

Section 1 Binding Green Infrastructure Allocation

Mandate that a minimum of 40% of the total Clean Water Plan budget — approximately $800 million of the $2 billion investment — be allocated to green infrastructure projects before tunnel construction begins. This is not a ceiling; it is a floor. The current $100 million GROW allocation represents roughly 5% of the total plan. We propose an eightfold increase, with a binding commitment rather than an adaptable guideline.

If green infrastructure projects demonstrate performance equal to or better than projected — as Philadelphia's have — the allocation should be eligible for increase. If projects underperform, the 40% floor still ensures meaningful investment in community-level solutions while gray infrastructure fills the gap.

Section 2 Expand and Restructure the GROW Program

The GROW program is currently the only mechanism through which green infrastructure funding can be accessed. We propose three reforms:

1. Remove the funding cap. The $100 million figure should not be a limit. Green infrastructure funding should scale with demonstrated demand and project pipeline, not an arbitrary cap.
2. Streamline the application process. Smaller community organizations and watershed associations should be able to apply for GROW funding without navigating a process designed for large municipalities. Technical assistance should be provided free of charge.
3. Allow non-GROW funding for green. As Lois Campbell of the Sierra Club noted, advocates have told ALCOSAN, "You can use other money." Green infrastructure should be eligible for funding from any Clean Water Plan budget line, not exclusively through GROW.

Section 3 Prioritize Equity and Environmental Justice

Sewer overflows do not affect all communities equally. Low-lying neighborhoods, communities with aging infrastructure, and low- to moderate-income areas bear the brunt of combined sewer overflows. Following Philadelphia's model, green infrastructure projects should be prioritized in these neighborhoods first.

We propose an equity scoring system for all green infrastructure projects, weighing factors including:

• Median household income of the project area
• Documented frequency and volume of sewer overflows in the service area
• Existing tree canopy and green space deficit
• Flood risk and climate vulnerability
• Public health indicators related to water quality

Projects scoring highest on equity criteria should receive priority funding and expedited review.

Section 4 Local Economic Impact Requirements

Because green infrastructure projects are smaller and more dispersed than gray infrastructure megaprojects, they create opportunities for local businesses that large tunnel contracts do not. We propose:

• A local hiring requirement for green infrastructure construction contracts, prioritizing residents of Allegheny County and specifically of the neighborhoods where projects are located.
• A small business set-aside, reserving a percentage of green contracts for firms with fewer than 50 employees and revenue below a defined threshold.
• Apprenticeship and workforce development partnerships with local trade schools and community organizations, building a pipeline of workers trained in green infrastructure installation and maintenance.

Section 5 Performance Monitoring and Public Reporting

To build the evidence base that Brenda Smith and other advocates have called for, all green infrastructure projects funded through the Clean Water Plan must include performance monitoring from day one. We propose:

• Real-time monitoring of stormwater capture volume for every project above a defined scale threshold.
• Annual public reporting of aggregate green infrastructure performance, published in plain language and distributed to all 83 ALCOSAN-served municipalities.
• An independent review panel including watershed associations, academic researchers, and community representatives to evaluate performance data and recommend adjustments to the green-gray allocation.

Section 6 Community Engagement and Governance

The Clean Water Plan affects 83 municipalities and more than 800,000 residents. The public must have a meaningful voice in how it is implemented. We propose:

• A standing Clean Water Plan Community Advisory Board with representation from watershed associations, environmental organizations, neighborhood councils, and public health advocates.
• Quarterly public meetings in rotating locations across Allegheny County, with childcare, translation services, and transportation assistance provided to remove barriers to participation.
• A public dashboard tracking Clean Water Plan spending, project status, and green infrastructure performance metrics, accessible to all residents.

The Cost of Inaction

If ALCOSAN proceeds with a gray-dominant plan, the consequences are clear and lasting:

A Note on Affordability

With the expansion of the wastewater treatment plant, rates are expected to increase. Affordability remains one of ALCOSAN's main concerns, as Executive Director Williams has acknowledged. We take this seriously. Green infrastructure does not increase total plan costs — it redirects spending from large gray contracts to smaller, distributed green projects that deliver more benefits per dollar. A green-first approach is an affordability strategy, not a luxury.

Furthermore, the local economic impact requirements in Section 4 ensure that ratepayer dollars stay in Allegheny County, supporting the same communities that pay the bills.

The Path Forward

ALCOSAN has said its plan is adaptable. We are asking them to adapt it — now, before tunnel designs are locked in and the momentum shifts irreversibly toward gray. The evidence from Philadelphia is clear. The technology is proven. The community demand is real. What is needed is political will.

This is our moment. Pittsburgh's three rivers defined this city's past. They should define its future — not as conduits for sewage, but as clean, living waterways that sustain our communities, our economy, and our identity. 3RiversProud.

Related Reading

Clean Water Plan, Policy & Advocacy

Understanding ALCOSAN's Wet Weather Plan and the Consent Decree

A 2008 consent decree requires ALCOSAN to eliminate sanitary sewer overflows and reduce combined sewer overflows. Here's what's at stake — and why the timeline keeps slipping.

August 10, 2026 8 min read

Green Infrastructure, Policy & Advocacy

Philadelphia's Green Infrastructure Model: Lessons for Pittsburgh

In 2011, Philadelphia won federal approval for a green-first approach to stormwater management. Eight years in, the data shows it works — and the benefits go far beyond clean water.

August 8, 2026 7 min read