When $1.29 Billion Is the Argument for Restraint

There aren’t many votes in which a $1.29 billion option represents the argument for restraint.

That result stands out. Nearly every Advisory Board vote in recent years has been unanimous. This one wasn’t.

After more than four years of planning, MWRA and its partners in Cambridge and Somerville have developed a proposal for the next generation of CSO control. The recommended approach carries an estimated $1.29 billion capital cost. More aggressive alternatives climb to nearly $4.74 billion, while a less expensive option would provide a more limited level of control.

The Advisory Board supported the Partners’ proposed level of CSO control—not a particular package of projects or a specific spending authorization. Some member communities believed even that approach would be too costly for what it delivers. Others supported the Advisory Board’s position while making the case for a less expensive alternative in their own comments to regulators.

What makes this unusual disagreement interesting isn’t simply that members voted differently. It’s what they were being asked to decide—and what the decision tells us about the choices still ahead.

The Updated CSO Long-Term Control Plan is the product of work that began in 2022, including extensive technical analysis, regulatory coordination, seven official public meetings, and numerous opportunities for community engagement.

It also builds on decades of earlier investment that dramatically reduced combined sewer overflows into the region’s waterways.

The Partners’ recommended approach, which the Advisory Board has termed Future Storm Protection, would pursue zero modeled CSO discharges during a climate-adjusted 2050 Typical Year. The Advisory Board supports that level of control and recognizes the substantial investment it entails.

Importantly, that recommendation does not constitute approval of individual projects or specific dollar commitments. Project design, implementation, financing, and cost allocation remain matters for further consideration.

But the alternatives do not end there.

Other approaches would provide greater protection during more severe storms, with estimated capital costs rising to approximately $3.46 billion and $4.74 billion.

The environmental benefits of those alternatives deserve serious consideration. So does the difference in cost.

The Advisory Board’s adopted comments question whether the additional benefits of those more expensive alternatives justify imposing billions of dollars in further obligations on communities and ratepayers—particularly when other sources of pollution also stand in the way of making these waterways consistently fishable and swimmable.

This is not an argument against cleaner rivers. It is an argument for making sure the investments intended to deliver them produce benefits commensurate with their cost.

That question becomes even more important when financial obligations extend across decades, and communities must continue funding their own water, sewer, stormwater, and other essential infrastructure.

If regulators ultimately require substantially greater CSO controls, state and federal funding must help pay for those additional requirements. The added burden should not simply fall on the same communities and ratepayers already funding the region’s other essential investments.

Those are consequential policy judgments. They are the substance of the position the Advisory Board adopted.

And they help explain why the vote was not unanimous.

Not everyone drew that line in the same place.

Some representatives considered the proposed level of control too costly. Norwood, for example, supported the Advisory Board’s comments while also advocating for the less expensive Limited CSOs alternative.

The Board’s own approach also reflected the regulatory circumstances. MassDEP had expressed concerns about earlier, less stringent alternatives, making their prospects for regulatory acceptance uncertain. The Advisory Board focused its recommendation on a substantial level of control it believed could be supported by regulators while challenging the justification for spending considerably more.

These are different assessments of the same underlying problem. And within a regional organization representing 60 member communities, they should not be particularly surprising.

In fact, there’s something familiar about the disagreement.

Anyone who remembers the early years of MWRA—or the public frustration over water and sewer bills during the Boston Harbor cleanup—knows that major regional improvements have long been accompanied by difficult arguments about cost and who should bear it.

The pattern is striking.

Capital spending climbed dramatically during the first major era of MWRA construction, reached its historical peak in the 1990s, and then declined into a long period of comparatively lower spending.

The forecast shows another substantial increase ahead, with projected annual spending approaching $1 billion around FY2030, expressed in constant FY2026 dollars.

The projects behind that increase are not optional luxuries. They include Metropolitan Water Tunnel redundancy, major investments in protecting and renewing Deer Island, and other essential water and wastewater infrastructure.

But those are not the only major investments that could lie ahead.

The chart reflects MWRA’s January 2026 proposed FY27 capital forecast. Since then, MWRA’s final FY27 CIP has incorporated $772.4 million in planned spending for seven future CSO projects.

But including those projects in the capital budget is not the same as final regulatory approval of the Updated CSO Control Plan. The ultimate scope, implementation, financing, and cost allocation remain subject to further decisions.

Whatever emerges from that process will need to be managed alongside MWRA’s other major infrastructure commitments.

That broader picture changes how we should understand the October 22 vote.

The question is not simply which level of CSO control the region should pursue. It is also how the resulting commitments will fit among the other major investments the region will need to finance, schedule, construct, and operate.

MWRA’s ability to deliver that work matters, too. Workforce capacity, engineering resources, construction management, and the practical limits of implementation deserve attention alongside the financial projections.

Many of these investments are necessary. That is precisely what makes the choices difficult.