Capital Program Planning for Massachusetts Gas Utilities

by | Oct 21, 2026

Massachusetts · Natural Gas Utilities

Massachusetts is deciding how much gas system to keep. Your capital plan is where that gets answered.

The DPU's Future of Gas order and a net-zero-by-2050 mandate put a ceiling on long-term throughput, even as the GSEP program obligates roughly half a billion dollars a year replacing leak-prone pipe. Every one of those forces moves the projects on your list. Invizion helps gas utilities re-sequence a capital portfolio in a click — and defend every decision.

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The bottom line: Massachusetts is actively deciding how much of its gas system to keep: the DPU's Future of Gas order and a net-zero-by-2050 mandate cap long-term throughput while GSEP still obligates roughly $0.5 billion a year in pipe replacement. The utilities that stay defensible will be the ones whose capital plans can re-sequence as fast as the policy changes.
1.6M1
Residential natural gas customers in Massachusetts — roughly 1.75 million counting commercial and industrial.
~17%2
Share of Massachusetts gas mains still considered leak-prone as of 2024.
>$40B2
Projected lifetime cost of the GSEP leak-prone-pipe replacement program — about $0.5 billion a year.
20503
Net-zero mandate behind the DPU's Future of Gas order — the ceiling on long-term gas throughput.

The Massachusetts Landscape

Four forces are moving your project list at once

None of these is theoretical, and none of them waits for your next budget cycle. Together they mean the capital plan you approved last year may already be the wrong plan.

System Integrity & Aging Pipe

Half a billion a year, chasing a shrinking window

Roughly 17% of the state's gas mains were still leak-prone as of 2024, and the 2014 Gas System Enhancement Plan (GSEP) law obligates utilities to replace them — at about $0.5 billion a year, on a path toward a lifetime cost projected to exceed $40 billion, targeting completion by 2039.2

The safety stakes are not abstract here: HEET mapped more than 20,000 gas leaks across Massachusetts in 2015,4 and the 2018 Merrimack Valley disaster — one death, dozens of fires, and over $1 billion in damage — reset the state's tolerance for deferred integrity work.5

Decarbonization & Electrification

A regulator asking how much gas system to keep

In its December 2023 Future of Gas order (D.P.U. 20-80), the DPU found that continuing to grow the gas system is inconsistent with the Commonwealth's net-zero-by-2050 mandate.3 It directed utilities to weigh non-pipeline alternatives — including networked geothermal — before major gas investments, moved to end the subsidy that lets new hookups be cross-subsidized by existing customers, and declined to endorse widespread hydrogen blending for building heat.3

With the 2021 climate law locking in a 50% cut by 2030 and net zero by 2050,6 every long-lived dollar spent replacing pipe now carries stranded-asset risk on a 2050 horizon.

Supply, Peaking & Reliability

At the end of a constrained pipeline network

Massachusetts sits at the end of constrained interstate pipelines into New England and leans on LNG and peaking supply to meet design-day demand on the coldest days — a structural exposure that turns winter commodity spikes into higher customer bills.1

With roughly 1.75 million gas customers depending on the system through the heating season,1 capacity and design-day planning stay non-negotiable even as long-term throughput is expected to decline.

Capital Recovery & Regulatory

Rising bills meet a shrinking customer base

The GSEP surcharge recovers pipe-replacement spending between rate cases, but at roughly $0.5 billion a year it has drawn sustained criticism as costly infrastructure being built for a system the state intends to shrink.2

Consolidation has already reshaped the sector: Eversource acquired the former Columbia Gas of Massachusetts for about $1.1 billion in 2020 after the Merrimack Valley failures,7 and now serves over 600,000 gas customers.8 Every dollar recovered from a declining base sharpens the affordability question.

Who Delivers Massachusetts's Gas

A few large investor-owned LDCs and a handful of municipal systems

Massachusetts gas distribution is dominated by investor-owned LDCs regulated by the Department of Public Utilities, alongside a small number of municipal gas departments. The pressures are shared; the accountability path differs.

Investor-owned gas LDCs

Rates & capital recovery regulated by the DPU

National Grid (Boston Gas & Colonial Gas) The state's largest gas LDC9
Eversource Energy (NSTAR Gas) Over 600,000 gas customers in 125 communities8
Eversource Gas of Massachusetts Former Columbia Gas; 300,000+ customers, acquired 20207
Liberty Utilities (New England Natural Gas) Fall River & southeastern Massachusetts10
Berkshire Gas 40,000+ customers, 20 western MA towns (Avangrid)11
Unitil (Fitchburg Gas & Electric) North-central Massachusetts12

GSEP replacement spending across these LDCs runs roughly $0.5 billion a year statewide.2

Municipal gas systems

Governed by their communities, not DPU rate cases

Holyoke Gas & Electric Municipal gas & electric department
Westfield Gas & Electric (Whip City) Municipal gas & electric department
Middleborough Gas & Electric Municipal gas & electric department
Wakefield Municipal Gas & Light Municipal gas & electric department

Massachusetts has only a handful of municipal gas departments; the vast majority of gas customers are served by the investor-owned LDCs on the left.

Rate-Setting & Oversight

Every capital dollar has to be defensible

The DPU sets rates and capital recovery for the investor-owned LDCs, and it is now the same body steering the sector's long-term contraction — so the question on every project is: why this, why now, why at this cost?

  • Department of Public Utilities (DPU) regulates rates, capital recovery, and safety for the investor-owned gas LDCs, and issued the Future of Gas order in D.P.U. 20-80.3
  • Gas System Enhancement Plan (GSEP) is the state's infrastructure-replacement surcharge, created by 2014 law to accelerate leak-prone-pipe replacement with cost recovery between rate cases — now running about $0.5 billion a year.2
  • The Future of Gas order (Dec. 2023) directs LDCs to evaluate non-pipeline alternatives, ends the new-hookup subsidy, and requires long-term plans consistent with net-zero-by-2050 — a structural shift in what capital the DPU will approve.36
  • The Columbia Gas / Eversource transition — a $1.1 billion acquisition after the 2018 Merrimack Valley failures — is a reminder that safety and integrity outcomes can reshape ownership itself.75

How The Capital Gets Recovered

The money is mostly ratepayer money — and it is being scrutinized

Massachusetts gas capital is recovered largely through rate base and the GSEP surcharge, not federal grants. That makes the affordability and stranded-asset case for each project the thing that has to hold up.

  • GSEP surcharge: ~$0.5B/year recovers leak-prone-pipe replacement between rate cases, with a lifetime cost projected to exceed $40 billion — the single largest capital driver in the sector.2
  • Rate base & DPU rate cases remain the primary recovery path for non-GSEP capital, with the Future of Gas order narrowing what qualifies as prudent long-term gas investment.3
  • Merrimack Valley settlements: $143M + $53M — the class-action settlement and federal criminal penalty that followed the 2018 disaster show how integrity failures convert into direct financial exposure.5
  • Non-pipeline alternatives — networked geothermal pilots and targeted electrification — are now an expected line of analysis before major gas spend, redirecting some capital away from traditional pipe.3

Where Invizion Fits

Turn Massachusetts's gas-system decisions into a defensible capital plan

Invizion is scenario-based capital portfolio optimization built for utilities. When a replacement mandate accelerates, throughput forecasts shift, or a decarbonization ruling lands, you don't re-plan by hand for weeks — you model it and decide with a record to stand behind.

1

Model the “what-if” before it's forced on you

A faster main-replacement schedule, a gas-line-extension ban, an RNG mandate — build the scenario and see the impact on the whole portfolio, side by side with today's plan.

2

Re-sequence 500 projects in a click

When priorities move, Invizion re-orders the portfolio automatically — accelerating, stretching, or deferring projects against the constraints you set, not weeks of spreadsheet surgery.

3

Give regulators or your board a defensible record

Every prioritization and trade-off is captured. When you're asked “why this project, why now,” the answer is documented — not reconstructed after the fact.

Massachusetts Gas, In Brief

Questions Massachusetts gas leaders are asking

Short, sourced answers — the same facts we dig into with utilities looking at their capital programs.

What did the DPU's Future of Gas order actually change?
In D.P.U. 20-80 (December 2023) the DPU found that expanding the gas system conflicts with net-zero-by-2050, directed utilities to weigh non-pipeline alternatives such as networked geothermal, moved to end the subsidy for new gas hookups, and was skeptical of hydrogen for building heat.36
How big and how expensive is the GSEP pipe-replacement program?
About 17% of Massachusetts gas mains were still leak-prone as of 2024. GSEP obligates utilities to replace them at roughly $0.5 billion a year, with a projected lifetime cost above $40 billion and a target completion around 2039.2
Who are the main gas utilities in Massachusetts?
National Grid (Boston Gas and Colonial Gas) is the largest, followed by Eversource, which serves over 600,000 customers including the former Columbia Gas of Massachusetts it acquired in 2020. Liberty Utilities, Berkshire Gas, and Unitil's Fitchburg operation round out the investor-owned LDCs.987
Why is the Merrimack Valley disaster still relevant to capital planning?
The 2018 over-pressurization killed one person, caused dozens of fires and over $1 billion in damage, led to $143 million in class settlements and a $53 million federal penalty, and forced Columbia Gas to sell its Massachusetts system to Eversource — the clearest illustration of how integrity risk becomes financial and structural risk.57
How is this capital recovered, and is there federal money?
Massachusetts gas capital is recovered mostly through rate base and the GSEP surcharge — ratepayer money, not federal grants — which is exactly why the affordability and stranded-asset case for each project matters so much.23
How does Invizion help Massachusetts gas utilities plan capital?
Invizion is scenario-based capital portfolio optimization for utilities. It lets you model how a Future of Gas requirement, a GSEP acceleration, a non-pipeline alternative, or a declining-throughput forecast reshuffles your whole project list, re-sequence the portfolio automatically, and keep a defensible record of every trade-off for the DPU.

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About the Author

GB

Guy Barlow

President, Invizion

Guy Barlow leads Invizion, a capital lifecycle management platform for water and wastewater utilities. He has spent two decades at the intersection of utility capital programs, funding, and analytics, helping utilities make faster, more defensible capital decisions.

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Invizion helps utilities model, optimize, and defend their capital programs. Explore how it works, or read our latest thinking on capital planning across the utility sector.

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This briefing was last reviewed September 2026.

Sources

  1. U.S. Energy Information Administration — Massachusetts number of natural gas consumers (2024): 1,604,279 residential, 138,545 commercial, 10,916 industrial. www.eia.gov
  2. HEET (Home Energy Efficiency Team) — GSEP overview: ~17% of pipes leak-prone as of 2024, ~$0.5B/year, projected lifetime cost above $40B, 2039 target, tension with net-zero 2050. heet.org/gsep
  3. Massachusetts Department of Public Utilities — Order in D.P.U. 20-80, Investigation into the Future of the Natural Gas Distribution Industry, issued December 2023. eeaonline.eea.state.ma.us
  4. HEET — statewide gas-leak mapping: more than 20,000 gas leaks mapped across Massachusetts in 2015. heet.org
  5. Merrimack Valley gas explosions (Sept. 13, 2018) — one death, dozens of fires, over $1B in damage, $143M class settlement (2019), $53M federal fine; Columbia Gas ordered to sell MA operations. en.wikipedia.org
  6. Massachusetts Executive Office of Energy and Environmental Affairs — Clean Energy and Climate Plan / Global Warming Solutions Act: 50% cut by 2030, net zero by 2050. www.mass.gov
  7. Columbia Gas of Massachusetts — 300,000+ customers; Eversource acquisition completed October 2020 for ~$1.1 billion; $53M fine. en.wikipedia.org
  8. Eversource Energy — serves over 600,000 natural gas customers in 125 Massachusetts communities. en.wikipedia.org
  9. National Grid US — Massachusetts gas delivery via Boston Gas Company and Colonial Gas Company (largest gas LDC in the state). www.nationalgridus.com
  10. Liberty Utilities (New England Natural Gas Company) — natural gas service in the Fall River and southeastern Massachusetts area. new.libertyutilities.com
  11. Berkshire Gas Company — more than 40,000 customers across 20 western Massachusetts communities; a subsidiary of AVANGRID. www.berkshiregas.com
  12. Unitil Corporation — Fitchburg Gas and Electric Light Company serves north-central Massachusetts; Unitil serves 75,900+ gas customers across NH, MA and ME. unitil.com