The employee-owned tunnel and heavy civil engineering firm that has spent seven decades solving the hardest problems beneath our feet.
Above: the Delve Underground wordmark - a 2022 rebrand of the former McMillen Jacobs Associates, a firm founded in 1954. Seattle, Washington.
There is a whole city beneath your city - a lattice of tunnels, shafts, and pipelines that carries your morning train, the water in your tap, and the power in your walls. You rarely think about it, which is exactly the point. Delve Underground is one of the firms that engineers it. Founded in 1954 as Jacobs Associates and known for years as McMillen Jacobs Associates, the company adopted the name Delve Underground in a 2022 reorganization, choosing a word that doubles as a job description: to delve is to dig, and to investigate deeply.
Today the firm employs roughly 350 people across 21 to 25 offices in the United States, Canada, Australia, and New Zealand. It is employee-owned - the people designing the tunnel also own the company - and it concentrates on four markets where the work is unavoidably below grade: transportation, water, wastewater, and energy. This is a profile of what that specialization looks like, who it serves, and why a 70-year-old engineering firm decided its name should be a verb.
Plenty of large engineering firms will build anything a client asks for - a bridge, a road, a stadium, a tunnel. Delve Underground made a different bet. It built its identity around the parts of a project that live below the surface, and around the specific disciplines that underground work demands: geotechnical, structural, mechanical, electrical, mining, and geological engineering, plus hydraulics, hydrology, and computational fluid dynamics modeling.
The result is a full-lifecycle practice. Delve designs new tunnels and shafts, delivers them through design-build and construction management, inspects and rehabilitates aging ones, and - when a project ends up in dispute - provides claims analysis and expert-witness testimony. It is unusual for one firm to both design a tunnel and be qualified to defend that work in a courtroom.
"Our new name reflects our company culture of working collaboratively and delving deep to inspire bold and responsive solutions."
— Victor Romero, President & CEOTransportation, water, and utility tunnels, deep shafts, and underground stations - designed for difficult ground and high groundwater.
Microtunneling, pipe jacking, and other no-dig methods that install and renew infrastructure without opening the street.
Condition assessment, monitoring, and rehabilitation of existing and aging tunnels and underground assets.
Design-build delivery, temporary works design, and construction management for heavy civil projects.
Geotechnical and multidisciplinary engineering, ground risk assessment, and hydraulic and CFD modeling.
Claims analysis, dispute resolution, and expert-witness services when underground projects go sideways.
Delve concentrates on four sectors where infrastructure is inherently underground. Relative emphasis shown below is illustrative of the firm's stated focus, not audited financials.
The customer list is mostly public and utility infrastructure: transit authorities, water and wastewater utilities, and departments of transportation, plus energy operators such as Pacific Gas and Electric and heavy-civil contractors that need a specialist on their team. These are B2B relationships, sold as professional engineering and consulting fees rather than products.
Underground work fails or succeeds on the ground itself. The Bay Tunnel, for example, sits 75 to 110 feet down in sandy and silty clays under high groundwater pressure, cutting through weathered Franciscan Complex bedrock. Delve's toolkit for such conditions includes ground freezing, grouting, dewatering, and rigorous ground-risk assessment - the discipline of pricing uncertainty you cannot see until you dig into it.
Large multidisciplinary rivals - Mott MacDonald, Arup, Jacobs Solutions, Hatch, and specialists like Brierley Associates and Aldea - compete for the same underground programs.
Delve's distinction is focus. Where a general engineering giant treats tunneling as one line of business among dozens, Delve organizes the entire firm around underground excellence, and it does so as an employee-owned company. That ownership structure matters more than it sounds: when staff own the firm, the incentive tilts toward the long project horizon and toward keeping the specialists who carry decades of hard-ground judgment. The 2022 rebrand also solved a plainer problem - years of confusion with other "Jacobs" firms across the architecture and engineering industry. A distinctive name is, quietly, a competitive advantage.
"Often the best way from point A to point B is underground."
— Delve UndergroundThe model is straightforward professional services: Delve earns fees from public agencies, utilities, and contractors for design, design-build, construction management, inspection and rehabilitation, and dispute resolution. Because the firm is employee-owned, the profit those fees generate flows to the people doing the work rather than outside shareholders.
Its market position is that of a mid-sized specialist in a field dominated by both global engineering conglomerates and small boutique consultancies. At roughly 350 people across four countries, Delve is large enough to staff marquee programs - San Francisco's Central Subway, Auckland's Waterview Connection, Seattle's Ship Canal Water Quality Project - yet focused enough to be the underground expert other firms call in. Its lineage runs deep in energy too: some of its earliest work was on Australia's Snowy Mountains hydropower scheme in the 1950s and the underground Hyatt Powerhouse at California's Oroville Dam.
The firm that becomes Delve Underground opens, focused on tunneling and heavy civil engineering.
Provides construction engineering and temporary works design for Australia's Tooma-Tumut Tunnel.
Jacobs Associates merges with McMillen LLC, broadening its water and energy capabilities.
Shareholders vote on Nov 17, 2022 to separate the underground business, effective December 1.
The firm publicly launches its new name and identity and announces new principals in January.
Marks 70 years of underground work and joins the International Hydropower Association.
It is a heavy civil and tunnel engineering firm that designs, builds, inspects, and rehabilitates underground infrastructure for transportation, water, wastewater, and energy projects, plus construction management and dispute resolution.
Yes. Founded in 1954 as Jacobs Associates, it became McMillen Jacobs Associates after a 2014 merger, then rebranded as Delve Underground in late 2022 / early 2023.
Victor Romero serves as President and CEO. The firm is employee-owned.
Roughly 350 team members across 21 to 25 offices in the United States, Canada, Australia, and New Zealand.
The Bay Tunnel, San Francisco's Central Subway, Auckland's Waterview Connection, the Ship Canal Water Quality Project, and hydropower work such as PG&E's Helms Pumped Storage Project.
Watch: project stories and demos on the firm's channel - youtube.com/@delve_underground ↗
Facts in this profile are drawn from Delve Underground's own site and public trade coverage. Figures such as revenue and office count are approximate. Contact: romero@delveunderground.com · +1 949-889-2523 · 1011 Western Ave, Seattle, WA 98104.