We know the ground because it’s ours.
all six New England states. Every area below sits on a different slice of the Boston Basin, and the ground is what decides the system. The notes are general to each area — not a substitute for a site-specific subsurface investigation.
Service areas
Where we work
Pick an area for the local subsurface note, the techniques that suit it, and the projects we've run there.
Back Bay & South End
Made land over tidal mud and marine clay, rowhouses on wood piles, and the GCOD over nearly all of it: underpinning, basement lowering and shoring for Back Bay and the South End.
Nineteenth-century fill over tidal mud and thick marine clay, with rock at a median depth of 123 ft in public logs. Buildings stand on wood piles, and nearly all of the land is inside the GCOD.
Beacon Hill
Glacial till on the hill, fill on the flat, party walls throughout: underpinning and basement lowering on Beacon Hill, where access is often by hand.
Dense glacial till under the hill and nineteenth-century fill over the river flats below it; rock is deep under both, and the flat is inside the GCOD.
South Boston & Seaport
Drumlins and shoreline fill under South Boston's triple-deckers, deep harbor fill under the Seaport: basement lowering, infill shoring and support of excavation below the water table.
Glacial drumlins and shoreline fill inland; the Seaport is made land on the harbor flats over soft clay, with rock at a median depth of 82 ft in public logs.
Cambridge & Somerville
Tight infill 4 to 8 feet from the neighbor, on ground that runs from filled flats and clay in Cambridge to shallow rock in Somerville: shoring, underpinning and drilled support.
Filled river flats, marine clay and glacial sand in Cambridge; thin till over shallow argillite across much of Somerville. Median depth to rock in public logs: 57 ft in Cambridge, 27 ft in Somerville.
Jamaica Plain & Roslindale
Puddingstone ledge on the hills, sand and gravel in the valleys: rock drilling, anchors and shoring for foundations and cuts in Jamaica Plain and Roslindale.
Thin till over Roxbury Conglomerate (puddingstone) on the hills and glacial sand and gravel in the valleys; the middle half of public logs found rock between 15 ft and 101 ft.
Allston-Brighton
Infill beside occupied houses, on ground that runs from filled Charles River flats in Allston to thin till and puddingstone in Brighton: shoring, underpinning and rock drilling.
Filled river flats over clay and sand in Allston; thin glacial till over Roxbury Conglomerate on Brighton's hills, with outcrops in places.
Ready to scope your foundation?
Tell us about the project and we'll put together a detailed quote within 3 days. We generally work with general contractors.
Or email plans to bids@earthsupportcorp.com