By accident, 18th-century wharf revealed

And the late-1700s wharf might have remained that way — embedded for the ages — had it not been for a recent accidental find.

Last June, as workers excavated portions of Newburyport’s Water Street for the city’s new waste-water operations building, they unearthed large, centuries-old slabs of granite. Based on maps and archaeological research, the giant rectangles of rock were identified as the capping stones of a 19th-century wharf built onto an earlier Revolutionary War wharf owned by Captain William Coombs.

And, as the city’s infrastructure project has continued for the past several months, archeologists have periodically been on-site to document additional finds from the 1700s and 1800s, including more capstones, cribbing supports, and, this month, timbers from an adjacent wharf.

Although many of the structural artifacts are too damaged or contaminated to save, local officials and historians call the find an extraordinary one, providing a conduit between modern times and the country’s beginnings.

“We’re thrilled — how could we not be?’’ said Newburyport Historical Commission member Tom Kolterjahn. “It’s exciting to uncover an important piece of our history.’’

When you think about archeology, you probably imagine workers in trenches by the pyramids or Indiana Jones types overseeing workers in the shade of Mayan temples — probably not at an East Coast waterfront clustered with houses and situated just off a tangled traffic square.

But last summer’s find has reinforced the fact that archeology doesn’t just happen in the pages of National Geographic — and that we never really know what rich history is beneath our feet.

“It’s a great discovery,’’ said Kolterjahn, adding that “often what gets lost is our history.’’

But unfortunately in this case, most of what was lost ultimately can’t be saved.

Much of the area at the intersection of Lime and Water streets — and thus the embedded relics of Coombs’ wharf beneath — is contaminated, largely due to an oil tank farm that operated there in mid 1900s, according to Bill Harris, a local lawyer and historian who compiled an extensive, 62-page history of the site. Thus, it would be difficult to protect it, according to local officials and visiting archeologists, because, in its state, it likely wouldn’t be eligible for the National Register of Historic Places or other historical designations.

Therefore, the bulldozers and excavators are still readying for construction of a new operations, control, and laboratory building on 115 Water St. — covering part of the area where the historical wharf was discovered — as part of Newburyport’s waste-water upgrade and improvement project. Along the way, experts from The University of Massachusetts Amherst’s Department of Archeological Services have been monitoring and documenting, and collecting unearthed artifacts.

Inevitably, some parts of the historic wharf will be disturbed; other parts (such as the granite slabs) will be pulled out, and other portions will remain in the ground, with most of it covered back up, according to project manager Pieter Hartford. Plans have been retooled a bit — as Hartford explained, the building will be shifted about 15 feet west from where the structure was unearthed to minimize the impact.

“We’ve come across something historical, but the integrity of it is no longer intact,’’ he said. However, “if we’re not preserving what’s there, we’re trying to document and learn from it.’’

Kolterjahn agreed that crews are “trying to preserve what they can, and leave as much of it intact as they can.’’

How it’s all been pieced (or rather de-pieced) together so far: In late November, UMass archeologist Timothy Barker determined that the granite caps initially quarried from the site in June likely date to the 19th century. Then, in an excavated trench amid contaminated water, he also identified hand-hewn timbers that probably constituted the crib of the initial wharf likely built by Coombs’s father, Philip Coombs, between 1734 and 1756, according to Harris. In December, more granite capping stones were uncovered, and, earlier this month, timbers from an adjacent wharf were revealed — all of this as local history boosters and buffs stood by.

“It’s fascinating to watch the process and to have a professional archeologist on-site,’’ said Kolterjahn, one of those onlookers.

Eventually, the UMass archeologists — who initially identified several sensitive areas by layering various historical maps over construction plans — will report their findings to the city’s historical commission and the Massachusetts Historical Commission.

At this point, though, many quandaries remain. “It’s evolving as we go along,’’ said Kolterjahn.

Researchers have scant early history to go on.

According to Harris’s research, Ralph Cross sold the site to Philip Coombs on Nov. 30, 1734, for 198 pounds. Somewhere in the 22 years between then and 1756, the elder Coombs is believed to have built a wharf on the waterfront property.

But then, in 1756, he was killed as a prisoner of France in the French-Indian War, and his son William inherited his property. Nearly a decade later, in 1765, the younger Coombs was authorized to build or extend a wharf, according to Harris’s research.

The ensuing Revolution was when the maritime structure made its impression on history. In 1775, it was operating privateers — privately owned and manned boats commissioned by the government to attack enemy ships.

That year and the next, Coombs also organized two key missions to the West Indies to import gunpowder and other military stores for the war — the first believed to be the first Colonial gunpowder importation mission, according to Harris.

Therefore, he said, this isn’t just about local history. “These wharves were of national significance,’’ Harris noted.

Meanwhile, the wharf provided iron, copper, tar, and nails, and was later used for various commercial activities, before Coombs, a Newburyport selectman and state representative, died in 1814.

After that, the wharf’s history goes quiet again, before reemerging in the records in 1860, when the state authorized Edward Kimball and Nahum Perkins to extend it 60 feet.

In the century-and-a-half since, the area was slowly filled in and many buildings were constructed, razed, and built again.

The goal is to have markers and signs on the site once it’s covered up, Kolterjahn said.