A 1,000-ton barge delivery at Steamboat Wharf raises a larger question about Nantucket’s landscaped summer, its mainland supply chain, and the aquifer beneath it all
Don Costanzo • July 7, 2026
From above, the scene looked almost absurdly simple: a barge tied up at the end of Steamboat Wharf, a tug alongside it, a loader pushing a reddish-brown mountain of mulch across the deck, and dump trucks cycling through the wharf before most of Nantucket had finished its first coffee.
But there was nothing small about what was happening. According to Nantucket Current’s public post, Holdgate Partners was unloading an estimated 1,000 tons of mulch from a tug and barge that arrived at Steamboat Wharf a few weeks ago. “They’ve been running 6-8 dump trucks since about 7:15 this morning,” a dock worker told the Current.
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At first glance, it was just another summer logistics scene: another barge, another material, another island business doing what has to be done when nearly everything Nantucket consumes must cross the water first. But the mulch raised a bigger question. Where did it come from? What exactly was it? Why did so much of it arrive at once? And on an island whose drinking water comes from a vulnerable aquifer beneath everyone’s feet, is 1,000 tons of imported mulch something Nantucket should be thinking harder about?
The answer is not as simple as “mulch is bad” or “mulch is harmless.” The more accurate answer depends on the source, the handling, the scale, and the island’s unusual dependence on the ground beneath it.
An Island Load, Not a Homeowner Delivery
The first thing to understand is the size. A thousand tons of mulch is not a few spring landscaping deliveries and it’s not a homeowner refreshing beds around a house. The USDA Natural Resources Conservation Service gives a rough conversion for wood mulch of about five cubic yards per ton, depending on density and moisture content. On that basis, 1,000 tons would be roughly 5,000 cubic yards of mulch.
That is enough to cover about 12 acres at a three-inch depth, using standard landscape geometry. The NRCS also notes that one cubic yard of mulch covers about 324 square feet at one inch deep, which gives a useful way to understand just how much area a shipment of that size represents. In other words, this was not a casual delivery, it was a contractor-scale inventory movement, the kind of bulk import that helps explain how Nantucket’s carefully manicured landscapes are made possible each season.
The island sees the finished version: edged beds, fresh plantings, private hedges, estate lawns, commercial landscapes, hotel grounds, and seasonal properties brought back into summer form. The barge showed the earlier step, before the mulch is spread thinly and made invisible by beauty. It also showed the basic reality of Nantucket’s economy that even the appearance of naturalness often arrives by tug.
The Likely Route: Mainland First, Probably New Bedford
There is no public document, at least among the available records, that identifies the exact loading port, invoice, supplier, or stockyard for this particular mulch shipment. Without a bill of lading, a supplier statement, or a company confirmation, the origin of this exact load cannot be stated as fact. But the available public evidence points in one direction: the mulch almost certainly came from off-island, and New Bedford is the most likely port of embarkation.
The Port of New Bedford describes itself as a hub for bulk and break-bulk cargo, including barge operations that move aggregate and break-bulk freight to Martha’s Vineyard and Nantucket. A 2026 Port of New Bedford request for information similarly notes that there are facilities in the port capable of handling dry bulk and break-bulk cargo, and that barge operations serve the islands.
That fits the visual evidence: loose bulk material, loaded on a barge, moved to Steamboat Wharf, then transferred to trucks. There is also a business clue. Nantucket Current reported in June 2025 that Robert B. Our Co., a Cape Cod construction company, already transported “huge amounts of aggregate and other materials to Nantucket by barge.” New Bedford Light also reported in June 2025 that a Cape Cod construction company was proposing a freight service between New Bedford and Nantucket.
Robert B. Our likely supplied this mulch load and New Bedford was likely the loading point for this shipment.
Holdgate, Robert B. Our, and the Business Behind the Barge
Holdgate Partners is not just a landscaper’s material seller. The company markets itself as a Nantucket excavation, construction, demolition, marine-work, material-sales, and disposal business. Its website lists material sales and delivery as part of its operations, including mulch among the materials sold on-island.
The barge was not an isolated curiosity. It appears to fit into a larger materials economy: excavation companies, marine contractors, aggregate suppliers, construction firms, trucking, barging, and island development all tied together. Robert B. Our Co., based in Harwich, describes itself as a site and utility construction company serving Cape Cod and southeastern Massachusetts. The company’s public materials business includes mulch and wood-processing operations, and Nantucket Current has reported on its existing barge activity to the island.
This is the hidden half of Nantucket’s built environment. The island debates house size, traffic, water use, landscaping, sewer capacity, labor, development, and the cost of living. But behind all of those arguments is a constant physical movement of material: sand, loam, stone, aggregate, lumber, fuel, food, waste, equipment — and mulch.
The mulch barge was visible because it was dramatic. But the operation itself was not unusual. It was the island’s dependency made visible for a morning.
What Kind of Mulch Was It?
Based on the images, the material appears medium-fine, shredded, and reddish-brown. It does not look like jet-black dyed mulch. It does not look like large, chunky bark nuggets. It looks more like a natural softwood bark mulch — likely pine, hemlock, or a blend.
Holdgate’s materials list includes several mulch products, including dyed mulch, generic mulch, aged premium black mulch, aged premium pine mulch, and hemlock mulch. Comparable New England mulch suppliers describe premium pine mulch as a natural aged bark product made from pine, spruce, and fir, with a cocoa-brown color and no color enhancement. Hemlock mulch, meanwhile, is commonly described as red-brown, fine-textured, aromatic, and dye-free. That makes the visual match fairly strong for a natural red-brown softwood mulch, likely pine, hemlock, or a related bark blend, probably aged, and likely sourced through a mainland New England supply chain.
The exact source wood is harder to pin down. It could come from regional forest-product byproducts, lumber-processing operations, or ground wood from recycling streams, if properly sorted. It could be a blended product sold under a local material supplier’s label. Mulch is not a single environmental category, as natural bark mulch and recycled construction debris mulch are not the same thing.
Left, a Tom Nevers estate, “The Dips” shows the scale of Nantucket’s modern landscape economy: 13 bedrooms, 19 bathrooms, expansive lawns, clipped hedges, pool decks, planting beds, driveways, guest structures, and outdoor living spaces that require constant seasonal maintenance. Right, “Harbor Hill,” a waterfront Nantucket compound once listed for $42.5 million, shows how the island’s luxury real estate boom extends far beyond the house itself. With 18,000 square feet of living space arranged as a village of connected “cottages” and extensive outdoor entertaining areas, properties like this require a year-round maintenance system. The mulch arriving by barge is not an anomaly; it is part of the supply chain that keeps properties like this looking effortless.
The Demand Side of the Mulch Barge
The barge did not create the demand, it answered it. A thousand tons of mulch looks shocking from above because the supply chain is usually hidden. By the time the material reaches the public eye, it has been spread into thin, tidy layers properties. The barge showed the scale before the work disappeared into the finished Nantucket look.
That demand has grown with the island itself. Nantucket’s year-round population rose from 10,172 in 2010 to (reportedly) 14,255 in 2020. Some estimates put it over 20,000 year-round. The summer population is far larger, often estimated around 80,000 when visitors and seasonal residents are included. The housing stock tells an even sharper story. In 2022, Nantucket had 13,619 housing units, but only 5,778 were occupied households; most of the rest were vacant, seasonal, recreational, or occasional-use homes.
That means Nantucket is not simply maintaining a town of year-round houses, it’s maintaining thousands of seasonal properties that have to be opened, cleaned, planted, edged, irrigated, mulched, and made ready and maintained on roughly the same calendar. Spring and early summer compress the work. Beds that sat through winter are refreshed. New houses are finished. Old houses are renovated. Rental properties are staged. Estates are prepared for owners who may only be here part of the year but expect the property to look finished when they arrive.
The change is also cultural. There was a time, within living memory, when most Nantucket homeowners cut their own lawns, kept simpler yards, left more of the native landscape alone, and used little mulch, if any. A yard might have been grass, sand, beach plum, bayberry, or whatever could survive without constant attention. The modern Nantucket landscape is different, it is more designed, maintained, irrigated, and more labor-intensive.
Real estate has pushed that shift. Nantucket has become one of the most expensive housing markets in the country. Recent luxury-market reporting put average property prices around $4.1 million and noted that Nantucket real estate prices had risen nearly 40 percent from 2019 into the post-pandemic period. In February 2024, Realtor.com data cited by the New York Post put Nantucket’s median asking price at $4.6 million and median sale price at $3.6 million. Those prices do not just buy houses, they buy expectations — clipped hedges, weed-free beds, fresh mulch, annual plantings, privacy screening, irrigation, and a property-management system that keeps the place looking effortless.
That “effortless” look requires an enormous amount of effort. The growth of seasonal mega-homes has not only increased the size of the houses, it has increased the square footage of designed outdoor space around them. Large houses come with long drives, pool areas, guest houses, terraces, outdoor kitchens, parking courts, foundation plantings, screening vegetation, and formal beds. Each one becomes part of the annual maintenance cycle. A single estate can absorb what once would have been a neighborhood’s worth of landscape material.
The same island that debates teardowns, gut rehabs, house size, traffic, sewer capacity, water use, and the cost of labor also produces a steady demand for the materials that make high-end seasonal properties look finished. The National Trust for Historic Preservation was already warning in 2000 that teardowns, gut rehabs, and the inappropriate sizing and siting of new homes were altering Nantucket’s cultural landscape. Two decades later, that transformation is visible not only in architecture, but in the ground around it.
The Groundwater Question
Nantucket’s sensitivity begins with the aquifer. The U.S. Environmental Protection Agency has designated Nantucket’s aquifer as a sole source aquifer. In its federal designation materials, EPA determined that the Nantucket Island aquifer is the sole or principal drinking water source for Nantucket, and that contamination of that aquifer would create a significant public-health hazard.
The town’s own PFAS information describes the public water supply as being served by Wannacomet wells located in Nantucket’s sole source aquifer, including shallow wells at about 75 feet and deeper wells at about 150 feet. That means Nantucket does not have the luxury of treating land-use questions as separate from water questions. What goes on the ground, runs off pavement, infiltrates through sandy soils all matter. Fertilizer, septic systems, wastewater, stormwater, construction activity, and landscape practices all eventually become part of the island’s water story.
But does that mean mulch itself is dangerous to groundwater? Not automatically. In ordinary landscape use, wood and bark mulches can be beneficial. They reduce erosion, retain moisture, moderate soil temperature, suppress weeds, and can improve soil structure as they break down. Washington State University stormwater research found that bioretention cells with mulch limited nitrite-nitrate export compared with no-mulch controls and reduced weed growth and maintenance effort.
So the issue is not simply the presence of mulch. A thin, properly applied layer of clean natural mulch spread across planting beds is not the same environmental problem as a poorly managed industrial stockpile or contaminated recycled wood product.
The Difference Between Clean Mulch and Problem Mulch
The dyes used in colored mulch are not usually the primary issue. UMass Extension says the common dyes used in colored wood mulch are typically carbon-based or iron-oxide-based, and iron oxide itself is not considered toxic. But UMass also emphasizes that the more important issue is the source of the wood. Recycled wood can be contaminated, particularly if it includes chromated copper arsenate, or CCA-treated, material from construction and demolition waste.
The Mulch and Soil Council makes the same basic distinction. Mulch made from natural forest products is generally regarded as arsenic-free, while recycled or reprocessed wood mulch can contain treated wood if the feedstock is not properly controlled. That is the environmental dividing line.
If this barge load was clean natural pine, hemlock, or bark mulch from a controlled source, then the groundwater concern is probably limited, especially if the material was quickly trucked out and spread across landscapes. If it was a recycled wood product with poor source control, the concern would be different. The question would no longer be “is mulch bad?” but “what was ground up to make it?”
There is no public evidence, from the available information, that this specific shipment was contaminated or made from treated wood. The images alone do not suggest that. The likely product category appears to be natural bark mulch. But the absence of a public source trail also means the public cannot independently verify the material’s exact composition. For an island built on one aquifer, that gap is worth noticing.
Stockpiles Are a Different Issue
Even clean mulch can create localized environmental concerns when stored in large piles. Researchers studying mulch recycling facilities have found that open mulch stockpiles can produce leachate and runoff during rain and snowmelt. That runoff can contain high organic loads and low levels of nutrients. In other words, a large wet pile of mulch behaves differently than a thin layer spread across a garden bed.
The barge was carrying bulk material in a harbor setting. If the mulch was quickly unloaded, trucked away, and stored properly, the risk would be much lower. If large piles sit exposed near water, wetlands, storm drains, or permeable ground without runoff controls, the risk becomes more legitimate.
The barge also points to something bigger than one shipment. Nantucket’s summer appearance requires enormous imported inputs. The island’s polished seasonal landscape does not emerge from sandplain ecology. It is constructed and maintained with irrigation, fertilizer, soil amendments, imported plants, stone, loam, edging, labor, equipment, and, in this case, thousands of cubic yards of mulch.
Mulch is often the least controversial of those inputs. Compared with nitrogen fertilizer, septic loading, wastewater discharge, and stormwater pollution, clean wood mulch is probably not among Nantucket’s biggest island-wide water threats. Local water-quality discussions have long focused more heavily on wastewater, fertilizer, nutrient loading, and stormwater than on mulch.
But scale changes perception. Seeing 1,000 tons arrive at once makes visible the cumulative footprint of landscaping across the island. One property’s mulch bed is ordinary. A barge full of mulch is a supply chain. And, a supply chain raises questions that individual homeowners rarely ask: where the material came from, who produced it, what it contains, where it is stored, and how its runoff is managed before it is spread thinly enough to disappear into the scenery.