By Ileen Gladstone, P.E., LSP – Senior Vice President
In any development project – whether it’s remediating an urban waterway, a rural river, or expanding a port terminal – you need to think about the soil from the beginning. That is, what are you going to do with all that soil your project generates? If you don’t figure out the costs of soil disposal early, you will bust your budget. This is especially true when you’re dealing with a brownfield site, that has been contaminated from historical industrial use. But planning early is about more than saving money; when you factor in soil/sediment waste management into planning and design development, you’ll save time while also helping the environment. In this blog, I’ll explore how our team accomplished that very goal with our remediation work on Massport’s award-winning Berth 10 – part of the Conley Terminal Modernization Project in Boston, Massachusetts.
Why is soil/sediment – whether moving it, solidifying it, reusing it, or finding it a new home – such a potentially expensive part of your project? If you need to move an excess amount of soil/sediment off site, you’re looking at the costs to stabilize it and truck it away – either to another project in need of fill, or to a landfill. Trucking and dumping are not only expensive, but those trucks contribute to CO2 emissions, cause wear and tear on roads, and contribute to traffic congestion in communities. And that’s if you’re working with clean, uncontaminated soil that can be safely used elsewhere or sent to a landfill without restrictions. What happens when you’re working with soil/sediment impacted with lead, oil, or other contaminants. That was our situation at Berth 10.
The Berth 10 project was a critical part of expanding Boston’s Conley Terminal so that the largest container ships – up to 22 containers wide – could arrive in Boston Harbor. Our work required us to design the new berth to expand the port’s facilities onto a former contaminated oil terminal adjacent to the existing container terminal. Constructing the new berth required cutting back the existing shoreline, which would expose oily soil, sediments, and residual light non-aqueous phase liquids that could seep into and contaminate the adjacent surface waters of Boston Harbor.
But here’s where early planning was key. From the start, we knew that Berth 10 was a remediation project – we had that contaminated sediment top of mind – to keep the Conley Terminal Modernization moving forward we had to protect the environment from historical contamination. We recognized that, through appropriate remediation techniques, contaminated soil/sediment could be beneficially reused on the Berth 10 project itself.
For this project, our team used a technique called In-Situ Soil Solidification (ISS). Essentially, instead of removing the contaminated soil/sediment and trucking it out to an approved landfill, we stabilized it on site, ensuring we immobilized the contamination. This also meant we could use the stabilized material as construction materials, saving the cost and environmental impact of trucking in new, clean material to this site.
ISS is just one on-site method that remediation experts can use to address contaminated material on a project site while reaping the many benefits of beneficial soil reuse. Whichever technology is right for your project, the important thing to remember is: Start planning early. Beneficial reuse of soil – especially if it requires on-site remediation – should never be an afterthought.
So, how did this advanced planning help with the success of the Berth 10 for Massport? Our remediation work and careful planning:
- Stabilized approximately 22,500 cubic yards of contaminated sediment;
- Rendered inert and repurposed 91,000 cubic yards of site material;
- Eliminated an estimated 7,300 truck trips for off-site disposal and another 4,900 trips that would have been needed to import new fill material;
- Saved an estimated 48,650 gallons of truck fuel;
- Eliminated an estimated 547short tons of CO2 emissions; and
- Preserved scarce landfill space.
The new Berth 10 Project captured Engineering News Record’s (ENR) prestigious Project of the Year Award for New England. But beyond the remediation piece, this work also contributed to Massport’s larger vision – to revitalize the Conley Terminal for the benefit of the economy – not just for Boston, but for the entire region.
To learn more about the beneficial reuse of soil, ISS and other on-site remediation techniques, and to start planning early for your next project, contact me.