Excavation and Construction Impact
The EPA sees construction as a major contributor to environmental issues – which is why they provide a monster 255-page guide outlining environmental obligations throughout construction projects. It’s a real page turner on responsible excavation.
It is important though, and it highlights much of the impact poorly-done construction can have on the environment. Dealing with storm water is the meatiest section, but there are also a number of other considerations for responsible excavation and construction. Dredging and filling wetlands is extremely sensitive, as are requirements for dealing with endangered species in relation to construction activities.
So why is storm water have such an emphasis? Well, during excavation and construction, soil is loosened and moved around. At the same time, pollutants are getting mixed in with that soil. Debris and chemicals get mixed in – no matter how hard you try, foreign matters will make it on to job sites. You may do a great job checking for oil spills and fuel leaks from your vehicles, but chemicals can get carried onto jobsites on the tires of your vehicles, on the boots of your workers, an
d so many other ways. The solution is to control the storm water discharge itself, providing filters and culverts that can mitigate what you can’t prevent.
That’s just one of the direct ways that responsible excavation has an impact. As noted in research, both by the construction blog Bimhow and the U.S. Green Building Council, the construction industry accounts for high percentages of energy usage, drinking water pollution, air pollution, and landfill wastes. Excavation in particular can also alter the amount of groundwater that flows, while asphalt and paving can lead to changes in water temperature in nearby waterways.
These impacts create problems on a global scale as well as on the local scale. For those of us in the vulnerable Chesapeake Bay area, it’s the latter that is most concerning.
Environmental Impact and the Chesapeake Bay
Particularly here in the Chesapeake Watershed, we need to be sensitive to the needs of the region. Everything rolls down through the watershed to the Bay, and the watershed encompasses over 64,000 square miles, going from New York to Norfolk. So even when we are working on projects far inland, there is the trickle downstream.
According to the Chesapeake Bay Foundation, the major contributors to the poor health of the Bay is the amount of nitrogen, phosphorus, and sediment leaching into the waters. Sediment is a direct result of construction work, and at its peak in the 1980s, the sediment load to the Bay was over 10 million pounds per year! In 2017, that number was down to 7.87 million pounds, and it continues to drop. Similarly, the nitrogen load to the Bay has dropped from 369.78 million pounds in 1985 to 219.04 million pounds and dropping in 2017.
Nitrogen and phosphorus are integral in creating algae growth, a necessity for the Bay. However, higher loads increase the level of algae growth, above what the Bay can tolerate. Too much algae leads to the blocking of sunlight, sunlight that underwater grasses need in order to thrive. These grasses, which serve both as food and as habitat for animals in the bay, will die off if not provided enough light. On top of that, when the algae dies, the bacteria that helps them to decompose consumes oxygen in the water, further effecting the animals and other plants.
Sediment also contributes to blocking sunlight, as clay and sand will turn the waters cloudy. But sediment settles out eventually, right? It does, but it settles directly onto the bottom-dwelling species of the bay.
Nitrogen, phosphorus, and sediment combine to create “dead zones” where bottom-dwelling species are having harder and harder times surviving. The sediment can settle onto oysters and clams, suffocating them. This leads to reduced harvests, impacting the restaurants and tourism in the region, and impacting those whose livelihood depends on harvesting them. While fish can move out of the dead zones, one of their most important foods – the Polychaete worm – is fairly stationary. So when the dead zone expands, these worms are killed off. That means less food for the rockfish, spot, and other Bay fish, leading to smaller populations or smaller sizes.
Responsible excavation is our aim at S.E.H. Excavating Contractor’s. By focusing on different aspects throughout a job, we can ensure that our environmental impact is minimized.
- Our team is highly experienced in developing and installing storm water solutions that mitigate the runoff and discharge that can come with storms. From basins and storm filters to bio-retention ponds and pervious paving, we know how to keep storm water from dumping more sediment and nitrogen into the Bay.
- As one of the few responsible excavation companies with on-site rock crushing and recycling capabilities, we don’t require offsite mining and trucking rock around the region – we can just take existing rock, asphalt, and concrete, and recycle it for use on site. This allows us to reuse, instead of creating more trash.
- During excavation, our team installs effective controls to prevent sediment runoff and erosion. Methods such as silt fences, super silt fences, berms, sediment traps, pumping stations, sediment basins, and more can all reduce the impact on the environment.
We love everything the Bay region provides. From the great seafood, to the weekend trips, it’s an integral part of our region. So join us in helping to ensure that the Bay continues to recover, by making environmentally sound choices in your responsible excavating projects!