Environmental Remediation within NJDEP-Regulated Wetlands

21 Jun Environmental Remediation within NJDEP-Regulated Wetlands

To the casual observer, environmental remediation appears to be highly physical and destructive work. In industrial and commercial (and even residential) areas of metropolitan New York and New Jersey, it’s not uncommon to see remediation work zones with bulldozers, dump trucks, excavators, and drill operators actively demolishing worksites and digging up the ground to reach areas of contamination. But there’s another aspect of this industry that is often overlooked: remediation is an environmentally restorative process. It is, in its essence, the practice of returning the landscape in a given area back to its natural state through the use of strategic scientific and technical applications. And this restorative process is especially true in the case of environmentally impacted wetlands.

Recently, ESA began work on a multifaceted project that involved the excavation and removal of toxic chemicals and heavy metals from a former industrial property in Monmouth County, New Jersey. In total, approximately 1.25 acres were impacted, .73 acres of which is NJDEP-regulated freshwater wetlands, which also includes 0.125 acres in a riparian zone. Because of the presence of this protected habitat, ESA engaged the services of a certified ecologist and wetlands expert to oversee compliance with the DEP’s required GP4 Freshwater Wetlands Permit and Flood Hazard Area Individual Permit.

One of the roles of the wetlands expert is to conduct a vegetative survey — coordinating with land surveyors to identify and tag every individual tree and shrub that must be removed during remediation. Then, during active remediation, the wetlands expert observes and documents the process to ensure all work is performed within the demarcated areas of disturbance in accordance with GP4 guidelines. Once remediation is complete, a replanting plan is executed to restore the ecosystem to its natural state.

That’s the short version of wetlands restoration. The full version is far more nuanced.

In wetlands remediation, the wetlands expert is tasked not only with identifying and quantifying each of the woody species present at the site, but also with assessing the health of the individual plants, as well as the status of the entire ecosystem prior to remediation. They need to understand what is currently growing there — and how well it’s surviving — in its pre-remediation state. The total number of woody plants and percentage of individual species tells the expert a great deal about the composition and diversity in the area. Conversely, the ecologist must be able to determine what should NOT be present – namely, non-native and/or invasive species. Thus, the ecologist must be able to assess the herbaceous layer of plants as well. From there, they must develop a replanting plan that reestablishes the species represented while also possibly introducing selected species typically found in similar habitats. The NJDEP requires a minimum 1:1 replacement ratio with plants of “equal or greater ecological significance.” It’s the wetlands expert’s job to ensure the proper ratios and species are used.

In ESA’s Monmouth county project, 36 unique woody species and 406 individual trees and shrubs identified within the wetlands disturbance area — including American Holly, Sweetbay Magnolia, Sassafras, Black Gum, and Sweet Pepperbush, among others — would need to be replaced. In addition, the project required that the herbaceous ground cover — grasses, sedges, and forbs growing on the forest floor — would need to be replanted. For that part of the project, two native seed mixes were developed and slated for broadcasting once remediation was complete.

But even the amateur home gardener knows that seeds and young plants can’t simply be set in place and left alone if they’re expected to thrive. Timing is everything. The timeframe for replanting depends on the growing season (typically spring or fall), temperatures, and weather conditions. For major restoration in a wetlands area, a landscaping company with specialized experience in wetlands vegetation is retained to execute the replanting plan developed by the ecologist.

And still, the work is not complete. Beyond the current growing season, ESA and the ecologist/wetlands expert must monitor the site for five years and submit annual monitoring reports in accordance with GP4 guidelines. A final report is then submitted and must be approved by the NJDEP in order to close out the project.

There are three things that are required to recreate a wetlands ecosystem: Hydric soils, wetlands vegetation, and wetland hydrology. The ecologist must ensure the stability of the site, noting any changes in hydrology or decline in vegetation, and take the necessary steps to mitigate any negative impacts by replanting natives or removing invasive species. By law, the plantings must have an 85% survival rate over 85% of the disturbed area and less than 10% coverage by invasive species. The fundamental goal is to restore the site to its former status of an undisturbed freshwater wetland.

The Monmouth County replanting phase will begin this fall, and the wetlands expert will continue to monitor progress for the next several years to ensure a healthy habitat for the newly planted wetlands vegetation. Not only is this a win for the environment, but it’s a win for the property owner who had the foresight to hire ESA to manage this intricate project. Because of ESA’s strategic execution, the amount of soil slated to be removed by a previous contractor was reduced by approximately 800 tons and saved the landowner more than $800,000 in the process. So, the next time you observe the physical activity of those bulldozers, excavators, dump trucks, and drill operators tearing up the ground at a remediation site, remember there are often weeks and months of strategic planning behind those activities, all designed to restore an ecologically viable landscape.