My first recommendation in the report would be, if it is absolutely necessary to expand the landfill, do so in a direction away from the estuary. It is crucial to maintain the vegetation near waterbodies and expanding the landfill in a direction towards the estuary would require a loss of vegetation. As a result, water runoff would pick up excess nitrogen and phosphorous from the bare soil that would enter into streams and make its way into the ocean (Chapin et al. 2011). Consequentially, nutrient over-enrichment of coastal ecosystems generally triggers ecological changes that decrease the biological diversity of estuaries (Ecological Society of America 2000). Further, increase in nutrient pollution of coastal waters has been accompanied by an increase in harmful algal blooms which decreases levels of necessary for the survival of wildlife (Ecological Society of America 2000). Also, runoff would increase erosion which would lead to actual trash from the landfill possibly making its way into the estuary. As a result, biodiversity may degrade from animals eating the trash once it makes its way into the waters.
I would also recommend creating a barrier between the landfill and the coastline to prevent as much erosion as possible. One idea to do so is to plant a cover crop along the coastline to absorb the nutrients before they seeps into the bordering streams.
Or, I included a video below showing how a particular lime landfill in Austria located near a river was contained using state of the art technology:
The engineers built concrete walls to prevent runoff from leaving the landfill area with routine groundwater lowering and soil air extraction. The wall was built with multiple layers of material to ensure reliable contaminant absorption. There is an erosion-resistant carbon layer over the entire landfill and a rainwater drainage mechanism, as well.
Source:
Chapin III, F. Stuart, Pamela A. Matson, and Peter M. Vitousek. 2011. “Principles of Terrestrial Ecosystem Ecology”, 2nd Ed. New York: Springer.
Ecological Society of America. 2000. “Nutrient Pollution of Coastal Rivers, Bays, and Seas”. Issues in Ecology. 7: 1-14.
Response by Amanda Ruffini:
Mary,
Good post! Just as Chapin et al. (2011) stated, loss of vegetation leads to an increase in runoff. Vegetation essentially acts like a buffer for the water to run through, with plants taking up nutrients being carried in the water. With vegetation in place, the amount of nutrients making it to the water system can be reduced. This can then reduce the chances of a cascading ecological effect the excess nutrients can have in terms of eutrophication and algal blooms, just as you have stated. I like the idea you have of the barrier as well! What crops then would you suggest should be planted to serve as a barrier? How much space do you think there should be between the landfill and the estuary to provide enough cover to reduce runoff?
My Response:
Hi Amanda,
Awesome questions!
Using native vegetation, which is naturally adapted to site- specific conditions, results in long-lasting, stress-tolerant, and low-maintenance plants. The selection of vegetation may affect the presence of burrowing animals that could negatively affect the barrier’s performance. Further, it may be useful to consider alternative plantings including grasslands, mixed meadows, scrub and shrub habitats, and woodlands to promote ecological habitats. Grasses (wheatgrass and clover), shrubs (rabbit brush and sagebrush) and trees (willow and hybrid poplar) have been used extensively as barriers (New Jersey Department of Environmental Protection 2014). It is important to consider that contaminant toxicity to specific plant species may prevent proper plant establishment. The potential for uptake and bioaccumulation of contaminants into the plant species should also be considered.
Also, I found a study that discussed how to select plant species for landfill revegetation. The researcher started by analyzing the soil after the landfill was removed. The soil at the landfill location was in a very poor condition with high bulk density and low organic matter and nutrient contents (Song 2018). Brassica campestris showed high coverage and a sufficient number of individuals in study quadrats sown with seeds (Song 2018). Results suggest that plant species with heavy seeds are the only ones that can adapt to the environment of a typical landfill due to the site’s aridity and low nutrient content (Song 2018). The reason is due to superior wind resistance and the capacity to provide sufficient energy for the initial growth of the plants for survival in such landfill environment (Song 2018).
I imagine the amount of vegetation cover space needed between the landfill and estuary depends on the impact of the landfill which depends on the size of the landfill and its contents. It would be difficult to estimate the need before observing the consequences of not having a vegetation cover at that specific location. I suppose there can be a trial and error method conducted. Or, scientists can look at other similar landfills with vegetation covers to make their decision.
Source:
New Jersey Department of Environmental Protection. 2014. “Technical Guidance on the Capping of Sites Undergoing Remediation”. Accessed November 10 2020.
Song, Uhram. 2018. “Selecting plant species for landfill revegetation: a test of 10 native species on reclaimed soils”. Journal of Ecology and Environment. 42 (30).
Response by Professor Fenton Kay:
Good post, Mary. Are there any plants that you can think of that might be particularly beneficial as a boundary between the landfill and the estuary?
Cheers!
Fenton
Response by Mariah Rivera:
Hi Professor Kay and Mary,
Mary, I love the idea of having a plant be a potential boundary between the landfill and the estuary. This is such an outside of the box concept and I really think a planner would be intrigued to do that idea!
I do have a proposition for a plant that could potentially be useful for this specific environmental need. There is an ice plant in California that is known for consuming and absorbing all of the nutrients and liquids that are in the ground and this specific plant is actually invasive to California, originally from Europe. It is actually classified as a coastal succulent shrub and would survive very well in low water areas in between a landfill and the estuary for it could absorb all of the pollutants while still releasing Oxygen into the water.
I would love to get other thoughts from students who have come into contact or heard about this specific plant before?
My Response:
Hi Mariah,
Thanks for suggesting the coastal succulent shrub! The ability to absorb excess nutrients is a necessary attribute for the plants composing the boundary. I also appreciate how you mentioned the importance of releasing oxygen into the water.
Hi Fenton,
I found some plants that were proven to be tolerant to toxic leachates. The majority of these barriers are built with common reeds (Stefanakis and Tsihrintzis 2014). Other plant species used are Phalaris sp., Scirpussp., Typha angustifolia, Typha latifolia, Solidago rigida, Rumex crispus, Cirsium vulgare, Urtica dioica, Salix spp., Cannabis sativa, and Carex acutiformis (Stefanakis and Tsihrintzis 2014).
Source:
Stefanakis, Alexandros and Vassilios Tsihrintzis. 2014. “Landfill Leachate Effluents”. Science Direct.
Response by Professor Fenton Kay:
Great catch, Mary – protecting your estuary with weed – what an idea. :O}>
Cheers!
Fenton
Response by Sofia Maldonado:
Mary,
Great post this week! I like how you pointed out the importance of keeping vegetation alive and healthy if expanding the landfill is necessary. Since plants are primary producers, they feed into so many different trophic structures (Chapin et. al. 2011). This is why in order to keep the system and surrounding habitats healthy, vegetation needs to be considered highly important during the expansion project.
Your video shows a great way to help vegetation receive less of an impact from the landfill runoff. The former industrial lime landfill in Austria poses the greatest risk for affecting environmental health due to its high pollutant levels (HUESKER 2019). In order to prevent future leaching of these pollutants into the nearby river they created a concrete barrier layered with ground water lowering technology and continuous soil/air extraction (HUESKER 2019). This approach reminds me of one I was researching for discussion B in that they are using multiple different approaches in one solution project. I believe that future mitigation efforts will need to use more of these multi-approach solutions in order to get the most effective results.
References
Chapin III, F. Stuart, Pamela A. Matson, and Peter M. Vitousek. 2011. “Principles of Terrestrial Ecosystem Ecology”, 2nd Ed. New York: Springer.
Environmental Engineering: Containment of a Contaminated Lime Landfill. HUESKER Group (2019). Accessed November 11, 2020.