The following case studies are provided to illustrate the positive results of implementing ecologically sound improvements to landfill post-closure management processes. These are highlighted in an attempt to provide aspirational models which can be incorporated within regulatory standards within the United States. Instead of simply being exceptions to the rule, they provide a forward-thinking model to how we can systematize repurposing landfills for both ecological and equitable benefit to the surrounding area:
I. Nanjido Ecological Park - Seoul, South Korea
Nanjido Landfill opened in 1977 along the outskirts of Seoul to store waste from South Korea’s largest municipality. While the landfill was active, hundreds of transient residents lived among the refuse and supported themselves financially by collecting scrap metal and other refuse sorted from the waste which they could sell for profit. By the time the landfill had run out of land and air space in 1993, more than 92,000,000 cubic meters of garbage was buried at the site (Yoo et. al. 2014). When it was closed in 1993, Nanjido Landfill presented several engineering and ecological challenges as the mountains of waste were at risk of collapsing into the adjacent Han River. The first priority for closure was to implement landfill gas and leachate treatment systems while reinforcing the mountains of waste before placing a permanent cap (Yoo 2020). In 1996, South Korea and Japan were selected to co-host the 2002 World Cup soccer tournament. Needing a space to site a new stadium to host the event, the City of Seoul selected the former Nanjido Landfill site for construction.
With less than five years before Seoul was set to host the World Cup tournament, construction began in 1997 on World Cup Park on the southernmost portion of the property adjacent to the waste site. While the stadium was being constructed, the city addressed the reinforcement, environmental remediation, and ecological redevelopment of what would eventually become Nanjido Ecological Park where the mountains of waste are located. As part of the city’s master plan for the park, Seoul urbanized the area by constructing residences, traffic systems, and public transit systems (including a rail line connection) while allocating for future growth (Yoo et al 2014). To relocate the impoverished transient residents who were once living within the landfill, the City of Seoul set aside purchase rights for permanently rented apartments and private housing for approximately 1,000 households at the new residential towers developed next to the park. The city then offered the residents and former landfill workers employment via job placement programs to support their new way of life without the landfill (Seoul Urban Solutions Agency 2021). By allocating for both employment and housing, the city was able to relocate residents living in unsafe and unhealthy conditions within the landfill site and expedite the construction process.
With the conversion of the former landfill to an ecological park, the ecology of the area began to show improvement almost immediately. As part of the environmental remediation initiative for the redevelopment, over one million native species of trees and plants were planted. Within three years, grass had covered the landfill cap and the variety of plant species on the site more than tripled in size (Yoo et al. 2014). By 2010, the Nanjido Eco Park was home to more than 500 native plant species – more than six times the amount at the time of landfill closure. Due to the increase in flora, the population of fauna – including birds, insects, amphibians, fish, and mammals – has more than quadrupled in size, which is a testament to the environmental health improvements of the area. Methane, a landfill gas, created by the decomposing waste was channeled via gas collection systems to heat World Cup Stadium and some of the surrounding residences. As a result, air, water, and soil quality has improved as well (Yoo et al. 2014). To this day, the entire site remains under close environmental and ecological surveillance to ensure the improvements continue.
In addition to environmental remediation measures, Nanjido Ecological Park is also host to a wide variety of public recreation options such as: walking trails, athletic fields, bike paths, campsites, picnic areas, urban gardens, eco center, and more. All of the parks combined across the former Nanjido Landfill site cover more 230 cubic meters of space. By 2014, the parks received nearly 10 million visitors annually. Because of their publicly available environmental education programs, Nanjido Ecological Park received the United Nations Habitat Special Award in 2010 (Yoo 2020). Once the site was selected for World Cup Park, the price of land surrounding Nanjido increased by sixty percent from 1996 to 1999 (Seoul Urban Solutions Agency 2021). Over the past two decades, a thriving shopping and cultural district has grown in the area surrounding the park – featuring a plethora of apartment buildings and housing developments. Although there were few homes nearby Nanjido Landfill previously due to the presence of a LULU, the sharp increase in housing indicates there is a significant demand now that the area has been repurposed into a popular recreation area.
II. Freshkills Park – Staten Island, New York
Originally Staten Island wetlands, the Freshkills area received its name from 17th century Dutch settlers who used the site as a fishing pond — in Dutch “fresh” translates to fish, “kills” translates to water (Bliss 2017). As World War II drew to a close, the population boom in New York City necessitated the creation of a nearby municipal solid waste landfill. The site selection process for the placement of the landfill was under the direction of New York City Planning Commissioner Robert Moses, who chose the Freshkills area to become one of New York City’s largest landfills. Opened in 1948, the landfill received over 150 million tons of waste over the course of five centuries and became one of the largest municipal solid waste sites in the country. By the mid-1980s, the landfill became New York City’s sole landfill, which became a major point of contention for Staten Island residents (Melosi, 2016). Since the landfill was sited in the 1940s, Staten Islanders made several efforts to secede from New York City for decades in response to bearing the burden of the metropolitan area’s waste and the nuisances associated with it. The landfill received its final barge of waste in 2001: one million tons of debris and human remains from the 9/11 Twin Towers attacks marked the final disposal at Fresh Kills Landfill (Melosi, 2016).
To cap Freshkills Landfill for permanent closure, significant modifications were made to reinforce the cells as the size and topography of the site presented challenges. Modifications included wetlands remediation and reclamation, creation of swales and retention ponds, stormwater management, improvements to the leachate management system, expansion of the landfill gas collection system, and the addition of two feet of top soil and planting soil (Freshkills Park Alliance, 2021). After a city-sponsored design competition in 2003, architecture firm James Corner Field Operations – known for their adaptive reuse projects such as the High Line – was awarded the project with plans to add multi-use trails, recreation areas, and wildlife refuges (Lippard, 2016). By 2010, the first public event was held at the newly-created Freshkills Park. Construction on the final cap and park are still in progress with portions currently open for public use. With a target completion date of 2036, Freshkills Park will be three times larger than Central Park once complete – the largest park developed in New York City in over a century (Bliss, 2017).
Since the landfill was capped and portions of the area were reopened as a park, home values surrounding Freshkills began to increase. For the purpose of comparison, the Arthur Kill waterway which creates the western border of Freshkills Park is also the border to the state of New Jersey. There is no way for residents on the New Jersey side to directly access Freshkills Park and would need to take a circuitous route with a vehicle or public transit along freeways and bridges to enter the park. Using this geographic separation as a control mechanism for comparing housing prices in the area, it is obvious that the homes directly adjacent to Freshkills Park are significantly higher than those across Arthur Kill which lack direct access to the park. For future studies, year-to-year housing prices could be compared alongside major opening milestones for the park to determine if the development has historically had a positive impact on median home values. An additional factor to study would be potential evidence of resident displacement in response to increasing cost of living — otherwise known as gentrification. Unfortunately for the sake of this study, this information was not readily available.
Both Nanjido Ecological Park in South Korea and Freshkills Park in the United States provide examples for aspirational models of large-scale regenerative redevelopment models for municipal solid waste landfills. By prioritizing resident use in conjunction with environmental improvements, there are numerous benefits to repurposing landfills. That said, neither case should be considered as a one-size-fits-all approach and can highlight certain limitations when considering the codification of regenerative reuse. Site-specific considerations — based on topography, local ecology, resident input, safeguards against resident displacement — must always be considered for any adaptive reuse project and landfills are no exception. Without precautionary policies, environmental amenities produced by these projects, such as parks, trails, walkability, and higher-density development, tend to result in higher land value and increased housing costs. This will make it harder for a low- and moderate-income households to live near the project, and neighborhoods are likely to become increasingly affluent (Immergluck & Balan 2017). Caution should be exercised on behalf of the municipality when approaching any large-scale redevelopment project in a low-income or majority-minority community.