Problems and solutions
It's not easy to spruce up a plot of land that once groaned under 9 million metric tons of trash and transform it into a flourishing public park.
Metropolitan Park director Hung Chin-hsun was present from the project's inception. Xi-qingpu Landfill held so much trash that was spread out over so wide an area, he says, the subsidence of the land in those first years after its closure was really appalling. For safety reasons as well as to avoid secondary contamination the first order of business was to interpose a waterproof membrane between the soil containing trash and multiple layers of earth tamped down on top.
Experts advised that in order to achieve optimal results for tree planting, it would be necessary to install a final layer at least two meters deep, a task which according to the initial calculations called for more than 800,000 cubic meters of dirt. Fortunately, at that time construction of Kao-hsiung's rapid transit system was in full swing, and the prodigious amounts of dirt excavated in that campaign found a ready outlet. This was in stark contrast to the building of Tai-pei's subway network some years earlier, in which the disposal of excavated soil caused a number of heated conflicts.
As for the thorny problems of seepage and methane gas, the park engineers have hit upon the tactic of "countering contaminants with contaminants," to wit, using a comprehensive drainage system to route the effluence back to into the trash. Nearly half of seepage water-approximately 150 cubic meters-can be diverted back into the decomposing trash daily, reducing the amount of liquid requiring treatment while also catalyzing the anaerobic fermentation that produces methane gas.
Methane is quite valuable as a renewable energy source, and simply put, the more of the gas there is, the more electricity that can be generated. There are now 135 separate wells for methane extraction at the former landfill, and 12 processing stations. Every year the value of the electricity generated this way reaches NT$3.68 million, making it the most productive biogas generator in the country.
Rising to the challenge
As a nationally managed park, it behooves Metropolitan Park to be that much more attractive than the other former landfill parks consisting of grassy fields and recreational facilities.
Nonetheless, it hasn't been easy trying to cultivate the luxuriant forest that such a vision demands. The park managers have already despaired of the more expedient method of transplanting, since it has resulted in low survival rates. Instead, they are turning to planting seedlings directly, which is more time and labor intensive, but it allows the trees to acclimate to the particularities of the soil from the time they are saplings.
For the park's flat spaces they selected indigenous species that are known for their toughness and adaptability, such as Indian almond, grey mangrove and the powder-puff tree, all prevalent in the coastal regions of Southern Taiwan; for the slopes they sought to nurture forth a "compound storied forest" like those found in Taiwan at low elevations, from ground-covering species through shrubs through each stratum on through the tallest trees. It is an approach emphasizing at once aesthetics and ecological viability, improving the survival chances of the various flora, while also fostering a variegated ecosystem capable of sustaining a network of interdependent organisms.
Naturally, soil that has played host to filthy garbage needs extra care and cultivation. By way of example, Hung points out that on average the trees did not grow well over the first few years, a problem that experts largely ascribed both to poor soil quality and the fact that the additional layer of soil layered on top turned out to be insufficient in quantity. Just as procuring good soil was turning into a potent headache, timely assistance started pouring in from both the Kaohsiung County and City governments and the private sector: fertile mud was dredged out of the Agong-dian Reservoir, and China Steel Corporation provided the soil excavated while enlarging their production facilities.
Purgatory redeemed
After 10 years tending to the soil and letting it convalesce, the Kaohsiung Metropolitan Park of today is a thriving natural space with grassy meadows, wetlands, and forests. Not only is it home to 120,000 individual trees and shrubs, but some 137 different bird species now make their perches there, including rare birds such as the Eurasian hoopoe, Japanese yellow bunting, Japanese paradise flycatcher, greater painted snipe, and fairy pitta.
"What used to be a living hell has become a paradise!" exclaims long-time resident Wu, unable to suppress a smile while contemplating the extraordinary transformation. The park has become a favorite recreational site for those in the neighborhood; moreover, its presence has pumped up real-estate prices, now sometimes in the ballpark of NT$250,000 per ping, and made it a magnet for new large-scale residential investments.
Metropolitan Park's contribution is made all the more meaningful by Kaohsiung's lack of any other significant green space. It has hosted major international events such as the 2009 World Games skydiving competition and was the site of the official flag raising ceremony commemorating the 100th year of the founding of the Republic of China at the beginning of 2011. Its phantoms thoroughly exorcised, what has emerged is a platform from which Taiwan can broadcast to the world.
In its ascent from perdition to paradise, Kao-hsiung Metropolitan Park has left a blueprint for other national environmental reclamation works. Its success confirms the truism that public works must coexist with nature whilst attending to the needs of citizenry.