July 28, 2023
By Naren Barade Sivaji
Waste generation, disposal and recycling play an important role in shaping sustainable living. New York city generates about 14 million tons of trash a year. So, what happens to all this trash? Waste, after collection, and depending on its kind, is composted or transported to recycling facilities, waste-to-energy facilities, or landfills.
Composting is a biological process that entails breaking down organic waste such as food and yard waste, by naturally occurring micro-organisms, into a soil like product called compost. The principal benefit of composting is the reduction of waste that reaches landfills. Organic waste decomposing in landfills results in release of methane and carbon dioxide which are both greenhouse gases that contribute to climate change. Therefore, with less organic waste reaching landfills, the quantity of greenhouse gas emissions can also reduce. That said, composting has other benefits too. Compost acts as a natural nutrient or fertilizer for soil, providing the necessary growth supplements to plants. Therefore, compost generated from organic waste can be added to soil in plantations, thereby contributing to the health of the soil and consequently the growth of plants. Plantations can meet their fertilizer needs by increasing reliance on compost and decreasing it on chemical fertilizers.
Joining the cities of San Francisco, Seattle and Los Angeles, New York is aiming to increase composting by mandating its residents to participate in the Curbside Organics Collection Program. The program requires residents to separate food waste for weekly curbside collection by the Department of Sanitation. While the program has started in the Queens borough, it aims to achieve citywide coverage by October 2024.
Recycling is the process of returning discarded material into use either in the same form or in a different form after applying industrial processes to reconstruct the waste. Recycling is applied in different ways depending on the kind of waste. Wastepaper and cardboard can be recycled to generate new paper and other paper-based material. Recycling wastepaper helps save trees and also reduces energy consumption during the manufacturing of recycled paper. Plastic waste of certain kinds is recyclable. The principal benefit of recycling plastics is that the plastic waste does not end up in landfills. Plastic waste can take up to 500 years to decompose in landfills and is therefore not ideal for disposal in landfills. Metal waste of almost every kind can also be recycled to produce new metal products. The manufacturing of new metal products through recycling as compared to manufacturing from new raw materials saves energy. Glass waste is not only 100% recyclable but also recyclable multiple times. As in the case of plastics, glass waste recycling also helps in avoiding glass from reaching landfills. Unlike plastics which can take up 500 years to decompose, glass waste can take up to a million years to decompose. Overall, recycling waste helps save energy required to manufacture new products from the recycled waste.
Apart from waste reaching recycling facilities, waste also reaches energy plants that convert waste to energy, i.e., electricity that can power homes and other establishments. For instance, about 30% of New York city’s waste is sent to such a plant for conversion to energy. New York city’s Department of Sanitation has a fleet of about 200 garbage trucks. After picking up trash from the city, they carry it all to transfer stations in the city. Once deposited in the transfer stations, the trash is transferred to large containers. The trash is then taken to the dock where tugs in turn use the waterways to transport it to a transfer station. From there, the waste is finally taken to a ‘waste-to-energy’ facility. These facilities are able to burn trash in incinerators and generate a temperature environment of 2000oF. The temperature is sufficient to heat up steam which propels the blades of a turbine. The mechanical energy from the spinning turbines is then converted to electrical energy. The energy generated from one facility is sufficient to power not just the facility but also about 46,000 homes.
After everything is burnt, what is left is ash and metal. While ash is transported to a landfill, the metals can be recycled and used in the manufacture of different products, including cars. While incinerating trash, the facilities also generate gases, many of which are poisonous. These gases are treated in several reactors. They are first treated in a scrubber which removes acidic gases. The reactors also use activated carbon to absorb pollutants. Next, the gases go through a bag house, comprised of filters, that further get rid of poisonous gases. Finally, what comes out is nitrogen, carbon dioxide and moisture. These waste to energy facilities are able to cut down a million tons of carbon dioxide that would have otherwise reached the atmosphere had the waste been dumped in landfills. Effectively, these facilities are not only generating energy that powers homes but also reducing the amount of carbon dioxide that reaches the atmosphere.
Waste that does not get composted, recycled or converted to energy ends up in the landfills across the country. For instance, much of the waste from New York is transported to landfills as far away as South Carolina and Ohio. The US Environmental Protection Agency has reported that nearly 50% of the municipal solid waste generated in America reaches landfills. The practice of dumping waste in landfills has unfortunately become a necessary evil because the recycling facilities and waste-to-energy facilities are unable to handle the large quantity of waste generated. Landfills can cause severe damage to the soil, water around the landfills, and surrounding environment and ecosystems. Though some landfills have the facility to remove gases such as methane and carbon dioxide released from the decomposition, a significant portion of the gases are usually released into the atmosphere. These gases contribute to climate change, particularly increase in the planet’s temperature. Very critically though, landfills can contaminate the surrounding soil and water because poisonous substances such as lead and mercury in the waste can spread to the soil and water. In addition to the environmental damage that landfills cause, they are harmful from a sustainability perspective because they eventually reduce the area and value of the land available for living.
Solutions towards sustainability
Cities and towns are constantly aiming to achieve the target of ‘zero waste’ to landfills. While the recycling ecosystem is already operating to reduce waste, recycling is still not enough to solve the problem of waste reaching landfills. A large part of the solutions lies in consumer discipline and corporate responsibility. Consumers have to adopt other sustainable practices such as reusing products (bottles, containers and bags) instead of replacing them with new ones, reducing waste by purchasing products that use less packaging or come in packaging that can be recycled, avoiding purchase of products (coffee, frozen foods) served or delivered in single use containers, avoiding generation of paper based documents if electronic documents can be a substitute, buying second-hand (furniture, construction material, appliances) to the extent practicable and also buying in bulk to reduce the quantity of packaging coming along.
Corporate establishments often become centers that generate large amounts of waste. They can initiate waste reduction programs by conducting audits to assess the amount and kind of waste generated. The audits will help them strategize solutions in terms of finding sustainable alternatives such as use of dryers instead of paper in restrooms, use of recycled products including recycled paper to print, going paperless by communicating electronically, and reducing plastic in food courts by encouraging employees to bring their own containers. It is useful to note that the US Environmental Protection Agency administers the Comprehensive Procurement Guideline Program that requires certain agencies/establishments to procure recycled/recovered material to meet their needs for such materials. The program has classified materials into 8 categories, namely construction products, landscaping products, non-paper office products, paper and paper products, park and recreation products, transportation products, vehicular products and miscellaneous products.