Waste generation has existed since the origins of the human as a result to natural resource extraction activities. As the population has been increasing, more resources are required to meet their wich has caused waste generation to become drastically aggravated.

According to the General Law for the Waste Prevention and Integrated Management (LGPGIR by its initials in Spanish), waste is classified in three categories: Urban Solid Waste (USW), Special Management Waste (SMW) and Dangerous Waste (DW). The General Law of Ecological Balance and Environment Protection (LGEEPA by its initials in Spanish) establishes the faculties and governmental responsibilities according to its government level, the USW are managed by municipalities, the SMW by states and the DW belong to federal competence.

Urban solid waste is the term used to refer to those generated in homes, on public roads or in establishments, they are mainly composed of organic waste with just over 50% of the total generation, the rest is composed of inorganic waste such as cardboard, electronics, glass, plastic, paper and others. However, the composition of the USW has been modified over time; In the 1950s organic waste production comprised about 60% to 70% of the total generation (SEMARNAT, 2016) so there is a tendency to produce more inorganic waste, which causes the useful life of a sanitary landfill to decrease dramatically as a result of the volume occupied.

In 2015, Mexico generated 53.1 million tons of urban solid waste (USW), each inhabitant produced about 1.2 kilograms daily. Of this generated waste, approximately 90% has a final disposal on an open dumpsite or on a poorly operated landfill (SEMARNAT, 2016). The high generation of waste is especially due to demographic growth, the high concentration of population in urban centers, the manufacture of easily deteriorable products, the purchasing capacity, and the lack of vision to use waste as raw material for new processes.

The largest generation of USW is in the central area of ​​the country, as an example, Mexico City has a population of 21 million 581,000 inhabitants and a generation per capita of 1.38 kg per day. In 2018, 13,073 tons of waste were generated per day and unlike many states, it does not have nearby final disposal sites, which implies that the waste is taken to sanitary landfills or open dumps in the State of Mexico or the State of Morelos, increasing the operating costs due to long transport distances. Every day in Mexico City, a total of 8,107 tons of waste enter final disposal, which represent a cost of $7 million Mexican peso just for daily disposing (SEDEMA, 2019).

In addition to this, the inadequate disposal of waste implies a negative impact on the environment, generating soil degradation, aquifers and air pollution, which in turn cause damage to the health of the population and ecosystems, as well as the proliferation of harmful fauna that represent sources of pollution and diseases. The decomposition of organic waste causes the emission of greenhouse gases such as methane (CH₄) and carbon dioxide (CO₂), which are highly dangerous, given that its generation inside landfills can cause explosions and fires due to gas accumulation, in addition to contributing to climate change (SEMARNAT, 2012).

Another important source of pollution is the leachates generated by the decomposition of organic waste mixed with liquids or humidity, the air, and the rest of the waste within the site. A relevant aspect is its toxicity, which will depend on the composition of the waste generated by the leachates, which may even contain heavy metals. Leachates can be dangerous for the health of the population and ecosystems, if there is no adequate infrastructure to retain them, they can infiltrate to the aquifers and cause severe damage to the population health.

Integrated Waste Management?

Although it is true that integrated waste management allows the regulatory, technological, administrative and financial activities to be carried out, as well as all the processes necessary for the proper management of waste, from its generation to its final disposal, these activities are not carried out in most of the states of Mexico.

Municipalities are responsible for managing the USW, but they are limited by lack of resources and programs, as well as lack of organization and lack of knowledge of the system. Waste management in most states of the country represents a limited scheme, generated waste is collected and transported to be taken to final disposal, either in a landfill or in an open dump.

Of all the waste generated, only 9.1% is separated from the source, therefore only a small percentage is taken to some form of recovery such as recycling (9.6%) and this percentage of recovery is also due to the pick inside landfill through and industrial collection.

Source: Equipo técnico EnRes, GIZ México, Dirección General de Fomento Ambiental, Urbano y Turístico SEMARNAT, & Dirección General de Energías Limpias SENER. (2018, septiembre). Proyectos de Aprovechamiento Energético a partir de Residuos Urbanos en México.

In order to achieve an integrated management, it is necessary to understand the role of the different key actors, such as governments, citizens and companies. It is up to governments to design and implement regulatory and economic policies and instruments that promote circularity and waste recovery. Is the citizens responsibility to learn about the programs designed and to carry them out, as well as to adopt sustainable consumption habits. Companies must make commitments to society to inform about their environmental footprint and seek to redesign their processes and products in order to reduce their environmental impact, as well as assume the environmental and societal impacts of their products along every step of its life cycle.

 

The vision of circular waste management in the SDGs

In the case of sustainable development, Mexico has adhered to international treaties, among which the 2030 Agenda stands out, which aims at the fulfillment of the Sustainable Development Objectives (SDGs), which involve a complete and interrelated vision in order to eradicate global problems. An important axis of the SDGs for waste management is Goal 12 dedicated to Responsible Consumption and Production, which aims to avoid over-exploitation and waste of natural resources. It is also focused on preventing, reducing, recycling, and reusing waste, among other aspects (UN, 2019).

The linear economy is the current economic model implemented in most countries and has been adopted under the assumption that natural resources would always be available for exploitation; however, it carries an incalculable environmental impact. The biggest flaw in the linear economy is that it seeks economic growth at the cost of production, consumption, and disposal, leaving out activities that allow waste to be reintegrated as a source of raw material for production processes.

One model that can guide us towards sustainable consumption and production and comply with SDG 12 is the circular economy, which proposes a higher performance approach to replace the linear economy. A circular economy seeks to rebuild capital, whether financial, manufactured, human, social or natural, and offers opportunities and solutions to all organizations. (Stahel, 2019).

Source: WBCSD. CEO Guide to the Circular Economy

Alternatives for the recovery of waste generated by companies.

Companies that decide to adopt waste management models not only obtain environmental benefits but can even obtain economic benefits by recovering and recycling waste, saving operating costs and reducing management expenses. Changes in production processes can make a great contribution to reducing waste generation, while the design of more environmentally friendly processes is a competitive advantage that companies can acquire by positioning them in more profitable and productive markets.

Currently there is an initiative to get companies to send less waste to landfills, this initiative is known as Zero Waste to Landfill and aims to reduce waste generation and take advantage of useful materials, so that the waste from a company can be used as a source of material for another, preventing waste from reaching final disposal. It is based on the principles of nature trying to imitate an ideal state where all material is used for some process. Nowadays there are companies that assume the responsibility they have with the environment as very beneficial contribution to their business.

Unilever

In 2015, Unilever announced that over 240 factories had achieved zero waste to landfills and successfully replicated this model at more than 600 sites in several countries, demonstrating that waste can be a source of alternative resources for the manufacture of other products. This model has greatly benefited the profitability of 200 million euros, while contributing to social development by creating more jobs and positioning them within the most sustainable companies (Unilver, 2016).

In 2019 Unilever announced two major commitments it will adopt to reduce plastic waste:

• Their first commitment is the reduction of its virgin plastic packaging by 50% by 2025, with a third part (over 100,000 tons) coming from an absolute reduction in plastic use.
• Their second commitment is to collect and process more plastic containers than they sell by 2025. Unilever will meet this target by investing directly and through partnership in waste collection and processing; buying and using recycled plastics in their packaging and participating in extended producer responsibility strategies where Unilever pays directly for the collection of their containers.

At the same time, Unilever will thrust the circular economy within its operations by reducing the number of plastic waste, collecting it, and making it into new containers, thus avoiding the manufacture of products with virgin plastic (Unilever, 2019).

Many other companies opt for coprocessing, which consists of entering waste into a cement kiln, either USW, SMW or DW that has been previously conditioned to serve as thermal energy or raw material in the cement production process. The waste is efficiently disposed without generating new waste, ash or additional emissions from the original process (FICEM, s.f.), as an example:

Kimberly-Clark from Mexico

In 2018, they managed to recover 99.58% of their waste and only 0.42% was disposed to landfill. In 2010 they deposited 55 thousand tons of cellulosic waste in landfills and currently they have managed to valorize 100% of their waste for 8 consecutive years by means co-processing (Kymberly-Clark de México, 2019)

CEMEX

CEMEX Global has managed to implement a circular economy model, taking advantage of waste to generate alternative fuel through co-processing, the cement sector, specially CEMEX is considered a “garbage eater”, since in 2018, they managed to process 32 times more waste from other sectors than the total of what they generate. In addition, within their cement production processes they take advantage of the waste generated to convert it into by-products as a substitute for cement or aggregates (CEMEX, 2019).