The explosive population growth combined with an increasing appetite for consumer goods, has led to an explosion in the amount of garbage we produce. Virtually every aspect of our daily lives generates waste, and it is impossible to think of any man-made process that does not create some waste. The spectrum ranges from refuse produced by all of us in our daily lives, to highly toxic industrial wastes from the production of specialized goods such as cars, electronics computers, cell phones and plastics. What happens to all this waste?
Some is recycled and re-introduced into the production cycle. Some is incinerated, and when this leads to the generation of electricity, useful steam or heat, it can be considered a form of recycling, or more appropriately, a conversion of waste to energy. The remaining waste winds up, as it has over the last three millennia, in a landfill. This basic method of placing garbage in large pits and cover it, at intervals, with layers of earth as remained relatively unchanged.
In Athens (500 B.C.) it was it was the responsibility of each household to taking their garbage to the disposal site located at a minimum of 1.5 kilometers from the city walls. With the Roman Empire, came the first garbage collection service. People threw their refuse into the streets from where it transported to an open pit, often located within the community, by horse-pulled carts. Centuries with no organized waste collection followed. Land was plentiful and people were few, and so garbage was simply dumped in convenient places and forgotten. By the 1700s, refuse had become a major problem: waste was still dumped in the streets and open burning of garbage was a common practice. And yet, it took another 150 years before scientific reports linking disease to filthy environmental conditions finally helped launch the ‘age of sanitation’.
In the United States, the modern concept of solid waste management first emerged in the 1890s. By the turn of the 20th century, a growing number of American cities provided at least a rudimentary level of solid waste collection and disposal, and around 1930 virtually all cities offered garbage collection services. Once removed from urban centers, the wastes were disposed of in a variety of ways, including landfills, incineration, water and, ocean disposal. The latter was outlawed 1933, however industrial and commercial wastes were exempted.
The post World War II era led to a significant escalation of the waste management problem for two reasons: consumerism (over-consumption) and the rise of the chemical age, which, together, resulted in dramatic changes in waste volumes, composition and toxicity.
The 1950s also brought us the so-called Sanitary Landfill, typically defined as an engineered method of disposing solid wastes on land by spreading the waste in thin layers, compacting it to the smallest practical volume and covering it with soil at the end of each working day. But despite the new terminology, it remained in essence an earth moving operation.
That only changed in the 1970s and 1980s, when people recognized that landfills were causing significant contamination of groundwater. The problem was compounded by the fact that once groundwater becomes contaminated it is exceedingly difficult to remediate.
As a result, a number of features were added. Bottom liners made of clays or synthetic materials such as impermeable high-density polyethylene were introduced to stop leachate from leaving the landfill. Caps made of similar materials were placed over the landfill to decrease the infiltration of precipitation. In addition, engineered collection systems were installed to capture leachate and gas. Monitoring of groundwater, surface water, and gas emissions became a routine part of landfill operations.
Despite all the improvement we have made to siting and operating landfills, the real problem is simply their large numbers and the expanses of valuable real estate they occupy. All along, landfills have been a child of convenience. Time has come to develop and implement waste management systems that do not impair our environment, use up valuable resources, or place limitations on future resources.
Public involvement is essential. Wastes are very democratic – they are produced by each and every one of us and so we all should contribute to the solution. The objective must be to minimize the impact on the environment through a combined strategy of reduction/reuse/recycling, and incineration and/or waste to energy conversion. Instead being the first choice, landfills will have to become the last resort.