Wastewater Emissions - An Overlooked Source?

by cstew92 on Novembre 28, 2016 - 4:26pm

The purpose of this article is to reveal a discrepancy in the the estimates put forth by the International Panel on Climate Change (IPCC) regarding global wastewater fossil carbon in their total greenhouse gas emissions. According to the IPCC their model when considering wastewater emissions relies on assuming that the carbon contained and released from wastewater is non-petroleum based – for example human waste. However, studies have shown that petroleum based products like detergents, and other household products have been found to leach harmful petrochemicals into the wastewater system, which eventually add to total greenhouse gas emissions.

As a result, researches from Colgate University and the University of California, Irvine have teamed up to conduct experiments investigating fossil-related carbon emissions from wastewater treatment facilities at various points in the treatment process on a municipal and industrial scale. Their findings suggest an increase of 12% to 23% in greenhouse gas emissions from wastewater in relation to initial estimates that only involve methane and nitrous oxide. The article provides a solution to this problem with emphasis on the idea of on-site carbon sequestration to help reduce the impact of wastewater treatment facilities.

As the son of a wastewater treatment operator this article really intrigued me on a personal level. The management of one of our most precious, yet abundant natural resources requires many factors to be accounted for. Some of which we do not yet have the practical or technical capabilities of understanding. Due to the vast abundance of water throughout our planet, management of this resource often poses uncertainty and in some cases – like the IPCC’s report, important factors are often overlooked. Freshwater is known as a renewable (flow) resource in that there is a large enough supply simultaneously entering and exiting the system that is sustainable for current human consumption. However, when thinking about water we sometimes disregard the fact that like all renewable resources, there is a threshold to which water can be sustainably consumed. This is known as the critical zone where extraction rates cannot exceed the rate of replenishment. If this occurs, freshwater could become a stock resource where it would only be available in limited supply.

In the case of the IPCC, omitting wastewater emissions data from their total emissions estimates reflects a level of ignorance due in large part to the fact that those in control used assumptions when considering the role of wastewater in greenhouse gas emissions. A level of uncertainty will always be present in any form of resource management; however, decisions still need to be made. The decision made by the IPCC to omit vital information regarding wastewater emissions demonstrates the ecological and scientific uncertainty that still remains in resource management. Also, this situation helps to demonstrate the power that the state has within resource management by allowing the omission of information to occur. It makes you wonder can inconsistencies like the one illustrated here be occurring in other cases involving environmental monitoring? As scientific research continues to be done, one may begin to question the integrity of those in power that maintain control and distribution of the information.


American Chemical Society. (2016, November 2). Wastewater treatment plants: An overlooked source of carbon emissions. ScienceDaily. Retrieved November 23, 2016 from www.sciencedaily.com/releases/2016/11/161102085229.htm