2011 Issue

35 T hE CommUnITy vIEW themselves as producers of commercially viable products, e.g., clean water, fertilizer, and energy. The quality of these products is being shaped by both envi- ronmental regulations such as those that govern water and residual reuse as well as the private marketplace. For example, establishing product quality specifica- tions for wastewater treatment residuals that highlight its fertilizer and soil condi- tioning characteristics creates financial opportunities for treatment plants that were not otherwise recognized. In other words, sustainable recycling of wastewa- ter residuals requires that product perfor- mance be both reliable and predictable. Certification of product performance can be an expensive undertaking requiring manufacturers to make significant finan- cial investments for laboratory and field testing. Fortunately, treatment plants have the benefit of validated and freely acces- sible computer models developed by the US Environmental Protection Agency [USEPA] and others that can be utilized to predict product performance. The fate of microconstituents in fertilizers that are derived from wastewater residuals can be modeled by the USEPA’s Multimedia, Multipathway and Multireceptor Risk As- sessment (3MRA) model. Model results can be used to quantify the impact of fertilizer quality and application rate as well as soil conditions on local surface water and groundwater quality. In recent years, the myriad benefits of recycling biosolids have been supported by both the scientific and regulatory com- munity through technical publications that describe the negligible environmental and public health risks associated with the management practice. However, there still remains a negative bias towards biosolids land application. Biosolids are nutrient rich (nitrogen and phosphorus) and contain a large amount of organic matter and a vari- ety of essential plant micronutrients. Future options for managingwastewater residuals remain important for treatment plants. The challenges and opportunities for treatment plants in developing effective residual management and communication Simulating our way to a greener future: Sustainable Residual Management Karthik Kumarasamy, Michael McFarland, and Kiran Bhayani A paradigm shift in the wastewater treatment community towards the principle of sustainability is slowly gaining foothold. The plants are recognizing their role beyond their traditional focus on water quality compliance. programs through adoption of the sus- tainability principles are highlighted here. Role of Communication in Problem Solving In many cases, simple changes in com- munication can lead to opportunities for sustainable residuals management. Once upon a time an old man who owned a herd of seventeen camels divided his herd amongst his three sons, one half of to be given to the oldest son, one third to the middle son, and one ninth of the herd to the youngest son. The three sons quickly got into a heated argument as seventeen did not divide evenly by 2, or 3, or 9. The sons decided to consult a wise old woman for advice. The woman thought for a long time and said: I do not have a solution for you three, but I do have a camel that I can give you that will expand your herd to eighteen. The first son took nine camels, one half of the now eighteen-camel-herd. The middle son took six camels. The youngest one took two camels as the father wished. This split left one camel which was gratefully returned to the wise woman. In the case of residual management, the high quality residuals product is a herd of seventeen camels and the simple communication change is the eighteenth camel. Products Approach With energy costs rising and biosolids disposal options becoming increasingly limited, innovative residuals management options must be established. If treatment plants were managed as a manufacturer of clean water, fertilizer and energy, the Figure 1: Wastewater Treatment Plant products: Clean water produced from wastewater (left), Anaerobic digesters and biogas production (center), and Fertilizers (right) Figure 2: Difference in forage growth in Skull Valley: Plot receiving biosolids (Center), Control plot with no application (Right) and biosolids application activity (Left)