When you are done eating an apple, you have a few different choices in terms of how to dispose of the core. If you simply throw it in the trash, it will end up in the local landfill and become just one more addition to the problem of global waste. However, if you compost that apple core, or place it into a green bin or equivalent organic “waste” collection unit, the inherent nutrients can be returned to the soil as part of a more natural and sustainable, life cycle. Many of us have come to understand that this approach is far more sensible – and preferable, to landfilling. Moreover, new technologies and management methods are further expanding our field of options. Included in this are approaches like co-digestion of organics and biosolids at wastewater treatment plants.
Some of these facilities are already embracing the possibility of shifting from the historical mindset of “waste” or “disposal” to that of recovery and re-use. This marks a paradigm shift in both thinking and action as these operations come to better understand there are solutions available that can be leveraged to maximize both the value and efficiency of their existing infrastructure and operations, thus converting these traditional plants into Wastewater Resource Recovery Centers (WRRC’s).
In this model, these new centers can be set up to receive and process organic food “waste”, as well as wastewater biosolids, converting these resources into products with higher and better uses, such as biogas, for green energy (electricity) to heat or power the plant, or that can be sold back to the grid, or even made into biofuel to power fleet vehicles. These are all measures that can reduce operational costs and extend the lifecycle and value of these centers. Fats, oils and greases (FOG) also used to be viewed as “waste” to be disposed of. Now, however, these materials are not only being accepted – but, in some cases, even actively sought after by some advanced WRRC’s where they are valued for their energy potential.
This convergence of organics and biosolids management is part of a larger trend toward landfill diversion and advanced resource recovery. Originally designed to manage wastewater, some of these treatment plants have evolved and are beginning to see the real potential to extract further value from these raw resources for the creation of renewable energy and other, valuable products while extending the service life of our existing landfills and reducing greenhouse gas emissions. This represents the next stage in the evolution of responsible, organics management and the movement toward resource recovery and expanding the circular economy.
About 50% of sewage biosolids generated in North America are currently converted into fertilizer and/or other, useful products, but we are still far behind countries like Norway, which are already reusing upwards of two thirds of their material. It should not really be too surprising then that biosolids and food waste can be treated and/or managed the same way. Ultimately, organic matter is organic matter.
Communities have a number of incentives to encourage integration and management of organic (food) waste and wastewater biosolids. Co-digestion means that all types of wet organic waste can be treated at one plant, which is an efficient means of recovering biogas and containing odors. Many jurisdictions have set waste diversion targets for themselves, but additional approaches and strategies to divert more organics are still required. Although composting programs have spread, they are still not available everywhere – and they are limited in their scope, so they cannot be relied upon as the only solution. Program diversification is key – both from the perspective of risk management, and practicality. Therefore, solutions that make better use of wastewater infrastructure will continue to receive interest and investment.
Where host sites have been proactive and implemented combined organics management solutions, they are already seeing how a wider strategy for resource recovery can be successful. And, now that some of these advanced technologies and turn-key solutions are proving to be reliable and cost effective, host sites will be looking to build further public awareness and goodwill so these organic management programs can be embraced and expanded. This is important because currently, across North America, far too much of these potentially valuable resources are still finding their way into the landfill. In fact, nearly a third of all landfill “waste” is organic, according to some estimates.
Thankfully, some forward-thinking states, such as California are leading the charge and already have plans in place to divert organics from landfills within the next decade. For a province like Ontario, where a third of all waste is organic and only 40% of that is recycled, even a ten percent increase in organic recycling would mean 275,000 tonnes of greenhouse gas emissions saved. However, the good news is that new, sustainable solutions have emerged and some are well positioned to help in the fight to reduce unnecessary waste.
As convergence continues to take hold, stakeholders from the various, relevant sectors, including generators, management, operations, regulatory bodies and solutions providers will need to expand their efforts in engagement and communications to ensure a cohesive and successful movement. A coordinated approach to managing these resource streams will result in higher percentages of resource recovery. Therefore, when that apple core arrives at a well-designed WRRC, it too can be turned into biogas for green energy, or utilized to create other, high quality, re-use products.
Not bad for a humble apple core. And once word spreads about the successes of organics convergence, imagine what a difference a thousand apple cores can make…or ten thousand…or more.
When it comes to biosolids and organics, our motto is; Nothing wasted. Everything to gain.