In the municipal wastewater treatment industry, it is conventional wisdom that the processing and disposal of solid waste materials (biosolids) represent about half of a facility's operating budget. Biosolids processing and disposal is a popular topic during meetings and seminars; numerous papers and case studies have been presented at Conferences and Technical Fairs; but nothing really new or innovative has broken through to popular use. The problem worsens over time. With energy prices on the rise, the costs to handle, transport, and dispose of biosolid waste materials rise as well. It seems that the industry is looking (or waiting) for some regulation to be promulgated that will solve all of these problems and change the landscape of the alternatives that are available to us.
State of the Industry
When evaluating biosolids processing and disposal options, the following alternatives are traditionally considered:
Figure 1: Processing and Disposal Options
These alternatives are evaluated on the basis of how they fit into the individual POTW process. Generally the evaluations are based upon the following three categories:
1.) Cost to Operate Process: Includes Labor, Maintenance, and Energy.
- Clearly, processes and technologies that require minimal labor and low maintenance, while producing more energy than they use are they ideal answer to this challenge.
- The degree to which each of these characteristics can be optimized is the holy-grail of the biosolids crusade.
2.) Capital Cost: Influences how technologically advanced of a solution will be pursued.
- Often the fear of taking on debt, drives decisions towards processes involving lowest capital cost.
- New avenues to fund and finance the relatively high cost of entry into the biosolids processing field are becoming available. They are connected to an ever-increasing public focus on renewable and sustainable energy. These financing solutions and/or enhancements are making these types of projects economically viable, where they wouldn't be under traditional SRF or bonded funding sources alone.
- When a properly designed process is backed with process guarantees in critical areas, there should be no limit to the capital cost, as long as the financing solution and operating costs combine to provide a positive cash flow.
3.) Disposal Costs: Treatment processes that reduce the mass of biosolids from the POTW dramatically affect the disposal costs and therefore the overall economics of the Biosolids challenge
- Hauling: The wetter the product the more it costs to haul. Influences the dewatering, and drying considerations
- Landfilling: No Recycle / Resource Recovery. Landfills are the end of the cycle. Limited landfill space. Risk of being at the mercy of the landfill
- Land Application: Currently challenged by limited available land, concerns about contamination & risks to public health, and lacking well established best management practices, and regulations.
Ultimately, facilities spend an enormous amount of money to study the options, weigh the political consequences, and then pick the lowest cost solution. In the end, biosolids handling and processing becomes an economically driven decision in which the “lesser evil” is chosen. The approach to developing a biosolids solution for a particular POTW facility inevitably becomes framed around the question: “How can we give this stuff away at the least cost to the municipality?”.
Changing the Rules
Recently people have begun challenging the notions of the commonly accepted practices that have been discussed above. There has been a great exchange of ideas taking place at the national level (WEF) and the state level in the MWEA Biosolids Committee on the questions that surround land application, namely the debate of Class A vs. Class B. This debate, however, focuses only on a single portion of the dilemma – disposal via land application.
In order to truly address the problems posed by biosolids, there must be a shift away from the commonly accepted notion of “biosolids are a waste product that must be disposed of in the least economically damaging mode as possible,” which focuses heavily on disposal options.
The new opportunities that biosolids processing and disposal present, must be recognized, acknowledged, and pursued.
Biosolids residuals must be thoroughly evaluated as products such as fertilizers, soil enhancements, and fuel sources. New markets for these products must be developed and pursued and impediments to existing markets must be challenged and overcome. Biosolids by-products such as biogas must be recognized for their value as a sustainable source of heat and electrical energy. Means of maximizing the surplus production of these by-products, through the use of existing and new technologies must be explored and capitalized upon.
If the challenges associated with biosolids are approached as opportunities instead of obligations, this industry can begin to change the rules that bind it. This will lead to the creation of thriving markets for biosolids residuals and by-products that currently don?t exist.
By challenging the traditional limitations placed on how POTWs are designed and operated, equipment and technologies that were once deemed “too expensive” can become lifetime value and revenue generators for the POTWs. Markets that did not exist for biosolids residuals and by-products will emerge, and as opportunities to sell these materials and extract their true value become more prevalent and even common-place, these markets will flourish.
Follow up with HESCO Regarding Biosolids
In the past year, HESCO has begun to challenge the current thinking in the industry, and we encourage you to do so also. In future Proactiviews, we will share with you some of the actions we have taken with our clients to begin to change the direction of biosolids and biosolids processing.
We would like to hear your thoughts on this subject:
- What are your thoughts on the current state of the biosolids industry?
- What questions or concerns did this article raise in your mind?
- What would you like to hear more about?
- If you could wish for one thing to change, what would that be?
- What challenges are you currently facing related to Biosolids?
There are two immediate ways that you can contact us:
1. Call Kevin Livingston or Glenn Hummel at 586-978-7200 and mention that you are following up on the ProactiView on Biosolids. We will be happy to discuss with you the details of your specific application or share more of our ideas on turning an obligation into an opportunity.