By Karen DeCampli
Many of us speculate on the challenges facing future generations. But generally speaking, wastewater industry professionals consider the future of the earth and, more specifically, biosolids management considerations. For many years, we simply dumped our biosolids in the oceans and buried them in landfills.
Ten years ago, the U.S. Environmental Protection Agency issued the "Standards for the Use and Disposal of Sewage Sludge" at 40 CFR Part 503. This rule:
• Occurred as ocean dumping was banned, landfill space was decreasing, and landfill costs were increasing, thus causing a shift to biosolids reuse.
• Created two levels of biosolids treatment with pathogen destruction. Both Class A and Class B allowed for land application, with more restrictions placed on Class B.
Today, because of research, sound public policies, and a widening variety of technical solutions, we view the immediate and long-term benefits of effectively processed biosolids as a safe, versatile and valuable product. Many communities, large and small, are studying or integrating processes in their wastewater treatment operations to achieve Class A, and Class A, being unrestricted for use, has opened up many options for communities.
Since the promulgation of the Part 503 regulations by EPA in 1993, public scrutiny of land application is driving a shift to higher quality biosolids. An unintended consequence of the regulation is that once the public became more aware of the two different levels of biosolids treatment, they began demanding that only Class A biosolids be applied to land in their communities, despite municipalities' efforts to safely manage Class B. Local government, however, is responsible for addressing local concerns and making decisions regarding the use and disposal options consistent with the requirements of the Part 503 rule.
But with all this material being generated now and anticipated in the future, where are we going to put it all. What will we do if the market becomes saturated with this material? The answer lies in innovation — thinking in new directions. This is why other beneficial routes are gaining popularity. For instance, a recent innovative technological advancement includes a technology that effectively eradicates biosolids. The new Cannibal™ Solids Reduction Process virtually eliminates traditional biological solids wasting from municipal or industrial wastewater treatment plants. An interchange recycle flow, between a side-stream bioreactor and the activated sludge process, destroys all biological waste products and drastically reduces capital and operating costs.
The members of the Water and Wastewater Equipment Manufacturers Association (WWEMA) are committed to developing advanced biosolids treatment technologies that meet and exceed federal guidelines and regulations. We are committed to working with consultants, volunteer groups, and other dedicated stakeholders to help impart safe environmental management systems.
Our objectives are 1) to develop market-advancing technologies to help communities recycle, reuse, or reduce biosolids, and 2) to support the EPA in its on-going efforts to enforce a sound public policy that encourages a well planned biosolids management program.
Whether the technology solution is stabilization, thickening, dewatering, drying, incineration, composting, or even biosolids elimination processes, we strive to raise the bar to go beyond simply complying with ever-changing environmental and regulatory requirements.
The good earth's soil is a living and life-giving system and a resource of incalculable value. Its long-term vitality depends on our ability to continue to bring innovative technologies forward.
About the author: Karen DeCampli is Director – Municipal Market at USFilter and is a member of the WWEMA Board of Directors.
Some examples of communities and the multitude of uses for processed biosolids include:• The Metropolitan Water Reclamation District of Greater Chicago, Fulton County, IL, used its biosolids to help reclaim 15,000 acres of degraded land left barren by strip (coal) mining.
• The Weyerhaeuser Company, King County, WA, has applied biosolids on its Snoqualmie tree farm, which has dramatically increased tree growth on soils otherwise naturally low in nitrogen.
• The Metropolitan Sewerage District of Milwaukee, WI, has packaged and sold its biosolids as Milorganite® organic granular fertilizer for more than 75 years.
• The City of Goldsboro, NC, installed a composting system to process 12,500 tons of biosolids and 12,000 tons of yard waste annually. Beneficial reuse of these composted materials help protect the local watershed and reduce the overall cost associated with disposal of the biosolids.
