Citrus County Landfill
On June 17 the Bioenergy Summer School traveled to Citrus County to tour an active landfill. For most of the interns, it was our first time visiting an active landfill. The first part of our tour focused on explanation of the on-site leachate treatment system. At great expense, most active landfills take their leachate and truck it off-site for differential treatment at wastewater treatment plants. The on-site treatment system at the Citrus County landfill had a succession of different treatment stages such as a nitrification tank which then progressed into a denitrifying tank. The system itself contained 200-600 mg/l of ammonia in the leachate and was regulated to keep a pH ranging from 6.5 to 8.5. An extensive amount of economically draining activated carbon in combination with variegated aeration periods also facilitated the treatment process. Methanol was used as the main energy source for the in-system microorganisms introduced from wastewater that help to break down the leachate. The color of the inflowing leachate was a relatively light color when compared to the coffee-colored leachate that is circulated through the closed Southwest Landfill in Archer, Florida. It takes 24 to 36 hours for a batch of leachate to completely circulate through the treatment process. This system processes and treats close to 3 million gallons of leachate annually.
The bioenergy team was able to learn how items deposited at the site were sorted categorically and ascertain the rigorous economic challenges faced when running a public facility of this kind. An extensive portion of revenue generated to run this landfill is accumulated through user and assessment fees. For the next part of the tour, the bioenergy team traveled to the top of the active portion of the site where we were able to encounter the open face of the landfill, which had the distinct odor of mulch. We were able to witness the unloading of different types of waste that were trucked in and then crushed by a bulldozer-like compactor. A great deal of the disposed material deposited on the face was plastic or cardboard based. The compactor operator must keep his eyes open for materials such as tires or propane tanks that are unloaded and dispose of these items in a separate location. Every night after the landfill closes, personnel spray the active face with a combination of latex paint and a feather-like compound. After finishing at the active face, the bioenergy team was able to view the on-site flare that burns off methane gas from the landfill. In the near future, it is a goal of the Citrus County solid waste management division to use this methane production as a transaction marker for selling carbon credits. Overall, this trip and the knowledgeable staff were able to educate the Bioenergy School on the extensive logistics and cost intensive aspects involved with landfill management that often go unnoticed even though these facilities are a core aspect of most counties.