Download 2013 Agenda in  PDF

The mission of the Hinkley Center for Solid and Hazardous Waste Management is to coordinate and engage in research, training and service activities related to solid and hazardous waste management.


Conversion Technologies

  • What are the costs of converting landfill gas (LFG) to vehicular fuel?
    Background:  Options for the beneficial use of LFG include LFG conversion to vehicular fuel.  The questions are:  l) How much does it cost; 2) what is the payback period; 3) how safe is it? You can contact the Project Manager, Coby Skye at 626-458-5163 for more information.  In March 2012, the Department of Sanitation for New York City issued a Request for Proposals for the private sector to permit, design, construct and operate a conversion technology facility to accept a small portion – less than 10% – of the City’s waste. Eligible proposers must demonstrate a proven, reliable, cost-effective, sustainable and environmentally sound conversion technology that uses waste collected by DSNY as a feedstock for generating a renewable resource. Proposers must be able to point to a facility currently in operation (a “reference facility”) using the same technology, so that the City can verify its performance.


  • What are some viable markets for recycled glass?
    Background:  Many Florida jurisdictions have a hard time finding viable markets for their recycled glass. With the increasing use of single stream MRF's in the state, the glass product is fairly dirty mixed cullet contaminated with paper, dirt and liquid residue.  Assistance is needed to identify processing systems to clean up the recycled glass and identify markets for the recovered glass.

  • What research can be performed to demonstrate the practical feasibility of using crushed glass in concrete, Hot Mix Asphalt (HMA), and other civil engineering products?  Is glassphalt economically viable or are incentives needed to promote its use?  Can a suitable design mix be developed using up to 15% glass as allowed in the DOT asphalt specifications? In addition, promising research has been conducted on mixing very finely ground glass (under ten microns in size) in with concrete as an admixture.   Will the addition of finely ground glass to concrete improve the engineering properties of the concrete in the same way that adding fly ash to concrete increases the strength of the concrete and also decreases the permeability of the chloride ion to travel from the outside of the concrete to the rebar in the concrete?  Making concrete that is less permeable to the chloride ion is a strategy being used to keep the reinforcing steel in bridges in coastal areas from corroding and causing cracking and weakening of the concrete used to construct bridges. What are the economics of converting recycled glass into very finely ground glass so that the finely ground glass can be added to concrete?
    Background:  Glass is one of the identified products for recycling under FDEP’s regulations.  Glass is allowed for use in asphalt as a “locally sourced product”.  Most County road departments do not encourage its use.  Reasons are two-fold: 1) unfamiliarity with applications using glass and lack of existing, proven design mixes; and 2) extra cost.  As with most recycled products, local governments' policies dictate materials and uses.  Without a viable recycling alternative, glass will continue to be a net loser for county recycling programs. 

Health & Safety

  • What are the health and safety issues and statistics in the solid waste management industry?
    Background:  Health and safety in all areas of solid waste management continues to be a significant issue.  An update to the University of Miami study (Solid Waste Management Health and Safety Risks: Epidemiology and Assessment to Support Risk Reduction , Englehardt, James, March 19, 2000) is suggested.  After several years of reduction in the injury/death rate in solid waste management, the rates are now reported to be increasing.  There is still not much known about risks to vision impairment by nuisance dust or on health impacts to workers from airborne bacteria and pathogens.
  • What is the ambient air quality on the tipping floor at transfer stations, Material Recycling Facilities (MRFs), sorting stations, and at organics composting facilities?
    Background:  Determine microbiology (bacterial pathogens) in air quality on tipping floor area, enclosed transfer stations, and in MRF's at sorting stations and at primary processing stations.  Findings may suggest a need for different or additional engineering controls and/or personal protective equipment which may be required to improve health protection for solid waste workers.

Groundwater Issues

  • What measures can be taken to prevent "reductive dissolution" of iron and arsenic beneath existing lined landfills?  What are some low-cost design and construction options for getting oxygen into the soils?  What are the options for new landfills that have not yet been constructed?  How can we avoid creating new groundwater contamination problems due to “the shadow effect” underneath new lined cells which have not yet been built? 
    Background:  Several locations around the state where lined landfills have been installed are experiencing groundwater contamination due to a lack of oxygen in the soil and/or groundwater beneath the liner. What are the best options for getting oxygen into the soil and groundwater beneath the liner for existing lined landfill cells and lined landfill cells that have not yet been built?
  • How does landfill gas impact groundwater?
    Background:  What are the constituents impacting the groundwater regime by landfill gas (LFG)?  We know LFG impacts groundwater but, how?  What are typical constituents?  What are the methods for identifying the LFG pathways to groundwater?


  • What are the best practices for handling wastewater treatment plant biosolids/sludge in landfills? 
    Background:  Land application of biosolids/sludge is becoming more and more difficult due to opposition by the public and due to new land use restrictions being imposed by local governments.  The net result of this is that the amount of biosolids/sludge going to landfills is increasing.  Handling this type of material correctly is crucial to avoid long-term issues that might impact the landfills.  Failure to properly mix the biosolids/sludge with appropriate bulking agents such as chipped wood or yard waste and spread the mixed material correctly might cause uneven settlement, leachate breakout, “slippage” or failure of a side-slope, a catastrophic “landslide” of the waste or other problems.
  • What are the economics and long-term performance of exposed geomembrane covers (EGC) in Florida?
    Background:  A long-term field study of EGCs and the materials used to construction EGCs needs to be conducted to evaluate their performance in Florida.  What are the maintenance and replacement costs for long-term use of an EGC?  What is the current track record for use of EGCs as an interim or final cover?  How often do they need to be repaired or replaced?  What is the suitability of an EGC when it is used as a final cover for Florida facilities?

Landfill Closure

  • What is an appropriate post closure care period for: 1) unlined C&D facilities, 2) unlined Class III landfills and; 3) slurry wall landfills?
    Background: How should operators and the regulatory community deal with unlined C&D facilities, unlined Class III landfills and slurry wall landfills in terms of “post closure care”?   Slurry wall landfills are designed to have a continuous gradient of the groundwater from the area outside the slurry wall towards the area inside the slurry wall.  After closure should groundwater still be pumped to maintain the gradient?  What are the criteria to establish this?  Should responsible parties be required to continue to pump groundwater from within the slurry wall landfill to keep the potentiometric surface of the groundwater within the slurry wall landfill depressed?
Landfill Leachate

  • Can constructed wetlands be utilized for onsite leachate treatment?
    Background:  Landfill leachate transportation and treatment at an offsite advanced wastewater treatment plant is expensive and energy-intensive. One possible method to reduce cost and energy requirements is to treat the leachate on-site using constructed wetlands.
  • What are the onsite leachate treatment options for landfills that have high chloride levels in their leachate from waste-to-energy ash?
    Background:  Some small counties that have Waste To Energy Plants are often unable to use local wastewater treatment plants (WWTPs) to dispose of leachate due to high chloride concentrations in their leachate.  Leachate is being trucked to wastewater treatment plants in coastal locations (Jacksonville, Miami, etc.).  Transportation and disposal costs are a large portion of their budget.  How can they reduce their costs?
  • What are the impacts of arsenic on leachate?
    Background:  Arsenic has become problematic in some leachates due to limits imposed by wastewater treatment plants on allowable arsenic concentrations in the leachate. There is evidence that a significant portion of the Asenic in leachate is present as an organic arsenic species such as trimethylarsine oxide.  Trimethylarsine oxide has been shown to be resistant to conventional pretreatment methods (e.g. iron co-precipitation). Confirmation of the sources of the arsenic and the identification of mechanisms of formation of organic arsenic compounds and treatment options would be of value. There is evidence that biological treatment is effective at breaking the organic complexes in some instances.  However, there is also evidence that some organic arsenic species such as trimethylarsine oxide are very resistant to conventional treatment technologies.  Organic arsenic can be particularly problematic in condensate from landfill gas collection systems as the concentration of arsenic in the condensate can be so high as to qualify the gas condensate as a Hazardous Waste under RCRA.  More information on this topic is available.

Landfill Mining

  • What are the issues, economics, and benefits of landfill mining?  What are the issues, economics, and benefits for land recovery for old landfills located on valuable real estate?
    Background:  Old landfills abandoned after the 1985 Subtitle C Rule change were typically covered with 2 feet of soil and mostly left alone.  The real estate beneath many of these landfills has become very valuable (i.e. Toytown Landfill in Pinellas County, Dade Landfill in Coconut Grove).  What are the issues for reuse of these lands?

Landfill Odor

  • How can sulfur compounds in Recovered Screened Materials (RSM) be stabilized such that they do not form compounds that have an objectionable odor when used for cover or fill purposes?  Can RSM be combined with conventional soils to create a usable soil fill product that does not have odor problems?
    Background:  Testing of constituents and demonstration that RSM meets either the residential or industrial clean up levels allowed for RSM use outside the landfill are subject to risk assessment evaluation.  For buried applications where human contact risk is limited, the potential for degradation of the drywall components under anaerobic conditions exists.  This degradation results in the emission of hydrogen sulfide and other related/similar reduced sulfur compounds and causes associated odor issues.  If the sulfur in RSM could be stabilized, more opportunities could be developed for general fill applications of RSM.  This issue is of particular interest in Dade, Broward and Palm Beach counties.


  •  How effective are anaerobic digesters used by small businesses?
    Background:  There is a need for practical applied research in the area of small anaerobic digesters for area livestock facilities such as horse and cattle ranches. Waste products (i.e. manure, straw) could be a source of energy for these facilities.
  • What are some uses for the by-products (alum, etc.) from a potable water treatment plant? 
    Background:  The Charlotte County Zemel Road Landfill is accepting about 18,000 tons of alum yearly.  Are there recycling options for this material (rather than disposing in a landfill)?  Disposal of drinking water treatment sludges via land application is a controversial topic in western Palm Beach County.


  • How effective are waste tire collection facilities and what are their environmental impacts? 
    Background:  There appears to be a great deal of waste tire export activity at the present time. It would be interesting to know what is happening with tires that are being exported from the US and what the environmental impacts are of this practice in other countries. We would like to know how effective these waste tire collection facilities are and what the experience has been, environmental assessment, etc.
Waste Composition

  • What is the composition of Florida's solid waste stream?
    Background:  Much of the composition data for Florida’s solid waste stream is old and dated.   There is a need for a statewide survey to identify and target materials that can be recycled to meet the state’s 75% recycling goal.  This work could build on previous research conducted by Drs. Reinhart and Townsend (


University of FloridaFlorida international universityUSFMiami UniversityFlorida A&MUCFFlorida StateFAUUniversity of West FloridaFlorida Institute of Technology