Pesticide Waste Disposal

Abstract: Pesticide disposal research has focused on development of a biologically-based system for cleanup and detoxification of pesticide wastes. Equipment has been developed and is being used to cleanup pesticide rinsewater wastes. The treatment system consists of batch sorption of pesticides onto an organic sorbent (e.g. peat), followed by separation (filtration) and finally degradation of sorbed pesticide in bioreactors during solid state fermentation (SSF). Field experiments are being conducted at three Virginia Agricultural Research and Extension Centers (AREC's) to evaluate the effectiveness of the process with regard to human effort, safety and economics and environmental safety. A second area which is being addressed is the bioremediation of soils contaminated with pesticides resulting from accidental spills. Investigations deal with the use of organic sorbents and other amendments such as used vegetable oil soil in an effort to first retard pesticide movement and subsequently to facilitate biodegradation.

Description: Extensive use of pesticides in US agriculture has resulted in several human health and environmental concerns. Some of these include: 1) the fate of pesticide residues in the environment once these compounds have been applied, 2) the need for appropriate disposal of dilute pesticide formulations and pesticide-contaminated products and, 3) methods for dealing with pesticide spills. These and other related problems are of importance because pesticides are finding their way into our water supplies. Further, environmental contamination due to pesticide usage is becoming more problematical for large chemical companies and applicators of pesticides because the options for disposal are limited. The U. S. Environmental Protection Agency has provided estimates on the occurrence and frequency of pesticide detection in national drinking water wells which were based on a national survey of drinking water wells in the United States. Interpretation of the results of this survey include estimates that about 10.4 % of 94,600 community water system wells and about 4.2% of 10.5 million rural domestic wells contain detectable pesticides above the survey?s minimum reporting limit. The USEPA estimates that less than one percent (0.6%) of the rural domestic wells contain at least one pesticide above the Maximum Contaminant Level (MCL) or Lifetime Health Advisory Level (HAL) . This information has been evaluated and a strategy developed for addressing issues relating to pesticides and ground water contamination. A recent review of literature obtained from studies of private and commercial properties indicates that point source groundwater contamination is most likely to occur at locations near or proximal to pesticide handling facilities. This contamination results from spilled pesticides and rinsates generated during cleanup of contaminated application equipment. Activities associated with pesticide application that have potential to contaminate the environment include disposal of 1) concentrated materials, 2) empty containers, 3) excess mixed material, 4) rinsewaters resulting from application equipment cleanup and 5) spills. In recent years, several of these issues have been addressed. A series of amendments to the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) have authorized U. S. Government control over storage and disposal of pesticides. The most recent amendments (FIFRA, Section 19, 1988) expanded USEPA's authority to regulate the storage, transportation and disposal of pesticides, pesticide containers, pesticide rinsates and pesticide contaminated materials. Since this legislation addresses a wide scope of complex issues, EPA has pursued it's implementation in three phases. Development of the regulations mandated by FIFRA, 1998 is a time-consuming process and, therefore, a significant portion of the rule-making is still pending final approval and adoption. Phase I proposes rules covering recall, reimbursement of storage costs, storage and disposal plans and indemnification to users for recalled, suspended and canceled pesticides. Phase II proposes regulations for pesticide design and residue removal provisions and standards for containment structures. Phase III is scheduled to address provisions on storage, disposal and transportation of registered pesticides. Since current options available to pesticide applicators are limited, new disposal technologies specifically addressing disposal of rinsewater and decontamination of spills are needed. The current options and emerging disposal technologies need to be considered in development of Phase III. The current options available for dealing with dilute pesticide rinsewaters include: 1) waste minimization, 2) rinsate recycling, 3) application of rinsates to labeled sites, 4) using evaporation or degradation pits, 5) carbon sorption and, 6) using commercial vendors to dispose of the wastes. Some of these methods are effective, but costly, or may involve complicated procedures or equipment. Appropriate disposal methods should result in the neutralization or degradation of toxic chemicals to a point where their residues or by-products are non-toxic and will not pose a threat to the environment. We believe that it is essential that pesticide disposal methods be effective, safe, inexpensive and relatively easy to implement. One promising approach utilizes biological agents (microorganisms) to degrade hazardous materials to non-toxic byproducts. The focus of our research has been to explore the use of organic sorbents on which hazardous materials may be sorbed and subsequently support chemical and microbial degradation of the sorbed pesticides. The overall goal of our pesticide disposal research is to develop pesticide disposal methods that are safe, effective and practical. The overall objective of this proposal will be to construct and evaluate a single unit pesticide rinsate treatment system. It is our intention that this rinsate disposal system can be used as a stand alone system or integrated into a pesticide loading/wash down facility. We envision that the adoption and use of this treatment system by the Virginia agricultural community will provide protection of our groundwater resources from pesticide contamination.

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Disciplines: Environmental Quality, Horticultural Systems, Integrated Pest Management, Landscape and Ornamental, Pesticides

Audiences: Agribusiness, Commodity Groups, Environmental Groups, Extension Agents, Government Agencies, Homeowners, Local Governments, Producers, Researchers