INTRODUCTION Underground storage tanks containing hydrocarbonbased fuels are found worldwide. Many of these tanks have leaks, allowing gasoline, diesel, oil, or other hydrocarbon materials to contaminate the surrounding soil. In 1992, only 2 million of the 5 million tanks in the U.S. were monitored for leaks. However, underground storage tanks represent only one of many sources of hydrocarbon c...

A promising in situ remediation alternative for metal oxyanions such as arsenic, chromium, and selenium is microbial reduction to insoluble oxide, sulfide, or elemental phases. An important question that must be addressed before this technology can be implemented is the stability of these phases. This paper describes an investigation of the stability of reduced arsenic and sulfide precipitates ...

ment has been subjected to EPA's peer and administrative reviews and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use. ii Foreword The EPA is charged by Congress with protecting the Nation's land, air, and water resources. Under a mandate of national environmental laws, the Agency str...

Introduction It is recognized that physical and chemical interactions between adjacent ground water and surface water bodies are an important factor impacting water budget and nutrient/ contaminant transport within a watershed (Winter et al., 1998). This observation is also of importance for hazardous waste site cleanup within the United States, since about 75% of sites regulated under the Reso...

Two series of new electroactive and photoactive coil-rod-coil and rod-coil-rod triblock copolymers, poly (pentadecamethylene carboxester)-block poly(p-phenylene benzobisthiazole) block poly (pentadecamethylene carboxester) (1), and poly(2,6-benzoxazole)-Woc£poly(benzobisthiazole decamethylene)-WocÄ:-pory(2,6-benzoxazole) (2), were synthesized, characterized, and used to investigate the self-ass...

EPA Methods 26 and 26A and Proposed Methods 0050 and 005 1 are in widespread use for collection and quantitation of stationary source emissions of halogens and halogen acids from a variety of source types. Considerable research has been conducted in evaluation of these methods, but research information about the methods has not been published in one convenient summary and much of the technical ...

This paper focuses on the method detection limit (MDL) and practical quantitation level (PQL) used in the sampling and analysis plans for the waste characterization and remediation programs at many federal facilities. The paper discusses the derivation and use of the MDL and PQL by the Environmental Protection Agency (EPA) and others, concerns raised regarding how EPA derives and uses the MDL a...

Recent changes in environmental regulatory paradigms, such as EPA’s performance-based measurement systems (PBMS), are lowering method compliance barriers for laboratories working under the Resource Conservation and Recovery Act (RCRA). One of the stated goals of PBMS is to educate the regulators and the regulated community on the inherent and intended flexibility of SW-846 methods. Operating un...

introductionthe expanding production of fuels, drugs, fertilizers, chemicals, and hazardous materials has caused considerable environmental contaminations. the contamination of soil and groundwater with petroleum hydrocarbon-based fuels as a result of accidental spills or improper storage has been reported frequently. iran is seriously facing soil contamination problem, due to owning 8.58% of t...

Large-scale (> 1 m) variability in hydraulic conductivity is usually the main influence on field-scale groundwater flow patterns and dispersive transport. Incorporating realis tic hydraulic conductivity heterogeneity into flow and transport models is paramount to accurate simulations, particularly for contaminant migration. Sediment lithologic descriptions and geophysical logs typically offer f...