Partitioning of Arsenic Species in Fine-Grained Soils

It has been theoretically and experimentally shown that rate-limited sorption/desorption can have a profound effect upon the transport of sorbing contaminants. The advection/dis-persion equation that has been traditionally used to model contaminant transport uses a retardation factor to account for sorption, thereby implicitly assuming local equilibrium between contaminant in the sorbed and aqueous phases. This assumption fails to consider the possibly large effects of rate-limited sorption/desorption.

The mass release characteristic of arsenic-contaminated soils at the Crystal Chemical site in Houston, TX, was examined. Soils were collected from beneath two former waste-water ponds that were the source of arsenic in the uppermost aquifer. Samples were typical of those found within the fine-grained components of local alluvial overbank deposits that comprise the bulk of the site. The dynamic test applied a continuing head of water, operating in an upflow mode, through 4-inch-diameter by 12-inch-long soil columns repacked to in-situ density. Three columns were constructed

The mass release characteristic of arsenic-contaminated soils at the Crystal Chemical site in Houston, TX, was examined. Soils were collected from beneath two former waste-water ponds that were the source of arsenic in the uppermost aquifer. Samples were typical of those found within the fine-grained components of local alluvial overbank deposits that comprise the bulk of the site. The dynamic test applied a continuing head of water, operating in an upflow mode, through 4-inch-diameter by 12-inch-long soil columns repacked to in-situ density. Three columns were constructed—

two containing predominantly clay, and the other containing clayey silt. Leachate from the most permeable column was collected over 42 pore volumes (equivalent to 120 years of extraction). Sharp declines in arsenic concentrations in the leachate were measured after just four pore volumes. A biphasic response was evident, consistent with published research on kinetically limited mass transfer of retarding solutes. The most responsive column was pulsed to elucidate the effects of diffusion and pulsed pumpingtwo containing predominantly clay, and the other containing clayey silt. Leachate from the most permeable column was collected over 42 pore volumes (equivalent to 120 years of extraction). Sharp declines in arsenic concentrations in the leachate were measured after just four pore volumes. A biphasic response was evident, consistent with published research on kinetically limited mass transfer of retarding solutes. The most responsive column was pulsed to elucidate the effects of diffusion and pulsed pumping.

Arsenic concentrations returned to baseline levels in less than three pore volumes.

These studies ultimately led to a joint assessment between Southern Pacific Lines (SPL) and EPA Region VI, which concluded that extraction and treatment of the shallow aquifer beneath the site was not feasible, in light of the aggressive restoration goal.     

Mercury Measurement and Its Control: What We Know,Have Learned,and Need to Further Investigate

ABSTRACT

Based on the available evidence of health effects, the U.S. Environmental Protection Agency (EPA) has been evaluating the need to regulate mercury releases to the environment. In response to the congressional mandates in The 1990 Clean Air Act Amendments (CAAA), the EPA has issued the Mercury Study Report and the Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units Report. In spite of the enormous effort represented by these reports, as well as the efforts of both the U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), in conducting the field measurement programs that form the basis for these reports, a definitive answer on the need for mercury regulation has not been found. However, the EPA, as well as other regulatory agencies and health researchers, have suggested a "plausible link" between anthropogenic sources emitting mercury and the methylation, bioaccumulation in the food chain, and adverse health effects in humans and wildlife.     

Mercury Measurement and Its Control: What We Know,Have Learned,and Need to Further Investigate

ABSTRACT

Based on the available evidence of health effects, the U.S. Environmental Protection Agency (EPA) has been evaluating the need to regulate mercury releases to the environment. In response to the congressional mandates in The 1990 Clean Air Act Amendments (CAAA), the EPA has issued the Mercury Study Report and the Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units Report. In spite of the enormous effort represented by these reports, as well as the efforts of both the U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), in conducting the field measurement programs that form the basis for these reports, a definitive answer on the need for mercury regulation has not been found. However, the EPA, as well as other regulatory agencies and health researchers, have suggested a “plausible link” between anthropogenic sources emitting mercury and the methylation, bioaccumulation in the food chain, and adverse health effects in humans and wildlife.

Policy-makers have recognized that regulations must be based on good science and that a number of issues still remain. These issues can generally be grouped into four main categories: emissions inventory, control technology, fate of releases, and health effects. This paper will discuss recent, ongoing, and planned studies to address the remaining issues regarding the presence of mercury in the environment, with an emphasis on those studies that are directly related to the DOE/Federal Energy Technology Center’s (FETC) programmatic effort.     

Multi-adsorbent Preconcentration and Gas Chromatographic Analysis of Air Toxics with an Automated Collection/Analytical System

Section 507 of the 1990 Clean Air Act Amendments (CAAA) requires states to develop a small business stationary source and environmental compliance assistance program to aid small businesses impacted by applicable air quality regulations. In general, the program consists of three main components: (1) a small business assistance program (SBAP) for providing compliance and technical assistance to small businesses; (2) an ombudsman for providing direct oversight to the SBAP; and (3) a compliance advisory panel consisting of members from both the public and private sector responsible for determining the overall effectiveness of the SBAP. The key component of the program for assisting small businesses is the SBAP. Providing the necessary assistance to small businesses regarding such issues as permit applicability, rights under the CAAA and emission control options will require the SBAP to develop both proactive and reactive components. The proactive component involves providing outreach services in the form of collecting and disseminating compliance and technical information to small businesses. The reactive component includes the establishment of an information clearinghouse for handling the many inquiries from members of the small business community who have never been subject to air pollution control regulations. States without the available resources to fully implement an SBAP may need to rely on contractor assistance. This paper briefly describes the establishment of the program, provides an overview of each of the program components, discusses many of the ways in which states may implement both the proactive and reactive components of the SBAP, and lists the types of contractors most suitable for SBAP assistance.     

Treatment of Halogenated Organic Vent Streams for the Reduction of Air Emissions

Abstract

This work presents a three-stage treatment system to process halogenated organic vent streams for compliance with the Hazardous Organic NESHAP (HON) Rule. The three stages are incineration, energy recovery, and wet scrubbing. In particular, this work concentrates on the design of the scrubber, which the HON Rule states must remove at least 99% of any halogens or hydrogen halides generated during the combustion step. Computerized process simulation was found to be ineffective in designing a scrubber for this application, so laboratory data on the partial pressure of the hydrogen halide species over aqueous solutions was employed. The number of overall gas transfer units required for 99% removal was found to be slightly less than 5, and the overall gas transfer unit height was found to be approximately 0.5 m.     

An Assessment of Source Contributions to Ambient Aerosols in Central Taiwan

Ambient aerosols were sampled at three selected sites in the coastal region of central Taiwan to obtain composition data for use in receptor modeling. All the samples were analyzed for 20 elements with an x-ray fluorescence spectrometer. The mass percentage of sulfates in particle samples was determined by ion chromatography, and mass percentages of elemental carbon (EC) and organic carbon (OC) were determined by an elemental analyzer.

Because the three sampling sites were located within 25 km of each other, the average chemical compositions were similar for particle samples taken at the three sites on the same day. However, the variation in composition from day to day was significantly influenced by wind direction and change in local sources, such as the burning of agricultural wastes. The abundant species in the coarse fraction (2.5-10 µm) were Al (0.5-4.0 µg/m³), Cl (0.1-4.8 µg/m³), Ca (0.2-3.4 µg/m³), Fe (0.2-2.8 µg/ m³), and K (0.1-1.4 µg/m³), while the abundant species in the fine fraction (<2.5 µm) were S (0.3-3.5 µg/m³), Cl (0.01-1.9 µg/ m³), K (0.04-0.98 µg/m³), organic carbon (0.01-10.5 µg/m³), elemental carbon (0-10.7 µg/m³), and sulfates (1.2-15.7 µg/m³).

Calculations for source apportionment were carried out using the CMB7 software developed by the U.S. Environmental Protection Agency (EPA). The main sources for the coarse fraction of ambient aerosols in the region were found to be marine aerosol, coal and fuel oil combustion, burning of agricultural wastes, and paved road dust. The main sources for the fine fraction were burning of agricultural wastes, diesel exhaust, coal and oil combustion, and sulfates. Source apportionment for the fine fraction was relatively sensitive to the types of sources selected for calculations and the compositions of the sources. The problem can be ameliorated by careful examination of possible sources and by use of local source profiles.     

The New Clean Air Act Operating Permit Program: EPA’s Proposed Regulations

The 1990 Clean Air Act Amendments added a new Title V to the Act which establishes an operating permit program for numerous sources of air pollution. Certain sources are currently required to obtain a construction or “new source review” permit; the 1990 Amendments will require many more sources to apply for a permit which will give them permission to operate. CAA Title V was modeled on the National Pollutant Discharge Elimination System (NPDES) permit provisions of the Clean Water Act, but there are important differences between the two statutes.

Although many states already have their own operating permit programs, by late 1993 every state must establish a program that meets the requirements of Title V and EPA’s implementing regulations. EPA recently proposed these regulations, and by the statutory deadline of November 15, 1991 hopes to issue final regulations establishing the minimum elements of state operating permit programs. These regulations will significantly affect implementation of air pollution measures for years to come because a Title V operating permit will have to assure compliance with all applicable CAA requirements. In addition, permitted sources will be required to pay fees to cover the costs of the permit program.     

A System for Abatement Control Strategy Evaluation

The Air Quality Control Program of the Commonwealth of Massachusetts has developed an implementation plan for the Metropolitan Boston Intrastate Air Quality Control Region as required by PL 90-148. An essential part of the plan was a set of control regulations designed to achieve and maintain an air quality compatible with adopted standards. Control strategy modeling was used as a tool in selecting the most appropriate regulations to achieve this goal. The body of information presented in this paper is directed to those state and county air pollution control officials concerned with the formulation and evaluation of regulations.

The paper details the procedures developed and presents a case history of their use in the region. The system is a synthesis of generally-available software and newly-developed computer programs to provide ahighly automated computational structure. It permits rapid simulation of the emissions resulting from the application of various control regulations. Predictions on the changes expected in ambient air quality levels are then made by the use of the Air Quality Display Model (AQDM).

The initial step in the application was a calibration of the system using predicted and measured annual concentrations. This step yielded correlation coefficients of 0.92 for sulfur dioxide and 0.85 for particulates. Subsequently, the system was used to evaluate the baseline case of uncontrolled sulfur in fuel use. Alternative sulfur control strategies were tested for compatibility with air quality standards. The principal strategies tested were: (a) 1% sulfur uniformly throughout the region; (6) 1% sulfur in core area of region, 2.2% sulfur elsewhere; (c) 0.5% sulfur in core area of region, 2.2% sulfur elsewhere; (d) 0.5% sulfur in core area of region, 1.0% sulfur elsewhere.

Strategies (b) and (d) were implemented into a time phased set of control regulations for the region.

Experience with the system has shown it to be a convenient and rapid method for simulating the effects of control regulations. Furthermore, the utility of this initial model warrants expansion of its application to the other air quality control regions in the Commonwealth.     

Sulfur Dioxide Emissions and Market Effects under the Clean Air Act Acid Rain Program

ABSTRACT

The Clean Air Act Amendments of 1990 (CAAA90) established a national program to control sulfur dioxide (SO₂) emissions from electricity generation. CAAA90's market-based approach includes trading and banking of Soumissions allowances. We analyzed data describing electric utility SO₂ emissions in 1995, the first year of the program's Phase I, and market effects over the 1990-1995 period. Fuel switching and flue-gas desulfurization were the dominant means used in 1995 by targeted generators to reduce emissions to 51% of 1990 levels. Flue-gas desulfur-ization costs, emissions allowance prices, low-sulfur coal prices, and average sulfur contents of coals shipped to electric utilities declined over the 1990-1995 period. Projections indicate that 13-15 million allowances will have been banked during the program's Phase I, which ends in 1999, a quantity expected to last through the first decade of the program's stricter Phase II controls. In 1995, both allowance prices and SO₂ emissions were below pre-CAAA90 expectations. The reduction of SO₂ emissions beyond pre-CAAA90 expectations, combined with lower-than-expected allowance prices and declining compliance costs, can be viewed as a success for market-based environmental controls.     

Maintaining High-Volume,Low-Pressure Surface-Coating Regulatory Compliance Using the U.S. Environmental Protection Agency’s Data Quality Objectives Process

Abstract

To effectively reduce the environmental compliance costs associated with meeting specific requirements under the Aerospace Manufacturing and Rework Facility’s National Emission Standard for Hazardous Air Pollutants rule, the U.S. Environmental Protection Agency’s (EPA) Data Quality Objective (DQO) process has been proposed as a suitable framework for developing a scientifically defensible surface compliance monitoring program. By estimating the variability associated with the air cap pressure of high-volume, low-pressure (HVLP) surface-coating spray equipment, the number of monitoring samples necessary for an affected facility to claim compliance with a desired statistical confidence level was established. Using data taken from the pilot test facility, the DQO process indicated that the mean of at least 21 HVLP air cap pressure samples taken over the compliance period must be ≤10 pounds per square inch (psig) gauge for the facility to claim regulatory compliance with 99.99% statistical confidence. Fewer compliance samples could be taken, but that decision would lead to a commensurate reduction in the compliance confidence level. Implementation of the DQO-based compliance sampling plan eliminates the need for an affected facility to sample all regulated HVLP surface-coating processes while still maintaining a high level of compliance assurance.     

“The Clean Air Act — A Time for Evaluation”

The Third Government Affairs Seminar sponsored by the Air Pollution Control Association was held in Washington, D. C. on April 16-17, 1975. The APCA South Atlantic Section was host for this very successful meeting. The General Chairman of the Seminar Committee was John V. Brink and the Program Chairman was Richard D. Grundy.

The seminar this year was conducted in three sessions. The first session, entitled “The Clean Air Act: State vs Federal Roles,” considered a topic that is receiving increasing emphasis as the national air pollution control program matures. This discussion was chaired by M. Barry Meyer, Chief Counsel and Chief Clerk, Senate Committee on Public Works.

The second session was “Land Use Planning Aspects of the Clean Air Act—Federal, State and Regional Roles.” Mrs. Mary Jane Due, Chairman of the Public Land and Land Use Committee, Natural Resources Section, American Bar Association, served as Moderator of this discussion of indirect source regulations, no significant deterioration, air quality maintenance—concepts that rely heavily on comprehensive land use planning.

“Clean Air Priorities—The Need for Flexibility,” was the title of the third session which was chaired by Austin H. Phelps, Manager Corporate Air Pollution Control, Procter and Gamble Company and President of APCA. The panelists considered the question of how appropriate the standard setting mechanisms of the Clean Air Act are for the resolution of present and future problems.

In this report condensed versions of the prepared statements of the participants are presented. A more extensive summary of the Proceedings, which includes questions and answers, is available from APCA headquarters. The remarks of John R. Quarles, EPA Deputy Administrator, who was the luncheon speaker, were summarized in the June APCA Journal(p. 642).     

Overview of the U.S. Environmental Protection Agency's Hazardous Air Pollutant Early Reduction Program.

Under provision of the Clean Air Act Amendments of 1990 Title III, the EPA has proposed a regulation (Early Reduction Program) to allow a six-year compliance extension from Maximum Achievable Control Technology (MACT) standards for sources that voluntarily reduce emissions of Hazardous Air Pollutants (HAPs) by 90 percent or more (95 percent or more for particulates) from a base year of 1987 or later. The emission reduction must be made before the applicable MACT standard is proposed for the source category or be subject to an enforceable commitment to achieve the reduction by January 1, 1994 for sources subject to MACT standards prior to 1994. The primary purpose of this program is to encourage reduction of HAPs emissions sooner than otherwise required. Industry would be allowed additional time in evaluating emission reduction options and developing more cost-effective compliance strategies, although, under strict guidelines to ensure actual, significant and verifiable emission reductions occur.     

Overview of Proposed Air Emission Standards and Guidelines for Municipal Waste Combustors

The EPA proposed regulations for municipal waste combustors (MWCs) on December 20, 1989. The regulations include (1) performance standards under Section lll(b) of the Clean Air Act (CAA) for new, modified, or reconstructed MWCs and (2) draft emission guidelines and compliance schedules for the states to use to develop control requirements from existing MWCs under Section 111(d).

This paper will outline the proposed air emission standards and guidelines, as well as the basis for the prescribed emission limits. The schedule for the remainder of the regulations development will also be discussed.     

Pennsylvania’s Compuiterized Air Monitoring System

The Pennsylvania Air Pollution Commission has developed a regulatory program based upon the control of local air pollution problems and reduction of pollutant levels in air basins. The geographical boundaries of 10 air basins have been established. The Commission’s air basin regulations will provide for the reduction of over-all pollutant levels and for emergency procedures in the event of adverse meteorological conditions. The paper discusses the format and objectives of the program.

In order to effectively enforce the air basin regulations and maintain the necessary surveillance of the state’s air quality, a "computerized real time on-line integrated air monitoring-data handling system" has been designed. The system will incorporate a network to constantly monitor the air in each air basin.The primary objectives of the system are: 1. Constant surveillance of air pollution in the air basins.

2. Provide information on air pollution potential alerts.

3. Aid in further development of air quality criteria and regulations.

The air monitoring network is estimated to include approximately 25 remote stations. Each remote will contain air pollution and meteorological sampling equipment and hardware to telemeter to a central station. The data will be transmitted over leased telephone lines. The central station in Harrisburg will contain the necessary hardware to receive and process data, calculate and display results and permit supervisory control of the network. Output options will include immediate display of edited data, command and alarm information, and presentation of statistical results.

Although the air monitoring system is one of the principle ingredients of the program, the air basin concept encompasses other component systems designed to knit together the entire air pollution control program in Pennsylvania.     

Interlaboratory and Intralaboratory Variability in the Analysis of Mercury in Coal

Abstract

With the passage of the 1990 Clean Air Act Amendments (CAAA), accurate determination of the concentration of mercury in coal has become an increasingly important issue. To address this issue, CONSOL R&D conducted a round robin analytical program to determine the interlaboratory and intralaboratory variability in the measurement of mercury in coal. CONSOL supplied homogeneous splits of Pittsburgh and Illinois #6 seam coals, and the NIST 1632b coal standard to eleven laboratories, twice each, over a one-year period. A twelfth laboratory analyzed the coals once. A European coal standard, certified for mercury, was analyzed at the completion of the round robin study to evaluate accuracy. The round robin participants included representatives from industry, government, and academia. The laboratories, which are experienced in mercury-in-coal analysis, used various state-of-the-art sample preparation and analysis procedures in the study. The round robin results indicate that a substantial level of variability exists in the mercury-in-coal determination. Earlier studies1 found similar results. The relative intralaboratory repeatability was 0.02 ppm and the relative interlaboratory reproducibility ranged from 0.04 to 0.05 ppm. The study showed that laboratory variability can be greatly skewed by outlier values. Fifty-six percent of the results for the European coal standard fell within a 95% confidence interval of the standard (0.138 ± 0.11 ppm). These results indicate that accuracy is not method-dependent.     

Clean Air and Energy: Reform of the PSD Provisions of the Clean Air Act

Air pollution regulation in the United States has come under repeated attack over the years for a number of reasons. Early in the past decade, prevention of significant deterioration (PSD) legislation, which protects currently clean areas, came into conflict with domestic energy production goals. This paper presents an applied analysis of present and alternative regulations for achievement of PSD air quality goals. A model of the Four Corners region of the Southwest is developed, and several policy alternatives tested in terms of economic efficiency and ability to achieve air quality goals. Alternatives examined include emission fees, marketable emission permits, and technological standards.     

EPA’s Clean Air Act Operating Permit Rules

Title V of the Clean Air Act requires tens of thousands of air pollution sources to obtain an operating permit incorporating all applicable requirements under the Act. EPA recently promulgated its controversial Title V regulations, which establish the minimum elements for state permit programs.

The new permit system is among the most important changes made by the 1990 Clean Air Act Amendments, and will significantly alter the way companies comply with air pollution requirements. Previously, the Act only required certain sources to obtain a new source review permit before constructing or modifying the facility (although many states established operating permit systems on their own). Now, all states must adopt operating permit programs consistent with the minimum federal requirements, and submit them to EPA by November 1993. Even though EPA has established minimum requirements, these programs are likely to vary widely from state to state.     

Innovative Technologies for Contaminated Site Remediation: Focus on Bioremediation

Bioremediation, the process by which hazardous substances are degraded by microorganisms, is at the forefront of a larger group of innovative remediation technologies being applied at hazardous waste sites worldwide. Although the process of bioremediation has been utilized for decades in the field of wastewater engineering, its application to soils and groundwater at hazardous waste sites is fairly new and still undergoing intensive development.

This article is intended to provide both an overview of the state of practice of bioremediation in hazardous waste remediation operations, and an inventory of issues to consider when evaluating the use of this technology for a contaminated site.

These topics will be the subject matter of a unique Bioremediation Satellite seminar to be broadcast on January 9, 1992. The seminar, a joint venture between the Air and Waste Management Association (A&WMA) and the Hazardous Waste Action Coalition (HWAC), is the first in a series of satellite seminars that will deal with innovative hazardous waste remediation technologies. The intent of these seminars is to design programs which will make hazardous waste practitioners more familiar with innovative remediation technologies so that they will consider using the technologies in future clean-up operations.     

An Assessment of Source Contributions to Ambient Aerosols in Central Taiwan

Ambient aerosols were sampled at three selected sites in the coastal region of central Taiwan to obtain composition data for use in receptor modeling. All the samples were analyzed for 20 elements with an x-ray fluorescence spectrometer. The mass percentage of sulfates in particle samples was determined by ion chromatography, and mass percentages of elemental carbon (EC) and organic carbon (OC) were determined by an elemental analyzer.

Because the three sampling sites were located within 25 km of each other, the average chemical compositions were similar for particle samples taken at the three sites on the same day. However, the variation in composition from day to day was significantly influenced by wind direction and change in local sources, such as the burning of agricultural wastes. The abundant species in the coarse fraction (2.5&#x0002D;10 µm) were Al (0.5&#x0002D;4.0 µg/m³), Cl (0.1&#x0002D;4.8 µg/m³), Ca (0.2&#x0002D;3.4 µg/m³), Fe (0.2&#x0002D;2.8 µg/ m³), and K (0.1&#x0002D;1.4 µg/m³), while the abundant species in the fine fraction (<2.5 µm) were S (0.3&#x0002D;3.5 µg/m³), Cl (0.01&#x0002D;1.9 µg/ m³), K (0.04&#x0002D;0.98 µg/m³), organic carbon (0.01&#x0002D;10.5 µg/m³), elemental carbon (0&#x0002D;10.7 µg/m³), and sulfates (1.2&#x0002D;15.7 µg/m³).

Calculations for source apportionment were carried out using the CMB7 software developed by the U.S. Environmental Protection Agency (EPA). The main sources for the coarse fraction of ambient aerosols in the region were found to be marine aerosol, coal and fuel oil combustion, burning

of agricultural wastes, and paved road dust. The main sources for the fine fraction were burning of agricultural wastes, diesel exhaust, coal and oil combustion, and sulfates. Source apportionment for the fine fraction was relatively sensitive to the types of sources selected for calculations and the compositions of the sources. The problem can be ameliorated by careful examination of possible sources and by use of local source profiles.     

Soil Remediation Techniques at Uncontrolled Hazardous Waste Sites

The A&WMA Critical Review entitled “Soil Remediation Techniques at Uncontrolled Hazardous Waste Sites” was presented by Ronald C. Sims, Department of Civil and Environmental Engineering, Utah State University, Logan, Utah. Dr. Sims presented his review at the 83rd Air & Waste Management Association Annual Meeting, held in Pittsburgh, Pennsylvania in June 1990. Prepared discussions presented during the Critical Review session are published here, along with some closing remarks by Dr. Sims. Ronald Harkov, Chairman of the Critical Review Subcommittee of the Publications Committee, served as moderator of the 1990 A&WMA Critical Review session.