Physicochemical treatment of hazardous waste

Table of ContentsChapter 1 Environmental Laws 1.1 Introduction1.2 Environmental Laws1.2.1 National Environmental Policy Act NEPA1.2.2 Occupational Safety and Health Act OSHA1.2.3 Clean W

CRC PR E S S

Treatment of Hazardous

Wastes

WALTER Z TANG

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No claim to original U.S Government works International Standard Book Number 1-56676-927-2 Library of Congress Card Number 2003055435 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0

Printed on acid-free paper

Library of Congress Cataloging-in-Publication Data

Tang, Walter Z.

Physicochemical treatment of hazardous wastes / Walter Z Tang

p cm.

Includes bibliographical references and index.

ISBN 1-56676-927-2 (alk paper)

1 Hazardous wastes—Purification I Title.

TD1060.T35 2003

In memory of my father, Yuxiang Tang

To my mother, Yongcui Hu, and

To my children, William and Elizabeth,

with love.

On average, one ton of hazardous waste per person is generated annually

by industries in the United States Before the Resource Conservation andRecovery Act of 1984, hazardous wastes were improperly disposed of intothe environment without any regulation As a result, remediation of thesecontaminated sites and management of the ongoing hazardous waste sourcesare two major tasks to be achieved by treatment technologies Due to thecomplex nature of the contaminated media and of the pollutants, environ-mental professionals are facing a host of questions, such as: What are thecontaminated media? What is the nature of the pollutants? What are theconcentrations of each pollutant? Among biological, physicochemical, orthermal technologies, if physicochemical processes are to be the solution, thetreatability of various pollutants must be assessed before a process can beproperly designed This book systematically examines the treatability ofhazardous wastes by various physicochemical treatment processes according

to the Quantitative Structure–Activity Relationships (QSARs) betweenkinetic rate constants and molecular descriptors

I have attempted to achieve five major goals in this book: (1) fundamentaltheories of thermokinetics such as the transition state theory are used tointegrate research findings in Advanced Oxidation Process (AOP) research;(2) reaction kinetics and mechanisms for each AOP are explained in terms

of elementary reactions and the reactive center; (3) QSARs are introduced

as methodologies to assess the treatability of organic compounds; (4) putational molecular descriptors such as the EHOMO and E LUMO are usedextensively in the QSAR analysis; (5) the kinetics of various AOPs are com-pared so that the most effective process can be selected for a given class oforganic pollutants

com-This book is divided into five parts Chapter 1 to Chapter 4 define thehazardous waste problems and physicochemical approaches to solve theseproblems Chapter 5 explains QSAR theory and its application to predictingmolecular descriptors and hydroxyl radical reactions Chapter 6 to Chapter

12 focus on each of the eight most important AOPs Chapter 13 presents amajor reductive treatment technology, zero-valence iron, and Chapter 14

compares each AOP according to its oxidation kinetics for specific classes oforganic compounds Each chapter begins with an introduction of the processand its historical development The intention is to demonstrate how funda-mental sciences guide the search for these innovative technologies Also,such introductions provide the information necessary for readers to delveinto the literature for current research topics Then, the principles of theprocess and the degradation kinetics, along with mechanisms of organic

pollutants are explained in terms of elementary reactions These elementaryreactions not only are important in assessing the treatability of organic pol-lutants using QSAR but are also critical in properly designing AOP processes.Finally, QSAR models are discussed to demonstrate the effect of molecularstructure on their degradation kinetics and to rank the treatability of eachorganic compound

This book is intended for graduates, engineers, and scientists affiliatedwith universities, consulting firms, or national laboratories and who aredealing with the remediation of hazardous wastes in water, groundwater,and industrial wastewater Due to the in-depth discussion of organic chem-istry, graduate students in environmental engineering and upper-levelundergraduates in chemistry, chemical engineering, or environmental sci-ences who intend to enter environmental engineering should find it useful

in their professional development Students will learn a systematic approach

to applying various sciences to the search for effective treatment technologies

in terms of thermokinetic principles Engineers will find the QSAR modelsextremely useful in selecting treatment processes for hazardous wastesaccording to the molecular structures of organic pollutants Scientists inindustrial and governmental laboratories, as well as designers and reviewers

in remediation projects, will also find the book helpful in their efforts torestore our environment and keep it clean

During the 1970s, the U.S Environmental Protection Agency designatedphase-transfer technologies such as air stripping and activated carbonadsorption as the best available technologies The search for mineralizingorganic pollutants shifted the focus from phase-transfer technologies to oxi-dative technologies after the Hazardous Waste Amendment in 1984 As aresult, AOPs were developed in laboratories, extended to pilot sites, andfinally applied in the field from the 1980s to the present The concept of anAOP includes any process that uses hydroxyl radicals as the predominantspecies; however, the concept failed to provide fundamental theories such

as transition state theory to guide research communities in their search forthe most effective oxidation processes In a strict sense, then, AOP should

be defined as a Catalytic Oxidation Process (COP), which would providesound scientific footing for the search for innovative technologies It is welldocumented that oxidants such as oxygen, ozone, and hydrogen peroxideoxidize organic pollutants slowly It is only when they are catalyticallydecomposed into other active species such as hydroxyl radicals that theactivation barrier of the activated complex can be significantly lowered Thecatalysts normally used are ultraviolet photons, transition metals or theirions, ultrasound, and electrons Increasing temperature and pressure canfurther enhance the catalytic effect

My research on AOPs began over 12 years ago at the University of ware When I worked on the degradation of phenols by a visible photon/CdS system, I had to wake up at midnight in order to take samples from aphotocatalytic reactor because the reaction half time in degrading 0.001-M

Dela-phenol is about 1 day After I found that Fenton’s reagent was an extremely

fast process, I added hydrogen peroxide and ferrous ion separately to thereactor The reaction half time reduced from one day to a few hours When

I added hydrogen peroxide first and then the ferrous sulfate, the reactionhalf time was reduced to a few minutes It became clear to me during myinvestigation of the oxidation kinetics and mechanisms of chlorinated phe-nols by Fenton’s reagent that the efficiency of AOPs depends upon both therate and the amount of hydroxyl radical generated and the molecular struc-ture of organic compounds

It has long been recognized that the treatability of different classes oforganic compounds differs significantly Furthermore, the treatability ofchlorinated compounds within a given class of organic pollutants decreases

as the chlorine content in a molecule increases Indeed, the carbon in chloride has been oxidized by chlorine so much that it is even insensitive tohydroxyl radical attack Therefore, elementary iron may be a more econom-ical way to reduce these pollutants rather than to oxidize them To quantifythe effect of chlorine, QSAR models are used to assess the effect of chlorine

tetra-on molecular descriptors such as EHOMO and ELUMO The treatability of organiccompounds by each AOP, then, can be evaluated using QSAR models of theoxidation kinetic rate constants and molecular descriptors

Thermokinetics, group theory, and computational QSARs should findbroad application in future research effort on AOPs for several reasons: (1)thermokinetics bridges thermodynamics and kinetics, which serve as thefoundation for QSAR analysis; (2) group theory may offer kinetic calculations

of activated complex for a given class of compounds, and the resultingdegradation rate constants can be more accurately estimated; and (3) as moredata regarding operational costs become available for each technology,QSARs may be incorporated into the calculations to estimate the operationalcost of a specific compound In addition, nanotechnology will becomeanother research focus in the next decade to develop nanoparticles such aselementary iron, TiO2, nanofiltration, and electromembranes in the physico-chemical treatment of hazardous wastes

About the Author

Walter Z Tang (B.S., Sanitary Engineering,Chongqing University, Chongqing, China, 1983;M.S., Environmental Engineering, Tsinghua Uni-versity, Beijing, China, 1986; M.S., EnvironmentalEngineering, University of Missouri-Rolla, 1988;Ph.D., Environmental Engineering, University ofDelaware, 1993) is an Associate Professor andGraduate Director for Environmental Engineering

in the Department of Civil and EnvironmentalEngineering at Florida International University(FIU), Miami, FL He has been a registered Profes-sional Engineer in Florida since 1993 Dr Tang has had extensive researchexperience over the past 14 years in the area of physicochemical treatmentprocesses; environmental applications of aquatic, organic, catalytic, and col-loidal chemistry; advanced oxidation processes; environmental molecularstructure–activity relationships (QSARs); and methodology in environmen-tal impact assessment

Dr Tang is the principal investigator for 14 research projects supported bythe U.S Environmental Protection Agency, the National Institutes of Health,and the National Science Foundation He has published 24 peer-reviewedpapers and 41 conference papers, co-authored one book, and contributedone chapter to a book Also, he has written graduate teaching manuals forthree different graduate courses He has been a referee for 12 journals andhas served as a proposal reviewer for the NSF and the National ResearchCouncil Dr Tang has organized and presided over 11 sessions at variousnational and international conferences on advanced oxidation processes(AOPs) and was the invited speaker at Florida Atlantic University in 2001

Dr Tang has supervised three post doctors, three visiting professors, and

35 graduate students in environmental engineering, and he has taught sixundergraduate courses and nine graduate courses in the Department of Civiland Environmental Engineering at FIU Dr Tang received FIU’s FacultyResearch Award in 1997, Faculty Teaching Award in 1998, and DepartmentalTeacher of the Year Award in 1998 He is a member of Chi Epsilon and islisted in Who’s Who in the World, Who’s Who in America, Who’s Who in Science and Engineering, and Who’s Who Among America’s Teachers

Since 1994, Dr Tang has been a co-principal investigator in joint researchprojects on AOPs with professors at Tsinghua University, Chongqing Uni-versity, and the Third Medical University of Chinese Military in Chongqing,China As a research fellow in the China–Cornell Fellowship Program

supported by the Rockefeller Foundation, Dr Tang offered six seminars atTsinghua University As a co-principal investigator from 1998 to 2002 of theTwo-Bases Program sponsored by the China National Science Foundation,

he advised a Ph.D student at Tsinghua University on his dissertation: QSARs

in the Anaerobic Degradability of Organic Pollutants Chongqing Universityand Chongqing Jianzhu University granted the visiting professorship to Dr.Tang in 1999 He won six joint research projects sponsored by the ChineseMinistry of Education for Chongqing University He was the invited speaker

at Nankai University and Gansu Industry University in 2002 and at WuhanUniversity in 2003 He was named the Outstanding Chinese Scholar in thesouthern region of the United States and served as a Foreign Expert in theState Sunshine Program of China The Chinese Ministry of Education invited

Dr Tang to Beijing as a state guest for the 50th anniversary of China NationalDay in 1999

I would like to acknowledge the contributions to this book made by myformer graduate students: Tzai-Shian Jung, Angela Pierotti, SangeetaDulashia, Todd Hendrix, Ricardo Martinez, Lucero Vaca, Stephanie Tassos,Rena Chen, Taweeporn Fongtong, Jiun-Jia Hsu, Kenneth Morris, Jose Polar,Carlos Hernandez, and Jeffrey Czajkowski I thank Jiashun Huang, DennisMaddox, and Pia Hansson Nunoo for their many hours devoted to typingand drawing of the figures I would like to thank all the students since 1991

at Florida International University (FIU) who took the graduate course,Advanced Treatment System, upon which the book is based Students whoassisted in this book include Bernine Khan, Lillian Costa-Mayoral, Christo-pher Wilson, and Oscar Carmona A special acknowledgment goes to Geor-gio Tachiev of the Hemisphere Center for Environmental Technology at FIUfor his constructive proofreading

I am grateful to Dr C.P Huang at the University of Delaware for ducing me to the research of AOPs Many QSAR models were developedthrough financial support from the U.S Environmental Protection Agency,National Science Foundation, and National Institutes of Health, and theirsupport is greatly appreciated Thanks go to Mrs Virginia Broadway at theUSEPA for supporting and administrating five EPA fellowships to my stu-dents over the last decade Dr William Cooper and his colleagues areacknowledged for their work on high-energy electron beams I would like

intro-to thank Dean Vish Prasad and Associate Dean David Shen of the College

of Engineering at FIU for allowing me to complete the book I am in debt toGail Renard and Sara Kreisman, my book editors at CRC Press LLC, whoprovided excellent professional guidance and spent numerous days editingand proofreading the manuscript

Table of Contents

Chapter 1 Environmental Laws

1.1 Introduction1.2 Environmental Laws1.2.1 National Environmental Policy Act (NEPA)1.2.2 Occupational Safety and Health Act (OSHA)1.2.3 Clean Water Act (CWA)

1.2.4 Safe Drinking Water Act (SDWA)1.2.5 Toxic Substances Control Act (TSCA)1.2.6 Resource Conservation and Recovery Act (RCRA)1.2.7 Hazardous and Solid Waste Amendments (HSWA)1.2.7.1 Comprehensive Environmental Response,

Compensation and Liability Act (CERCLA)1.2.7.2 Superfund Amendments Reauthorization Act

(SARA)1.2.7.3 Clean Air Act (CAA)1.3 Summary

References

Chapter 2 Environmental Hazardous Wastes

2.1 Introduction2.2 Classification of Hazardous Pollutants2.3 Sources of Hazardous Waste

2.4 Contaminated Media of Hazardous Wastes2.4.1 Groundwater

2.4.2 Soil2.4.3 Air2.4.4 Sludge and Sediments2.5 Distribution of Hazardous Pollutants in Contaminated Sites2.5.1 National Priorities List Sites

2.5.1.1 Contaminants2.5.2 Resource Conservation and Recovery Act2.5.2.1 Contaminated Media

2.5.2.2 Contaminants2.5.3 Underground Storage Tanks Sites2.5.3.1 Contaminated Media2.5.3.2 Contaminants2.5.4 Department of Defense2.5.4.1 Contaminated Media

2.5.4.2 Contaminants2.5.5 Department of Energy2.5.5.1 Contaminants2.5.6 Waste Sites Managed by Other Federal Agencies2.5.6.1 Contaminated Media

2.5.6.2 Contaminants2.5.7 Sites Managed by States and Private Companies2.5.7.1 Contaminated Media

2.5.7.2 Contaminants2.6 Conclusion

References

Chapter 3 Physicochemical Treatment Processes

3.1 Introduction3.2 Treatment Technologies3.2.1 Phase Transfer Technologies for Halogenated VOCs andNonhalogenated VOCs

3.2.1.1 Air Stripping3.2.1.2 Soil Vapor Extraction (SVE)3.2.2 Phase Transfer Technologies for Halogenated SVOCs,Nonhalogenated SVOCs, and Non-VOCs

3.2.2.1 Activated Carbon Adsorption3.2.2.2 Soil Washing

3.2.3 Thermal Treatment Processes3.2.3.1 Thermal Desorption3.2.3.2 Dehalogenation at High Temperature3.2.3.3 Incineration

3.2.4 Solidification/Stabilization (Vitrification)3.2.5 Advanced Oxidation Processes (AOPs)3.3 Established Treatment Technologies and Their Markets3.3.1 National Priorities List Sites

3.3.1.1 Remedial Technology3.3.1.2 Remediation Cost3.3.2 Resource Conservation and Recovery Act3.3.2.1 Remedial Technologies

3.3.2.2 Remedial Cost3.3.3 Underground Storage Tank Sites3.3.3.1 Remedial Technology3.3.4 Department of Defense

3.3.4.1 Remedial Technology3.3.4.2 Remedial Cost3.3.5 Department of Energy3.3.5.1 Remedial Technology3.3.5.2 Remedial Cost3.3.6 Waste Sites Managed by Other Federal Agencies

3.3.6.1 Remedial Technology3.3.6.2 Remedial Cost3.3.7 Sites Managed by States and Private Parties3.3.7.1 Remedial Technology

3.3.7.2 Remedial Cost3.4 How to Select Treatment Technology3.4.1 Nature of Pollutants

3.4.2 Concentration of Pollutants3.4.3 Contaminated Media3.5 Summary

References

Chapter 4 Advanced Oxidation Processes

4.1 Introduction4.2 Chemical Kinetics4.2.1 Zero-Order Reactions4.2.2 First-Order Reactions4.2.3 Second-Order Reactions4.2.4 nth Order Reactions4.3 Transition State Theory4.4 Oxidants

4.4.1 Oxygen4.4.2 Hydrogen Peroxide4.4.2.1 Molecular Structure4.4.2.2 Speciation of Hydrogen Peroxide4.4.2.3 Thermodynamics of Hydrogen Peroxide4.4.2.4 Reaction Mechanism

4.4.2.5 Ionization4.4.2.6 Free-Radical Formation4.4.2.7 Decomposition

4.4.2.8 H2O2 as an Oxidizing Agent4.4.2.9 H2O2 as a Reducing Agent4.4.2.10 OH•H2O2 Complex4.4.2.11 Geometries

4.4.2.12 Energetics4.4.2.13 Frequencies4.4.2.14 Environmental Applications of H2O24.4.3 Ozone

4.4.3.1 Molecular Ozone Reactivity4.5 Catalysts 110

4.5.1 Ultrasound4.5.2 Photon4.5.3 Transition Metals4.6 Catalyst Support4.7 Influence of Temperature and Pressure

4.8 Summary

References

Chapter 5 Quantitative Structure–Activity Relationships

5.1 Introduction

5.2 Fundamental Theory of QSAR

5.2.1 Effects of Molecular Structure on Reactivity5.2.2 Electronic Effects

5.2.3 Steric Effects5.2.4 Molecular Descriptors5.2.5 Linear Free-Energy Relationships5.2.6 Hammett LFER

5.2.6.1 Sigma (s) Constants5.2.6.2 Hammett’s Reaction Constant r5.2.6.3 Sigma Minus (s–) and Sigma Plus (s+) Constants5.2.7 Taft’s LFER

5.2.8 Quantum-Chemical Calculations5.2.9 Principle of Quantum Mechanics5.2.10 Procedure for Quantum-Mechanical Calculations5.2.11 Dipole Moment

5.2.12 Energies of HOMO and LUMO5.2.13 Octanol/Water Partition Coefficient5.3 Chlorine Effect on Molecular Descriptors for QSAR Analysis

5.3.1 Dipole Moment5.3.2 ∆E

5.3.3 Octanol/Water Partition Coefficient (Log P)5.4 QSAR in Elementary Hydroxyl Radical Reactions

5.4.1 Substituted Alcohols5.4.2 Chlorinated Alkanes5.4.3 Substituted Phenols5.4.4 Substituted Carboxylic Acids5.4.5 Substituted Benzenes

5.4.6 Substituted Alkenes5.5 QSAR Models between KHO· in Water and KHO· in Air with MolecularDescriptor (MD)

6.2.6 Transition State Approach by Tang and Huang

6.2.6.1 Competitive Method6.2.6.2 Dechlorination Kinetic Model

6.2.6.2.1 Pseudo First-Order Kinetic Model6.2.6.2.2 Dechlorination Kinetic Model Using

Transition State Theory 6.2.6.2.3 Oxidation Model of Unsaturated Aliphatic

Compounds6.3 Oxidation of Organic Compounds

6.4.2 Highest Occupied Molecular Orbital Energies

6.4.3 Lowest Unoccupied Molecular Orbital Energies

6.4.4 Octanol/Water Partition Coefficient

7.3.1 Alcohol

7.3.2 Alkane

7.3.3 Alkene

7.3.4 Bentazone7.3.5 Aromatic Hydrocarbons7.3.6 Carboxylic Acid

7.3.7 Ether7.3.8 Halide7.3.9 Ketone7.3.10 Chlorophenol7.3.11 Xenobiotics7.3.12 Mixture of Chemical Compounds7.3.13 Chlorinated Aliphatic Compounds7.3.14 Textile Wastewater

7.4 QSAR Models7.4.1 Dipole Moment7.4.2 EHOMO

7.4.3 ELUMO7.4.4 Octanol/Water Partition Coefficient7.4.5 Hammett’s Constants

7.5 Engineering Applications7.5.1 Process Description7.5.2 Radiation Intensity7.5.3 Hydrogen Peroxide Dose7.5.4 Temperature

7.5.5 Carbonate/Bicarbonate Ions7.5.6 Natural Organic Matter7.5.7 Inorganic Hydroxyl Radical Scavengers7.5.8 Substrate Concentration

7.5.9 pH7.5.10 Nitrate7.6 SummaryReferences

Chapter 8 Ultraviolet/Ozone 283

8.1 Introduction8.2 Decomposition Kinetics of UV/Ozone in Aqueous Solution8.2.1 pH Effect

8.2.2 Concentration of Oxidants8.2.3 Effect of Photon Flux in the UV/Ozone System8.2.4 Radical Scavengers

8.3 Degradation Kinetics of Organic Pollutants8.3.1 Atrazine

8.3.2 Humic Acids8.3.3 Volatile Organic Compounds8.3.4 Chlorophenol

8.3.5 Protocatechuic Acids8.3.6 Propoxur

9.2.2 Hydroxyl Radical Formation

9.2.3 The Role of Adsorption in the UV/TiO2 Process

9.2.4 Characteristics of TiO2 Surface

9.2.5 Adsorption of Organic Compounds on TiO2

9.3 Degradation of Organic Pollutants

10.3.1 Process Description of SCWO

10.3.2 Effects of Operating Parameters of SCWO

10.3.2.1 Reaction Time10.3.2.2 Oxidants10.3.2.3 Temperature10.3.2.4 Pressure10.3.2.5 Catalysts10.4 Degradation of Hazardous Wastes in SCWO

10.4.1 Carbon Monoxide

10.4.2 Aliphatic Organic Compounds

10.4.3 Methane and Methanol

11.2.2.1 H2–O2 Combustion in Cavitation Bubbles11.3 Degradation of Organic Pollutants in Aqueous Solutions11.3.1 Phenol

11.3.2 Monochlorophenols

11.3.3 2-Chlorophenol

11.3.4 Chlorinated C1 and C2 Volatile Organic Compounds11.3.5 Pentachlorophenate

12.2 Chemistry of Aqueous Electrons

12.2.1 Formation of Radical Species

12.3.5 Disinfection of Sewage Sludge

12.3.6 Estimation of Removal Efficiency of Organic Pollutants12.3.7 Radical Scavenger Effect

12.3.7.1 Methanol12.3.7.2 Bicarbonate/Carbonate Ions12.3.7.3 Dissolved Organic Carbon12.3.7.4 Oxygen

13.3.1.4 Nitroaromatic Compounds13.3.1.5 Nitrates and Nitrites13.3.2 Reduction of Heavy Metals

13.3.2.1 Chromium13.3.2.2 Arsenic13.3.2.3 Uranium13.3.2.4 Mercury13.3.3 Reduction of Inorganic Pollutants

13.3.3.1 Chlorine13.4 QSAR Models

13.5 Engineering Applications

13.5.1 Continuous and Funnel-and-Gate PRBs

13.5.1.1 Characteristics of Reactive Media13.5.1.2 Types of Reactive Media

13.5.2 Monitoring

13.5.2.1 Planning the Monitoring Effort13.5.2.2 Compliance Monitoring13.5.2.3 Performance Monitoring13.5.2.4 Microbial Characterization13.5.3 Engineering Improvement

14.4.2.1 Oxidation Processes Using UV Radiation14.4.2.2 AOPs Using Ozone

14.4.2.3 AOPs Using Fenton’s Reagent

14.4.4.1 Ozone Treatment14.4.4.2 UV/TiO2

14.4.5 1,3,5-Trichlorobenzene (TCB) and Pentanoic Acid (PA)14.4.6 Polycyclic Aromatic Hydrocarbons (PAHs)

14.4.6.1 Anthracene14.4.6.2 Pyrene14.4.6.3 Phenanthrene14.4.6.4 Fluoranthene14.4.6.5 Benzo(a)pyrene14.4.7 Chlorinated Aliphatic Compounds

on public health and the environment did not attract the attention of thegovernment until the 1970s Since 1970, the government has been taking anactive role in protecting the people of the United States from various forms

of hazardous waste, and, as a result, a regulatory-driven industry known as

environmental remediation was generated(LaGrega et al., 1994) Ten majorpieces of legislation were passed to provide this protection:

• National Environmental Policy Act (NEPA)

• Occupational Safety and Health Act (OSHA)

• Clean Water Act (CWA)

• Safe Drinking Water Act (SDWA)

• Toxic Substances Control Act (TSCA)

• Resource Conservation and Recovery Act (RCRA)

• Comprehensive Environmental Response, Compensation and bility Act (CERCLA)

Lia-• Hazardous and Solid Waste Amendments (HSWA)

• Superfund Amendments and Reauthorization Act (SARA)

• Clean Air Act (CAA)

Each law attempts to achieve specific goals by setting environmental dards for different classes of hazardous waste Treatment technologies areresearched by universities and companies and implemented by the environ-mental remediation industry

stan-2 Physicochemical Treatment of Hazardous Wastes

1.2 Environmental Laws 1.2.1 National Environmental Policy Act (NEPA)

The objective of this act is to declare a national policy which will age productive and enjoyable harmony between man and his environ- ment; to promote efforts which will prevent or eliminate damage to the environment and biosphere and stimulate the health and welfare of man;

encour-to enrich the understanding of the ecological systems and natural sources important to the Nation; and to establish a Council on Environ- mental Quality (NEPA)

re-The National Environmental Policy Act (NEPA) requires federal agencies toassess the environmental impact early in the planning process of any project.For those projects that are expected to have an effect on the quality of theenvironment, the proposing agency is required to file a formal environmentalimpact statement In addition, the NEPA has had an impact in certain areas;for example, it has:

• Provided a systematic means of dealing with environmental cerns and has included environmental costs in the decision-makingprocess

con-• Opened governmental activities and projects to public scrutiny andpublic participation

FIGURE 1.1

Cumulative growth in federal environmental laws and amendments in the United States

0 20 40 60 80 100 120

1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

SDWAA

TSCA RCRA

CERCLA HWSA

SARA CAAA

CRAA PPA

CAA FWPCA NEPA

Years

1.2.2 Occupational Safety and Health Act (OSHA)

To assure safe and healthful working conditions for working men and women; by authorizing enforcement of the standards developed under the Act; by assisting and encouraging the States in their efforts to assure safe and healthful working conditions; by providing for research, infor- mation, education, and training in the field of occupational safety and health; and for other purposes (OSHA)

To achieve its vision, the Occupational Safety and Health Act (OSHA) hasestablished three interdependent and complementary strategic goals toguide the development of programs and activities for the agency The suc-cessful accomplishment of any one of the strategic goals would not be pos-sible without parallel successes in achieving the other goals For example,the focus on reducing hazards, exposures, injuries, illnesses, and deaths inthe workplace would be difficult to achieve without realizing the goals thatcall for the engagement of workers and employers in this effort, as well asthe development of strong public confidence and support for its activities

1.2.3 Clean Water Act (CWA)

The Clean Water Act (CWA) focuses on keeping streams, rivers, lakes, andbays clean and safe The origin of the CWA can be traced back to the Riversand Harbors Act of 1899, which prohibited the discharge of all refuse otherthan sewage (ironically) to any navigable water of the United States It alsovaguely included permitting authority for the Army Corps of Engineers Thegoal of this act was more likely to keep the waterways free from obstructionthan to keep them clean Over the next 50 years, very little attention wasgiven to our waters, and as a result water pollution rose to crisis proportions

by the 1970s A clear example of this occurred in Cleveland, OH, in June of

1969, when the Cuyahoga River caught fire due to the massive amounts offloating chemicals and oil In 1971, the nation was moved by Ralph Nader’sbook, Water Wasteland, which outlined serious water quality problemsthroughout the country (Adler et al., 1993) These events caused the govern-ment to pass the Federal Water Pollution Control Act Amendments of 1972,which created what we now know as the CWA Earlier versions of the actwere the primary vehicles that provided federal money for local water pol-lution control construction

4 Physicochemical Treatment of Hazardous Wastes

The CWA is based on a simple idea: No discharges to water are allowed

by anyone without a permit In regard to the issue of private property vs.federal government intervention, the CWA establishes regulations only fordischarges to the waters of the United States This includes all navigablewaters, their tributaries, and areas that flow to waters of the United States

at some point during the year (e.g., dry riverbeds) Subsequent legal sions have included the groundwater that eventually flows to a body ofwater in the United States The CWA has three levels of goals (Adler et al.,1993):

deci-• Zero discharge is allowed

• All waters should be fishable and allow swimming

• No toxicities are allowed in any waters of the United States

The CWA established a National Pollutant Discharge Elimination System(NPDES) program to be developed and overseen by the U.S EnvironmentalProtection Agency (USEPA) It requires that all dischargers of any type ofpollutant apply for an NPDES permit These permits set specific limits forpollutant discharges and attempt to stop pollution at its source The twomain groups that must have an NPDES permit are industrial facilities andwastewater utilities The effluent limitations vary for each NPDES permit;however, most limitations are taken from technology-based effluent limita-tion guidelines issued by the USEPA As a result, different levels of effluentlimitations have been established depending on the treatment efficiency ofdifferent technologies, including:

• Best practicable control technology (BPT) is the minimum level setfor all pollutants

• Best conventional technology (BCT) applies to conventional ants

pollut-• Best available technology (BAT) applies to toxic and unconventionalpollutants

• Best available demonstrated technology (BADT) is used for newdischargers

Another factor that must be considered in the NPDES program is thereceiving water body The CWA requires states to classify each water bodybased on its actual or potential use Water quality standards are then devel-oped for each classification Once this process is complete, water qualitymanagement plans are written to keep dischargers within these limits

To assist the states, the USEPA has created a general set of water qualitystandards that includes criteria for 137 pollutants This information is pro-vided in the USEPA report Quality Criteria for Water 1986, also known as the

Gold Book When applying standards to source dischargers, the NPDES

Environmental Laws 5

permit includes these water-quality-based effluent limitations (WQBELs).Rather than focus solely on individual pollutants, whole effluent toxicitytests have become more commonplace (Moore and Vicory, 1998) These testsreflect the overall toxicity of an effluent on various organisms so as to obtain

a clearer picture of the quality of the water A somewhat controversialrequirement of the CWA is the process for establishing total maximum dailyloads (TMDLs) for each water body Each state plan must include theseTMDLs, which set the maximum amount of each pollutant that should befound in a water body The TMDLs are then divided among the NPDESpermit holders that discharge to that water body Unfortunately, this taskhas been found to be much more complex and costly than originally thought

In fact, the USEPA is being sued by many different organizations over thestrict deadlines It has been estimated that TMDL studies alone will costbillions of dollars throughout the United States, and that they will not becompleted for another 8 to 13 years (Hun, 1998b) To help the states, theUSEPA organized a TMDL Advisory Committee in 1996 to coordinate thedevelopment of TMDLs and to ensure that the proper stakeholders areinvolved

The CWA also addresses oil and hazardous substances It expressly hibits the discharge of oil or hazardous substances in harmful quantities tothe waters of the United States The USEPA has classified 300 hazardoussubstances according to the levels of danger they present to health and theenvironment These substances are listed by their Chemical Abstract Number(CAS#) and are provided by the USEPA If a discharge of any of thesehazardous substances or oil occurs that is above the reportable quantity (RQ)level, the National Response Center (NRC) must be notified Severe penal-ties, including jail and fines of up to $10,000, can be issued for failing tonotify the NRC Also, the CWA places the responsibility of all costs ofcleanup with the dischargers

pro-One final aspect of the CWA focuses primarily on pretreatment programs.The majority of CWA regulations eliminate direct discharges into U.S.waters; however, indirect pollution sources that discharge into the collectionsystem of a downstream treatment plant are also regulated through pretreat-ment requirements Because these sources of pollution do not require anNPDES permit, certain standards have been created to prevent industrialpollutants from passing untreated through the downstream treatment pro-cess These standards are typically regulated on the local level Any violation

of the CWA is subject to enforcement by the USEPA, including civil finesand/or criminal penalties The CWA also gives citizens the right to suedischargers which helps prevent unauthorized releases

1.2.4 Safe Drinking Water Act (SDWA)

The Safe Drinking Water Act (SDWA) was passed in 1974 and was cantly amended in 1996 The goal of the SDWA is very straightforward: to

signifi-6 Physicochemical Treatment of Hazardous Wastes

protect the public from harmful substances in their drinking water Theregulation gives the USEPA the authority to develop drinking water stan-dards for each substance To date, rules for over 80 contaminants (i.e., tolu-ene, PCBs, lead, cadmium, etc.) have been promulgated National PrimaryDrinking Water Regulations (NPDWRs) are set for each contaminant Inorder for a contaminant to be regulated by the SDWA, it must satisfy thefollowing conditions:

• The contaminant must have adverse effects on human health

• The pollutants must be likely to occur in public drinking watersystems

• Regulations will have positive impacts on reducing the amount ofcontaminants found in the drinking water supply

The USEPA is required to develop maximum contaminant level goals(MCLGs) for each contaminant and then set the maximum contaminantlevels (MCLs) in the NPDWR as close to the MCLGs as feasibly possible,based primarily on cost and available technology The SDWA does state,however, that every NPDWR must present different technologies that willmeet the MCLs If testing is not easily available for a particular contaminant,the USEPA can establish a specific requirement that a certain treatmenttechnology be used For example, because Cryptosporidium is not easilydetected in water, filtering is often required for utilities that use surface water

as a source

The SDWA states that the USEPA must decide whether or not to regulate

at least five different contaminants every 5 years, and that every 5 years theymust publish a list of chemicals from which these contaminants are to beselected This list is known as the Drinking Water Contaminant CandidateList and is subject to public review and comment (Pontius, 1998) To validatethe analysis of the USEPA, the SDWA requires that they consult with theScience Advisory Board Even though the USEPA must first select chemicals

to review that pose the greatest threat to health, the SDWA allows theregulation of a chemical without scientific proof of danger should there be

a valid health threat However, every analysis must consider a benefit/coststudy before regulation of a contaminant occurs

1.2.5 Toxic Substances Control Act (TSCA)

The Toxic Substances Control Act (TSCA) was passed in 1976 after muchdebate in Congress, despite intense lobbying by chemical manufacturers(Davis, 1993) It was the first environmental law that tried to look at theother end of the pipe In other words, it tries to prevent the manufacture oftoxic substances rather than try to control their discharge Prior to the TSCA,the USEPA was solely in a reactive stance and able to regulate chemicalsonly after the damage was already done

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The role of the TSCA is to identify all commercially manufactured icals that come in contact with the general population and then to regulatethe chemicals, based on their characteristics All newly created chemicals arereviewed and approved before they can be manufactured in or importedinto the United States Although over a million chemicals are known to exist,less than 100,000 are commercially produced in or imported into the UnitedStates Pesticides, tobacco, drugs, food products, cosmetics, and certainnuclear materials are excluded from the TSCA and are regulated underseparate laws

chem-One of the first tasks required by the TSCA in 1976 was for the USEPA toassemble a list of all commercially produced chemicals already in existence

in the United States This information was largely provided by the variouschemical manufacturing companies and included over 60,000 substances.Since development of the initial list, more than 25,000 chemicals have beenadded Although only new chemicals are required to go through the reviewand approval processes, the TSCA authorizes complete testing of existingchemicals

Before a company or organization can manufacture or import a new ical, it must provide the USEPA with a Pre-Manufacture Notice (PMN) andmust first identify whether the chemical can be considered new by compar-ing it to the USEPA’s chemical inventory The PMN must include a chemicaldescription, plan for production, list of intended uses, and effects on healthand the environment Substances used only in research and development orfor export do not require a PMN

chem-It is the responsibility of the USEPA to determine the hazards to healthand environment of all existing chemicals, and the agency can also imposerestrictions on the manufacture of certain chemicals; however, the burden is

on the USEPA to show any possible harm, thereby protecting industries fromunnecessary regulations The TSCA does authorize the USEPA to requirethat a manufacturer test its chemicals if it feels that a concern for humanhealth or the environment exists Again, to protect industry, the USEPA mustdevise the testing procedure If the USEPA determines that an existing chem-ical is being used in new ways, a Significant New Use Rule (SNUR) can beissued The SNUR requires a PMN to be written by the manufacturer andsubmitted to the USEPA

With so many chemicals in existence, the USEPA has had to set prioritiesfor testing chemicals First, low-volume chemicals, which are produced orimported at a rate of less than 10,000 pounds per year, were excluded.Approximately 25,000 chemicals are in this category Second, polymers,which typically are not toxic, were dropped from the list, which left approx-imately 15,000 nonpolymer chemicals produced or imported in quantitiesfrom 10,000 pounds per year up to 1 million pounds per year As a result,the USEPA has focused its testing on the 3000 to 4000 high-production-volume (HPV) and nonpolymer chemicals (USEPA, 1998b)

The testing of just one chemical can take a team of scientists 2 to 3 yearsand require up to 300 laboratory animals and as much as $300,000 or more;

8 Physicochemical Treatment of Hazardous Wastes

therefore, the TSCA also created the Interagency Testing Committee (ITC)

to determine which potentially toxic chemicals to analyze first The ITC ismade up of representatives from the Council on Environmental Quality, theDepartment of Commerce, the National Science Foundation, the NationalInstitute of Environmental Health Sciences, and the National Institute forOccupational Safety and Health If existing or new chemicals “present unrea-sonable risk of injury to health or the environment,” then the USEPA can:

• Prohibit manufacture of the chemical

• Prohibit or limit certain uses

• Dictate quantity and concentration limits for its manufacture

• Require quality control measures during its manufacture

• Require tests to show compliance with regulations

• Establish recordkeeping requirements

• Require labeling and public disclosure

The burden to show unreasonable risk is on the USEPA, although it hasbeen very difficult for them to enforce these regulations Included in theRegulation of Unreasonable Risk section of the TSCA is specific mention

of polychlorinated biphenyls (PCBs) These chemicals were extensivelyused in commercial and industrial manufacturing beginning in 1929 PCBshave various applications in cooling electrical equipment, heat transfersystems, and hydraulic fluid Not until the 1970s did the effects of PCBs

on health and the environment begin to be understood PCBs are of nificant concern because of their property of bioaccumulation The chem-ical is absorbed into the tissue of humans and wildlife and is not released

sig-As it accumulates, the risk for cancer, birth defects, skin lesions, and liverproblems increases

By 1979, the production of PCBs had been phased out because of the strictregulations of the TSCA Only totally enclosed products that include PCBsare exempted Also, a threshold of 50 parts per million (ppm) was established

by the USEPA, as concentrations under that level do not cause unreasonablerisk Since the inception of these regulations, high levels of PCB concentra-tions have dropped from 12% of the American population in 1979 to nearly0% in the late 1980s (Rosenbaum, 1995) In addition to PCBs, the TSCA hasalso been used to help reduce the unreasonable risk of asbestos in the envi-ronment In 1986, the TSCA was amended to include the Asbestos HazardEmergency Response Act The primary function of this act was to removeasbestos from the nation’s schools, and it was passed in response to studiesthat found asbestos to be an airborne carcinogen In 1989, the USEPA issuedregulations that would phase out all uses of asbestos in commercial products

by 1997

The TSCA contains important reporting and recordkeeping requirements.Any manufacturer or importer that finds a chemical substance to be a hazard

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to health or the environment must send immediate notification to the USEPA.Also, they must keep all records pertaining to adverse reactions to health orthe environment for 5 years Additionally, all employee allegations regardingadverse affects must be kept for 30 years

Penalties associated with the TSCA can be very steep Civil penalties of

up to $25,000 per day can be issued, and criminal prosecution may also bepursued The greater the damage to the environment, the greater the fines,which increase accordingly The TSCA Civil Penalty Policy has been created

to determine appropriate penalties for each violation Proposed penaltieshave been as high as $17 million

1.2.6 Resource Conservation and Recovery Act (RCRA)

The Resource Conservation and Recovery Act (RCRA) was originally passed

in 1976 with little fanfare while the Congress was debating the TSCA It wasamended in 1978 and again in 1984 (the Hazardous and Solid Waste Amend-ments) RCRA is the broadest federal law covering the management of solidwaste, and it has established a “cradle to grave” ideology It regulates wastethrough all aspects of its life, from waste generators to storage facilities,transportation, treatment, and finally disposal An important goal of theRCRA is to reduce or eliminate the generation of hazardous waste Although

no regulatory requirements for hazardous waste reduction have been ated, the USEPA is counting on the high cost of compliance with the RCRA

cre-to provide economic incentive for such a reduction (Duke and Masek, 1997).This regulation focuses on two types of solid waste: nonhazardous municipal waste and hazardous waste, where solid waste is defined as any “garbage,refuse, sludge, and other discarded material, including solid, semisolid, liq-uid, or contained gaseous material.”

Subtitle D of RCRA covers nonhazardous solid waste generators, porters, treatment facilities, storage facilities, and disposal sites Extensiverules governing municipal solid waste landfills (MSWLs) have been devel-oped, including how to design, construct, operate, monitor, and close alandfill, as well as leachate systems and caps The nonhazardous wasteregulation is left for the states

trans-Subtitle C of RCRA is the primary vehicle for managing hazardous waste

in the United States Hazardous waste is defined as any solid waste, or acombination of solid wastes, that because of its quantity, concentration, orphysical, chemical, or infectious characteristics may:

• Cause or significantly contribute to an increase in mortality or anincrease in serious irreversible or incapacitating reversible illness

• Pose a substantial present or potential hazard to human health orthe environment when improperly treated, stored, transported, dis-posed of, or otherwise managed

10 Physicochemical Treatment of Hazardous Wastes

The two classes of hazardous waste as defined by RCRA are characteristic waste and “listed” waste Characteristic waste is defined by the properties itexhibits The four characteristic properties are as follows:

• Ignitability, which is determined by the flash point of the substance

• Corrosivity, which occurs when the waste has a pH less than 2 orgreater than 12.5

• Reactivity, which is based on the ability of the waste to rapidly changeits state

• Toxicity, which is determined using the toxicity characteristic ing procedure (TCLP)

leach-“Listed” waste is any waste that contains a substance that is “listed” by theUSEPA as hazardous This type of waste has been listed based on the waste’s

“toxicity, persistence, and degradability in nature, potential for accumulation

in tissue, and other related factors such as flammability, corrosiveness, andother hazard characteristic.” Rules have been developed by the USEPA toensure proper disposal of these types of hazardous waste The mixture rulestates that any substance mixed with a “listed” hazardous waste becomes ahazardous waste If it is not a “listed” waste, but instead a characteristicwaste, and the mixture does not exhibit any of the characteristics, the mixture

is not considered hazardous The “derived from” rule states that any wastederived from the treatment of a “listed” hazardous waste remains a hazard-ous waste Similar to the mixture rule, if the by-product of a characteristicwaste does not exhibit any of the hazardous characteristics, it is not consid-ered hazardous

The USEPA established a Hazardous Waste Identification Rule (HWIR),which allows certain types of low-risk waste listed as hazardous by theUSEPA to be exempt from hazardous waste regulations, as long as they can

be safely handled as solid waste (USEPA, 1998a) The agency establishedrisk level criteria according to affects of the waste on health and the envi-ronment The HWIR has saved a significant amount of money on treatment,storage, and disposal and encourages pollution prevention and treatment

In the past, there was no reason to treat a “listed” hazardous waste if theby-products would still be considered hazardous

Another aspect of the RCRA covers treatment, storage, and disposal (TSD)permits Every TSD business is required to obtain a TSD permit and abide

by certain minimum standards These detailed standards are provided inthe RCRA and include rules for design, construction, operation, and closure

of TSD facilities Each TSD must also develop a Preparedness and Preventionreport, as well as a Contingency Planning and Emergency Preparednessreport Typically, states handle the TSD permitting program; however, theirstandards can be no less stringent than those of the USEPA

Because RCRA regulations begin at the “cradle,” or generation, of ous waste, any business or organization that generates more than 100 kg of

hazard-Environmental Laws 11

hazardous waste in any one month qualifies as a hazardous waste generatorand requires a USEPA generator identification number As the constantremoval of hazardous waste from a generation facility could become incred-ibly expensive, the RCRA allows hazardous wastes to be stored for up to 90days on-site before it must be removed If it remains on-site for longer than

90 days, the facility automatically becomes a hazardous waste storage facilityand must comply with the stricter TSD rules (Davenport, 1992)

The RCRA has also outlined a set of systematic rules governing the port of hazardous waste A detailed manifest system was established, where

trans-a mtrans-anifest is to be preptrans-ared for etrans-ach shipment of htrans-aztrans-ardous wtrans-aste Themanifest includes information on the generator, the nature of the waste, andthe quantity Each transporter of the waste is required to sign and verify themanifest and keep a copy When the waste reaches its destination, a copysigned by all parties is returned to the origination point to verify arrival ofthe waste This system ensures that no waste is lost or disposed of improp-erly

A final section of the RCRA concerns underground storage tanks (USTs).Under the RCRA, the USEPA requires that all USTs be protected againstspills, corrosion, and overfills within 10 years of the promulgation date Over

1 million USTs are known to exist in the United States, and many leakhazardous substances (e.g., petroleum products) into the ground andgroundwater (Danner et al., 1998) The RCRA requires that all facilities withUSTs must do one of the following:

• Upgrade existing USTs to meet the new standards

• Replace the UST completely

• Close the UST

Many small tanks and wastewater treatment plant tanks have been exemptfrom these rules Penalties for noncompliance with the UST guidelines can

be up to $10,000 per day All other violations of the RCRA can carry similarpenalties, including steep fines and jail time Civil penalties can be assessed

up to $25,000 per day per violation of the RCRA Criminal penalties up to

$250,000 and 15 years in jail can be imposed for knowingly putting someone

in imminent danger by violating the RCRA Similar to other environmentallaws, the RCRA authorizes citizen suits in the event that the USEPA fails toimplement the RCRA

1.2.7 Hazardous and Solid Waste Amendments (HSWA)

In 1984, Congress passed amendments to the RCRA that are known as theHazardous and Solid Waste Amendments (HSWA) The HSWA were filledwith specific deadlines and requirements to ensure that the USEPA imple-mented the RCRA (Rosenbaum, 1995) In the early 1980s, the Reagan admin-istration cut USEPA spending and effectively slowed the work of the agency

12 Physicochemical Treatment of Hazardous Wastes

down to a crawl For example, as mentioned previously, the RCRA requiredthe USEPA to develop a list of harmful wastes to be regulated Althoughover 1000 chemicals were likely to qualify for the list and 450 were identified

in 1980, only five new types of waste were identified in the next 6 years(Rosenbaum, 1995)

One of the main components of the HSWA is the land disposal ban forhazardous wastes This land ban states that no hazardous waste can bedisposed of on land until it has been treated to have concentrations ofchemicals under a certain level The USEPA was given the responsibility tocreate these levels and provide a proper treatment method for each waste.The universe of hazardous waste was broken down into three categories;these groups of waste were evaluated, and specific treatment methods andstandards were developed The treatment standards have been based pri-marily on available technology rather than on potential risks (Hendrichs,1991) If, after treatment, the waste no longer meets any of the criteria underwhich the waste was listed, it can be unlisted This process requires anextensive petition to be filed with the USEPA and can take several years to

• The prohibition of exporting hazardous waste without express mission from the government of the receiving country

per-1.2.7.1 Comprehensive Environmental Response, Compensation and

Liability Act (CERCLA)

The Comprehensive Environmental Response, Compensation and LiabilityAct (CERCLA, or Superfund) was passed in 1980 It was the first law to focus

on the necessary environmental response to uncontrolled hazardous wastesites or potential hazardous waste releases throughout the country TheSuperfund law was significantly amended in 1986 by the Superfund Amend-ments and Reauthorization Act (SARA), which is discussed in the nextsection, and was last reauthorized in 1990 It has been scheduled for reau-thorization for the past several years, but agreement on changes to the acthas not yet been reached

In 1980, President Carter pushed hard for the CERCLA to be passed —mainly in response to various environmental tragedies in the news, such asthe Love Canal toxic waste site near Niagara Falls and the valley of drums

in Kentucky People wanted someone to be held accountable for the toxicwaste sites that littered the country The CERCLA focuses on two issues:responding to existing uncontrolled hazardous waste sites and preventing

Environmental Laws 13

any potential areas An important distinction must be made, however Thegoal is not necessarily to remove the waste, but to remove the harm.First of all, the CERCLA requires all hazardous waste releases over aprescribed threshold, known as reportable quantities (RQs), to be reported

to National Response Center Action is taken from that point to determine

if it will be a CERCLA site The CERCLA also established development of

a National Contingency Plan This plan includes all procedures for handlinghazardous waste in the United States The act also requires the creation of

an uncontrolled hazardous waste site ranking system (HRS) The HRS mines if a site should be placed on the National Priorities List (NPL), which

deter-is a ldeter-ist of all the Superfund sites

The HRS system is based on risk to health and the environment Thecriteria examined include the groundwater migration pathway, surface watermigration pathway, soil exposure pathway, and air migration pathway (Hen-drichs, 1991) The ranking attempts to quantify the risk each site poses on arelative scale Only those sites placed on the NPL will receive CERCLAfunds; however, regulations in the CERCLA can still be applied to non-NPLsites

The actions at NPL sites are coordinated through a National ResponseTeam to work with other agencies, such as the Federal Emergency Manage-ment Agency (FEMA) and the Nuclear Regulatory Agency (NRC), so that

no overlapping takes place The main effectiveness of the CERCLA is in theassignment of financial obligation to the potentially responsible parties(PRPs) A PRP is anyone who generates, stores, transports, treats, or dis-poses of hazardous waste on the affected site Another important part ofthe CERCLA establishes a fund to finance costs and expenses incurred incleanup that will eventually be assigned to the PRPs The governmentwanted to immediately assign the financial responsibility of the cleanups

to the PRPs; however, it knew that very few organizations would have themoney available to begin the remediation process Therefore, these fundscover costs until they can be reimbursed Also, it was clear from the begin-ning that the federal government would have to carry some of the financialburden due to insolvent or nonexistent companies The preliminary goalwas an 80/20 split, where the PRPs would finance 80% of the costs and thefederal government would cover the rest

The fund is supported by four taxes: a petroleum tax, hazardous chemicalstax, imported substances tax, and environmental tax The original 1980CERCLA Act was created with a trust fund of $1.6 billion by Congress The

1990 reauthorization increased the aggregate cap on Superfund revenue to

$11.97 billion (Hendrichs, 1991) In the next reauthorization, the Clintonadministration was pushing for “orphan share” funding from a separateaccount to cover contributions for insolvent or defunct parties (USEPA,1997) The goal of the CERCLA, however, is to clean up the hazardous wastesites It authorizes the USEPA to order PRPs to remediate waste sites orremove hazardous substances The USEPA or PRPs can develop a prelimi-nary nonbinding allocation of responsibility (NBAR), which divides the

14 Physicochemical Treatment of Hazardous Wastes

costs among the PRPs As the name implies, the allocation is nonbindingand can be shifted at any time

Relatively small PRPs, known as de minimis parties, are allowed earlyrelease from CERCLA requirements The USEPA has completed settlementswith 15,000 small-volume contributors at hundreds of Superfund sites Bysettling with the USEPA, small polluters are not dragged into the problems

of bigger polluters

Hazardous wastes must be either removed or remediated through term remedial action Removal is merely the elimination of any furtherrelease of the hazardous waste The three types of removal actions are:

long-• Classic emergency removal actions of a waste that poses an diate threat to health or the environment (e.g., truck spill on high-way)

imme-• Time-critical removal actions, which are taken when a response must

be made within 6 months of an action memo (e.g., spill in an trial site in a residential area)

indus-• Non-time-critical removal actions, where no significant change isexpected at the waste site (e.g., remote industrial site)

If it deems it necessary, the USEPA can require an expedited response action(ERA) at a site that would require an immediate engineering evaluation/cost analysis (EE/CA) After a removal action is completed or determinedunnecessary, the long-term remedial action must be undertaken First, aremedial investigation/feasibility study (RI/FS) is performed to determine

a proper course of action This can involve:

• Assessing the site conditions

• Evaluating alternatives to select a remedy

• Performing pilot treatability studies

The USEPA established a National Remedy Review Board in 1995 to reviewall remedies This board has saved an estimated $31 million, and future costreductions of more than $725 million are expected (USEPA, 1998b) Theremedial investigation (RI) will also include identification of “applicable orrelevant and appropriate requirements” (ARARs) These are remediationstandards, standards of control, or other criteria or limitations developed byfederal or state law Applicable requirements are those that have been pre-viously used at a CERCLA site for the same waste Relevant and appropriaterequirements are those not formerly used for waste at a CERCLA site butwhich address the problem Advisories and guidance to be considered canalso be issued, but they are not as binding

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Among the many different types of ARARs are ambient or specific requirements, which can be levels set by other laws, such as MCLs,National Ambient Air Quality Standards (NAAQS), or CWA, CAA, andTSCA regulations, and the long-term remedial action would have to meetthose goals Because not that many ambient or chemical-specific require-ments have been established, other types of ARARs must usually be identi-fied An alternative is for the USEPA to use carcinogenic potency factors orreference doses to set the proper level of treatment It must be remembered,though, that each ARAR is specific to the remedial activity and not thepollutant

chemical-A feasibility study is necessary after the remedial investigation to makesure the proper remedial action has been selected Once that has been com-pleted, the USEPA publishes a Superfund Record of Decision (ROD), whichdescribes the remedial action selected The next step is the remedial design/remedial action phase, which can include:

• Storage and confinement

• Perimeter protection using dikes, trenches, ditches, and clay cover

• Cleanup of released hazardous substances

• Recycling, reuse, diversion, destruction, or segregation of reactivewastes

Over 1400 Superfund sites are on the NPL list Table 1.1 compares theprogress of the program from January 1993 through the end of fiscal year

1997 The program had completed the cleanup of over 900 sites by 2001 andreported a 20% reduction in cleanup duration, or 2 years on average PRPshave paid 75% of long-term Superfund costs — over $12 billion Legaldecisions, such as holding previous owners and operators liable for pastpollution prior to the CERCLA, will continue to ensure the success of theprogram

16 Physicochemical Treatment of Hazardous Wastes

1.2.7.2 Superfund Amendments Reauthorization Act (SARA)

The Superfund Amendments Reauthorization Act (SARA) was passed in

1986 and made two major changes to the original CERCLA First, it lished the Emergency Planning and Community Right to Know Act (EPCRA)

estab-in Title III; second, it estab-increased spendestab-ing for Superfund sites to $8.5 billionand provided new cleanup standards that use the best available technologies(Rosenbaum, 1995)

The primary goal of the EPCRA was to develop proper emergency ning for hazardous waste releases and give communities the right to knowwhat hazardous substances are being manufactured or processed in theirarea To make sure that communities know what chemical substances arebeing manufactured, processed, or stored in their vicinity, the EPCRArequires businesses and organizations to submit Material Safety Data Sheets(MSDSs) for all OSHA-regulated substances at its facility The MSDSs caninclude:

plan-• Facility information

• Identity of the chemical and its hazardous components

• Physical and chemical characteristics of hazardous substances

• Fire and explosion hazard data

• Reactivity and health hazard data

• Precautions for safe use and control measures

Also, Form R must be submitted to report the release of any toxic chemicals.The EPCRA requires the USEPA to track releases and make the informationavailable to the public In addition, facilities must submit yearly ToxicRelease Inventory (TRI) reports for all permitted and non-permitted dis-charges (Davenport, 1992) The second goal of the EPCRA is emergencyplanning, primarily to improve preparedness on the state and local levels inthe event of a toxic chemical release SARA requires every state to create aState Emergency Response Commission (SERC) and also to identify localdistricts These local districts are usually county governments, and they are

TABLE 1.1

Comparison of Superfund Progress (1993 vs 1997)

tl

Source: USEPA, 1998b.

Environmental Laws 17

responsible for having a Local Emergency Planning Committee (LEPC) EachLEPC must develop an emergency plan and take into account all facilities

in its district that manage toxic chemicals

Section 302 of the EPCRA establishes threshold-planning quantities (TPQs)for extremely hazardous substances (EHSs) Any facility that goes over theTPQ must submit a report to the SERC and LEPC Section 304 requires thatfacilities must immediately report any release of an EHS or CERCLA haz-ardous substance over the reportable quantity levels These reports must besubmitted to the SERCs and LEPCs for all areas possibly affected An imme-diate phone notification is required with a follow-up written report Also,the EPCRA requires that all facilities that produce MSDSs under OSHA mustsubmit a list of chemicals to the SERC, LEPC, and local fire departments.Reports are only required if the substance is found over normal thresholdquantity levels

A similar report is required of any facility with MSDS requirements underOSHA for hazardous chemicals It must submit one of two different emer-gency and hazardous chemical inventory forms Tier I provides aggregateinformation on each hazardous chemical with the type of health and physicalhazards it presents and the estimates of daily quantities at the facility (max-imum and average daily amounts) Tier II is the most complete report andcontains all information provided in Tier I It is commonly preferred bygovernment agencies and includes chemical-specific information, such asthe following:

• Chemical or common name

• Physical and health hazards

• Estimates of daily maximum and average amount present on-site

• Number of days the chemical is stored on-site

• Manner of storage and specific location on-site

The EPCRA is enforceable with fines of up to $25,000 per day and 2 years

in prison depending on the violation The focus of the USEPA to date hasbeen on violations of the immediate notification of release rule

1.2.7.3 Clean Air Act (CAA)

The Clean Air Act was originally passed in 1963 and was primarily a source

of government funding for air pollution control A follow-up law in 1965,the Motor Vehicle Air Pollution Control Act, regulated the emissions fromnew vehicles and was the first action taken by the government to control airpollution The Clean Air Act Amendments of 1970 and 1977 established what

we now consider to be the true goals of the CAA

The CAA created a system for the federal government to set goals for theair quality of the country and identify a means of achieving them Passage

of this law showed the first need for a federal Environmental Protection

18 Physicochemical Treatment of Hazardous Wastes

Agency The CAA required the government to establish the National ent Air Quality Standards (NAAQS), which would protect the public healthfrom air pollution These standards would be identified by the USEPA andset the maximum concentrations for each pollutant in the ambient, or out-side, air The CAA identified six criteria pollutants to be regulated:

regu-The CAA was amended again in 1990 to include the following:

• More stringent motor vehicle standards

• Additional toxic air pollution regulations

• A new system to reduce sulfur dioxide and nitrogen dioxide sions

emis-• A unified operating permit program

• Phase-out of chlorofluorocarbons (CFCs)

• Additional penalties for violations of the CAA

The toxic air pollution regulations in the 1990 amendments contain ments expressly for hazardous waste emissions The CAA established theNational Emission Standards for Hazardous Air Pollutants (NESHAPs),which applies to those substances that are harmful to public health A list

require-of 188 substances has been developed that the USEPA must regulate underthe CAA Similar to nonhazardous pollutants, a source is designated as major

if it discharges over 10 tons per year of any one of the 188 listed substances,

or over 25 tons per year of any combination of substances All other ary sources of hazardous air pollutants are considered area sources.The USEPA is responsible for creating and enforcing the NESHAPs for allhazardous air pollutant sources The CAA states that new or existing majorsources must have emission standards based on the maximum availablecontrol technology (MACT) to reduce hazardous air pollutant emissions TheMACT standards are based on the performance of the best 12% of the controldevices in the same source category These MACT emissions requirementswere extended in 1997 to cover wastewater biosolid incinerators at publiclyowned treatment works (POTWs) that have the potential to discharge cad-mium, lead, and mercury (Richman, 1997)

station-Environmental Laws 19

Area sources may be assigned emissions standards based on generallyavailable control technologies (GACTs); however, the USEPA can requireMACT standards, depending on the circumstances In order to ensure thatthe USEPA does not hamper an industry, the CAA included a MACT Ham-mer clause This provision states that the USEPA must review permits on acase-by-case basis if they have not created a standard for a particular haz-ardous air pollutant This would likely result in standards that are moreoverprotective than they would be after a normal review process The CAArequired MACT standards to be set for all major source categories on aschedule to be completed in a 10-year period A list of 173 major sourcecategories that emit one or more of the 188 listed pollutants has been pub-lished

The CAA also directed the USEPA to develop a list of 100 substances thatare dangerous to human health if accidentally released Using this list, theCAA requires every stationary source using any of these substances in excess

of the threshold level to have a risk management plan to reduce the chancesand/or severity of an accidental release The CAA also established the Chem-ical Safety Board to investigate and report the accidental releases of hazard-ous pollutants, in much the same way that the National Transportation SafetyBoard (NTSB) investigates highway and airplane crashes Great strides havebeen made in the implementation of the Clean Air Act Major pollutantreductions were achieved with the removal of lead and other additives fromautomobile fuel, as well as requiring catalytic converters on vehicles todestroy the remaining hydrocarbons that are not burned in the engine.Unfortunately, at least 15 “pollutants of concern” are still being deposited

in major U.S waters through air pollution (Hun, 1998a) This list includescadmium, dichlorodiphenyltrichloroethane (DDT), PCBs, and mercury

1.3 Summary

The environmental laws governing hazardous waste are a relatively recenteffort by the U.S government They are still undergoing fine-tuning, andsome aspects still require major adjustments Most of these environmentalregulations are less than 20 years old, and we have already seen majorimprovements Air pollutant levels have been reduced, hazardous wastesites are being remediated, and rivers and bays once too polluted to swim

or fish in are now clean Most importantly, the population is becomingmore aware of the vital role that the environment plays in our lives Thephilosophy of the 1970s was that all potential problems imaginable had to

be prevented The priority of the 1980s was renewal of the economy and

a trend toward cost-effective regulations, but now it is recognized that thepossibilities to be safeguarded against are too numerous for this approach

to be affordable

20 Physicochemical Treatment of Hazardous Wastes

The common theme of the environmental movement is that good mental quality is good for the economy in the long run The short-runeconomic dislocation problems were largely ignored in the 1970s Munici-palities and corporations were expected to pay whatever was needed tocorrect past environmental problems and to provide future environmentalprotection, no matter the price The balancing of economic and environmen-tal goals is likely to take the form of moderation in achieving some environ-mental goals that adversely affect economic activities To the extent possible,regulations will move away from the command-and-control type ofapproach generally used today Also, more practical emission standards withbuilt-in economic incentives will be established so that cost-effective pollu-tion control technologies can be used that provide overall lower pollutantsover the life of the equipment

Danner, B et al Don’t get buried alive, Environ Protect., July, 1998.

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Duke, L.D and Masek, B., Evaluating progress in toxic pollution prevention for two industrial sectors, 1987–1993, Environ Eng Sci., 14, 81–95, 1997.

Environ Technol., April, 1998b.

McGraw-Hill, New York, 1994.

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Richman, M., EPA may hold biosolids incinerators to strict CAA emissions standards,

Water Environ Techno., May, 1997.