Donald l. Wise

EDITED BY

DONALD L. WISE

Northeastern University Boston, Massachusetts

DEBRA J. TRANTOLO

Cambridge Scientific Inc. Belmont, Massachusetts

Marcel Dekker, Inc.

New YorkaBaselaHong Kong

Library of Congress Cataloging-in-Publication Data

Process engineering for pollution control and waste minimization / edited by Donald L. Wise, Debra J. Trantolo. p. cm. -- (Environmental science and pollution control: 7) Includes bibliographical references and index. ISBN 0-8247-9161-4 (alk. paper) 1. pollution. Waste 2. minimization. I. Wise, Donald (Donald L. Lee). U. Trantolo, . I. Debra J II Series. TD191.5.W6 1994 628.5-dc20 93-4601CIP

The publisher offers discounts this book when ordered in bulk quantities. more information, write on For to Special Sales/Professional Marketing at the address below. This book is printed on acid-free paper. Copyright 0 1994 by Marcel Dekker, Inc. All Rights Reserved.be Neither this book nor any part may reproduced or transmitted in anyform or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by an information storage and retrieval system, without permission in writing from the publisher.

Marcel Dekker. Inc. 270 Madison Avenue, New York, New Current printing (last digit): l0987654321

York 10016

PRINTED IN THE UNITED STATES OF AMERICA

Preface

A clean environment is a goal to which we all strive. However, we have been the victims of activities. The severe environmental damage a result of industrial growth and defense-related as damage to our environment is substantially affecting our overall health and welfare. It is a credit to our human spirit that we remain optimistic and share an enthusiasm about environmental issues. The numbers of registered wastesites are alarming, and continue to grow daily. No longer can we casually consider wastean acceptable by-product of our everydayactivities. While the consumer hasbegun to embrace the concept of waste reductionas, for example,in the practice of recycling, the large-scaleindustrialconcern has also turned to wastecontrolmethods. Whether driven by governmentmandate,socialresponsibility,economics, or other forces, waste control and waste minimization practices are increasingly welcomed. Process Engineering Pollution Control and Waste Minimization for provides an up-to-date source of technical information relating to current and potential pollution control and waste minimization practices. Over recognized experts provide an in-depth treatmentof this rapfifty idly growing field that draws its resources frommany disciplines. We have deliberately solicited input from governmental, industrial, and academic specialists ensure a multidimensional to presentation of the pollution control and waste minimization schemes that shaping our enare vironmental outlook. The text is divided into five parts. It begins with the presentation of general engineering considerations and the regulatory, ethical, and technical framework within which these processes are managed, then enters into specific wastelwastewater pollution control technologies that are used throughout industry. Models for potential control and minimization techniques are offered, and industry-specific case studies complete the text. Throughout, we have attempted to provide a sense that the scope waste control and minimization be immense, but it is of may not overwhelming. We trust that this book will provide a contribution to this important field and emphasize the need for continued progress. One way to better our environment is to eliminate or reduceiii

iv

Preface

pollution at the source. Potentially great benefits await us if we can develop economical, effective, and efficient solutions to our waste generation problems. All readers of this text will contribute something to the environment of tomorrow.Donald L. Wise Debra J. Trantolo

Contents

Preface Contributors

iiiix

Part I Engineering Issues In Pollution Control and Waste Minimization : Process Engineering for Pollution Control and Waste Minimization John Hanna and Osawaru A. Orumwense Selection of Least Hazardous Material Alternatives Alvin F. Meyer Multiple Approaches to Environmental Decisions Douglas M . Brown Introduction to Engineering Evaluation for Contaminated Sites David S. Wilson, Alan C . Funk, Ronald G . Fender, and Marilyn Hewitt Innovative Approaches to Cleanup Level Development Ronald J. Kotun, Richard F. Hoff, Robert J. Jupin, Diane McCauslund, and Patrick B. Moroney Designing to Prevent Pollution James Lounsbury Biochemical, Genetic, and Ecological Approaches to Solving Problems During 171 situ and Off-site in Bioremediation 0. A. Ogunseitan

3

17

2547

87

145

V

vi8

Contents

Commandments of Waste Management Donald K. Walter A Proactive Approach to Environmental Management: Meeting and Environmental William E. Schramm and Stella S. Schramm Health Hazards Associated Pollution with Control Waste and Minimization Patrick D . Owens

193

9

mpetitive s

213

1 0

227

Part 11: Methodologies of Waste Control 11 Techniques for Controlling Solid and Liquid Wastes Hsai-Yang Fang and Jejhrey C. Evans

247

l2

Solidification and Stabilization Techniquesfor Waste Control A. Samer Ezeldin and George P. Korj?atis Soil Remediation with Environmentally Processed Asphalt @PATM) M. Testa and D. L. Patton

271

l 3

297

S.

1 415

Lead Decontamination of Superfund Sites Ann M . Wethington, Agnes Y. Lee, and Vernon R. MillerA Secure Geologic Repository for Hazardous Waste Residuals Thomas R . Klos

311

331363

1 6

Photocatalytic Degradation of Hazardous Wastes

M. S. Chandrasekharaiah, S. S. Shukla, J. L. Margrave, and S. C. Niranjan1 718

Photocatalytic Oxidation of Organic Contaminants Allen P. Davis Biodegradation of Organic Pollutants in Soil Paul D . Kuhlmeier Siallon: The Microencapsulationof Hydrocarbons Withina Silica Cell Tom McDowell Remediation of Heavy Metal Contaminated Solids Using Polysilicates George J. Trezek Fluidized Bed Combustion for Waste Minimization: Emissions andAsh Related Issues E. J. Anthony and F Preto .

377405

1 9

425

20

441

21

467

Part 111: Wastewater Treatment 22 An Overview of Physical,Biological, andChemicalProcesses for Wastewater Kanti L. Shah

489

Contents23 24

vii513

FreezeConcentration: Its Application in HazardousWastewaterTreatment Ray Ruemekorf OrganoclaySorbents for Selective Removalof OrganicsfromWater and Wastewater Steven K. Dentel, Ahmad I. Jamrah, and Michael G. Stapleton Removal of Chromate,Cyanide,and Heavy MetalsfromWastewater Klaus Schwitzgebel and David M . Manis Neutralization Tactics Acidic for Industrial Wastewater Christopher A. Hazen and James I. Myers

525

25

535

26

557

Part Iv:Modeling for Pollution Control 27 IntroducingUncertainty ofAquifer Parametersinto an OptimizationModel Robert L. Ward28

569

Application of Total QualityManagement(TQM)Principles Prevention Programs Prasad S. Kodukula

to Pollution591

29

PC Software for OptimizingGroundwaterContaminantPlumeCaptureand Containment Richard C . Peralta, Herminio H. Suguino, and Alaa H. Aly597

30

Horizontal Wells Subsurface for Pollution Control George Losonsky and Milovan S. Berjin

619

Part V Industry-Specific Pollution Control Pollution Control and Waste Minimization in Military Facilities 31 Merrit R Drucker32

637

Waste Reduction Strategies for Small Businesses Dan A. Philips Contaminated Soils in Highway Construction Namunu J. Meegoda Management of Waste Compressed Gases Dan Nickens Pollution Control in the Dairy Industry T Viraraghavan . Landfill Gas Collection and Destruction Systems: Evaluating Toxic Emissions and Potential Health Risk Karnig Ohannessian, Anna Peteranecz,and Thomas Kear

643

33

663

34

685

35

705

36

715 727

Index

This Page Intentionally Left Blank

Contributors

AlaaH.Aly Utah State University, Logan, Utah E. Anthony J. CANMET, Ottawa, Canada Milovan S. Beljin University of Cincinnati,Cincinnati,Ohio Douglas M. Brown TheLogistics Management Institute,Bethesda, Maryland M. S. Chandrasekharaiah Houston Advanced Research Center,TheWoodlands, T~xas Allen F? Davis University o Maryland,CollegePark, Maryland f Steven K. Dentel University of Delaware,Newark, Delaware Merrit F? Drucker Army Management Staff College, Fort Belvoir,Virginia JeffreyC.Evans Bucknell University, Lewisburg, Pennsylvania A. Samer Ezeldin Stevens Institute o Technology,Hoboken, New Jersey f Hsai-Yang Fang Lehigh University, Bethlehem, Pennsylvania Ronald G. Fender Environmental Resources Management Group,Exton, Pennsylvania Alan C. Funk Environmental Resources Management Group,Exton, Pennsylvania John Hanna TheUniversity of Alabama,Tuscaloosa, Alabama Christopher A. Hazen MilesInc., New Martinsville, West Virginia Marilyn Hewitt Environmental Resources Management Group,Exton, Pennsylvania Richard F. Hoff Chester Environmental, Monroeville, Pennsylvania Ahmad 1. Jamrah University o Delaware, Newark, Delaware f Robert J. Jupin ChesterEnvironmental,Monroeville, Pennsylvania ThomasKear OP&L,Inc., San Diego, California Thomas R. Klos Envirovest Management, Houston, Texas Prasad S. Kodukula Woodward-Clyde Consultants, Overland Park, Kansas George F? Korfiatis Stevens Institute o Technology,Hoboken, New Jersey f RonaldJ.Kotun Chester Environmental, Monroeville, Pennsylvania

X

Contributors

Paul D. Kuhlmeier Consulting Environmental Engineer,Boise,Idaho Agnes Y Lee . US.Bureau of Mines,Rolla,Missouri George Losonsky Eastman Christensen Environmental Systems,Houston, Texas James Lounsbury National Roundtable o State Pollution Prevention Programs, Silver f Spring, Maryland David M. Manis EET, Austin, Texas J. L. Margrave Houston Advanced Research Center,TheWoodlands, Texas Diane McCausland Chester Environmental, Monroeville, Pennsylvania TomMcDowell Siallon Corporation, Laguna Niguel, California Namunu J. Meegoda New Jersey Institute o Technology, Newark, New Jersey f Alvin F. Meyer A. F. Meyer and Associates,Inc.,MeLean,Virginia Patrick B Moroney . Chester Environmental, Monroeville, Pennsylvania Vernon R. Miller U.S.Bureau o Mines,Rolla, Missouri f James 1. Myers MilesInc., New Martinsville, West Virginia DanNickens Earth Resources Corporation, Ocoee, Florida S. C. Niranjan Rice University, Houston, Texas 0.A. Ogunseitan University o California,Irvine, California f KarnigOhannessian OPdiL,Inc., San Diego, California Osawaru A. Orumwense The University o Alabama,Tuscaloosa, Alabama f Patrick D. Owens Tosco Refining Company,Martinez,California D. L. Patton Applied Environmental Services, Inc., San JuanCapistrano, California Richard C. Peralta Utah State University, Logan, Utah AnnaPeteranecz OPdiL, Inc., San Diego, California Dan A. Philips Pensacola JuniorCollege,Pensacola, Florida F. Preto CANMET, Ottawa, Canada Ray Ruemekorf NIRO, Columbia, Maryland Inc., Stella S. Schramm University o Tennessee,Knoxville, Tennessee f William E. Schramm Oak Ridge National Laboratory, Oak Ridge, Tennessee Klaus Schwitzgebel EET, Austin, Texas KantiL.Shah OhioNorthernUniversity, Ada, Ohio S. S. Shukla* Houston Advanced Research Center,TheWoodlands, Texas Michael G. Stapleton University o Delaware,Newark, Delaware f Herminio H. Suguino Utah State University,Logan,Utah S. M. Testa Applied Environmental Services, Inc., San JuanCapistrano,California George J. Trezek Greenfield Environmental, Carlsbad, Californiaand University o Calf ifornia at Berkeley, Berkeley,California T. Viraraghavan University o Regina,Regina, Canada f Donald K.Walter US.Department of Energy,Washington, D.C. Robert L. Ward Ohio Northern University, Ada, Ohio Ann M. Wethington US.Bureau of Mines,Rolla, Missouri David S. Wilson Environmental Resources Management Group,Exton, Pennsylvania_________

*Current affiliation: Lamar University, Beaumont, Texas

'


ENGINEERING IN POLLUTION ISSUES CONTROL WASTE AND MINIMIZATIO

Part I


Process Engineering for Pollution Control and Waste Minimization

John Hanna and Osawaru A. OrumwenseThe University o Alabama f Tuscaloosa, Alabama

1.

INTRODUCTION

As a part of the material cycle, ores and fossil fuels are extracted from the earth, processed, and converted into metals, chemicals, and other processed (high value added) materials. Hence, any expansion in the world economy increases the demand for minerals and metals with subsequent increases in the amount of waste generated. Wastes are generated by the mining, mineral processing, metallurgical, and chemical industries at an estimated annual rate of over 2.3 billion tons. The accumulated solid wastes at both active and inactive mining sites approach a whopping 30 billion tons [l]. These wastes include gases, dusts, sludges or solutions, ashes, and a variety of massive solid materials such as overburden, waste rocks, tailings, and slags that must be disposed of at low cost with a minimum of environmental degradation. A large volume of the wastes is normally disposed of at locations close to either the mining sites or processing plants. Evidence of these can be found in Minnesota, Utah, Alabama, California, Tennessee, Idaho, Montana, and other states having high mining and industrial activities. A significant amount of the tailings is disposed of in impoundments, which range in size from a few acres to large ponds covering thousands of acres. Wastes from processing plants pose the most difficult disposal and environmental problems in view of the physical and chemical properties of the wastes as well as the enormous volumes involved, and consequently a large expanse of land must be used for the disposal [2]. A typical example is the Florida phosphate slimes. The overburden and waste rocks with characteristic high contents of pyrite, heavy metals, and radioactive materials also present potential environmental and health problems. Unfortunately, most of the mineral processing wastes have been excluded from the Resource Conservation Recovery Act of 1976 (RCRA). However, this situation is changing with the stringent environmental regulations introduced in recent years, which have necessitated that precautions be taken to both minimize and control waste disposal. Hence, the mineral or metal

3

umwense 4

and

Hanna

constituents in wastes, whether of little or no economic value, must be amended their enfor vironmental impact or as a source of resource supply.

II. SOURCE OF WASTESA. Mining and Processing Solid WastesMost operations in the extraction and processing cycle generate wastes (refer to Figure l), but the extent to which a material can be classified as a waste depends on a number of factors. These include1. Sources andvolumesofwasteproduced 2. Potential dangers to health and the environment 3. Long-term reactivity with air and/or water and mobilization to the environment 4. Present disposal practices and alternative disposal methods 5 . Cost of disposal and potential use of the wasteOverburden Sub-grade mlnerals -Slurries - cI Flnes

I II

" "

RAW MATERINS EXTRACTION mlnlng, quanylng. dredglng. exploratlonOres. crude 011. coal. etc.

I

-

-

Spoils

I I

Imllllng. washlng. concentratJon. upgmdlng

RAW MATERINS BENEFICIATION

III

I I

Concentrates. refined 011.gas. minerals

I

--

Talllngs Sands"S1urrlea

Dusts

-

"

I I +I I

SolUUOns

Ingots. plgs. chemicals. energy

$

U

1

Chemlcals

I

7

t

stags Smoke Fumes Muds -Dresses solutlons Resldues Ash

-

MANUFACTURING AND SERVICES assembly, packing. transportation. energydlstrlb.

-- -

Coods and servias

I

Pulp Dust Smoke Fumes solutlons

"

DrossesGrlndlng CIlpplngS

4'3I

I

I I

I I I I I

vI

I

I

Fumes Dusts

--J

s01uu0nsMetals. glass. -paper. p~asuc.etc. Smokes

L-

Figure 1 Mineralwastematerialssupply,utilization,anddisposalsystem.

Process Engineering for Pollution Control

5

The following are typical examples of the waste generatedby mining and related processing industries. It has been reported that in the production of about 1.6 million tons of copper in 1976, 1 billion tonsof materials were processed. This breaks down to million tonsof overburden, 684 264 million tonsof tailings, 5 million tons of slag, 3.3 million tons of sulfur dioxide,and about 100 billion gallons of process water [3]. The iron industry is one source of enormous amounts of waste, since most of the iron concentrates used in the manufacture of iron and steel are derived from relatively low grade high ores. spically, raw ores assaying25-33% Fe are mined and beneficiated to produce quality pellets assaying 60-65% Fe and 5% Si for the manufacture of iron and steel. About 330 million long tons of iron ore was mined in the United States in 1976, and the amount of wastes generated was about 200 million tons [4], excluding the slag and dust wastes from the steelmaking step. Conventional magnetic and gravity separation processing of magnetic and nonmagnetic taconites of the Lake Superior Region resulted substantial iron losses of about 20-30% in the in tailing products [5]. On the other hand, the more advanced beneficiation of the tailings from techniques such as flocculation and flotation processes reduced the iron lost in the rejects as to low as 10%. The loss is partly due to the mineralogical compositionof the ores and the grain size of both iron and gangue. High iron losses are observed for Birmingham red hematite ore, for instance, because it produces more slimes than taconite ores. This is oneof the factors responsible for the relatively poor recovery of iron from run-of-mine material and the generation of large tonnages of wastes, particularly in large-scale beneficiation operations. The Florida phosphate industry another sourceof a tremendous volumeof wastes. In the is production of phosphate, the soft minerals in the matrix, particularly clays and the very fine phosphate aggregates,are dispersed readily in water, forming slimes duringthe hydraulic mining, transportation, and separation steps. These slimes are difficult to recover, and in addition they impair the beneficiation operation. About one-third of the phosphate content the matrix of is lost in the slimes, which are generally discarded as wastes. The Florida phosphate slimes are characterized byveryslow settling and trap a highvolume ofwater. Currently, impounded slimes are stored behind earth dams and pose a serious threat to the environment. The reclamation of the land and enormous volumes of water important for resource conservation and are in order to comply with stringent environmental regulations. The recovery of the phosphate values discarded in the slime and tailingfractions containing about 30%-40% of the phosphate present in the mined matrix would enhance the economy of the phosphate industry expand and the available resources. The impact this on reducing potential environmental hazards is enorof mous. The phosphate losses at the current rate of rock production of about 40 million tons per year includes over 11 million tons of high grade phosphate that is lost in the slimes annually. Vasan [6] has estimated that about1.5 billion tons of phosphate slimes is accumulated over the years in dams together with about 4.5 billion tons of water. The coalmining industry is another sourceof a large volume of solid wastes. The methods used in the past for cleaning coal were highly inefficient and resulted in high coal losses in waste streams duringthe mining and washing operations [2]. The washer waste fines are normally storedin above-ground impoundments. Quite number of processing plants still indulge a in the practice of discarding coal fines.As a result, about 25% of the coal mined is disposed of as waste.Based on the current rate of coal production of about 1 billion tons, about million 250 tons of wastes is produced annually, and out of this, about 200 million tons is coarse particles and 50 million tons is fines. The amountof coal in coarse waste particles is more than 30 million tons of carbon per year, while the corresponding amount in the fine fraction is about 30 million tons on an annual basis. The disposal of coarse waste particles is not a serious problem

6

Hanna and Orumwense

in most coal preparation plants,as they are usedas landfill. The fine-size wastes, on the other hand, are a problem because of the difficulties experienced in dewatering and the characteristic relatively low structural strengthof fine particles, which prevent fines from being used landas fill [7].

B. Mining and ProcessingLiquidWastesEffluents from coal preparation plants and drainage from waste disposal sites have a characteristic dark color and have high concentrations of suspended particles that cause not only siltation due to the settling of coarse particles, but also water pollution, both of which have negative effects on aquatic lives[2,7]. Effluents from coal cleaning plantsand mines are also reputed to have a great impact on the environment through the phenomenon as acid mine known drainage (AMD). This is oneof the causes of the destruction of forestsand vegetation today. Acid drainage is reported be causedby the reaction,between oxygen, water, and iron sulfides to such as pyrite and marcasite. Microorganisms are known to enhance the rate of this reaction. The most common techniques for mitigating acid drainage are neutralization using either lime, limestone, soda ash, or caustic soda; reverse osmosis; and treatment involving silicates [7]. These techniques are discussed in detail later. The highly acidic solutions produced dissolve several heavy metals in the waste pilesor impounded material and become loaded with a host of environmentally undesirable heavy metal species, sulfates, and other anions. On the other hand, the water discharged from some mines contains valuable metals such as copper and uranium that couldbe recovered economically. Copper is usually extracted from such discharges by either cementation or liquid ion exchange. Mine drainage containing9-12 ppm U O is stripped by ion exchange as exemplified by the operation in the Ambrosia Lake ,, 300-600 ppm A , , and 10-20 ppm U O , on 10 ,, district [8]. The acid mine drainage containing the other hand, is stripped by a combination of ion and liquid ion exchanges [9].

C.Coal

UtilizationWastes

As a result of burning coal in boilersand electric power plants, a large quantityof ash is produced. The amount of ash generated by power plants in 1977 is estimated to have been about67.8 million tons, of which 48.5 million tons was ash, 14.1 million tons bottom ash, and the fly remainder boiler slag. During that year, about6.3 million tons of the fly ash, 4.6 million tons of the bottom ash, and 3.1 million tonsof the boiler slag,or approximately 21%of the total ash generated, was recycled in such products as concrete blocks, asphalt, and roofing materials [lo-121.

D. Metallurgical WastesThe production of alumina by the Bayer process each year is accompanied by simultaneous formation of about 7 million tons of red mud that consists of a substantial amount of valuable minerals and dissolved salts. These wastes are estimated to contain a large amount of caustic soda, 1.2 million tons of alumina, 1.7 million tons of iron, and about 450,000 tons of titania [13]. These pose severe environmentaland health hazards. In steelmaking, over 2 million tons of dust and gases is generated by electric and basic oxygen furnaces annually. The dust contains a substantial quantity of lead (0.4-2.6%), zinc (6.3-24.8%), manganese (0.5-5.3%), and copper (0.03-0.27%) in addition to iron [14]. Similarly, in manufacturing stainless steel, a large amount of metals is as wastes. Powlost 5 ell et al. [l51 estimated that approximately million poundsof molybdenum is lost in stainless steel furnace dust each year.

Process Engineering for Pollution Control Table 1 Characterization of FoundryDust Analysis (wt. %) location Sample Alabama Ohio Michigan New Hampshire Pennsylvania Massachusetts West Virginia

7

cu Pb13.52 0.50 7.50 0.24 0.79 0.75 4.90

Zn65.34 63.70 56.70 44.70 54.80 65.04 78.25

Fe3.01 1.10 6;30 0.58 5.80 0.30 2.95 0.15 5.80 460 0.06 6.86 0.15 2.40 39 0.61

c 10.06 0.54

Toxicity(mg Pb/L)530 440 764 188 6

0.66 04 .01.30 0.5 1 0.05

A large amount of dust is produced brass and bronze foundries and secondary smelters by annually in the United States. The baghouse dusts vary in composition, but the main constit(40-78%), copper (10-15%), and small amounts lead and tin. Most of the zinc of uents are zinc is present at ZnO, while the remainder is in the form brass or bronze alloys. A typical charof acterization of dust from some foundries is presented in Table1. These wastes are considered to be hazardous because of the high lead contents. During the production of elemental phosphorus using an electric furnace, a large amount of toxic wastes such as sludge, slag, gases, and phossy water are also generated. It is known that between 5 and 10% of the elemental phosphorus that is produced is left behind in the sludge. The compositionof the other solid constituents the sludge is4040% SO,, 5-15% of CaO, 2-4% Fe,O,, and 2-5% P,O, [16]. In general, the ratio of phossy water and sludge that are formed to the amount of elemental phosphorus produced is about 1. Phosphorus wastes 5: pose both environmental fire hazards,and these wastes are produced a rateof 1.5 million and at tons annually. 111.

METHODS OF CONTROL AND TREATMENT OF BULK SOLID WASTES

A number of measures are taken to minimize or render bulk solid wastes safe for disposal. These include the extraction of heavy metals or toxic constituents from the waste materials or using either physical, chemical, bioremediation techniques.On the other hand, some wastes are either recycled used directly, but more often a combination or of these techniques is applied to achieve maximum process efficiency. The following methods are classified according to the source of the solid wastes.

A. Copper Mine WastesCopper mine wastes are increasingly important because of the very of most available low grade copper ores. Rule and Siemens [l71 have shown that the bulk flotation method is effective in extracting such metal values as copper, cobalt, and nickel from copper mine wastes with recoveries in the range of 54-95%. The primary problem in using the flotation method for this purpose is the intimate association of the valuable minerals or metals (minor) with the predominant gangue materials. Consequently, a high degree of fineness is necessary in order to ensure liberationand subsequent separationof the metal values. However, reagent consumption is also expected to be high. In most instances, the residues still contain fairly high levels of valuable minerals or heavy metals and as a result mustbe subjected to further treatment. Pressure leaching or bacterial leaching (bioleaching) is often used for this purpose.

8

Hanna and Orumwense

B IronOre Wastes .In the past, many iron tailing ponds were subjected to gravity concentration[l81 to recover the iron contents. Jones and Laughlin Steel Corporationin Calmet, Minnesota, is an example of a company that at one time combined flotation and gravity concentration treating iron wastes for to recover the metal values. The presence of a large amount of slimes and the high impurity contents of either the initial ores or the wastes impaired the recovery of iron from the wastes. In contrast, selective flocculation and high-intensity and high-gradient magnetic separabe tions [l91 are some of the other techniques that can used effectively totreat such materials. Waste materials can also be subjected to reductive roasting magnetic separation to reduce and the energy required for processing.

C.Phosphate

Rock Wastes

Phosphate slimes are known to be not only difficult to recover but also economically unsound. However, the associated adverse environmental impact necessitates treatment. Laboratory tests on waste pond materials, low-grade washer products, and some raw Tennessee phosphate ores have shownthat some of the phosphate can be recovered. Market grade phosphate concentrates assaying 60-82% P205can be obtained in substantial amounts using the anionic flotation method [20]. Direct digestion of the phosphate matrix with sulfuric acid is an alternative approach for the minimization of slime disposal problems.This process producesa simple waste consisting of gelatinous slime, sand, and gypsum. The composite is a compact sandy cake that could be 95% used as a filling materialin mined-out areas while about of the P205is recovered as useful material [2l ,221.

D. Fine CoalWastestechniques have been proposedfor treating coal wastes. These gravity separation are and flotation [23,24]. The use of Humphreys spirals to treat coal wastes has been established. Although such treatmentsare capable of yielding high-grade coal concentrates, the recovery is relatively low. Also these techniques only applicableto feeds withparticle size coarser than are 200 mesh. Besides,a substantial amountof the coal is lost the tailings-about 10-71% [24]. in Therefore, techniques thatare suitable for fine particles processing are required to supplement the spirals in order to improve coal recovery.This has led to the development of a process that is based on a combination of gravity separation and froth flotation. In this process, Humphreysspirals are used to recover the coarse coal particles while column flotation is employed for the minus 200 mesh fractions [24]. Mechanical flotation can size also be used in place of spirals to separate the coarse particles. In this manner, both the quality and the recovery of coal are improved significantly. Similarly, thepyrite present in the wastes can be removed, and by doing so, acid drainage problems can alsobe mitigated. It is also possible to employ a bioleaching techniqueto eliminate the pyrite constituents from coal wastes. This can be achieved by allowing bacteria to oxidize the pyrite in coal wastes as feed.TWO major

E Phosphorus Wastes .The methods of treating phosphorus waste include physical, chemical, and bioleaching techniques. The physical methods include sizing, sedimentation, centrifugation, cycloning, and flotation [25-27, 311, while air oxidation, chlorine oxidation, electrolytic oxidation, catalytic

neering Process

for Pollution Control

9

oxidation, distillation, CS2 extraction[28-331, and ion exchangeconstitute the chemical methods. Most of these processes either partially separate or oxidize phosphorus from the impurities. Therefore, a combination of two treatment techniques is necessary for complete remediation of phosphorus wastes. Another factor necessitating this methodology is the associated low operating costs for such schemes. A combination of clarification and chlorination techniques has been developed extractfor ing elemental phosphorus from phossy water [26]. However, the associated residual chlorine has an adverse environmental impact, and this renders the technique impractical, The ERCO process is based on the use of nascent oxygen to oxidize elemental phosphorus prior to subsequent separation [33]. Another method uses distillation as the basis for the remediation of phosphorus from sludges [29]. The high operating costs associated with these methods have limited their application. In many cases a major part of the phosphorus wastes are present in the coarse particles. Anazia et al. [31] have shown that between 26 and 29% by weight of the particles in the tested sludge samples (obtained from FMC Corporation Pocatello, Idaho, andthe TVA at Muscle of Shoals, Alabama) are coarse phosphorus particles containing 82-91% P4. It was also demonstrated in the same study that about61-88% of the coarse phosphorusparticles can be recovered by screening. The fine fractions represent 71-74% byweightof the sludge and assay 5-21% P4. The as-received unsized sludge can also be subjected to flotation to separate phos61 phorus concentrates assaying between and 78%. P4 with a recovery in the range of 71-79% depending on the characteristics of the wastes. The tailings assayed between and 18% P4and 9 constitute about 59-68% of the sludge [31]. It is obvious, therefore, that the fine fractions or tailings must likewise be subjected to further treatment using other methods. The phosphorus remainingin the physical separation rejects can be extracted after air oxidation treatment at ambient temperatures. These form the basis for the proposed two-step method comprising either flotation or screening and conventional air oxidation for the treatment of phosphorus sludges [31]. However, the P4 concentrations in the refuse from the oxidation step can be as much as 4%, which is still high in terms of toxicity. A long air oxidation period several days or weeks of may be necessary to achieve 90-95% conversion of P4 to H3P04 at an ambient temperatureof 3 . Under these conditions the oxidation rate of P4 in water is slow and 0C is influenced by many factors such as pH, oxygen content, temperature, presence of metal ions, and degree of dispersion of colloidal material [34]. Therefore, an incomplete conversion of P4 to oxyphosphorus compounds occurs during the conventional oxidation process because the reaction kinetics appear to be influenced by other factors such as agitation, particle size, and surface coating [34]. This process has been further developed at the University of Alabama such that the oxidation and conversion of P4 to soluble oxyphosphorus compoundsare enhanced significantly [32, 351. In the new process, the insoluble P4 is converted to highly soluble and nontoxic compounds thatare easy to extract from the rest the sludge. This improvement has achieved of been by employing a novel reactor design known as HSAD to expedite the remediation operation. Thus, depending on the P4 content a sludge, an almost complete oxidationof phosphorus is of r achieved in about 1-3 h , and the resultant acid solution can be employed in the manufacture of either phosphoric acid or fertilizer by-product by neutralization. The chemically inactive solid waste can be dried and safely disposed of as nonhazardous landfill product. Someof the results obtained employing this processare given in Table 2. The advantagesof the HSAD technique includeshort processing duration, high efficiency, simple configuration, low cost, and applicability to various phosphorus wastes. The process requires no catalysts, chemical oxidants, or high temperatures [35].

10

Hanna and Orumwense

Table 2Test No.1

mid Results of HSAD West Oxidation of Phosphorus Sludge [32]Product Weight Solution Residue 35.40 Feed(g)

Weight (%)64.60

P4 Analysis (%)~ ~~

P4 Removal (%)99.97 0.03 10 0 0. 0 99.94 0.06100.00

50.20 27.51 77.71 49.76 26.68 78.44

1 00 0.0

53.39" 0.02 34.50 54.35" 0.05

2

63.44 Solution 36.56 Residue

Feed

100.00

34.50

"Equivalent P4analysis of oxyphosphorus compounds.

F. 'Brass and Bronze Foundries DustBaghouse zinc dust is processed by using sulfuric acid leaching and electrolysis or crystalli[36,37]. The zinc extractionattainable with this method zation to recover zinc and other metals is in the range of 89-99%. Basically, the method involves the use of strong sulfuric acid and intense aeration to dissolve the zinc oxide and metallic copper from dust. The lead, tin, and the zinc metal alloys present in dust are not dissolved by sulfuric acid and remain with the solid the residues. The leach residues, which account for 20-50% by weight of the dust and are rich in a number of metals, can be further treated to extract the metallic components [36]. The pregnant leach liquor is subjected to electrowinning to produce metallic zinc. However, the zinc electrowinning operation is adversely affected the presenceof chloride ions or some metals. by Hence, additional measures required to eliminate chloride ions andother impurities in order are to produce high-grade metallic zinc. This can render the whole process expensive. Alternatively, the crystallization technique is employed to recover the zinc from the leach liquor as zinc sulfate salt.

IV. ADVANCEDREMEDIATIONTECHNOLOGYA. Leaching

The most common method of recovering the metal values from low-grade sources such as waste dumps or heaps is leaching. Leaching is a process in which a solid material is contacted with a solvent in order to selectively dissolve some of the components. The objectives of leaching metals from sludge include dissolution of the metal values recycling or subsequent septhe for aration by other methods, to render wastes nonhazardous,or to render wastes amenable to further treatment. Leaching is known to account for about 10% of the yearly copper production. The commonly used leaching agents are sulfuric acid, hydrochloric acid, ferric chloride, nitric acid, ferric sulfate,ammonia or ammonium carbonate, hydroxide, and microorganisms such as bacteria, yeast, and fungi. Unfortunately, many factors concerning leaching such thesize and heightof dumps and as factors affecting solution percolation and kinetics and recovery the valuable metals from the of the leach of pregnant liquors in general still require detailed studies and information dissemination. The fact that many of the minerals in wastes canbe recovered inexpensivelyby leaching implies that some of the problems associated with the disposal of fine wastes canbe alleviated. Biological remediation of wastes is accomplished by using naturally occurring microorganisms such as bacteria, yeast, and fungi to treat contaminants. Its use is rapidly increasing. However, the microorganisms requirea wide rangeof macro and micro nutrientsfor their met-


I1

abolic activities and growth. The environment is generally poor in the nutrients such as nitrogen, phosphorus,andcarbonrequired by the microorganismsforsustenance,andsome contaminants exhibit a certain degree of resistance to different microorganisms. These are the primary causeof the slow rate of breakdown of contaminants. Therefore, successful bioleacha ingoperationrequiresthegrowth of appropriatemicroorganismsthatcan be inducedby manipulating conditions suchas the availability of nutrients, temperature, electron acceptors, and aeration.

B. PrecipitationPrecipitation is one of the common means of remediating wastewater. In this method, chemicals are used to alter the physical state of dissolved or suspended metals and to enhance subsequent separation using sedimentation techniques. Chemicals such caustic soda, lime, soda as ash, sodium borohydroxide, sodium phosphate, ferrous sulfide, and sodium sulfides are used to induce precipitation. It is sometimes necessary to subject wastewater to some form of pretreatment such as filtration, destruction or organic matter and cyanides, metal reduction, neutralization, and/or oil separation prior to precipitation. Some metals as typified hexavalent chromium are difficult to precipitate in the form in by which they occur and must be reduced if the operation is to be successful. Reducing agents commonly used include sulfur dioxide, sodium bisulfite, sodium metabisulfite, and ferrous sulfate. Similarly, to effect sedimentation and subsequent separation of precipitates, flocculants are sometimes required. Lime, alum, and polyelectrolytes are used for this purpose. The major characteristics of wastes that have an impact on precipitation operations are the type and concentration of metals, amount of total dissolved solids, concentration of residual complexing agents, and amount of oil and grease present in the wastes. Metal-laden wastewater resulting from electroplating, pigment manufacture, the photographic industry, battery manufacture, nonferrous metal industriesare usually subjected to and precipitation treatment.

C. Exchange IonIn the ion-exchangeprocess,metalions in a dilute solution are substituted for identically charged ions electrostatically bonded to the surface of an immobile solid medium. The solid medium can be either a naturally occurring inorganic zeolite or a synthetic organic resin. Ion exchange is a reversible chemical reaction. Therefore, loaded resin or exchange medium is the placed in a pure solution of appropriate pH and the trapped metal ions are released. This method is applicable only to liquid wastes or pregnant solutions. (1) The performanceof the process depends on the concentration and valenceof the metal constituents, (2) the presence of competing ion species, and (3) the presence of dissolved or suspended solids and organic compounds. Therefore, the feed toan ion-exchange system must be subjected to pretreatment. Thismethod results in about 95% metal recovery and high purity products. This method is fully developed and is used commercially to remove chromium, copper, nickel, cadmium, silver, and zinc from wastewater.

D. Electrolytic RemediationElectrolytic cell is the primary device used in electrolytic remediation. It consists of an anode and a cathode immersed in an electrolyte. When an electric current is applied to an electrolyte solution, the dissolved metals are reduced and subsequently deposited at the cathode. The electrolytic remediation technique isalso known as electrowinning because the metals recovered are of high purity. This is one of the most effective methods for remediating chelated

12

Hanna and Orurnweme

metals, which are difficult to retrieve by other techniques. This method has the advantage of producing metal-laden free sludge, but it is limited to solutions containing a fewtypesof elements. Electrolysis can be used to remediate cadmium, chromium, copper, lead, tin, and zinc. However, such treatments involve a high energy expenditure. Wastes containing copper and certain other elements must be leached with hydroxides before being subjected to electrolytic treatment. A variation of the electrolytic technique known as electrodialysis is obtained when a membrane is placed between the anode and cathode such that the mobilitysome ions throughthe of membrane is obstructed. Electrodialysis can be used for remediating wastes from such sources as gold-, chromium-, silver-, zinc-, nickel-, and tin-plating operations where the ion concentration is low and would not be economical for electrowinning. Most feeds for electrodialysis is a compulsory treatment must be filtered to remove suspended solids. Besides, pH control pretreatment measure because the effect on metal of separation. When electrodes having a high surface area are employed, metals removalof about 98% can be achieved.

E. Membrane SeparationThe membrane separation method encompasses such techniquesas filtration (microfiltration, ultrafiltration, etc.), reverse osmosis, and electrodialysis. Thefiltration technique is used after the sludge hasbeen pretreated for the removal metals. The technique also usedto pretreat of is feeds destined for subsequent treatmentby both reverse osmosis and electrodialysis. Reverse osmosis and electrodialysis used to retrieve metalsor plating compounds from are wastewater. The electrodialysis method is described in the preceding subsection. Reverse osmosis (RO) systems characterized by having a number of modular units connectedeither in are parallel or series or a combination of the two. The applicationof this method to the remediation of metal-laden sludgeis limited by the pH range in which the membrane can be used. Cellulose acetate membranes are not suitable for use at pH above 7, while amide and polysulfone membranes can be used in the pH range between 1 and 12. The performance of R 0 systems is impaired by the presence of colloidal matter, dissolved organics, and insoluble constituents. It is recommended that the feeds to R 0 systems be subjected to such pretreatments as pH adjustment, carbon adsorption, and filtration. The method is used commercially to remove brass, chromium, copper, nickel, and zinc from metal-finishing wastes. These techniques canbe used to produce effluents with very low metal constituents, provided, of course, that adequate pretreatmentshave been carried out. Metal removal onthe order of 99% can be achieved by making use of a combination of precipitation and filtration.

F. EvaporationEvaporation is a simple method for remediationof mixed materials based onthe difference in volatility. Hence, the concentration of metals is brought about by the reduction in the volume of the waste. The primary instrumentation used for this purpose includes rising film, flash, and submerged tube evaporators. Cadmium, chromium, nickel, zinc, copper, and silver from platingbaths are retrieved in theelectroplatingindustry by using this method.However, this method of remediating wastes is cost-effective only when a very small volume of waste is involved.

G. EncapsulationSoluble silicates and their derivatives are very effective for the stabilization and fixation of hazardous wastes.Silicates are used in waste treatment because their inherent characteristics of

gineering Process

Control Pollution for

13

such as alkaline nature (pH 20-14), ability to form gels, and reactivity with multivalent cations, and because their disposal poses no potential danger the environment. to Soluble silicates are polymeric and condense on aging to form anions having a siliconoxygen-silicon linkage that are complex and exist in various chain lengths and cyclic structures. Silicates react with metal ions form insoluble amorphous metal silicates. These metal to pH silicate complexesare insoluble over a large range compared with simple metal hydroxides. This is responsible for the increased resistance to leachingmetals in solidified wastes and is of perhaps the main feature of silicates in waste treatment. Soluble silicates are made by fusing sodiumcarbonate or potassiumcarbonateandsandinafurnace at 1450F. Theresultant nSiO,Na,O compound has silica (SiO,) to alkalinity (Na,O) ratio in the rangeof 1.6:3.9. The SiO,Na,O ratio has great significance subsequent use silica because only compounds havin of ing high ratios are employed in the manufacture of products such as gels, precipitated silica, and zeolites and in the treatmentof wastes. Setting agents commonly used waste treatment include Portland cements, pozzolanic in fly ashes, and cement or lime kiln dust. The active components in setting agents are such derivatives as the mono-, di-, and tricalcium silicates formed when the agent is mixed with water. The physical properties and behavior of setting agents are strongly influencedby the calcium silicate content, as this is directly related to the number and strength of the resultant bonds formed. Silicates also reduce the permeability reducing calcium hydroxide inclusion formaby tion or the presence of voids in the structure of the material. The treatment hazardous waste of with setting agents can be subdivided into two categories, stabilization and fixation. Stabilization is a chemical process transforming a liquid waste into a solid. The setting of agents are mixed with the waste, and when they set up or harden, the waste material is entrapped in the structure. The procedure used stabilization operation involves premixing in the the waste and setting agents before introducing soluble silicate. The role of silicates stain the bilization process includes the reduction of setting time, decreasing of the permeability, increasingofthecompressivestrength,andreductionofboththeamountofsettingagents employed and the volume of the treated waste. Fixation, on the other hand, is similar to stabilization in many respects, but rather than merely entrapping the wastes inclusions, the wastes modified and bonded into a cementas are like matrix. Hence the solubility or leachability of hazardous components is reduced dramatically. In this manner, the toxicity and mobility ofheavymetalwastesarechangedbythe treatment. The treatment steps involve mixing the waste with cement kiln dust as a setting or agent and water. Thereafter, a soluble silicate is introduced and mixed thoroughly. The procebe must be used when a waste dure is recommendedif a good result must obtained, and cement can is tobe fixed. Portland cement is the most effective setting agent that be used with silicates for this purpose. The reason is that during hydration cement produces gels that help to encapso sulate waste. Lime-based materials not produce a large amount of gels during hydration, do the amount of bonded wastes is reduced. Therefore, lime-based setting agents should not be used for waste fixation.

REFERENCESHill, R. D., and Auerbach, J. L., Solid waste disposal in the mining industry, in Fine Particles ProSomasundran, e d . ) , SME-AIME,NewYork, 1980, pp. 1731-1753. cessing, Vol. 2 (? 2. Hanna, H. S., and Rampacek, C., Resources potential of mineral and metallurgical wastes, in Fine Particles Processing,Vol. 2 ( ? F Somasundaran. ed.), SME-AIME, New York, 1980, pp. 1709-1730. 3. Mineral Trends and Forecasts, US. BureauofMines, 1979. 4. Klinger, F L., Mineral facts and problems-iron, . Bull. 667, U.S. Bureau of Mines, 1976, pp. 5251.545.

14

Hanna and OrumwenseChem. Eng. Prog.,

5 . Rampacek, C., The impact of R&D on the utilization of low-grade resources,

February, 57-68, 1977. 6. Vasan S., Utilization of Florida phosphate slimes, Proc. 3rdMineral Waste UtilizationSymp., Chicago, 1972, pp. 171-177. 7. Moudgil, B. M., Handling and disposal of coal preparation plant refuse, in Fine Particles Processing, Vol. 2 (! F Somasundran, ed.), SME-AIME, New York, 1980, pp. 1754-1779. 8. Spendlove, M. J., Bureau of Mines research on resource recovery, IC 8750, U.S. Bureau of Mines,1977. 9.

Ross, J. R., and George D. R., Recovery of uranium from mine waters by countercurrent ion ex-

IO. 11.12. 13. 14.

15.16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 3 1. 32.

change, RI 7471, U.S. Bureau of Mines, 1971. Faber,J.H., Coal Technology Conference, Houston, Texas, 1978. Brackett, G . E., Production and utilization of ash in the United States, Proc. 3rd. Int. Ash Utilization Symp., Pittsburgh, Penna., IC 8640, U.S. Bureau of Mines, 1974, pp. 12-18. Jackson, J., Total utilization of fly ash, Proc. 3rd Miner. Waste Utilization Symp., Chicago, Ill., 1972, pp. 85-93. Dean, K. C.,Utilizationofminemillandsmelterwastes, Proc. 2nd MineralWaste Utilization Symp., Chicago, Ill., 1978, pp. 138-141. Dressel, W. M.. Barnard, F G., and Fine, M. M.. Removal of lead and zinc and the production of ! prereduced pellets from iron and steel making wastes, RI 7027. U.S. Bureau of Mines, 1974. Powell, H. E., Dressel, W. M., and Crosby, R. L.,Converting stainless steel furnace flue dust and 8039, U.S. Bureau of Mines, 1975. wastes to a recyclable alloy, RI Slack, A. V (ed., Phosphoric Acid, Parts 1 and 2, MarcelDekker,NewYork, 1965. . Rule, A. R., and Siemens, R. E., Recovery of copper, cobalt and nickel from waste mill tailings, Proc. 5th Mineral Waste Utilization Symp., 1976, pp. 62-67. Fine, M. M., and Heising, L. F., Iron ore waste occurrence, beneficiation and utilization, Proc. 1st Mineral Waste Utilization Symp., Chicago, Ill., March 1968. pp. 67-72. Colombo, A. F., Jacobs, H. D., and Hopstock, D. M.,Beneficiation of Western Mesabi Range oxidized taconite, RI 8325, U.S. Bureau of Mines, 1978. Lamont, W. E.,etal.,LaboratoryflotationstudiesofTennesseephosphatesinthepresenceof slimes, RI 7601, U.S. Bureau of Mines, 1972. White, J. C., Fergus, A. J., and Goff, T. N., Phosphoric acid by didect sulfuric digestion of Florida land pebble matrix, RI 8086, U.S. Bureau of Mines, 1975. White, J. C., Goff, T. N., and Good, I? C., Continuous circuit preparation phosphoric acid from of Florida phosphate matrix, U.S. Bureau of Mines, 1978. Browning, J. S . , Recovery of fine-size waste coal, Final Rep. U.S.Dept. of Energy, Contract ET76-G-01-9005, Univ. Alabama, May 1978. Hanna, J., and Kalathur, R., Recovery of fine size coal from impounded wastes, Miner. Metall. Processing, November, 174-179. (1992). Fleming, J. D.,Removalofphosphorus,aliteraturesurvey,TennesseeValleyAuthority,Muscle Shoals, Alabama, 1970. Barber, J. C., Recovery of phosphorus from dilute waste streams, U.S. Patent 4,595,492 (July 17.1969).

Crea, D.A., et al., Recovery of phosphorus from electric furnace sludge, U.S. Patent 3,615,218 (October 1986). Post, L. B., et al., Recovery of phosphorus from electric furnace sludge, U.S. Patent 3,615,218 (October 1971). Holmes, W. S., Lowe, E. J., and Brazier, E. R., Phosphorus distillation, U.S. Patent 4,081,333 (Mar. 28, 1978). Hinkebein, J. A. Recovering phosphorus from sludge, U.S.Patent 3,436,184 (April 1969). Anazia, I., Jung, J., and Hanna J., Recovery and removal of elemental phosphorus from electrical furnace sludge, Min. Metall. Processing, May, 64-68 (1992). Hanna, J., and Jung, J., Phosphorus removal by dispersed air oxidation, Miner. Metall. Processing November, 200-205 (1992).


15

33. Deshpande, A. K., Oxidation of phosphorus in aqueous medium, U.S. Patent 3,971,707 (July 27, 1976). 34. Sullivan, J. H., Jr., et al., A summary and evaluation of aquatic environmental data in relation to establishing water quality criteriafor munitions-unique compounds. Part 3. White phosphorus,Final Report, Water and Air Research, Inc., Gainesville, Ha., April 1979. streams, Proc. Haz35. Hanna, J., and Jung,J., Remediation of phosphorus from electric furnace waste ardous Materials Control, HMC-South '92. New Orleans, La., Feb. 26-28, 1992, pp. 34-39. 2nd Annual Environmental 36. Hanna,J.,andRampacek.C.,Recoveringzincfrombaghousedust, f Society, Milwaukee,Wisc.,Aug. 23-24, 1989, Affairs Conf. o theAmericanFoundrymen's pp. 119-126. 36. CommodityDataSummaries,Phosphates, U.S. Bureau of Mines, 1978. . 37. Powell, H. E ,et al., Recoveryof zinc, copper and lead-tin mixtures from brass smelter flue dusts, RI 7637, U.S.Bureau of Mines, 1972. 38. Proceedings 3rd International Symposium, IC 8640, U.S.Bureau of Mines, 1974.


2Selection of Least Hazardous Material Alternatives

Alvin F Meyet .A. E Meyer and Associates, Inc. Mckan, Virginia

1.

INTRODUCTION

A. SummaryThis chapter addresses the underlying purposesof accomplishing measures to select the least hazardous of alternative materials used planned for use by industrial and governmental enor tities. It then discusses the relationship of substitution processesother considerations in the to decisionprocess. An overview of someapproaches for selectionmethodsispresented.A methodology originally developed for the U.S. Navy is described, along with examples.

B. Substitution Methods as an Element of Pollution Prevention1. Substitution Controls vs. A longstanding principle of environmental control and industrial hygiene is that the first and basic consideration in control of hazards is the elimination of the hazardous component, or if that is not feasible, then the substitution of a lesser hazard The concept of eliminating [l]. the source or reducing the amount of toxic materials includes in addition to substitution of materials such other measures process or operation2 changes, properdesign of operations, as and housekeeping. The importance of eliminating the need for costly environmental control measures by substituting less dangerous or less offensive materials also is of longstanding recognition[2]. Likewise, the economic advantages of industrial waste recovery is not a new concept. 198% was that Nonetheless the primary approachto environmental control, until the late of using &end of the pipe control measures. This was primarily in response to the focus of environmental regulations specifying limits to be met treatment or other control measures. by In the early 1990s there emerged a steady increase in recognition both in regulatory agenties [e.g., u.S. Environmental Protection Agency (EPA),the Department of Defense1 and in the private sector that a comprehensive, cost-effective approach to environmental quality in17

18

Meyer

cludes source reduction, recovery, and reutilization, with treatment and ultimate disposal as the last resort. The Pollution Prevention Act of 1990 established these concepts in a national policy that pollution should be prevented or reduced at the source whenever feasible.

II. HAZARDOUS MATERIAL SUBSTITUTION ACTIONA. Statutory and Regulatory RequirementsThere are many statutory and regulatory requirements that directly or indirectly create the need for hazardous material assessment. These include federal statutes and their implementing regulations or standards, executive orders requiring federal agency compliance, and state and local codes, standards, and regulations. The Department of Defense (DOD) and the military departments and agencies have requirements that implement the federal mandates and some requirements that predate them. 1 . Federal Codes, Standards, and Regulations The primary federal statutes and their implementing regulations regarding environment, safety, and health are the Clean Air Act, Resource Conservation and Recovery Act (RCRA), Clean Water Act, Safe Drinking Water Act, Toxic Substances Control Act (TSCA), Emergency Planning and Community Right to Know Act (EPCRA), Pollution Prevention Act of 1990, Occupational Safety and Health Act (OSHA), Hazardous Materials Transportation Act, and the National Environmental Policy Act (NEPA). These acts taken together impose a need to examine the feasibility of using materials that are less hazardous, are less costly, or impose fewer administrative or other regulatory compliance resource requirements.

2. Possible Application of Department of Defense Methodologies A Risk Assessment Code (RAC) procedure was developed by the Department of Defense in the early 1960s [3]. Initially, it was designed to provide a means of ranking hazards associated with new weapon systems. Subsequently, the procedure was adapted in 1981 to rate occupational safety and health deficiencies. In its simplest form, the procedure provides a rating scheme based on a matrix to estimate the severity of effects of the hazard and the probability of occurrence, with the results stated as a risk assessment code. The range is from RAC 1 (catastrophic impact) to RAC 5 (negligible) (see Table 1). The later (1981) procedure, which is still in use, includes a cost effectiveness index and an abatement priority ranking. The revised procedure takes into account, with a numerical algorithm, such circumstances of exposure and resultant effects as the OSHA Permissible Exposure Limits (PEL), number of employees involved, effects of exposure (ranging from death to minimal lost time, disease, or injury), and duration of exposure. It is firmly established in the military services procedures for evaluating and prioritizing occupational safety and health hazard abatement requirements. The RAC schemes deal primarily with chemical and safety hazards ratings, with no consideration for environmental ramifications. Recently there has been an increased focus on the environmental aspect of hazardous materials use on the decision-making process. Unlike the long history of chemical and safety hazards rating schemes, there are no universally accepted systems for environmental hazards and risk acceptance. One possible method is a European model, described below.3. A European Method for Priority Selections and Risk Assessment A study requested by the European Community Commission to provide a practical approach for priority setting among existing chemicals was prepared by Sampaolo and Binetti [4]. Using this

Least Hazardous Material Alternatives Table 1 Risk Assessment Code Rating SchemeaHazard Severity (HHSC) Mishap probability (MPC)A1 1

19

B1

C2 3

D3

I I1 111 IV

2 3

2 3 4

45 5

45

aInterpretation of HM selection Risk Assessment Code: RAC 1 = high risk (imminent danger of life or property; possible civil or criminal action) RAC 2 = serious risk (may result in severe injury or illness on or off site, potential for major damage to environment, and resulting notice of violation) RAC 3 = moderate risk (may cause few illnesses or injuries or significant property damage or environmental impact on or off site) R A C 4 = low risk (can result in only minor impact on or off site or only violation of a standard without damage) RAC 5 = negligible (insignificant impact)

model, an individual property or a number of properties of a given chemical can be evaluated and then ranked with those of other substances. This flexibility allows for evaluating different relationships. For example, one might want to compare only the intrinsic properties with respect to direct personal exposure in a particular circumstance or with respect to environmental exposure. Certain chemicals might have different relative rankings for these two categories. This model offers a number of advantages: The system is simple and flexible enough to be adapted to different and specific needs (i.e., personal exposure to general exposure, risk from domestic exposure vs. professional exposure, etc.). It is a self-improving system because new information can be input and the result can be refined further. This model uses three sets of parameters to evaluate risk and the priority of a given chemical: assessment of intrinsic properties, risk assessment or potentiality, and priority assessment.

Intrinsic Properties. Intrinsic properties of a substance are based on the set of physicochemical , toxicological, and ecotoxicological properties that are considered fundamental (or intrinsic) to the first evaluation of the substance. Each element of the intrinsic property (e.g., molecular weight under the physicochemical category) is assigned a numerical value that corresponds to its level of danger. From this information a score is developed for each intrinsic property, which also addresses the availability or nonavailability of the data. These intrinsic properties are considered additive and determine the intrinsic danger of the substance independently of external agents or factors that may influence it. External Factors. Risk assessment or potentiality includes not only the intrinsic danger of a substance but also the external factors that can influence the danger. These external factors include the quantity of the substance on the market, the plurality of possible exposures, and the size of the risk population. As an example, a substance may be highly dangerous, but if it is not on the market it will not pose any effective risk, and thus its intrinsic risk will be minimal. Priority Meusurement. Priority assessment involves both the known or presumed danger of the chemical and the degree of the lack of knowledge of the substances properties. A priority measurement can be made by calculating the ratio of the weighted figures for properties without data to those figures with available data. Both the risk assessment and priority assessment parameters can affect the intrinsic properties of a substance by multiplying or canceling them.

20

Meyer

111.

LIFECYCLE AND MANAGEMENT CONSIDERATIONS

A. LifeCycleConsiderationsRegardless of the methodology usedin rating hazardous properties of a material, the selection process for the least hazardous involves more than environmental, safety, and health considerations. In addition to assessmentsto determine the least harmful material based on haza ardassessment(suchasthealgorithmdescribed later in this chapter), there are major considerations that must be carefully assessed.1. BasicFeasibilityandEngineeringConsiderations

A fundamental question that should addressed is: Does the substitute perform adequately for beits intended use? This requires determination of the following:1.

2.3.

4. 5. 6.

Favorable vs. adverse effects on required performance of the material(s) in production, operations, and maintenance situations. Creation of new or different hazards (such substitution of a less toxic material with fire as a hazard potential for one that is highly toxic but has a low hazard or no hazard). Durability and life cycle times to failure (as with a low volatile organic compound(VOC) paint that may or may not last as long in a very hot or very cold climate). Maintainability of equipment involved in using a substitute. Possible process or equipment changes that may be needed. Environmental and/or OSHA controls required even if it is the lesser hazard.

2. LifeCycleCostConsiderations There are costs and benefits associated with the engineering feasibility considerations that and need to be assessed. In addition, there are many other costs associated with the life cycle of hazardous material. That life cycle extends from the time of concept through procurement, storage, use, and disposal. It is beyond the scopeof this chapterto do more than highlight such costs. It is also beyond its scope to describe the economic analyses required to evaluate the relative costs and benefits of two or more candidate materials for selection. Among the many costs that should be taken into account in the selection process are those shown in Table 2. A very useful guide for comparing alternatives is the EPA Pollution Benefits Manual [5]. The EPA Pollution Benefits Manualprovides for a financial analysis approach compare to alternatives for pollution prevention. It involves four-tier cost analysis from which economy a feasibility of alternatives can be evaluated. The four tiers are as follows:Tier 0,Usual costs. The alternatives are identified, and all normal costs associated with each are determined. These include investment (depreciable capital, expenditures), operating costs, and operating revenues. Table 2 Life Cycle HazardousMaterialsCostsandCostAvoidance Considerations Acquisition Supply and storageUse

Waste treatment Other disposal Emission control Inventory control Engineering/process controlkhange Training

Safety Hazard/risk assessment ENEIS Permits Personal protection Medical monitoring Spill prevention and control Regulatory overhead Liability

Least

21

Tier l , Hidden Costs. These include such investments as monitoring equipment, protective equipment, control technology, and operating costs such as reports, monitoring training, and medical costs. Tier 2, Liability Costs. Included are penalties, fines, and future liabilities. Tier 3 , Less TangibleCosts. These include costs such as those associated with labor relations, and public relations. The results of the tier analyses are thenincorporatedintocostsummariesandfinancial worksheets, which result in an assessment and/or comparison of any cost savings for each alternative. This procedureallowsforcomparison of relative costs and benefits of selected alternatives.

B. Management Decisions and Actionsfor Selection of Least Hazardous Material1. Driving Forces The basic driving forces for managementto consider in the selection of less hazardous materials, in addition to regulatory requirements, include the life cycle cost considerations discussed above and such needs planning for new products or processes (or changes to existing as ones), avoidance of new and long-term liabilities, and the possible benefitsof participation in such voluntary programs as the U.S. EPA Industrial Toxics Project (ITP). Other benefits include improved employee and community relations.

2. Closing the Loop Once decisions are made for substitution, a large number of follow-on actions are needed. These include planning for phase-outthe existing in-use of materials, development of new specifications and technicaldata documents, trainingof personnel, provision of any necessary controls, and compliance with any new permit or similar requirements.

W. DESCRIPTION OF METHODOLOGYA. Overview of the Navy Substitution AlgorithmThe hazardous material substitution algorithm developed the U.S.Navy also had wide POfor tential for selection or substitution of least hazardous materials in civilian applications [6].1. The Navy Model The hazardous material substitution algorithm sufficiently flexible that it can either serve as is a preliminary screeningto identify the most likely candidate further study or become a part for of a much more detailed and sophisticated decision model. In the first instance, the model would be useful to an industrial or commercial concern or to a military installation comparing materials proposed vendors as substitutesfor existing materials conforming to regulatory by not requirements. The second application would be for screening as part of an in-depth decision process for changes to production operations, or comparison of newly synthesized materials for possible large-scale application throughout a major industry. For maximum utility, the Navy model is adaptable to either simple manual computations or computer applications.

2. Description of the Algorithm The algorithmis used to assign numerical points for various hazard descriptor elements such as toxicity, duration of personnel exposures, number of persons exposed, related medical effects, fire and explosion potential, requirements for personal protective equipment, anda limited assessmentof environmental impact and control requirements. These include volatile latter

22

Meyer

organic chemicals, EPA Reportable Quantities, and EPAs List of Lists materials (40 CFR 302,4) among others. The points assigned are totals that providea numerical score and risk assessment code a (RAC). This provides for determination of a hazardous material selection factor (HMSF), which allows for materials to be compared with one another numerical terms. The result in can then be used as an entry point into the foregoing overall decision process. The input data are readily available. Principal among these are the Material Safety Data Sheets (MSDS) required by 29 CFR 1910.1000, OSHAPermissible Exposure Limits (Table 2 29 CFR 1910.100), and EPA Publication 56014-90-011 Title 111 List of Lists. The RAC procedure is based on a commonly used system safety analysis method (MIL-STD-882), and the basic approach to the point algorithm is the previously described DoD system for rating occupational, safety, and health hazards.

B. Understanding the Basis for the PointsThe following brief information providesan understanding of the basis for selecting the range of numerical values for the algorithms points. Toxic Effects The evaluation should include the frequency and duration of possible worker exposure. This includes whether the material presents toxic hazardson brief, short-term exposures associated with high concentrations and accidental releases or primarily causes harm from extended exposure to relatively low concentrations. Materials that are irritants or sensitizers or that are skin suspect or known carcinogens, teratogens, or mutagens require special attention even if the projected quantities are small. In many instances, the MSDS will only summarize the toxicity data of the individual components of the mixture andwill not provide information concerning specific toxicological studies on the material itself. In such cases, judgments will have to be based on consultation with also such approved sources the Navy Environmental Health Center. Attention must be given as to any information indicating that the material known skin sensitizer or possesses allergenic is a is properties. A suggested source of reference regarding toxic hazardsthe National Institute of Occupational Safety and Health (NIOSH) Pocket Guide to Chemical Hazards available from the US. Government Printing Office. 2. Characteristics Physical Characteristics. Materials with a high vapor pressure are more likely to be easily dispersed into the environment than those with lower vapor pressures. Those with low flash point and low boiling point (flash point lower than 73F and boiling point below 100F) are extremely hazardous from fire and explosion viewpoint compared with those with points a flash greater than 100F. Liquids with specific gravities less than 1.O present fire-spreading hazards because such materials float on water. A toxic material with a high vapor pressure is more of a hazard in a confined work area than one with the same toxic properties but a much lower vapor pressure. This is because the higher vapor pressure will afford a greater risk of room atmospheric contamination. ChemicalCharacteristics. Wheremixtures are involved, it is importanttounderstandthat those that include aromatic organic chemicals are generally toxic (and often pose greater more fire and explosion hazards) than those classed as aliphatic chemicals. Among the chemical characteristics that must be considered are stability, reactivity with other chemicals (forexample, is the material an oxidizer or corrosive?), and solubility, not only in water but in other media.1.

Least

23

Circumstancesof Exposure. In addition to the specifics of probable work areas, questions on the distribution of material throughout theweapon system life cycle or on-shore activity need to be considered. Localized use (in a single work area) of a material determined to be highly hazardous presentsa different setof concerns with respectto approval decisions than those that apply to a material with moderate hazard potential that is widely used. Among the considerations that should be examined are size of the work force or number of persons at a work site, present and/or needed engineering or other controls, and work area environmental conditions that affectthe hazard (temperature, humidity, the presence of other chemicalsthat may be synergistic or additive, etc.). During a general review and evaluation a proposed material, quesof tions need to be examined with respect to the interactionof the proposed material with others already approved and its use in the system or work areas and with nearby operations. For example, it would be a mistake to approvea new cleaning solvent with a high vapor pressure and low flash point for use in shops in which arc welding is conducted. EnvironmentalImplications. The potential for hazardous waste (HW) generation and compliance with various federal, state, and local codes, standards, and regulations must be evaluated. Insomegeographical areas, regulationson useand/or release of volatileorganic compound air pollutants are very severe and may require special controls if a material is approved. Similar concerns must be examined with regard to air quality and water permits. Because of the, widevariety of such requirements,the points used in thismethod are simplified. More detailed ratings may have to be developed by the user for some analyses.

V. CONCLUSIONS AS TO UTILITY OF THE METHODOLOGYThe hazardous material substitution algorithm developed for the U.S. Navy has been tested extensively and found to be a useful first screening tool.It also fills the need for a wide variety of applications in the civil sector. As indicated earlier in this chapter, itis only one element of the decision process. It is also essential to note that although one goal be the elimination of hazardous mamay terials that affect people or the environment, in many instances complete elimination is not feasible. The selection method, and other considerationsin the decision process, provide fora rational and cost-effective determination the most suitable material. As stated by EPA (Polof lution Prevention 1991, EPA 21P-3003) and the Pollution Prevention Act of 1990, when pollution cannot be prevented, reduced at the source, or recycled, it should be treated in an environmentally safe manner . . . and disposal or other release to the environment should be employed only as a last resort and should be conducted in an environmentally safe manner.

ACKNOWLEDGMENTSThis chapter is based in part on AFMA-TR-91001, Development of Guidance for Selection/ Substitution of Less Hazardous Materials, for the U.S. Naval Supply Systems Command, underUSAFcontractF3361589-D-4003,Order16,A. F. MeyerandAssociates,Inc.with Engineering-Science, Inc. Publication rights to this chapter are retained by the U.S. Government. Copies of the basic technical report can obtained from Defense Technical Information be Center.

REFERENCES1. Patty, F T ,IndustrialHygieneToxicology, Vol. 1 , Inter-SciencePublishing Co., Chicago, 1948. . . 2. Meyer, A. F , Jr., Engineeringbiotechnologyinoccupationalhealth, Trans. Am. Soc. Civil Eng., . 121: Paper No. 2798 (1956).

243.

Meyer

~

U.S. Department of Defense, Deparfment o Defense Occupational Safety and Health (OSH) Prof grams, DODI 6055.1A. 9 Sep 87. 4. Sampaolo, A., and Binetti. R., Regulatory Toxicology and Pharmacology, Vol. 6, 1986. 5. U.S. EnvironmentalProtectionAgency, Pollution Benefits Manual, October1989. 6. U.S. Navy, Naval Supply Systems Command, Development of guidance for selection substitution of less hazardous materials, Tech. Rep. AFMA-TR-91001. 1992.

Multiple Approaches to Environmental Decisions

3

Douglas M. BrownThe Logistics Management Institute Bethesda, Maryland

1.

THE IMPORTANCE OF DECISION MAKING

It would be difficult to overstate the importance of the environment as a policy issue. Aside from the ecological implications of decisions in many nonenvironmental policy fields, environmental policies have impacts on other policy fields. The recent controversy over whether jobs protecting the spotted owl should weigh more or less heavily than protecting the of timber industry workers is not going to be solved here. The important thing is to realize that environmental policies, often considered to be based on scientific analysis, must include consideration of nonscientific issues such as fiscal realities, economic growth policies, and cultural values. Even race has surfaced as an issue in this field [l]. Because of the weakness of the current state of the art in fundamental measurability of environmental policies, an appreciation of the impact of such policies can only be hinted by at using other proxy measures. While environmental activists prefer to see environmental protection as a universally superior good not subject to such comparisons,the fact is that protective activities incur costs. Whether theyare continuing expenses or just investments that will result in lower costs later on is a matter of interest, but it does not relieve societyof the obligationto pay the bills until the investments mature. In the end, all policy costs are experienced by societys consumers and taxpayers. Individual firms, of course, can be punished with criminal sanctions forced into bankruptcy over or environmental breaches; but as a rule governments and entire sectors of industry simply pass the costs along in the form of coerced tax hikes or industry-wide price hikes. Thus, neither government or industry (in a wide sense) pays for environmental protection except to the extent that when consumers or taxpayers find themselves with no more money to spend, the popular taste for government or the industrial product may evaporate. or Those who believed that 1970s Great Society programs the 1980s defense buildups the nearly achieved this national policy bankruptcy point should look closely at the environment. The cost to the taxpayer of dealing with environmental problems is expected to exceed 6%of25

26

Brown

the Gross National Product mid-decade. That is the size of the entire defense budget during by the peak of the Reagan buildup. Simply cleaning known hazardous waste sitesat federally up owned facilities is expected to cost over$125 billion [2], with the figurebeing adjusted upwards every year. Newly recognized threats are being discussed that will only add to the potential size of of this burden[3,4]. In addition, consumers will bear anadditional burden. Some this burden is hidden in the priceof consumer goods, as those private-sector firms that continue in business rather than declaring bankruptcy either pay for required cleanups, self-insure against the need to clean up in the future, or develop new processes to avoid becoming a party to a future cleanup. In some cases, businesses will choose to go out of business rather than risk personal or corporate liabilities of staggering proportions. At the least, this will reduce the number of choices available to consumers, and at the worst, employees will be thrown out of work and further impact on other taxpayers. All in all, there are compelling fiscal and social reasons for ensuring that our very real environmental problemsare identified and dealt with in prudent and responsible ways. Money spent on the environmenteither directly by governments on behalf of consumersor indirectly by consumers through higher prices charged producers as a result of regulations, cannot be by spent on other worthy causes such as consumer and national savings and debt reduction, urban issues, transportation networks, and national security: whatever your policy preferences are, environmental spending competes with And, if not properly thought out, environmental polit. icy can compete with itself. For instance, the EPA has spent years convincing the public that toxic wastesites are a tremendous sourceof health risks and must be dealt with promptly whatever the cost. The publication of the Unfinished Business report [4] requires the EPA to reeducate the public that in its new view many other threats are more risky; EPA competes for funding for those higher risks against an established, costly effort that the EPA itself established and plansto continue. A micro version of the same argument canbe made at the level of the individual producer so facility. Statutory responsibility or not, an organization cannot devote many resources to environmental protection that it can no longer afford to remain in business. Environmental actions, even where deemed socially worthy, must compete for funding with programs, and other where the available funding does not cover all perceived needs, then environmental spending itself must be prioritized. In short, for regulator, policy analyst, and facility manager,a sound basis for making environmental decisions essential to the development and effective execuis tion of a holistic, complex, and credible program for the protection of health and resources. While some may argue for a policy based strictly on scientific evidence, others argue for environmental policies based onemotion, and yet others argue thatthe costs of delay on the one hand and regulation on the other are socially destructive, environmental managers are faced with a situation where something hasto be done that will satisfy all sides without bankruptcy. Thus, while decision theoryis not the cornerstone of environmental science, it may well be the keystone of environmental management.

II. ENVIRONMENTAL ROLESEnvironmental threatsare produced and dealt with organizations whose missionsare broader by than simply protectionof the environment. Environmental agencies, however, havethe mission of ensuring that producers do not forget their environmental responsibilities. Those responsibilities are to the third player in this process: the public. Through the political process, the public caused an environmental policy be put in place to protect healthand the environment, to and at the grass-roots level the public maintains oversight onthe specific actions of both reg-

Environmental

Management 27

Table 1 Policy RolesCharacteristic PolicyviewpointSinglefocus on narrow portion of environmental issues. Mission pollution Prevent all and punish all polluters. Objectives worst Focus on resources Resources Cleanup threat. costs do not detract from primary mission. Extract payment for pollution. Deters, does not repair, problem. Complete operation with environment as part of the whole. Produce products and pay for environmental protection. Minimize resource drain. Cleanup costs are taken from funds otherwise available for mission. Focus on avoidance, then cleanup. Avoids, evades, or repairs problem.Does not generally under-

stand or get involved.

Seeks products andprotection. No perceived threat is acceptable. Pay in either case, through taxes or prices. Passivity until aroused; then paranoia. Suffers consequences.

Approach Policy effect

ulators and producers. The differencesin the roles of regulators, producers, and the publicare summarized in Table 1. The most familiar enforcement agency is a police department. It has a single focus on a statutory area (in thiscase, public order). The primary responsibilities (preferably) to deter are criminals, which itself deters further crime or, when that fails, toseekoutandapprehend crimes. In addition to fines levied through the punishment process, such departments colmay lect fees to recoup their costs of doing business, thereby reducing the burden on their budget (and, in theory, on the taxpayer). Frequently, however, there is no payor, either because the guilty party has been apprenot hended or because the enormityof the crime makes financial restitution, even with damages, unacceptable or so high as to be unpayable. Such cases, which are the norm more than the exception, make it necessary for the department to absorb the cost of enforcement; but such expenses are budgeted for and appropriated over and abovethe cost of normal operations, not at the expense of those operations. We expect them to deter and apprehend, not to repair, the problem of crime. In those few jurisdictions where victim compensation is considered, it does not come out of the police operating budget. It is not generally expected that the enforcer will have to police itself (although such occasions do arise, and have arisen in most of our major cities over the past 15 years, and are generally poorly handled). In some jurisdictions, we see a cooperative enforcement approach [5]: community policing or the cop on the beat, to match the environmental metaphor with police example. a Nonetheless, thosecooperative approaches are part of an overall enforcementstrategy; the regulator coaches the producer toward compliance rather than taking over the operating responsibility itself. Finally,we expect the police to focus on the worst problem-catching murderers rather than staking out shoplifters. The producers have a completely different set of responsibilities, foremost of which is the the factthat they must continue on with their production task order to survive; environmental in issues are a secondary concern. When a cleanup does become necessary, the producer must pay, and its payment comes out of its normal operating expenses. To some degree, consumers will absorb someof this cost, but in general, passing on too much of the cost will simply drive

28

Brown

the producer out of business (unless the producer happens to be a government agency). With limited discretionary funding available for environmental restoration, then, producers need to accomplish as much as possible with the resources they have. Normally, government regulatory agencies act as enforcers. Once enforcement has occurred, however, one is faced with the need to restore the situation. Then, and especially in the case of the Superfund, the government becomesa producer and needs to act and think like one. Finally, there is the public. The public tends to be easily excited over health and safety issues, although a much smaller (but more active) group maintains vigilance overnon-human health and natural resources, and very small groupis both active in and knowledgeable about a global ecology issues. In addition, the public is concerned about jobs, general economic issues, property values, and the quality of life in communities. Thus, the public concerns tend to be more diffuse than the single focus enjoyed by enforcers and producers. Because of that diffuseness, the public seldom speaks with a coherent voice, which makes it easier for activists and extremists on all sides of an issue to misrepresent or override the public will. While the federal governments National Environmental Policy provides processes for Act public involvement, as do a number of state statutes, there is at present no real requirementto go along with public preferences as long as the pro forma requirementsare met. Thus, on any given decision, the public can be and often is ignored. The more this happens, of course, the more the public comes to see the regulator as well as the producers as its enemy, especially as these parties will b

Documents

Donald l. Wise