WATER POLLUTION CONTROL RESEARCH SERIES 11040 GKK 06/71
       Environmental Impact
                 of
          Highway Deicing
ENVIRONMENTAL PROTECTION AGENCY • WATER QUALITY OFFICE

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                   WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Reports describe the results and progress
in the control and abatement of pollution of our Nation's waters.  They provide
a central source of information on the research, development and demonstration
activities of the Water Quality Office of the Environmental Protection Agency,
through in-house research and grants and contracts with the Federal, State
and local agencies, research institutions, and industrial organizations.

Previously issued reports on the Storm and Combined Sewer Pollution Control
Program:
11023 FOB 09/70
11024 FKJ 10/70
11024 EJC 10/70

11023 — 12/70
11023 DZF 06/70
11024 EJC 01/71
11020 FAQ 03/71
11022 EFF 12/70

11022 EFF 01/71
11022 DPP 10/70
11024 EQG 03/71

11020 FAL 03/71
11024 FJE 04/71
11024 DOC 07/71
11024 DOC 03/71

11024 DOC 09/71

11024 DOC 10/71
Chemical Treatment of Combined Sewer Overflows
In-Sewer Fixed Screening of Combined Sewer Overflows
Selected Urban Storm Water Abstracts, First Quarterly
Issue
Urban Storm Runoff and Combined Sewer Overflow Pollution
Ultrasonic Filtration of Combined Sewer Overflows
Selected Urban Runoff Abstracts, Second Quarterly Issue
Dispatching System for Control of Combined Sewer Losses
Prevention and Correction of Excessive Infiltration and
Inflow into Sewer Systems - A Manual of Practice
Control of Infiltration and Inflow into Sewer Systems
Combined Sewer Temporary Underwater Storage Facility
Storm Water Problems and Control in Sanitary Sewers -
Oakland and Berkeley, California
Evaluation of Storm Standby Tanks - Columbus, Ohio
Selected Urban Storm Water Runoff Abstracts, Third
Storm Water Management Model, Volume 1 - Final Report
Storm Water Management Model, Volume II - Verification
and Testing
Storm Water Management Model, Volume III -
User's Manual
Storm Water Management Model, Volume IV - Program Listing
                                    To be continued on inside back cover

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Environmental Impact of Highway Deicing
            ENVIRONMENTAL EROTECTION AGENCY
                WATER QUALITY RESEARCH
            Edison Water Quality Laboratory
     Storm and Combined Sewer Overflows Section, R&D
               Edison, New Jersey 08817
                      11040 GKK
                      June 1971

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                                 DISCLAIMER
     This report has been reviewed by the Municipal Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publi-
cation.  Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
                                      ii

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                              ABSTRACT

Deicing agents for removal of Ice and snow from highways and streets
are essential to wintertime road maintenance  In most  areas of the U.S.
Due to the ever-Increasing use of highway  delclng materials, there has
been growing concern as to environmental effects resulting from these
practices.  This state-of-the-art report critically reviews the avail-
able Information on methods, equipment  and materials  used for snow and
Ice removal; chlorides found In rainfall .and  municipal  sewage during
the winter; salt runoff from streets and highways;  delclng compounds
found In surface streams, public water  supplies, groundwater, farm ponds
and lakes; special additives Incorporated  Into  delclng  agents; vehicular
corrosion and deterioration of highway  structures and pavements; and
effects on roadside soils, vegetation and  trees. It  Is concluded that
highway delclng can cause Injury and damage across  a  wide environmental
spectrum.  Recommendations describe future research,  development and
demonstration efforts necessary to assess  and reduce  the adverse Impact
of highway delclng.  This report was prepared by the  Storm and Combined
Sewer Pollution Control Section, Edison Water Quality Laboratory, Water
Quality Office of the Environmental Protection  Agency.

KEY WORDS:  Additives, concrete deterioration,  environmental damages,
            groundwater contamination,  highway  delcing, plant toler-
            ances, public water supplies,  salt  storage, vehicular
            corrosion, water pollution  effects, wintertime highway
            runoff.
                                     PeijiepaT

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nocTORHHO  yBe/iMHHBaionerDCFi npHMBHSHMF npe>TMBo.neflHbix Marepna^oB Ha floporax, cra/iM
BOSHMHaTb  3a6oTH o noc/iEflCTBMHX fl;ifl oKpywaionero rwpa BbrreKaionMX MS aroM npaKTMKM.
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oSopyflOBaHWHX M naTepna^ax npnpiEHflKU4Mxefl npn yfla/iEHMM onera n flbfla; o x;iopMflax
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               , rpyHTOBofl aofle, npMxyropHHX npyflax n Daepax; o oneu|na/ibHbK
           BHBflpeHHbix B npoTnao^eflHye cpEflcrsa; a HoppoauM nosoaoK M yxymABHMM
flOpOWHbK HOCfpOBH M HOCTOBbK; M 0 B/1MHHMM H3 npMflOpOWHyffl HOHBy, paOTMTB flbHOOTb
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       6bi/i cocras^eH DTfle^eHMen no HOHTpo/ira sarpnaHSHHR floiMflSBbx H
oroHHbix sofl /laSoparopHM MMBHM SftucoHa ftm anpefle^eHun Ha^ecTBa aoflu npw
           HaneoTBa soflbi ynpae^RHMH aai;HTN OKpywaKmero nwpa.
 HaTeropMM:   FlpMoaflKM,  yxymABHMe fieroHa, noBpsmqeHMfl oKpywaemero nnea,
             aarpnsHBHMe fpyHTOBofi soflbi, oSea^ewMaaHke flopor, rpaHM4bi
             BbHOC/lHBOCTH paCTBHMH, rOpOflCKMB BOflOCHadWBHMH, XpaHSHMB
             conn,  KoppoaMB noaoaoK, noe^eflcraMH aarpflaweHHfi sofl, 3MHHMB
             flOpOWHyB CTOHM.
                                 Auszug

 Enteisungsmittel  zur Beseitigung von Els und Schnee von Landstrassen und
 Strassen  sind ftlr die Strassenunterhaltung im Winter in den meisten Bezirken
 der  Vereinigten Staaten Wesentlich.   In folge des "limner grosser werdenden
 Gebrauches  von Strassen enteisungsmitteln, wurde man Immer meht urn die
 daraus  entsprlngenden EinflUsse aud  die Umwelt besorgt.  Dieser Bericht
 betrachtet  kritisch die gegenwSrtigen Kenntnisse von den Methoden, GerSten
 und  Meterialien die zur Beseitigung  von Schnee und Els benutzt werden; von
 Chloriden die sdch im Winter im Regenwasser und in. stadtischen AbwSssern
 vorfinden;  vom Salzabfluss von Strassen und Landstrassen; von Enteisungs-
 verblndungen die  sich in OberflSchenwaaser laufen, im Wasser von Hffentrichen
 Wasserverteilungsanlagen, in GehSft  teichen und in Seen vorfinden; von den
 Son  derzusatzmitteln die in der Enteisungsmitteln einverlelbt werden; von
 der  Korrosion von Fahrzeugen und der allmBhliche Zerstb'rung von Strassen-
 bauwerke  und - pflastern; und von den Wirkunken auf den Erdboden, die
 Fflanzen  und die  Baume an den Landstrassenr&ndern.  Man konmt zu dem Schluss
 dass die  Landstrassenenteisung es vermag Verletzungen und Schaaen in einen
 brelten Band des  Umweltspektrums zu  verursachen.  Empfehlungen betreffen
 zukdnftige  Forschungs- und Entwlcklungstatigkeit sowie Versuchsmassnahmen
 die  erforderllch  sind um den ungtinstlgen Einfluss der Landstrassenentiesung
 auszuwerten und zu vermindern.   Dieser Bericht wurde von der Abteilung fUr
 Verunreinlgungskontrolle von Regenwasser- und Hischkanalisatlon des Edison
 Wasseruntersuchungslaboratoriums des WasserqualitHtsamtes der Umweltschutz-
 verwaltung.

 Schldsselworte:  Zusatzmittel,  Betonzerstorung, Umweltschaden, Grundwasser-
                  ver unreinigung, Landstrassenentelsung, Planzentoleranzen,
                  Bffentliche Wasserversorgungsanlagen, Salzlagerung,
                  Fahrzeugkorrosion,  Auswirkungen der Wasserverunreinigung,
                  Landstrassenwasserablauf 1m Winter.
                                      ill

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                              Resume

Les agents degivrants pour 1'enlevement de la glace et la nlege des chemins
et des rues sont^essentiels a 1'entretlen des voles en hivers dans la plupart
des regions des Etats Unis.  Du a 1'utilisation toujours plus repandue des
materiaux degivrants pour les chemins, un aouci s'eleva  concernant les effets
environnementals resultant de cette technique.  Cet rapport de presente une
revue critique de 1'information disponible sur las mfithodes, 1'outillage et
lea materiaux employes pour 1'enlevement de la glace et la nelge; sur les
chlorures qui se trouvent dans 1'eau de.pluie et les eaux d'egouts  municipales
en hlver; sur le decoulement du sel des rues et des chemins; sur les composes
degivrants qui se trouvent dans les fleuves superficiels, les approvisionne-
ments d'eau publics; leas eaux souterraines, les abreuvoirs et les lacs; sur
des additifs spe'ciaux incorpore's aux agents degivrants; sur la corrosion
vehiculaire et la deterioration des structures et des par 1men13 des chemins;
et sur 1'effets sur les sols, la vegetations et les arbres situea au bord des
voles.  On conclut que la degivration des chemins peut faire du tort et du
dommage au travers une bande epandue du spectre environnemental.  Les
recommendations d£crivent les efforts futurs de recherche, de developpement
et de demonstration qui seront n£cessaires a eValuer et a reduire 1'Impact
adverse de la degivration des chemins.  Cet rapport fut prepare par la
Section de Controls de la pollution des egouts d'eau de pluie et des egouts
mixtes de la Laboratoire Edison pour determination de la qualite d'eau du
Bureau de Qualite  d'eau de 1'Administration de Protection environnementale.

Hots clef:  Additifs, deterioration du bgton, dommages environnementals,-
            contamination des eaux souterraines, degivration des chemins,
            tolerances des plantes, approvisionnements d'eau publics,
            magasins du sel, corrosion vehiculaire, effets de la pollu-
            tion d'eau, decoulement des chemins en hlver.


                                  Resumen

Agentes descongelantes para la eliminacidn de hielo y nieve de las calles y
carreteras  son esenciales para el mantenimiento de las vias de comunicacidn
en la mayor parte de  los Estados Unidos durante el invierno.  Debido  al
aumento constante de  materiales descongelantes en las carreteras existe una
creciente preocupacirfn en cuanto a  los efectos surgidos como resultado de
estas practices  en  el medio ambiente.  Este informe de estado-del-arte
revisa  criticamente la informacifin  existente sobre metodos, equipos y
materiales  uaados para la remocidn  o eliminacidn   de nieve y hielo; cloro
encontrado  en depositos de lluvia y desagues municipales durante el in-
vierno;  sal derramada en las  carreteras y calles; compuestos de materiales
descongelantes encontrados en la superficie de arroyos, de abastecimientos
de aguas publicas,  aguas subterraneas, estanques de granjas y lagos,
agregados especiales  incorporados a los agentes descongelantes, corrosion
de vehfculos y deterioracidn  de estructuras de las carreteras y pavimentos;
y sus usos  sobre  el terreno contiguo a las mismas, su vegetaci£n y arboleda.
Como conclusion  se  ha determinado que la descongelacidn de carreteras puede
causar  grandes danos  y perjuicios a una gran parte del medio ambiente.  Las
 recomendaciones  describen investigaciones a realizarse en el futuro, ex-
plicando y  demonstrando los esfuerzos neceaarios requeridos para estimar
y reducir los  impactos adversos en  el descongelamiento de carreteras.
 Este informe  fue preparado por la  Seccidn de Control Combinado de Tormentas
y Polucidn  de  Cloacas en el Laboratorio Edison para la Cualidad del Agua,
 Oficina de  Cualidad del Agua  de la  Agenda  de Protecci6n del Medio Ambiente.

 Falabras  Claves:   Agregados,  Deterioraci<5n  del Cement o, Daflos al Medio
                   Ambiente Contaminacio'n de Aguas Subterraneas, Desconge-
                   lamiento de Carreteras, Tolerancia de Plantas, Abaste-
                   cimiento de Aguas Publicas, Reservas de  Sal, Corrositfn
                   de  Vehfculos, Efectos de  Polucio'n en el agua, Derrames
                   en  las Carreteras durante el invierno.


                                    RESUHO

 Agentes para o degelamento, na  remogao do gelo e da neve das auto-estradas
 f ruas, sao essenciais para a manutengao das vias de comunicagao na maior
 parte dos Estados Unidos, durante  o inverno.  Devido ao constante aumento
 no uso de materials degelantes nas  estradas tern havido uma crescente  preo-
 jjupagao quanto aos efeitos  resultantes  destas priticas ao meio ambiente.
 Este relatOrio do estado-da-arte  revisa criticamente a informagio existente
 sobre os metodos, equipamento e materials usados para a remogao  de neve e
 de gelo;  chlorureto encontrado  em depdsitos de chuva e esgotos municipals
 durante o inverno; sal  escoado  das  ruas e estradaa^ compostos de materials
 degelantes encontrados na  superficie  de rios, em abastecimento de aguas
 pnblicas,  aguas subterraneas, estanques de  fazendas e lagos; aditivos
 especiais incorporados  aos  agentes  degelantes; corrosio de velculos e
 deterioramento das estruturas e pavimentacao  de estradas;  e  efeitos nos
 solos proximos as estradas; na  vegetagio  e  drvores.  Foi  concluido que o
 degelamento de estradas  pode  causar danos e prejuizos a uma  larga faixa do
 meio ambiente.   As recomendagoes  descrevem  as pesquisas para o futuro, fazem
 uma explanagao e demonstracao dos  esforcos  necessaries para^a determinag^o
 e a redugao do impacto  adverso  no  degelamento de estradas. Este  relatdrio
 foi preparado pela Secgao  de  Controle Combinado das Tempestades  e da
 Poluigao de Esgotos,  Laboratdrio  Edison para  a Qualidade  da  Agua, Escri-
 t6rio da Qualidade da Agua da Agenda de  Protegao  ao Meio Ambiente.

 Palavras chaves:  Aditivos,  deterioramento  do  cemento, danos ao meio  ambiente,
                   contaminagao  das £guas  subterraneas, degelamento de  estradas,
                   tolerancia  de plantas,  abastecimento de  aguas  publicas, re-
                   servas  de sal,  corros§o  de  veiculos, efeitos da poluigao da
                   agua,  escoamento das estradas no  inverno.

                                            IT

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                               CONTENTS


Section                                                            Page

            - ABSTRACTS                                              i

            - FIGURES                                              vi

            - TABLES                                               ix

            - FOREWORD                                             xi

  I         - CONCLUSIONS                                            1

  II        - RECOMMENDATIONS                                        5

  III       - SNOW AND ICE REMOVAL - MATERIALS AND OPERATIONS      11

                 Deicing Materials - Bare Pavement Policy          11
                 Abrasives                                         15
                 Chloride Salts and Properties                     16
                 Marine Salt                                       17
                 State Usage                                       18
                 Highway Salt Applications                         18
                 Costs of Highway Salts                            19
                 Operations, Equipment and Methods                 20
                 Other Deicers                                     32
                 Salt Storage                                      32

  IV        - RAINFALL AND OTHER SOURCES                           45

  V         - SEWAGE                                               47

  VI        - RUNOFF FROM STREETS AND HIGHWAYS                     51

                 Wisconsin Studies                                 51
                 Syracuse, New York                                51
                 Chicago, Illinois                                 51
                 Des Moines, Iowa                                  52

  VII       - SURFACE STREAMS, RIVERS                              55

                 Various Rivers in the State of Maine              55
                 Meadow Brook, Syracuse, New York                  55
                 Major Rivers in the United States                 56
                 Sleepers River Basin, Vermont;                    56
                   Hydrologic Salt Balance
                 Chloride Levels in Milwaukee Streams              57
                 Oxygen Demand of Deicers                          57
                 Dumping of Snow into Nearby Streams and           58
                   Water Bodies; Chloride, Oil and Lead
                   Content

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                           CONTENTS (Cont'd)
Section

  VIII      - FARM PONDS, LAKES
                 Farm Ponds-State of Maine                          59
                 The Great Lakes, Lake Erie                         59
                 Wisconsin                                          59
                 First Sister Lake, Ann Arbor, Michigan;            60
                   Salt-Induced Stratification
                 Irondequoit Bay, Rochester, New York;              60
                   Salt-Induced Stratification
                 Possible Salt Stimulation of Algal Growths         61

  IX        - WILDLIFE                                              63

  X         - DEICING ADDITIVES                                     65

                 Ferric and Sodium Ferrocyanide, Anti-Caking        65
                   Agents
                 Corrosion Inhibitors                               67
                 Chromate Additives Used As Rust Inhibitors         67
                 Phosphate Additives Used As Rust Inhibitors        69

  XI        - PUBLIC WATER SUPPLIES, GROUNDWATER, INDUSTRIAL        71
              WATER USES

                 Public Water Supplies                              71
                 Groundwater, Well Supplies                         71
                 Michigan                                           71
                 Wisconsin and Illinois                             72
                 New Hampshire                                      72
                 Maine                                              72
                 Ohio                                               73
                 Connecticut                                        73
                 Massachusetts                                      73
                 Industrial Water Supplies                          75

  XII       - CORROSION OF VEHICLES                                 77

                 Cost Damages                                       77
                 How Corrosion Occurs                               77
                 Comparative Studies                                78
                 Mufflers, Tailpipes                                79
                 Rust Inhibitors                                    79
                 Other Preventative Measures                        79
                                   Vi

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                           CONTENTS (Cont'd)


Section                                                            Page

  XIII      - EFFECTS ON HIGHWAY STRUCTURES AND PAVEMENTS            81

                 Review by Massachusetts Research Council            81
                   And Findings of U.S. Highway Research
                   Board and Representative States
                 Comments of Calcium Chloride Institute              82
                   and Portland Cement Association
                 Other Deicing Compounds                             83
                 Effects on Underground Utilities                    83

  XIV       - EFFECTS ON SOILS, VEGETATION, TREES                    85

                 Soil Chemistry, Salt Movement Through Soil          85
                   Into Plants
                 Wintertime Infiltration                             88
                 Salt Levels In Roadside Soils Along Maine           88
                   Highways
                 Chloride Content of Soils and Plants on             90
                   National Park Grounds, Washington, D.C.;
                   Correlation With Plant Injury and Death
                 Sodium And Chloride Content Of Grasses,             91
                   Salt Tolerances
                 Salt Injury to Trees, St. Paul, Minnesota           92
                 Sodium And Chloride Levels In Sugar Maples          92
                   And Silver Maples In New Hampshire,
                   Massachusetts, Vermont And Connecticut;
                   Correlation With Injury And Death
                 Salt Tolerance Of Individual Plant Species;         94
                   Fruit, Vegetable And Field Crops, Grasses,
                   Trees And Ornamentals
                 Effects Of Salt Spray On Vegetation And Road-       96
                   side Environment

  XV        - SUMMARY                                               101

  XVI       - ACKNOWLEDGMENTS                                       105

  XVII      - REFERENCES                                            107
                                  vii

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                                FIGURES
Figure                           Title                             Page

   1        Diesel powered truck with wing plow and                 21
            straight blade

   2        Snow blower                                             21

   3        Diesel powered dump truck with salt spreader            22
            insert and snow plow

   4        Left to right:  dump truck with salt spreader           22
            insert and plow, truck with interchangeable
            plow, front-end loader, and snow blower

   5        Twin-disc salt spreader with tail-gate screens          23
            (placed inside truck body) to prevent salt
            lumps from reaching feeder ports

   6        Salt spreader                                           23

   7        Salt spreader                                           24

   8        13-Ton salt spreaders with V-plows                      24

   9        New design salt spreader with screen grid over          25
            top to preclude salt lumps

  10        Salt spreader being loaded at salt storage depot        25
            by front-end loader

  11        Department trucks plowing city streets                  26

  12        Front-end loader removing cleared snow into             26
            receiving trucks

  13        Front-end loader clearing city streets                  27

  14        Front-end loaders keeping city streets open             27

  15        Heavy-duty snow blower                                  28

  16        Snow blower removing street accumulated  snow into       28
            receiving trucks

  17        Front-end loader depositing snow into snow-             29
            melter
                                  viii

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                           FIGURES (Cont'd)


Figure                           Title                             Page

  18        Dumping snow into nearby waterway                       29

  19        Open salt storage pile, downtown Chicago, Illinois      35

  20        Open salt storage pile, Milwaukee, Wisconsin,           35
            estimated quantity 41,000 tons

  21        City stockpile of rock salt remaining after winter's    36
            use, mid-February, Milwaukee, Wisconsin

  22        Typical salt storage pile in downtown New York          36
            City

  23        Moving salt by front-end loader inside enclosed         37
            storage structure

  24        Covered salt stockpile located adjacent to the          37
            Maumee River in Toledo, Ohio

  25        Salt storage - Approximate construction cost            38
            $3 to $5 per Ton of capacity

  26        Salt storage - Approximate construction cost            38
            $3 to $5 per Ton of capacity

  27        Salt storage - Approximate construction cost            38
            $3 to $5 per Ton of capacity

  28        Salt storage - Approximate construction cost            39
            $50 to $75 per Ton of capacity

  29        Salt storage - Approximate construction cost            39
            $50 to $75 per Ton of capacity

  30        Salt storage - Approximate construction cost            39
            $50 to $75 per Ton of capacity

  31        Salt storage - Approximate construction cost            39
            $50 to $75 per Ton of capacity

  32        Salt storage - Approximate construction cost            40
            $15 to $20 per Ton of capacity

  33        Salt storage - Approximate construction cost            40
            $10 to $30 per Ton of capacity
                                   ix

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                           FIGURES (Cont'd)
Figure                           Title                            Z2SS

  34        Salt storage - Approximate construction cost           40
            $20 to $30 per Ton of capacity

  35        Salt storage crib                                      41

  36        Salt storage shelter                                   ^

  37        Salt storage building                                  41

  38        The "Beehive" - Concrete base forms removed;           42
            note posts for retaining ring roughly placed

  39        The "Beehive" - Third ring of panels being             42
            placed; placing of panels by electrical truck

  40        The "Beehive" - Fourth ring completed                  42

  41        The "Beehive" - Building with all panels in            43
            place; note air vents at top

  42        The "Beehive" - Method of loading; first stage         43
            by truck and dozer

  43        The "Beehive" - Method of loading; second stage        43
            by conveyor

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                                TABLES


Table                            Title                             Page

 I          Reported Use (Tons) of Sodium Chloride, Calcium         12
            Chloride and Abrasives by States and Regions in
            the United States, Winter of 1966-1967

 II         Chloride Content of Various Waters                      45

 III        Monthly Chlorides at Milwaukee Sewage Treatment         48
            Plant (mg/1), 1965-1969

 IV         Special River Sampling, Milwaukee Sewerage              49
            Commission, January 16, 1969

 V          Salt Tolerance of Fruit Crops                           97

 VI         Salt Tolerance of Vegetable Crops                       97

 VII        Salt Tolerance of Field Crops                           98

 VIII       Salt Tolerance of Grasses and Forage Legumes            98

 IX         Salt Tolerance of Trees and Ornamentals                 99
                                   xi

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                               FOREWORD


Under provisions of the Federal Water Pollution Control Act, as amended,
the Office of Water Quality Research in the Office of Research and Moni-
toring within the Environmental Protection Agency, is authorized to
conduct various basic and applied research; and to develop and demonstrate
the results of this research.  These activities are undertaken through
in-house efforts of the EPA Laboratories, or accomplished through various
grants and contracts funded and sponsored by the Office of Water Quality
Research — Research, Development and Demonstration Program.

This report, Environmental Impact of Highway Deicing, has been prepared
by the staff of the Office of Water Quality Research — Storm and Com-
bined Sewer Pollution Control Branch, and represents a significant effort
in compilation of broad-base information available in the subject area
and assessment of the full impact of highway deicing practices on the
environment.  This program of the Division of Applied Science and Tech-
nology in the Office of Water Quality Research, has continuing active
interest in highway deicing because of its inherent responsibilities in
the evaluation, control and treatment of waste overflows from combined
sewers and discharges of sewered and non-sewered urban runoff.  Because
of serious pollution existing in many receiving streams in this country,
and the increasing public awareness of these ever important problems,  ,
it is appropriate that the environmental issues concerned with highway
deicing be reviewed and examined in much greater depth.

The use of deicing salts and other materials for removal of ice and
and snow from highways, roads and streets, is essential to wintertime
road maintenance operations in most areas of the U.S.  This report is
mainly derived from a detailed review of the literature, and from con-
tacts with various groups and individuals knowledgeable of the potential
and real consequences of highway deicing.  This report focuses on the
characteristics of snowmelt runoff and the effects of highway deicers and
their associated additives upon surface  streams, rivers, lakes, ponds,
groundwaters, private, public and industrial water supplies.  The report
also describes snow removal operations,  chlorides in rainfall, the effects
of deicing salts upon wildlife, roadside vegetation, and the corrosion
of vehicles and highway structures caused by highway salts.

Several research projects in the past have studied alternative deicers
in place of the chloride salts, and various non-chemical methods for
removing ice and snow from roads and highways.  None of these materials
and methods in contrast to the sodium and calcium chloride salts, are
apparently considered economical or reliable for widespread use.

Except for a) limited research by State highway departments and possibly
by the Federal Aviation Authority; b) investigations nearly completed
by the Virginia Polytechnic Institute for the U.S. Highway Research
Board; and c) recent completion of corrosion studies by the American
Public Works Association, there is no known large-scale research being
                                   xii

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carried forth at the present time on highway deicing and its environmen-
tal effects.  The majority of results from the VPI-HRB study have been
previously made available.  National Cooperative Highway Research Program
Report 91 by VPI and HRB published in 1970, contains considerable informa-
tion on the subject of highway deicing and constitutes an important refer-
ence used by this EPA study.

Suggestions and recommendations are given in identifying present research
and development needs toward alleviation of detrimental effects caused by
highway deicing.  This report should also serve to outline and describe
procedures that may be necessary for complying with current Federal regula-
tions on environmental protection during the design phase of highway
projects.  The National Environmental Policy Act of 1969, Executive Order
11514 on "Protection and Enhancement of Environmental Quality," and the
Highway Act of 1970 make provisions for determining environmental impact
of major Federal actions including all Federal-aid highway projects.
Adherence to these provisions could involve various aspects such as calcu-
lating salt runoff concentrations and loads; modification of existing surface
drainage; suitability of roadside plantings and vegetation cover; the fate
and disposition of salt runoff after leaving the highway surface; and the
possible need for runoff treatment.
                                   xiii

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                               SECTION I

                             CONCLUSIONS
1.  Review of the literature, and numerous contacts with groups and
    individuals knowledgeable of highway deicing operations and the
    associated consequences, indicate that highway salts can cause
    injury and damage across a wide environmental spectrum.  Further-
    more, it is believed that many of these effects although not yet
    evident in certain areas of the country, may well appear in the
    near future.  Effects of highway deicing appear most significant
    in causing contamination and damage of groundwaters, public water
    supplies, roadside wells, farm supply ponds, and roadside soils,
    vegetation and trees.  Deicers also contribute to deterioration
    of highway structures and pavements, and to accelerated corrosion
    of vehicles.

2.  Sodium chloride and calcium chloride are used almost exclusively
    as deicing agents because of their efficiency in melting ice and
    snow, availability, and relatively low material cost.  Most deic-
    ing salts are now applied "straight" onto streets and highways.
    In 1947, less than one half million tons of deicing salts were
    used in the U.S.  Annual use of these salts increased to around
    9 million tons in 1970, and by 1975, annual use is expected to
    approach 12 million tons.  Quantities of sand, cinders and other
    abrasives for wintertime road maintenance have decreased consider-
    ably in recent years.  Chemicals are fast-acting whereas abrasives
    attack the problem only after ice and snow are formed.

3.  Practically all highway authorities in the U.S. firmly believe that
    ice and snow must be removed as quickly as possible from roads and
    highways, and that "bare pavement" conditions are essential to pro-
    tect the lives and safety of motorists using these roads.  This
    policy is also considered proper in minimizing disruption of normal
    business, commercial and public activities and services which could
    be seriously affected by adverse winter conditions.  Maintaining
    bare pavement conditions does, however, require frequent and liberal
    applications of road deicers and/or more precise spreading.

4.  Road salts are usually applied at rates of 400 to 1,200 pounds of
    salt per mile of highway per application.  Over the winter season,
    many roads and streets may receive more than 20 tons of deicers
    per lane mile, which is equivalent to 100 tons salt or more applied
    per mile of roadway for multiple-lane highways.  In using highway
    deicers,  it is not necessary to melt more than 10 percent of the
    ice cover and possibly much less.  Vehicular traffic will normally
    melt the remaining ice and snow quickly and efficiently.

    Excessive application, misdirected spreading and wasting of road
    salts occur frequently.  Improved spreading practices if equated in
                                - 1 -

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    terms of direct annual cost savings, may possibly amount to several
    million dollars Nationwide without sacrificing the quality of winter-
    time road maintenance. -*

5.  Materials storage sites are a frequent source of salt pollution to
    groundwaters and surface streams.  Deicing salts are often stock-
    piled in open areas without suitable protection against inclement
    weather.  Salt-laden drainage often has direct access to nearby
    water supplies.  Careful site selection and properly-designed materi-
    als storage facilities would serve to minimize incidents of water
    supply contamination and provide for better product handling and
    quality control.  In certain cases, diversion and interception of
    salt drainage are indicated, and treatment of these flows may also
    be required.

6.  The special additives found in most road deicers cause considerable
    concern because of their severe latent toxic properties and other
    potential side effects.  Significantly, little is known as to their
    fate and disposition, and effects upon the environment.  The complex
    cyanides used as anti-caking agents and the chrornate compounds used
    as corrosion inhibitors have been found in public water supplies,
    groundwaters, and in storm and combined sewer flows.  Unusually
    small amounts of cyanide and chromium are sufficient to cause rejec-
    tion of public water supplies and cause death of fish and associated
    aquatic organisms.  The phosphate additives also used for corrosion
    control, may contribute significantly to nutrient enrichment in
    lakes, ponds and streams leading to algal blooms and noxious condi-
    tions .

    Recent information supplied by the salt industry cites reduction in
    the amounts of sodium ferrocyanide added to highway salts and further-
    more, that sale of chromium-treated salts was stopped in early 1971
    by the largest supplier in the field.  These changes are not con-
    sidered sufficient to modify the recommendations in this report con-
    cerning deicer additives.  These measures are viewed in terms of the
    potentially serious nature of both cyanide and chromium additives, the
    continuing importance of these compounds, and the absence of field
    data on the fate, disposition and persistence of these materials in
    the environment.

7.  A sufficient number of incidents and detailed studies have been
    described to show the adverse impact and significant damages caused
    by deicing salts to groundwaters, public water supplies, household
    supplies, farm ponds, lakes and small streams.  Use of deicing salts
    has caused many wells and groundwater supplies to be abandoned or
    replaced.  In less severe cases of salt intrusion into public water
    supplies, salt-free patients have been cautioned to make certain
    changes, possibly converting to use of bottled water.  Unfortunately,
    rectification of a contaminated groundwater aquifer generally requires
    many years after remedial measures are first initiated.
                                — 2 —

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 8.  Road deicing salts are found in high concentrations in highway run-
     off.  Large salt loads enter municipal sewage treatment plants and
     surface streams via combined and storm sewers, and direct runoff.
     Concentrations of chlorides as high as 25,000 milligrams per liter
     (mg/1) have been found in street drainage, and up to 2,720 mg/1 in
     storm sewers.  Surface streams along highways and those in urban
     areas have been found to contain up to 2,730 mg/1 chlorides.  Influ-
     ence of highway salts upon major rivers in the U.S. at this time
     appears relatively minor.  Nevertheless, it is recognized that there
     is inadequate surveillance data to clearly define this area and more
     information is necessary.

     Earlier reports in the literature inferred for highway salt appli-
     cation, that approximately one-half of these salts would be readily
     flushed into the surface runoff and receiving streams, whereby the
     remaining salts would be generally retained in the local area.  How-
     ever, recent studies carried forth in Chicago, Syracuse and north-
     eastern Vermont, indicate that most if not nearly all this salt load
     given sufficient time, in certain cases, may find its way into down-
     stream waters.  Both the Syracuse and Vermont investigations noted
     that these loads were being contributed to street sewers and surface
     streams throughout the year, and were adding significant salt to
     stream baseflows particularly in the summertime.  Additional studies
     providing material salt balances for selected watersheds, are con-
     sidered important in better understanding hydrological influences in
     the overall transport of these deicing salts.

 9.  Much of the general literature is somewhat inconclusive on vehicular
     corrosion and deterioration of highway structures and pavements
     caused by deicing salts.  Some of the more recent reports however
     are more definitive.

     The majority of in-depth studies support the conclusion that deicing
     salts are a major cause of vehicular corrosion.  Likewise it is con-
     cluded from the literature that rust inhibiting additives do not
     produce results which would Justify their continued use.  Frequent
     car washing is likely the best protection possible.

     Concrete pavements and concrete bridge floors and decks show least
     resistance to attack by road deicers.  It probably would be best
     never to apply road salts to concrete surfaces but a compromise
     is necessary between deicing, progressive surface deterioration,
     protective treatments, and preventive and corrective maintenance.

     It is also recognized that deicers may attack and cause damage to
     telephone cables, water distribution lines, and other utilities
     adjacent to streets and highways.

10.  There is no doubt that highway deicers can seriously disturb a
     healthy balance in soils, trees, and other vegetation comprising
     the roadside environment.  Total soluble salts, and sodium and
                                 - 3 -

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chloride ions reduce soil fertility and structure, depress plant
water uptake, and are toxic to plants and vegetation above certain
limits.  Total soluble salt increases in soils have been noted up
to 100 feet from previously salted highways, and progressive accumu-
lation of salts in the roadside area has been verified.  The state of
health of vegetation, or conversely the degree of damage to vegeta-
tion, may be correlated with chloride and sodium levels in plants
and soils.  Salt tolerance varies considerably between different
plant species and is an important criteria in properly selecting
vegetation along new highways.  Following severe damage by salts,
extensive corrective measures may be indicated.
                             - 4  -

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                              SECTION II

                            RECOMMENDATIONS
Based on Conclusions detailed in Section I of the report, it is recom-
mended that:

1.  A Deicer Users Manual be developed describing snow and ice removal
    practices and the best systems of applying deicing chemicals to
    streets and highways.  Several highway agencies and the salt indus-
    try are known to have various instructional materials which are
    principally directed to operational performance.  The best data in
    this area should be incorporated into the Manual.  Pollution of the
    surrounding environment and potential in cost savings do not warrant
    excessive salting, and the Deicer Users Manual should give utmost
    priority to environmental protection.  The Manual should include but
    not be restricted to:

         a)  Absolute minimum amounts of deicing chemicals necessary
             to maintain safe traffic flows;

         b)  Critical points or places of application;

         c)  Higher degree of instrumentation, improved calibration,
             and increased reliability of existing and new deicing
             equipment;

         d)  Proper maintenance and repair schedules;

         e)  Methods of salt spreading to optimize operational and
             manpower efficiencies;

         f)  Means for rating materials and methods;

         g)  Development of suggested prime systems and alternatives;

         h)  Incorporation of European and British practices as they
             may apply in the United States.

2.  A Manual of Design and Recommended Practice be prepared for storage
    facilities and methods of handling deicing materials throughout
    storage.  Although certain instructional materials are available
    from highway agencies and the salt industry on proper salt storage,
    there has not been an adequate acceptance of approved practices
    and a proper recognition of pollution problems associated with
    materials storage.  Many storage sites are located on marginal lands
    adjacent to streams and rivers, deicing materials are often stock-
    piled unprotected in open areas, and too frequently these sites
    have become chronic sources of ground and surface water pollution.
                                 - 5 -

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    As a minimum, the Manual of Design and Recommended Practice should
    describe:

         a)  Proper siting of materials storage to eliminate pollution;

         b)  Adequate covering of storage sites to protect materials
             and preclude surface drainage;

         c)  Suggested design of storage facilities, particularly
             enclosed structures;

         d)  Adequate foundation and footings;

         e)  Desirable sequence and timing of materials delivery;

         f)  Best methods for handling and moving products to and
             from, and within the storage facility;

         g)  Suggested precautions in placing, mixing, treating
             and withdrawing materials to reduce product waste
             and damage;

         h)  Materials quality control methods;

         i)  Minimum supervision requirements for the various
             operational phases;

         j)  Suggested minimum codes for deicing materials storage
             to be adhered to by Federal, State, county, local and
             other authorities responsible for wintertime road
             maintenance.

3.  Increased recognition of environmental pollution problems caused by
    highway deicing be fostered at Federal, State, county, and local
    levels.  This recognition should include program development and
    funding so as to provide for greatly increased training, environ-
    mental impact awareness, and demonstration of optimum procedures
    and techniques necessary in wintertime highway deicing.  This con-
    certed effort in training and education should be primarily directed
    to highway department personnel at the working levels, and it is
    believed this program would be most appropriately and effectively
    carried forth by the State highway departments and their designees.
    Training support by the industry should improve such programs.

4.  Detailed investigations be conducted both in the laboratory and
    field on the various additives mixed with deicing materials to
    determine their potential hazards, and safe levels of use.  In
    view of the limited amount of data available on deicing additives
    and toxic nature of some additives, proper justification on the
    continuing use of these products is sought.  This should include
    comparative merits of substituting and/or developing other additives,
                                 - 6 -

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    or none at all.  These studies should additionally cover but not be
    restricted to:

         a)  Collection and analysis of data obtained from continuous
             monitoring of selected deiclng storage and application
             areas.

         b)  Basic research particularly on the cyanide and chromium
             additives, with regard to chemical reactions and pathways;
             environmental interferences; and direction, movement,
             persistence and degradation of additives through soil,
             vegetation and water.

         c)  Relationship of present water and air quality use criteria
             to those levels of additives expected to be found in water,
             air and soils.

         d)  Development of a comparative test for rating the toxicity
             level and potential hazards of various additives.

         e)  Determination if purposes intended by product use are
             being met.

5.  Consideration be given to initiating a program designed to obtain
    base-line data on long-term environmental changes that may be
    taking place due to the increasing use of deicing chemicals.  Such
    a program would denote need for preventive and corrective measures
    before severe and irreversible damage to our natural resources
    occurs.  Program implementation would require support from State,
    county and local water resource agencies, and various highway
    authorities, as well as the Federal government.  The program should
    provide continuous data for:

         a)  Levels of deicing chemicals present in surface waters,
             groundwaters including recharge areas, and in highway
             runoff;

         b)  Levels of deicing chemicals found in selected soils and
             vegetation;

         c)  Corrosion levels prevailing for selected vehicles, high-
             way bridges, pavements, buildings, etc., correlated with
             known uses of deicing chemicals;

         d)  Presence of deicing ions in other critical areas as future
             needs indicate.

6.  Federal, State and local highway authorities give appropriate con-
    sideration in highway design to road deicing and the control,
    collection and treatment of ensuing salt runoff.  Where intensive
    deicing operations warrant, initial plans may include rerouting
                                 — 7 —

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    new highways to minimize adverse effects upon roadside resources,
    and providing for accelerated runoff away from susceptible soils,
    grasses and trees.  Broader implementation of salt runoff control
    may involve extensive drainage, alteration of existing drainage
    patterns, diversion canals, underground pipelines, and various
    ponds and lakes.  Conveyance and storage units should be aestheti-
    cally blended into the roadside landscape.  Collected drainage
    utilizing flow regulation, may possibly be released safely down-
    stream.  Otherwise, terminal point storage or treatment of this
    drainage may be necessary.

    In control and treatment of highway runoff, it may be advantageous
    to separate the concentrated salt flows from dilute flows.  Recy-
    cling of salt flows and recovery of salts by evaporation or other
    means may be proved feasible.  Treatment of these flows would be
    enhanced by research, development and demonstration of alternative
    concepts and methods.

7.  Information be compiled and disseminated on best selection of road-
    side plantings, and remedial measures for restoring roadside
    vegetation damaged by deicing chemicals.  Plantings should be gener-
    ally chosen on the basis of maximum salt tolerance, but trade-offs
    are indicated with respect to shape and contour of the land,
    protection of other resources, existing plantings, local climate,
    State highway codes, availability of highway maintenance funds, etc.

    Damage of natural or implanted growth in roadside areas is fre-
    quently followed by accelerated erosion of side slopes, loss of
    aesthetics, and severe sedimentation of nearby streams.  Treatment
    of soils by gypsum and lime, and treatment of foliage by certain
    liquid sprays, are indicated as being practicable for restoring
    roadside vegetation where deicing chemicals have stunted natural
    growth, reduced soil fertility or created toxic conditions in
    vegetation.  Review of remedial methods presently available is
    considered highly appropriate.  New methods should be developed by
    additional research and demonstration.  In cases of severe damage,
    greater use of artificial materials and functional settings may
    be possible.

8.  Continued practices of removing and dumping the enormous quantities
    of snow from streets and highways into nearby water bodies or onto
    water supply watersheds be fully evaluated, particularly in terms
    of unit pollutant loads and various effects imposed upon these re-
    ceiving streams.  These snow and ice accumulations have been shown
    to contain high content of chlorides, oils and metallic lead due
    to road deicing, vehicular traffic and other urban wastes.  This
    problem has received scant attention, and only recently have these
    snow deposits been cited as a significant contributing source of
    roadway pollution.  There is immediate need for both monitoring and
    case study data in order to determine the extent and severity of this
    problem.  Such results should serve to define possible requirements
                                 - 8 -

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     in modifying current snow dumping practices and developing safer
     means of ultimate snow disposal.

 9.   The various suppliers and highway authorities make available full
     information on marine salts - their current and future expected
     use in highway deicing, chemical composition, physical properties
     including melting efficiencies, and comparison with the common
     chloride salts.  Marine salts may be different in composition and
     have even greater pollutional consequences compared to the mined
     sodium chloride salts.  Further evaluation of the environmental
     impact of marine salts should be made after background data are
     available.

10.   Results, findings and recommendations of past studies dealing with
     corrosion of automobiles and deterioration of highway structures
     and pavements potentially caused by road deicers, be made readily
     available to outside users.  Timely presentation of pertinent
     findings should be given in the widely-used technical journals.
     Considerable data is believed to exist on deicer-caused damage to
     structures and vehicles, which if made available, may suffice most
     needs in this area.  Continuing evaluation is nevertheless required.

11.   Highway authorities and the suppliers of deicing materials investi-
     gate and make available their full results and experience on the
     merits and demerits of various substitute materials that could be
     used in place of the common chloride salts.  A major objective is
     to identify those highway deicers having high efficiency and demon-
     strated minimum side effects.  Can current products be modified for
     greater deicing efficiency, less damage, or even beneficial impact?
     Would lesser known products compete successfully if they were produced
     in much larger quantities?  It is intended under this recommendation
     that similar data would be made available on those deicers presently
     used for ice control around airports and around the home.

     The various agencies, users and suppliers of highway deicers should
     thoroughly investigate previous methods that have shown potential
     promise, and likewise research and development of new concepts
     of snow and ice removal should be accelerated.  Increased use of
     abrasives may be indicated for various conditions supported by
     economic comparison studies.  Dark materials which could potentially
     absorb more solar energy when spread onto streets and highways, merit
     attention.  Greater use of rubberized snow plows, air jet snow throw-
     ers, and substitution of studded tires by polyurethane tire chains
     represent some of the ideas coming on scene today.  New concept
     development would seem to hold reasonably high promise as alterna-
     tive methods of the future.
                                 - 9 -

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                             SECTION III

             SNOW AND ICE REMOVAL-MATERIALS AND OPERATIONS
Deicing Materials-Bare Pavement Policy

Each winter across this country, highway snow removal and deicing opera-
tions begin anew.  Chemicals and deicing materials for highway mainten-
ance over the winter of 1966-1967 approximated 6.3 million tons of sodium
chloride, 0.25 million tons of calcium chloride, and 8.4 million tons
of abrasives.  Requirements for Canadian highways over this same period
were estimated as 1.1 million tons sodium chloride, 18,000 tons calcium
chloride and 3.4 million tons of abrasives(1).

Looking ahead we can expect a substantial increase in over-all use of
highway deicers.  For sodium chloride alone, deicing use in the United
States is estimated around 9 million tons for the past winter of 1970-
1971.  Projected annual use for 1975 is 11 to 12 million tons(2,3).
The twenty-one States in the eastern and north-central sectors of the
United States use more than 90 percent of all sodium chloride and calcium
chloride sold as highway deicers across the country.  The eastern States
also are heavy users of abrasives, consuming more than 70 percent of
the U.S. total, whereas the north-central States and western States,
respectively, utilize about 10 percent and 12 percent of this total.
Data are presented in Table I giving reported amounts of sodium chloride,
calcium chloride and abrasive materials deployed for highway deicing by
individual States and Regions during the winter of 1966-1967.

We may well ask why are the chloride salts preferred for highway deicing
and why are such enormous quantities necessary?  Winter highway mainten-
ance is a complex problem involving large amounts of resources, manpower
and materials at considerable cost.  In 1964, the Highway Research Board
reported that the cost of snow and ice removal in the 33 snow-belt
States was $151 million, or 8 percent of all highway maintenance costs
in that year for those States.  Recent costs are undoubtedly much higher.
Snow removal is a vital function for many towns and cities and may cost
the municipality from 25-50 percent of its entire street maintenance
budget(2).

Until the 1960's, highway maintenance departments principally relied on
the use of abrasives such as cinders, sand, washed stone and slag screen-
ings for snow and ice control.  Abrasives are intended to embed into the
snow and ice surface and to provide increased traction and skid preven-
tion.  Unfortunately abrasives compared to chemical deicers are less
efficient in melting snow and ice (aided by highway traffic); may easily
be blown off the road by wind and traffic conditions; require greater
application time; and are more costly both in their application and
cleanup.  At the end of the winter, large amounts of abrasives must be
retrieved from shoulder areas, catch basins, and conduits in order to
establish proper road drainage(4).
                                 - 11 -

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                                TABLE I

       REPORTED USE (TONS) OF SODIUM CHLORIDE, CALCIUM CHLORIDE
       AND ABRASIVES BY STATES AND REGIONS IN .THE UNITED  STATES,
                       WINTER OF 1966-1967^'
      STATE

  EASTERN STATES

Maine
New Hampshire
Vermont
Massachusetts
Connecticut
Rhode Island
New York
Pennsylvania
New Jersey
Delaware
Maryland
Virginia


  NORTH-CENTRAL STATES

Ohio
West Virginia
Kentucky
Indiana
Illinois
Michigan
Wisconsin
Minnesota
North Dakota


  SOUTHERN  STATES

Arkansas
Tennessee
North Carolina
Mississippi
Alabama
Georgia
South Carolina
Louisiana
Florida
  SODIUM
 CHLORIDE
   99,000
  118,000
   89,000
  190,000
  101,000
   47,000
  472,000
  592,000
   51,000
    7,000
  132,000
   77.000

1,975,000
2,146,000


    1,000

   17,000
CALCIUM
CHLORIDE
  1,000

  1,000
  6,000
  3,000
  1,000
  5,000
 45,000
  6,000
  1,000
  1,000
 22.000

 92,000
511,000
55,000
60,000
237,000
249,000
409,000
225,000
398,000
2,000
12,000
9,000
1,000
6,000
10,000
7,000
3,000
14,000
1,000
 63,000
  2,000
ABRASIVES
  324,000
   26,000
   89,000
  423,000
  335,000
   86,000
1,694,000
1,162,000
   70,000
    2,000
   40,000
  204.000
4,455,000
   43,000
  230,000

   77,000
   60,000
    6,000
  102,000
   84,000
   13.000
  615,000
   75,000
                                   18,000
                 2,000
                 75,000
                                 - 12 -

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                           TABLE  I  (Cont'd.)
      STATE

  WEST-CENTRAL STATES

Iowa
Missouri
Kansas
South Dakota
Nebraska
Colorado


  SOUTHWEST STATES

Oklahoma
New Mexico
Texas


  WESTERN STATES

Washington
Idaho
Montana
Oregon
Wyoming
California
Nevada
Utah
Arizona


District of Columbia
1966-1967 REPORTED TOTALS-'
                         c/
  SODIUM
 CHLORIDE
   54,000
   34,000
   25,000
    2,000
   10,000
    7,000

  132,000
    7,000
    7,000
    3.000

   17,000
    2,000
    1,000
    4,000
    1,000
    1,000
   11,000
    4,000
   28,000


   52,000

   36.000

4,376,000
CALCIUM
CHLORIDE
  2,000
  3,000
  2,000
  1,000
  8,000
165,000
ABRASIVES
   68,000

   31,000
   36,000
    6,000
  150.000
  291,000
                  2,000

                  1,000

                  3,000
                155,000
                 47,000
                 80,000
                200,000
                 43,000
                 94,000
                 50,000
                 56,000


                725,000
6,164,000
a/  Data taken from Salt Institute 1966-1967 Survey for U.S. and
    Canada(1).
b_/  Represents data by all governmental authorities reporting within
    each State.
c/  Overall values given in Table I represent about 75 percent of  true
    values (reported and unreported) of salts and abrasives used in
    1966-1967.  With confidential data and appropriate adjustments,
    the Salt Institute estimates that U.S. total consumption for the
    winter 1966-1967 was 6,320,000 tons sodium chloride, 247,000 tons
    calcium chloride, and 8,400,000 tons abrasives.
                                 - 13 -

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The demand that roads be safe and usable at all times, and that June
driving conditions be provided in January, has in recent years led  to
adoption of a "bare pavement" policy by practically all highway depart-
ments in the snow belt region.  This has required greatly increased
use of deicing salts, in many cases replacing the abrasives previously
used.  Chemical deicers directly attack and melt the ice and packed
snow surfaces.  As the salt dissolves and melts the upper ice, the
resulting brine solution penetrates through the ice and most importantly,
causes a break in the tight bonding of ice to the pavement.  Chemicals
also prevent the formation of new ice.

In 1947, less than one-half million tons of salts were deployed  through-
out the U.S. for highway deicing, and most of this was admixed with sand
and cinders to keep the abrasives from freezing and to facilitate
materials handling(2,5).  Today, the very large majority of sodium
chloride and calcium chloride is applied "straight" onto highways and
total amounts exceed 9 million tons annually.

Various chemical deicers are commercially available including rock  salt,
calcium chloride, and other chlorides, the common ammonium salts, various
alcohols, glycerol, and special composition products(6,7,8) .  Potentially
any material which readily mixes with water and lowers the freezing point
of water may be appropriate for melting ice and snow.  Some deicers produce
excess heat which serves as an advantage.  Availability, cost and effi-
ciency are considered main criteria in selecting a deicer, and because
of  these factors, sodium and calcium chloride are used almost exclusively
for  highway ice and snow control.  Of the chloride salts used, sodium
chloride represents about 95 percent and calcium chloride 5 percent.

It  is  the firm philosophy of highway authorities in the U.S. that bare
pavement conditions are essential to adequately guarantee the safety
and  lives of motorists using these roads and highways.  Highway
officials state that savings from the use of highway salts cannot be
adequately measured.  For example, it can never be known the number
of lives saved, the number of personal injuries avoided, and how much
automobile and property damage is averted by substituting bare pavement
for  ice and snow packed roads.  It is generally true that little
sympathy or understanding is shown by the average motorist caught
within an unexpected or untimely traffic jam or when a quick early
morning freeze causes solid ice on every road in the area.  If things
go wrong, public reaction is vehement and instantly directed to  the
duly-elected public officials, the city government, or to supervisors
and work personnel in the highway department.

Highway officials believe the general public is not adequately appraised
of improved safety and reduction in highway deaths.  Rather they  feel
the public and others unjustifiably stress corrosion damage to cars,
vegetation damage, and salts in ground and surface waters, as being
all  too important.  Infrequently, but sometimes, the well-intentioned
defenders of highway salting do show a tendency to overstate their
                                  -  14  -

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position.  We cite a few cases from the literature such as:  "We might
ask the question - Is a life worth a shrub", or, "I wonder how many
motorists would go along with a policy that would possibly spare a tree
and cost them their lives...", or, "All it  (salt) does is keep some
of the taxpayers around to see another winter"(2,4,5,6,7,9).  At this
point, let us turn to the specifics of snow removal operations and the
various ways in which deicing chemicals are used.
Abrasives

Although the use of abrasives has declined, some 6-9 million tons of
abrasives spread onto roads during 1966-1967 show that abrasives are
still quite important for wintertime highway maintenance.  Some States
such as Oregon, because of alleged damage caused by deicing chemicals
to automobiles and concrete roadways and structures, continue to depend
almost exclusively on abrasives.  Salts are used only in emergency
situations(4) and data in Table I show that Oregon in 1966-1967 used
only 1,000 tons of chemicals compared to 200,000 tons of abrasives.

Abrasives such as cinders and sand are treated with sodium chloride or
calcium chloride at the rate of 50 to 100 Ib. salt per cubic yard
material.  This treatment measure prevents freezing of the material
in storage, and enables better handling, loading and spreading of the
abrasives.  Salts may be added to the abrasives in dry form or as a
brine spray.  This treatment also serves to increase the embedding
potential of sand, cinders, etc.  Abrasives are mainly used to improve
traction in critical areas, especially on hills, curves, intersections,
bridges, etc.  It is reported where previously eight 4-ton truck loads
of abrasives were required to cover 4 miles of roadway, in contrast,
using salts, the same area can be covered with only one 4-ton truck
load of salt.  Today's safety standards are indicated as requiring
immediate attention to snow and ice control before serious hazard is
created.  Unfortunately abrasives attack the problem after ice and snow
have accumulated(4,5,9).

The Idaho Department of Highways in a recent report of April 1971(10),
indicates that they will continue to rely on a "complete" sanding program,
which is determined to be more feasible than complete salting.  "When
the public demand becomes more inclined toward the increased convenience
and safety of salting than toward the monetary outlay required, then the
complete salting policy or modification thereof may be more feasible."
The current sanding policy of the Idaho Department of Highways gives
Immediate priority for sanding hazardous locations such as sharp curves,
high grades, combination of grades and curves, bridge decks, interchanges
and intersections.  However, if availability of sand becomes critical,
and/or extreme hazardous conditions develop, the Department may then
consider straight salt.  This report(10) attempts to economically compare
the alternatives of complete salting and complete sanding vs. the present
sanding policy used by the Department.  In 1970, the Department expended
around $600,000 for wintertime sanding of State roads, and it is recognized
                                 - 15 -

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the annual cost of sanding is steadily increasing.  Experiences in Oregon,
Idaho and other western States show the need for realistically comparing
abrasives and deicing salts with respect to cost, effectiveness, and
environmental problems.  The Idaho results also suggest that use of sand
in place of salt particularly for less critical areas, should be given
greater consideration.
Chloride Salts and Properties

Sodium chloride and calcium chloride are generally used separately,  but
may be mixed together to satisfy certain road conditions.   Chlorides are
quite prevalent in nature comprising about 0.15 percent of  the  earth's
crust and 2 percent of seawater.  Chlorides are important in  the  human
body in maintaining critical body functions and physiological processes,
and are recognized as a vital ingredient for sustaining plant and animal
life.  Calcium and sodium likewise are considered essential elements
which respectively comprise 3.6 percent and 2.6 percent of  the  earth's
crust.  These chemicals are purchased as rock salt and calcium  chloride
in relatively unrefined states.  Rock salt is 94 to 97 percent  sodium
chloride, and the ASTM specification for purchasing calcium chloride for
highway use specifies a minimum of 94 percent calcium chloride(9).

Calcium chloride is appreciably more soluble than the sodium  salt in
water and due to its solubility, the calcium salt creates a lower
freezing point and will dissolve more ice than an equal amount  of sodium
chloride.  The calcium salt liberates heat going into solution, and
has deliquescent and hydroscopic properties.  The calcium salt  will
readily absorb moisture when the relative humidity is higher  than about
30 percent, which gives it certain advantages over rock salt  in highway
deicing.  Because it absorbs water, calcium chloride also finds use
in controlling dust from unpaved roads in the summer.  However, serious
difficulties are oftentimes encountered in storing calcium  chloride(4,5,9).

In ice control, sodium chloride is considered more effective  over longer
periods and cuts deeper, but the calcium salt reacts faster.  Conse-
quently, the two salts are frequently mixed in different ratios depending
upon given weather conditions so as to utilize the best characteristics
of both chemicals.  Calcium chloride becomes increasingly effective
the greater the temperature differential below freezing.  Many  recom-
mendations may be found in the literature on the best ratio of  calcium
to sodium mix.  An APWA Research Report describes a satisfactory  mixture
for storm conditions  (other than that controlled with straight  sodium
chloride), as being made up of 1 part calcium chloride and  2  parts rock
salt by volume.  For hard-packed snow and heavy ice, they indicate
sometimes a 1:1 mix is used.  Mention was also made of a 15 percent
calcium mix.  The Massachusetts Legislative Research Council  report(4)
describes a 1:3 mixture of calcium:sodium as being effective  near 30°F,
ranging to a 1:1 mixture found effective under very severe  icing  condi-
tions and very low temperatures.  The Council also indicates  that a
mixture of two parts chemical  (1:3 calcium to sodium by weight) to one
                                  - 16 -

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part abrasive would be almost as effective as  straight chemical  in melting
action and furthermore would provide good skid protection(4,6).

From the standpoint of equilibrium, it has been calculated that  600
pounds of sodium chloride applied per mile of  20  foot width road coated
with 0.2 inches ice  (or 2 inches of snow) would melt about 10 percent
of this ice cover.  This is sufficient to loosen  the surface bond and
maintain bare pavement conditions.  It should  be  specially noted that
except under very low temperatures  (below 10°F) and very light traffic,
the rate of ice or snow melting will primarily depend upon traffic
volume rather than the melting properties of the  deicing chemicals used.
Although 8,000 pounds of salt are theoretically required to completely
melt a one-eight inch covering of ice from one mile of two-lane  roadway
at 20 F, good highway practices would use only 300-500 pounds of salt,
which when combined with traffic load, would produce adequate snow and
ice removal(4).  Fast experience indicates that deicing chemicals are
effective and economical when the snowfall is  relatively light,  up to
depths of 2-3 inches.  For heavy snowfalls there  must be heavy reliance
upon plowing and other mechanical means of removal(4,6).
Marine Salt

The State of Massachusetts in the early 1960's, conducted field tests
comparing the efficiency of rock salt with marine  (solar) salt and found
encouraging results for the marine  salt.  This deicing agent obtained by
evaporating sea water, was reported approximately  equal to rock salt in
cost, and was successfully used by  several New England towns on their
local roads(4).  Marine salts are reported to have generally similar
characteristics to the commercial deicers but there may be notable dif-
ferences, particularly in smaller particle size of the marine salt
possibly creating a faster melting  action compared to straight sodium
chloride.  Although there is a lack of firm data in the literature, it
appears that substantial quantities of salts originating from sea water,
have been marketed in recent years  as highway deicers.  Marine salts
are probably being sold separately  or mixed together with commercial
rock salt amounting to hundreds of  thousands of tons annually.

The industry more or less uses the  term marine salt as "meaning a homoge-
nous crystal or occluded crystal containing all of the sea's ingredients"(11).
On the other hand, solar salt would seem to broadly encompass all salt
derived from the ocean whether recently evaporated salt, or the salt de-
posits laid down many millions of years ago, today being mined from the
land by conventional means.  Commercially manufactured marine salt is
reported to be normally produced by fractional crystallization.  Sodium
chloride, with a minimum of impurities, is selectively precipitated
within concentrating and crystallization ponds over aQrather narrow oper-
ating range of solution densities (i.e., 25.5  - 29.5  Baume)i/.  The

TJA term frequently used in the chemical industry to designate densities
of solutions.  Based upon an arbitrary scale of specific gravities de-
veloped by the French chemist Antoine Baume.  At 60/60 F, for materials
heavier than water, °Be=145-145/Sp. Gravity of material; for materials
lighter than water, °Be=140/Sp. Gravity of material-130.


                                 -  17 -

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large majority of calcium carbonate, calcium sulfate, magnesium sulfate
and other impurities precipitate outside this range.  The sodium chloride
salt is separately collected, and then washed and refined to yield a
reasonably high assay(11,12).

It is known that the composition of major constituents in sea water
approximate 30.5% sodium, 55.1% chlorides, 3.7% magnesium, 7.7% sul-
fates, 1.2% calcium, 1.1% potassium, 0.2% bromides and 0.4% bicarbonates
and carbonates(13,14,15).  Although commercial marine salts exclude im-
purities to a large extent, information on product composition is not
readily available.  Further data on marine salt is greatly desired as
to its composition; its comparative deicing efficiency; and significantly,
the potential consequences of sulfates, magnesium, potassium and other
available constituents possibly contributing to environmental pollution.
State Usage

The  States experiencing greatest use of deicing chemicals are  those
located  in the eastern and north-central regions of the U.S.   In  the
100,000-200,000  ton per year use category, we may include the  States of
Maine, New Hampshire, Vermont, Connecticut, and Maryland  (data in
Table 1  adjusted for sources not reporting).  In the 200,000-400,000 ton
category, we have the States of Massachusetts, Indiana, Illinois  and
Wisconsin.  The  leading States in highway salt consumption as  of  the
winter of 1966-1967 were Minnesota - about 570,000 tons, Michigan -
590,000  tons, New York - 680,000 tons, Ohio - 740,000 tons, and Pennsyl-
vania -  850,000  tons (see Table I).  It is noted the State of  New
Hampshire although relatively small in area, has used highway  salts
since the mid-40's, and over this period the cumulative use of highway
salts in that State alone has probably exceeded 2.3 million tons.
 Highway  Salt Applications

 The  common  sequence generally starting as soon as possible after  the
 snowfall arrives  is salting the highway, plowing, then resalting  as many
 times as necessary during the storm.  In Massachusetts, salting com-
 mences when snowfall is about one-inch, and the salt  is permitted to
 remain about 60 minutes before snowplowing.  In other areas,  snowplows
 will follow immediately behind salt application, which seems  less desir-
 able.  Environmental problems are minimized by deploying chemicals as
 sparingly as possible  to maintain safe traffic flows.  However, the
 literature  also emphasizes that the "bare pavement" policy requires
 frequent and liberal applications of deicing chemicals.  In some  cases,
 salts are applied as soon as or even before snow occurs, based upon
 weather  forecast  probability.  We tend to believe there have  been
 frequent instances where highway salts were used but  no snow  followed.

 Salt application  rates represent an important operational criteria.
 A 1966 APWA report(7)  indicates that highway authorities in the U.S.
                                  -  18  -

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tend to fall into one of two categories using either 0.04 Ib. salt/square
yard/application, or 0.25 Ib. salt/square yard/application.  In his review
of practices in Connecticut(16), Prior found that single applications
of 1,000 Ib. salt per mile on main highways are not uncommon; that rates
of 0.14 to 0.20 Ib. salt per square yard per inch of snow (equivalent to
1.4 tons per mile of two-lane road per inch of snow) are suggested for
effective snow removal; and also, that annual salt used on certain high-
ways in ConnecticutQmay exceed 20 tons per mile.  Hanes et. al.,(5)
notes at 20 F to 25 F or above, recommended rates are 500-800 Ib. sodium
chloride per mile of two-lane road and 800-1,100 Ib. per three-lane mile.
However, in certain cases, rates as low as 200 Ib. per mile give satis-
factory results.  When temperatures are below 20°F-25°F, rates are nearly
the same but mixtures of calcium chloride and sodium chloride are used.
Recommended ratios are in the range of 1:10 to 1:1 calcium to sodium salt.

Highway salt consumption in Maine is approximately 400 Ib. per lane mile
per application, equivalent to 25 tons salt per season used on a two-
lane highway(17).  Over the 1965-1966 winter, Massachusetts, the District
of Columbia, Pennsylvania and Illinois are known to have applied an
average of 20 to 37 tons of salt per lane mile.  Additionally, the 1970
summary by Hanes et. al.,(5) estimates that several States apply more
than 20 tons per lane mile over the season to a number of their highways.
In response to this latter study(5), 13 States cited definite damage
to trees and vegetation caused by highway salts, and 12 States reported
incidents of water contamination.  Schraufnagel from his experiences in
Wisconsin, further estimates during the winter of 1964-1965, the State
applied an average of 15.8 tons of salt per mile of roadway.  Nevertheless,
salt applications for certain counties in Wisconsin were much higher than
the State average.  For example, the data show that Milwaukee County over
the winters of 1961-1964 applied 66.8 to 92.1 tons per year of chloride
salts per mile of State highways in that county(9).  We believe that cer-
tain sections of major State highways and toll roads in the U.S. currently
receive in excess of 100 tons of salt per mile road during the winter
season.

Although the total use of calcium chloride for dust control and road
shoulder stabilization appears to be only around 20,000-30,000 tons
per year in the U.S.(5), applications are relatively heavy at times
and some damage has resulted from these practices.  Schraufnagel(9)
reports that dust control involves applications of calcium chloride
around 1-2 Ib. per square yard equivalent to 6 to 12 tons per mile for
a 20 foot wide roadway.  Road bed stabilization requires in the order
of 6 to 12 tons per mile per inch of compacted depth.  Therefore, a
6 inch compacted depth for a 20 foot wide road would use 36 to 72 tons
calcium chloride per mile.
Costs of Highway Salts

Purchase costs for the straight chloride salts will depend upon many
factors but chemical costs will fluctuate less than those required in
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applying the salts onto roads and highways.  Schraufnagel(lS), based
upon Wisconsin experiences, reports in 1967 that rock salt was about
$10 per ton delivered in bulk, and calcium chloride about $47 per ton
delivered in bag lots.  He also notes that costs of both salts were
lower at that time compared to 1960.  A 1964 Massachusetts study(4)
reports that calcium chloride was purchased in bags at $40 per ton,
and the average cost for sodium chloride  (presumed to be bulk) was
around $13.50 per ton.  Sodium chloride is preferably shipped in the
summer months and protected in storage by use of laminated paper,
canvas tarpaulins or polyethylene sheets.

A price of $1.20 per ton was quoted for sand in Massachusetts, to which
must be added hauling and spreading costs, $6-10 per ton for  spring
cleanup of sand, and $3 for each of the 25,000 catch basins in the State
requiring subsequent cleaning.  Current costs for sodium chloride in
Massachusetts approximate $12 per ton for purchasing rock salt, and
another $6-8 for hauling and spreading, giving a total cost around
$18-20 per ton salt applied(19).  In Maine, these same functions may
require higher costs ranging from $12-15 per ton for purchasing sodium
chloride and $8-10 per ton for its application(17).  Costs for mixing
calcium chloride with rock salt for a 1:1 or 1:2 (calcium to  sodium
salt) blend are quoted around $1.25 for each ton of calcium chloride
used(6).

Since practically all deicing salt sold today is treated with anti-caking
additives(20), it would seem the above costs include these anti-caking
agents.  Deicing salts containing added corrosion inhibitors  such as the
chromate or phosphate salts are reported 30-40 percent greater in cost
compared to plain rock salt(21).
 Operations,  Equipment and Methods

 The  large majority of deicing salts and abrasives are currently applied
 to road  surfaces by various mechanical means.  Tail-gate spreaders  and
 hopper-type  spreaders are commonly used for highway salting.   Standard
 dump trucks  with discharge pipes; front-end loaders; angle loaders;
 public service  trucks, jeeps, etc., equipped with ready-mounted plows;
 portable and non-portable melters, and other devices may comprise the
 snow and ice control equipment available at any one time.  New York City
 having an extensive array of snow-fighting equipment available has
 recently received ninety-five "electronically-controlled" 10-wheel  salt
 spreaders to complement its snow cleanup operations.  This spreader is
 capable  of distributing 14 cubic yards or 15 tons of salt before re-
 loading (22, 23).  Various types of snow-fighting and deicing equipment
 found in current use are illustrated by Figures 1 to 18.—'

 Chemicals are often spread in about an 8-foot concentrated width down
 the  center of the pavement or driving lane.  The disc spinner  spreads
 a/   Mention  of  trade names or commercial products does not constitute
 endorsement  or  recommendation for use by the Environmental Protection
 Agency.
                                  -  20 -

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         FIGURE  1
 Diesel  powered  truck with
wing plow and straight blade
          FIGURE 2
        Snow blower
     Courtesy of city of
      Chicago, Illinois
              21

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                  FIGURE 3
       Diesel powered dump  truck with
     salt spreader insert and snow plow
                 FIGURE 4
Left to right:  dump truck with salt spreader
 insert and plow, truck with interchangeable
   plow, front-end loader, and snow blower
             Courtesy  of  city  of
              Chicago,  Illinois

                   22

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                  FIGURE 5
   Twin-disc salt spreader with tail-gate
screens (placed inside truck body) to prevent
    salt lumps from reaching feeder ports
             Courtesy of city of
            Milwaukee, Wisconsin
                  FIGURE 6
                Salt spreader
             Courtesy of city of
               New York, N.Y.

                     23

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f
                 FIGURE 7
              Salt soreader
                 FIGURE 8
    13-Ton salt spreaders with V-plows
            Courtesy of city of
              New York, N.Y.

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              FIGURE 9
New design salt spreader with screen
grid over top to preclude salt lumps
              FIGURE 10
 Salt spreader being loaded at salt
 storage depot by front-end  loader
         Courtesy of city of
           New York, N.Y.

                  25

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               FIGURE 11
Department trucks plowing city streets
               FIGURE 12
   Front-end loader removing cleared
      snow into receiving trucks
          Courtesy of city of
            New York, N.Y.

                   26

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                 FIGURE  13
  Front-end  loader clearing city streets
                 FIGURE 1<*
Front-end loaders keeping city streets open
            Courtesy of city of
              New York, N.Y.

                     27

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               FIGURE 15
        Heavy-duty snow blower
               FIGURE 16
Snow blower removing street accumulated
      snow into receiving trucks
          Courtesy of city of
            New York, N.Y.

                   28

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             FIGURE 17
    Front-end loader depositing
       snow into snow-melter
            FIGURE 18
Dumping snow into nearby waterway
       Courtesy of city of
         New York, N.Y.

               29

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the salt over a much wider width of pavement compared to "dribbling"
techniques.  For many spreaders, the rate of salt application will depend
upon the gate opening, spreader engine speed, and truck speed.  Many
spreaders appear to have an application range from 0 to about 2,000 Ib.
salt per mile with incremental settings of 200 Ib.  This equipment is
frequently known to have good precision but to be lacking in reasonable
accuracy.  Furthermore, much of the available equipment is not metered.
Volumetric devices for controlling the rate of spread include gravity
and belt conveyances, or a screw drive utilized for delivery of material
through an orifice.  The positive displacement ability of a helical
screw or grooved cylinder turning at a fixed speed is also used for
metering.  Within a typical town or community, the most economical
approach usually involves purchase of equipment to handle the average
winter storm expected and to contract for equipment and services beyond
the average demand.  Contract services frequently include plowing and
hauling(5,6,7).

The proper application and spreading efficiency of highway salts have
generated some studies but nonetheless this area has not received
deserved attention.  The Highway Research Board in a 1967 report(24)
indicates there are several challenges presented by previous research
findings.  One important task is to improve present maintenance prac-
tices including the over-application of highway salts where conditions
do not warrant; poor regulation of spreading equipment which distributes
salt material beyond the pavement break; and too many improperly-located
and inadequately-protected stockpiles of chloride salts.  Greene(25)
cites the viewpoint of the Bureau of Public Roads that improper calibra-
tion of salt spreaders is extremely common.  Improper calibration and
operation of equipment leads to excessive salt application rates, which
not only increase over-all costs but also contribute to damage of
vegetation and water supplies, and increased deterioration of concrete
pavement and structures.

In Ontario, it is claimed $1 million per year is saved in better appli-
cation of highway salts(25), and in the State of Maine over recent years
salt use is reported to have been reduced some 30,000 tons annually due
to improved practices(17).  Greene estimates operational savings of
several million dollars per year are possible Nationwide without reduc-
ing the quality of wintertime road maintenance(25).

Partly due to  improper snow control practices but also because environ-
mental side effects are not given careful consideration, snow mixed
with brine is  piled alongside highways representing heavy localized
salt concentrations.  During salt spreading, a portion of the salt is
scattered off  the side of the road.  In plowing, the snow may be easily
pushed 15 feet or more from the edge of the pavement.  This snow has
been found to  contain up to one-percent salt, i.e., 10,000 mg/1.  After
the ridges disappear, salt accumulations and burned-out vegetation are
often observed as white strips parallel to the roadway.  There is con-
siderable wasting of salt due to misdirected or excessive spreading(5
17,19,24).
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 Significant  improvements  in wintertime road maintenance  practices  would
 be derived from better  field  testing and  control,  good equipment with
 good maintenance  schedules, greater use of mechanized equipment, fre-
 quent calibration,  increased  reliance and improvement of salt  metering
 instrumentation,  education and  awareness  through the ranks  particularly
 at the working level, concerted effort and increased training  most
 appropriately carried forth at  the State  highway department level, and
 due consideration given to proper environmental protection.

 Besides chemical  melting, various methods of  thermal melting are avail-
 able which may become more prominent in the future.  External  and
 in-slab thermal melting systems have greatest application in areas
 where any accumulation  of ice and snow is considered extremely hazardous.
 Such areas include  expressway ramps, bridge decks, busy  intersections,
 toll plazas, etc.   External systems are either gas or electric operated
 and utilize  infrared energy for melting.  In-slab  systems may  comprise
 embedded, electrically-heated cable, pipes carrying heated  liquid  or
 steam, or electrically-heated reinforced  wire mesh.  In-slab systems,
 although protected, are subjected to stress and strain caused  by slab
 movement and invite high maintenance and  repair costs because  the  system
 is buried within  the slab.  External systems  are easier  to  maintain but
 are more vulnerable to  damage caused by vehicles, vandalism, and similar
 conditions(6,7).  Electric grids were installed in a test section  of a
 street in Washington, D.C., but the system was reported  too high in cost
 and power demand  to enable widespread use(26).

 In contrast  to thermal  melting  systems which  prevent the formation of
 ice and snow, "snow melters"  are available used in clearing streets as
 an alternative to the ever-rising costs of snow hauling  and dumping.
 These machines which come in  various sizes up to 85 tons per hour  gen-
 erally consist of a heat source, melting  chamber, and discharge system.
 Mobile melters are deployed on  urban streets  with discharge into storm
 drains, whereas stationary or pit melters are centrally  located or
 situated in heavy-use areas such as airports, large parking lots,  etc.(6),
 An 80 ton/hour melter can handle 6 inches of  snow on 200,000 square feet
 of pavement  in about 3.5 hours.  Description  was given(7) of a 75
 ton/hour melter in Boston positioned at a street intersection  and  fed
 by two 3-cubic yard front end loaders.  Lockwood et. al.(7)  comment
 that unless  streets are so narrow as to impede movement  of  trucks,
 there is little savings in removal time provided sufficient trucks are
 on hand to otherwise equal the  capacity of the snow melter.

 Purchase of a snow melter is  generally based  upon  savings in cost  of
 hauling and dumping snow.  As of 1965, there  were  some 50 mobile and
 stationary snow melters available in the  U.S. and  Canada(6).   Special
 conditions may justify  the use  of snow melters or  installation of
 thermal melting systems described above.  However, even  today  both
methods are generally considered quite expensive compared to spreading
 of deicing salts on city streets followed by  normal snow removal opera-
 tions .
                                 -  31 -

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Other Deicers

There is consistent opinion in the literature that possible alternatives
to sodium chloride and calcium chloride, which are reliable and economi-
cal, will not come into large-scale use in the foreseeable future.
Substitute deicing compounds which meet special conditions or which are
otherwise suggested for possible use include urea, urea combined with
calcium formate, the various chlorides such as magnesium, potassium,
aluminum and lithium chloride, ammonium acetate, methyl and ethyl alcohol,
isopropyl alcohol, ethylene glycol, glycerol, aldol, mixed amides, and
chemical dyes.  From available data, it appears that the above chemicals
are considerably higher in unit cost compared to rock salt.  Experience,
operational data, and knowledge of environmental effects are lacking for
the substitute deicers.  However, certain of these compounds are suspect
in terms of toxicity, increased corrosion of metals and concrete, eutro-
phication potential, and hazards in handling(4,5,6,7,18).

Urea, mixtures of urea and ammonium-sodium nitrate and phosphate salts,
and mixed amides appear to be most frequently deployed for airport
runway deicing.  Urea is less corrosive than sodium chloride but
must be used in quantities about twice that for rock salt, and is about
6 times higher in unit product cost.  The aviation industry is mainly
concerned about stress corrosion in aircraft metals, consequences to the
air frame and structural failure.  Cost of chemicals and effects upon
concrete pavement and ground structures are of secondary importance.
Ethylene glycol has in the past been used by airports and is also im-
portant for deicing car windshields.  Calcium chloride and the ammonium-
potassium nitrate and phosphate salts are sold for home use in clearing
sidewalks and driveways of ice and snow(4,5,6,8,18).
Salt Storage

Cities, towns, counties and other highway authorities receive large
quantities of deicing salts shipped by truck, barge and rail car.
These shipments generally arrive throughout the summer and  fall months.
The governmental authority should logically plan and select appropriate
sites for storing these materials for wintertime use.  Salt suppliers
recommend that these products be received and stockpiled over the
summer, usually no later than September.  As more cities, counties, and
States are changing to "straight salt" programs, timely deliveries are
becoming more difficult.  For deliveries late in the year, many towns
and cities may pay more for shipments that require greater  time to
receive.  Replacements in January, February and March may be extremely
scarce or almost impossible to locate, particularly during  severe winters
when many authorities are seeking additional stock(20,27).  Typical salt
storage areas in New York City, Chicago and Milwaukee are shown in
Figures 19 to 23.  Figure 24 illustrates a covered salt stockpile in
Toledo, Ohio.  From the standpoint of water pollution control, fully
covered stockpiles as illustrated in Figures 23 and 24 are highly pre-
ferred over open storage.
                                 -  32 -

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Bulk salt represents the most economical material obtainable and  bulk
salt storage generally provides maximum availability and convenience
at least overall cost.  The large majority of highway salts have  been
previously stored outdoors with or without covering, and placed directly
on the ground or upon bituminous or concrete pads.  In recent years
however, more highway authorities have turned to protected or roofed
enclosures and others have provided suitable covering for open stock-
piles.  Enclosed structures are recommended in order to:  1) abate
contamination of nearby streams, wells, and groundwater by excess salt
runoff; 2) improve aesthetics in the local area; 3) prevent formation
of lumps and reduce frozen crust in the salt piles; 4) eliminate  heavy,
caked salt in the pile thereby facilitating easier handling by mechanical
equipment; and 5) enable better control over stored materials and more
efficient loading and unloading(20,27).

Deicing salts may be stored in unused buildings, garages, covered sheds,
elevated storage bins, domed structures, cribs, and upon elevated plat-
forms, or pallets.  Stockpiles outdoors are preferably placed on  storage
pads and should definitely be covered with heavy tarpaulin, canvas or
other protective materials.  Salt storage sites should permit easy access
by trucks, front-end loaders and similar equipment, and be situated so
that trucks and salt spreaders do not have to "dead-head" long distances
before reloading.  The Salt Institute recommends that all storage pads,
cribs and similar structures be located at sites completely free of
groundwater.  They suggest that bituminous pads be placed upon crushed
aggregate and salt-stabilized subgrades.  Fads should be crowned  to
enable drainage away from the pile on all four sides.  Additionally,
drainage ditches, pipes or tiles may be necessary around salt storage
areas to prevent contamination of local ground and surface water
supplies.  In certain instances, impoundment basins may be essential
to capture and retain this salt drainage(20,27).

Examples of the types of salt storage facilities most frequently used
in the United States are illustrated in Figures 25 to 37.  It is noted
that construction costs as given for these storage facilities were
prepared around 1965, and are undoubtedly somewhat below current  esti-
mates.  The more expensive structures are often reported to be the least
expensive to use depending on local climate, amounts of stored materials,
type of equipment available and services.  For bulk salt storage, the
following figures are useful:

                  Stored salt ** 80 Ib. per cubic foot
                  One cubic yard salt = 2,160 Ib.
                  One ton salt = 25 cubic foot
                  One ton salt » 0.926 cubic yards

With the natural angle of repose of rock salt of 32 , 1,000 tons  of salt
stored in a conical pile covers a ground area circumscribing a circle
67.1 feet in diameter or 3,540 square feet.  The height of the pile is
21 feet and the exposed surface area of the pile (for purposes of cover-
ing) is about 4,180 square feet(27).
                                 - 33 -

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In a Salt Institute publication of 1967(20), it is reported the State
of Ohio has used various wooden structures providing shelter for up  to
100,000 tons bulk salt.  Floors are constructed of asphaltic concrete
and the capacities of individual structures range from 200 to 1,000  tons
salt.  The State of Iowa indicates they have built some 160 pole-wood
structures giving protection to stored salt.  Three sizes are used:
a 20x30 foot building with 100 tons capacity; a shelter 20 by 40 feet
with 150 tons capacity; and a structure 28 by 56 feet holding 300  tons
of salt.  The buildings are supported with treated timbers 6x8 inches
lined on the inside with 2x12 inch lumber, and have galvanized steel
roofs and sliding doors.

Fitzpatrick(28) of the Ontario Department of Highways has described  a
dome-like structure or "beehive" now being used to store large quantities
of sand-salt mixtures in the Province.  The beehive is rather unique in
storing up to 5,000 cubic yards of sand-salt under one roof with a clear
span free of posts, poles or pillars.  Trucks, front-end loaders and
other equipment can easily move about the structure for loading and  un-
loading.  The beehive during and after assembly is shown in Figures  38
to 43.  A 24-inch thick concrete foundation is used into which is
inserted a series of posts inside the vertical walls for purposes  of
adding a sand retaining ring so as to keep the stored material away
from the base of the structure.  The beehive approximates a cone
100 feet in diameter by 50 feet high, and consists of a 20-sided shell
constructed of 2x6 inch lumber overlaid by three-eighth inch plywood and
asphalt shingles.  Each of the 20 sides is in the form of an isosceles
triangle made up of 9 panels diminishing in width to the top of the
structure.  The 20 sides are bolted together and the top is added  to
complete the beehive.  The Department of Highways indicates they can
load the building with sand up to 80 percent of full capacity, and with
improved handling procedures they will eventually fill the entire  dome.
The structure requires about 900 man-hours for completion once the pad
has been laid.  Costs are reported around $3.50 per square foot of floor
area equal to $5.00-$6.50 per ton of sand-salt mixture stored(28).
                                 - 34 -

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                                                 I
                   FIGURE 19
Open salt storage pile, downtown Chicago,  111.


              Courtesy of city of
               Chicago, Illinois
                   FIGURE 20
    Open salt storage pile,  Milwaukee,  Wis.
        estimated quantity 41,000 tons
              Courtesy of city of
             Milwaukee, Wisconsin

                      35

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                 FIGURE 21
City stockpile of rock salt remaining after
winter's use, mid-February, Milwaukee, Wis.

            Courtesy of c ity of
            Milwaukee,  Wisconsin
                 FIGURE 22
       Typical salt storage pile in
          downtown New York City
            Courtesy of city of
              New York, N.Y.

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               FIGURE 23
   Moving  salt by front-end loader
   inside enclosed storage structure
          Courtesy of city of
            New York, N.Y.
               FIGURE 2U
Covered salt stockpile located adjacent
  to the Maumee River in Toledo, Ohio
            Courtesy of the
            Salt Institute,
            Alexandria, Va.

                     37

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                         FIGURE  25

    Approx. Construction Cost $3 to $5 per ton of capacity
    Rock salt  can easily be stored outdoors.   This shows a rec-
     tangular-conical pile of  bulk salt covered by a tarpaulin
      held down by stakes.  The  platform is approximately 30'
      square and is composed of  3" planks held up by V by V
      wood sills.  It will hold  approximately a 40-ton minimum
                      carload of bulk salt.
                        FIGURE 26

    Approx. Construction Cost $3 to $5 per ton of capacity
   Rock salt  may also be stacked against a garage or shed wall.
    Here a portable conveyor stacks it.  The  pile is covered by
    a tarpaulin and anchored at the lower end by large rocks.
                       FIGURE  27

Approx. Construction Cost $3 to $5 per ton of capacity
 Open bin storage like this  is favored by many Ohio communities,
   and the dimensions shown  here are given to scale.  The roof
   has « very  large overhang in order to protect the open salt
   from the weather.  Trucks are backed up to the bins and the
   salt is partly dumped and partly shoveled in.  It is removed
   by shoveling  into trucks, or portable conveyors may be used.
                  Courtesy  of  the
                  Salt  Institute,
                  Alexandria,  Va.

                                38

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          FIGURE  28
              FIGURE  29
             Approx. Construction Cost
            $50 to $75  per ton of capacity
      Approx. Construction Cost
    $50 to $75 per ton of capacity
 Standard steel bins like those used by
 contractors for cement, sand and gravel
   provide excellent rock salt storage
 space.  Dump trucks feed salt into the
 portable conveyor, which carries it up
             to the bin.
 The  same type  of bin as  that shown in
Figure 28, except that a  vertical chain
     and bucket elevator  is used.
          FIGURE  30
                                                                                  FIGURE  31
              Approx. Construction Cost
            $50 to $75 per ton of capacity
        Approx. Construction Cost
      $50 to $75 per ton of capacity
   In hilly communities the bin may be
placed close to a hillside to facilitate
              loading.
       This variation on the bin in Figure 30
          follows the contour of the hill.
                                       Courtesy of  the
                                       Salt  Institute,
                                       Alexandria,  Va.
                                                    39

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                        FIGURE  32

  Approx. Construction Cost $15 to $20 per ton of capacity
 Many communities use this method of storing  bags of rock salt
 outdoors.  The sketch shows 50 tons of bags  placed on a plat-
   form about 30' wide with the bags many layers deep.  The
 planks are 3" and supported by V by 4" sills.  The bags are
 covered by  a tarpaulin held down by rocks. Note the  method
of piling bags on the outside  of the pile. Trucks  are apt to
  bump into the pile while backing up for loading, and it is
important that the stacking be in such a way  that the bags, stay
            firmly in place or else fall inward.
                        FIGURE 33

  Approx. Construction Cost $10 to $30 per ton of capacity
     Bulk salt stored under a shed.  The salt  is loaded in by a
    portable conveyor,  which is also used for  getting it out and
                  onto trucks for distribution.
                        FIGURE 34
    Approx. Construction Cost $20 to $30 per ton of capacity
  This piling arrangement, similar to that in Figure 32, features
  a platform about  3' off the ground  in order to facilitate load-
   ing onto trucks.  Under these conditions, the storage is not
  over 40 tons of salt as a rule.  The tarpaulin is held in place
                by tying underneath  to the posts.
                    Courtesy  of  the
                    Salt  Institute,
                    Alexandria,  Va.

                                 ho

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                                                                       FIGURE  35
                                                                   Salt  Storage  Crib

                                                  Here  is a crib  with walls built of  2 x 6  tongue and
                                                  grooved creosote treated material. Posts  are railroad
                                                  ties set three feet apart on center. Note the 2x4 cleat
                                                  nailed to crib wall  posts as tie-down  for  tarpaulin  or
                                                  other covering.
                 FIGURE 36
          Salt Storage Shelter


Umbrella structure  protects material from weather.
Panel on both sides keeps salt from collecting  around
posts.
                                                                         Courtesy of  the
                                                                         Salt  Institute,
                                                                         Alexandria,  Va.
                                                             FIGURE  37
                                                    Salt  Storage Building
                                           Tie corner  posts of storage buildings together with
                                           underground galvanized cables with turnbuckles.

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                                                         FIGURE  38
                                                      The "Beehive" -
                                                   Concrete  base forms
                                                   removed;  note posts
                                                    for  retaining ring
                                                      roughly placed
      FIGURE 39
   The "Beehive" -
Third ring of panels
being placed;  placing
     of panels by
  electrical truck
                                                         FIGURE 40
                                                      The "Beehive"
                                                        Fourth ring
                                                         completed
                   Courtesy of J. R. Fitzpatrick,
                 Dept. of Highways, Ontario,  Canad;
                                 U2

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                                                         FIGURE 41
                                                      The "Beehive"  -
                                                    Building with all
                                                  panels in place;  note
                                                    air vents at top
     FIGURE 42
  The "Beehive" -
Method of loading;
  first stage by
  truck and  dozer
                                                        FIGURE 43
                                                      The "Beehive" -
                                                    Method of loading;
                                                      second  stage  by
                                                         conveyor
                 Courtesy of J. R. Fitzpatrick,
               Dept. of Highways, Ontario, Canada

                                43

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                              SECTION IV

                      RAINFALL AND OTHER SOURCES
The amount of impurities and the mineral quality of rainwater, particu-
larly chloride content, has been of continued interest to scientists,
agronomists, chemists, and others.  Special stormwater studies conducted
by the Taft Sanitary Engineering Center in Cincinnati, Ohio provided
analysis of rain samples of August 1963 through November 1964(29).
Average data for rainfall at this location shows the following:  pH - 4.8;
total suspended solids - 13.0 mg/1; chemical oxygen demand - 16.0 mg/1;
total nitrogen (N) - 1.3 mg/1; inorganic nitrogen  (N) - 0.7 mg/1; hydro-
lyzable phosphates (PO^) - 0.24 mg/1; and organic chlorine (mostly re-
flecting chlorinated hydrocarbons) - 0.28 mg/1.

Junge et. al.,(30) studied rainfalls in many areas of the United States
and concluded that the oceans are a major source of chlorides in rain-
water.  They found that calcium content of rainfall is the highest for
storms over the Southwest principally derived from dust storms(29,30).
Fanning and Lyles(5,31) believe that salt content of rainwater decreases
in proportion to the logarithmic distance inland.  The rainfall at
Cirencester, England, was found to contain an average chloride content
of 3.2 mg/1 over a 26-year period equivalent to an annual deposit of
36 pounds NaCl per acre(32).  At Mount Vernon, Iowa, the average level
of chloride in rainwater was 10.6 mg/1 from October 1913 to June 1914,
and 7.1 mg/1 from October 1914 to June 1915(5,33,34).  The following
table prepared by Klein(35) compares rainwater with surface waters,
groundwaters, sewage, and seawater in terms of average chloride content.
                               TABLE II

                 CHLORIDE CONTENT OF VARIOUS WATERS5-'

                                                    \
        Type of Water                          Chlorides  (mg/1)

     Rainwater                                         2
     Upland Surface Water                             12
     Unpolluted River Water                          <15
     Spring Water                                     25
     Deep Well Water                                  50
     Drinking Water                           10-20  (but variable)
     Weak Sewage                                      70
     Medium Sewage                                   100
     Strong Sewage                            Up to  500
     Urine                                         4,500-5,000
     Sea Water                                    20,000

     a/  From Klein, 1959(35)
                                 - 45 -

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Besides chlorides being universally present in rainfall, other sources
of chlorides include the leaching of salt from underlying rocks and soils
which is more common in the western and mid-west U.S.; salt contribution
by domestic, commercial and industrial wastewaters; salinity present in
irrigation return flows particularly in the western States; air pollution
fallout from industrial stacks, automotive emissions, open dumps, etc.  It
is much beyond the scope of this report to describe and document each and
every source of chlorides.  The information given herein focuses on road
deicing salts, although some data are given for rainfall and municipal
sewage.  Unless indicated otherwise, extreme care has been taken with all
data presented in this report to describe the various effects and conse-
quences of highway salts on the environment, and to exclude all other
influences.
                                 - 46 -

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                               SECTION V

                                SEWAGE
Domestic and municipal sewages contain high chloride content relative  to
surface and groundwaters, but quite low compared to sea water  (see Table
II).  Chlorides are generally considered a persistent or non-degradable
type of pollutant.  The chloride content of sewage is essentially un-
changed as it passes through conventional sewage treatment plant processes.
Furthermore, the chlorides in treated waste effluents are not  significantly
changed after discharge into receiving surface waters nor are  the chlorides
biologically assimilated to any large degree.  These chloride  sources
directly add to the total chlorides already existing in surface streams(5,
9,35).

Human wastes, particularly urine, contain appreciable amounts  of chlo-
rides.  Sawyer indicates the excreta represents an average of  about
6 grams chlorides per person daily, and adds approximately 15  mg/1
chlorides to the composite sewage flow(9,36).  Domestic sewage has a
chloride level around 50 mg/l(9,37).  O'Conner and Mueller(38) cite
values of 5-9 grams chlorides per person daily, equivalent to  4-7 pounds
per capita per year.  To allow for kitchen wastes and the effluents from
commercial and small manufacturing establishments, a value of  20 pounds
chlorides per capita per year is often used.  This is equivalent to
40-80 mg/1 chlorides added to sewage, depending upon the per capita
water consumption.  In Madison, Wisconsin where the water supply has a
hardness of about 300 mg/1, Schraufnagel(9) indicates household water
softening could easily raise the chloride content in domestic  sewage by
100 mg/1.

The chloride level in the effluent from the Nine-Springs sewage treat-
ment plant in Madison, Wisconsin was 287 mg/1 in April 1965(9).  At
Green Bay, Wisconsin, operational data collected by the Metropolitan
Sewerage District showed average chlorides of 255 mg/1 in the  treatment
plant sewage over the 12 months of 1964.  In contrast, the municipal
water supply of Green Bay has a chloride content of only 7 mg/1.  It is
noted that monthly chloride values in Green Bay sewage were 285-312 mg/1
from January through April representing the period of street deicing,
compared to 196-283 mg/1 over the remaining months of 1964(9).

An excellent record has been maintained on chloride content of incoming
sewage and effluents taken every 8-hours at the Jones Island East and
West treatment plants of the Milwaukee Sewerage Commission over the
period of at least the last five years.  The question has been raised
whether increasing chlorides, particularly in the wintertime,  have any
possible effect on Milwaukee treatment plant efficiencies.  This ques-
tion cannot be adequately answered.  Nevertheless the summary  of
monthly chloride values from 1965-1969 given in Table III shows a
well-defined annual pattern.  There was little difference in chloride
content between treatment plant influent and effluent(39).
                                 - 47 -

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It is readily observed that chloride content in Milwaukee sewage was
highest in the winter months of January, February and March coinciding
with the period of street salting and snowmelt.  The next highest
chloride values were recorded for the months of December and April.
Milwaukee has an extensive combined sewer system serving approximately
15,000 acres, of which about one-half is in the downtown area.  Street
runoff and snow melt are collected into these combined sewers and
received at the Jones Island treatment plants.  Higher concentrations
of chlorides in municipal sewage during the winter is believed  to  be a
typical pattern in many cities due to highway salting and the lower
sewage flows experienced at this time of the year.
                               TABLE III

         MONTHLY CHLORIDES AT MILWAUKEE SEWAGE TREATMENT PLANT
                          (mg/1), 1965-1969*/
          Month            Average 1965-1969          Range

         January                   203               175-245. ,
         February                  200               190-23(£'
         March                     196               170-230
         April                     172               160-185
         May                       154               140-160
         June                      137               120-155
         July                      126               105-145
         August                    125               110-135
         September                 127               115-140
         October                   131               120-150
         November                  140               125-160
         December                  169               150-190
         a/  From Milwaukee, Wisconsin Sewerage Commission, May 1970(39).
         b_/  Excludes one February value.


Milwaukee personnel indicated to the best of their knowledge, there are
no unusual or extraneous contributions to the sewerage system in the
wintertime that would not also exist in the summertime(39).  Thereupon,
total daily chloride loads were calculated for both winter and summer
months.  Each monthly chloride value was an average of approximately
240 separate samples.  It is shown that average daily chloride loads in
the wintertime are 140-170 tons, compared to 90-110 tons per day in the
summertime.  For separate years of record, chloride loads were 40-50
percent higher in winter compared to summer.

The Milwaukee data also show surprisingly high chloride sewage concen-
trations for individual days, e.g., 570-600 mg/1 for January 16-18, 1969,
                                 - 48 -

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and 500 mg/1 for February 26, 1969.  These chloride  loads  were around
330 tons per day or three-fold the normal summertime loads.   Additional
results collected by the Milwaukee Sewerage Commission on  January 16,
1969 for chloride levels in  the Milwaukee River and  other  major water-
ways in the Metropolitan area are given  in Table  IV.   The  large majority
of chlorides found in the Kinnickinnic,  Menomonee and Milwaukee Rivers
on January 16 is believed directly attributable to deicing salts placed
on the streets and highways  in the Milwaukee area.   The  Commission
reports(39) that over the last two years, annual  salt application by
the city of Milwaukee has been around 36,000 tons, and another 90,000
tons of salt have been applied by Milwaukee County.   Direct  street run-
off from salted streets in Milwaukee during mid-January  1969  likely
contained chlorides in the range of 2,000 to 5,000 mg/1.
                               TABLE IV

        SPECIAL RIVER SAMPLING, MILWAUKEE SEWERAGE COMMISSION,
                          January 16, 19691'
                                      Water
     Location                    Temperature  ( C)       Chlorides  (mg/1)

Kinnickinnic River at                  10.0                   2,005
  Chase Avenue

Menomonee River at 13th St.            10.5                     200
  and Muskego

Menomonee River at 70th and             5.0                   2,730
  Honey Creek Pkwy.

Milwaukee River at Silver               4.0                   2,680
  Spring Road

Milwaukee River at Port                 6.5                   1,510
  Washington Road


a/  Records received from the Milwaukee Sewerage Commission, May 1970(39),
                                 - 49 -

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                               SECTION VI

                    RUNOFF  FROM STREETS AND HIGHWAYS
 Wisconsin  Studies

 Schraufnagel  reports(9)  during 1956-1957  that  sampling stations were
 established throughout Wisconsin  to  study the  runoff  from salt-treated
 highways.  In the  Chippewa  Falls  area,  wintertime  highway runoff was
 found  to contain up  to 10,250  mg/1 chlorides,  but  the receiving stream
 did not exceed 46  mg/1 chlorides.  Street runoff during the summer
 contained  only 0-16 mg/1 chlorides and  the receiving  stream had
 0.5-2.0 mg/1  chlorides.   In Madison,  Wisconsin, wintertime street run-
 off had chloride levels  ranging up to 3,275 mg/1.   It is interesting
 to note for street runoff in Madison, suspended solids were as  high as
 3,850  mg/1, reflecting considerable  sand  and dirt  flushed off the streets
 during the winter.  This drainage generally had BOD levels in the range
 of 20-30 mg/1,  although  3 of the  12  samples contained around 100 mg/1
 BOD.   For  another  case in Wisconsin  of  drainage originating from a large
 snow pile  along Lake Monona, this runoff  showed a  chloride level of
 1,130  mg/l(9).
 Syracuse, New York

 The fate of deicing salts  following  their application  onto  streets  and
 highways is not precisely  defined.   It  is known  that these  salts within
 the hydrologic system may  be  stored  in  the  soils,  groundwater, and  vege-
 tation comprising the roadside environment.   Hawkins(40) believes that
 deicing chemicals may also be stored in the  street itself,  including:
 the snow and ice cover; on the street surface; and directly within  the
 street masonry concrete, cobbles and other  street  construction materials.
 Hawkins observed summer "leakage" of salt upward onto  the surface of
 street concrete and cobbles for several hills and  grades in Syracuse,
 New York, previously receiving heavy amounts of  deicers.  A white-colored
 cast on the road surfaces  and interstices persisted well into the early
 fall, and the presence of  salt was easily confirmed by the  "fingertip"-
 taste test.  The resupply  of  salt from  lower depths in the  street layer
 or below the street was strongly suggested by the  reappearance of salts
 after spring and summer rains.  These salts  find their way  into street
 and storm sewers throughout most of  the year(40).
Chicago, Illinois

During the winter of 1966-1967, the American Public Works Association
studied the chloride content in runoff from Kennedy Expressway  in
downtown Chicago, Illinois.  The highway drainage area consisted of
102 acres of which about half, or 52 acres were paved.  Runoff  samples
were collected from February 16 to April 1, 1967, during which  time
                                 - 51 -

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there was 14 inches of snowfall and 126 tons of salt applied to the test
area.  At all times except during the most severe temperatures, runoff
flows were in excess of 0.1 cfs(41,42).  When highway salts were not be-
ing applied, the chloride content of drainage varied from 1,900 to
4,500 mg/1, and runoff was as high as 0.3 cfs.  During snowfalls, the
chloride in highway runoff ranged from 11,000 to 25,000 mg/1, and the
flows varied from 0.1 to 1.5 cfs.  This study further indicates that
nearly all the deicing salts subsequently left the area in the form of
runoff.

The APWA study in Chicago also calculated that a chloride level of
1,300 mg/1 could be expected in the runoff, assuming 1.5 tons of salt
are applied per mile of two-lane highway for each inch of snowfall(41).
In comparison to these figures, the 1970 Highway Research Board litera-
ture review(5) determined that 600 Ibs. of salt ger mile if applied to
a 20 foot wide road with 0.2 inches of ice at 25 F will produce an
initial salt solution of about 69,000 mg/1; at 10 F, the resulting salt
solution will be around 200,000 mg/1.  These saturated solutions will
of course become more dilute as melting of the snow and ice continues.
Considering these values, it is not surprising to see various references
citing several thousand parts per million salt being carried in highway
runoff.  The salt content of highway drainage will depend upon many factors
including ambient temperature, amounts of precipitation, quantity of salt
applied, traffic patterns, and volume and rate of surface flow.

Sullivan(41) recognizes that wintertime highway runoff will eventually
run into freshwater streams and natural or man-made lakes or ponding
areas.  He cautions that unless there is adequate dilution, the salt
concentration in street runoff may in the future have adverse effects
upon fish life or vegetation.  The suggestion is made that "monitoring
of such storm areas should be carried on at various depths to detect
significant changes in concentration".  Secondly it is advised..."if a
chloride balance is to be maintained in a river to limit chloride to an
acceptable level for potable water supplies, (then) the runoff from
urban areas must be accounted for and allowances made in the discharge
rates  (permitted) from industrial plants at the time of any low winter
flows."
Des Moines, Iowa

Henningson, Durham and Richardson, Inc. recently completed a detailed
study for the FWQA on combined sewer overflows and stormwater runoff
in the city of Des Moines, Iowa(43).  Part of the program was directed
to characterization of wintertime runoff, and chloride data were
collected from a number of combined sewers and storm drains over the
period of December 1968 through March 1969.  The drainage areas are
largely residential and there are no large concentrations of commercial
and business establishments where exceptionally heavy street salting
may be expected.  The Des Moines area experienced a relatively severe
winter in 1968-1969 and quantities of road deicing materials used from
                                 - 52 -

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December 1968 through March 1969 approximated 9,270 tons untreated rock
salt, 295 tons of calcium chloride and 225 tons of rock salt treated
with a rust inhibitor.  Total deicers used were 9800 tons, with a
chloride equivalent of 5830 tons.

The Thompson Avenue storm drain serves an area of 315 acres classified
mainly as residential.  Results for this storm drain showed that approx-
imately 15,000 pounds of chlorides were carried off in the runoff from
January 15 to March 2, 1969, which approximates 48 pounds per acre.
The study indicates:  1) although appreciable snow and sleet, and heavy
salt applications occurred prior to January 15; 2) little snowmelt had
taken place before mid-January but nevertheless; 3) much of the salt
applied before January 15 was no longer on the streets.  Four discrete
snowmelt periods provided the following data for the Thompson Avenue
drainage area:
   January 15-16, 1969
   February 4, 1969
   February 5, 1969
   February 25, 1969
   0.236 inches runoff
   0.049 inches runoff
   0.038 inches runoff
   0.149 inches runoff
               3.75 Ibs. Cl~/Acre
              11.80 Ibs. Cl~/Acre
               3.52 Ibs. Cl~/Acre
               1.63 Ibs. Cl~/Acre
                                       Total =    20.7  Ibs. Cl~/Acre
Sequential sampling illustrates that chloride levels are highest at the
beginning of runoff and concentrations decrease rapidly thereafter.
Individual results for the Thompson Avenue storm drain ranged from a
low of 9 mg/1 chlorides on January 17, 1969 to a maximum of 2,320 mg/1
on February 21, 1969.  Typical data for individual samples collected on
February 4-5, 1969 are given below(43).
   February 4, 1969
   February 4, 1969
   February 4, 1969
   February 4, 1969

   February 5, 1969
   February 5, 1969
   February 5, 1969
   February 5, 1969
 2:15 PM
 3:15 PM
 4:15 PM
 5:15 PM

12:15 PM
 1:15 PM
 3:15 PM
 4:15 PM
Flow - 3.9 cfs
Flow - 3.7 cfs
Flow - 2.5 cfs
Flow - 1.1 cfs

Flow - 0.2 cfs
Flow - 1.5 cfs
Flow - 3.1 cfs
Flow - 2.5 cfs
1477 mg/1 Cr
1228 mg/1 cr
1045 mg/1 el'
 920 mg/1 cr

 743 mg/1 cr
 260 mg/1 el'
 579 mg/1 cr
 502 mg/1 cr
Salt levels in the runoff collected from the Cummins Parkway storm drain,
serving a predominately new residential area of 356 acres, demonstrated
patterns similar to the Thompson Avenue storm drain(43).  Periods of
snowmelt produced high chloride concentrations and the range of indi-
vidual results varied from 18 mg/1 on January 16, 1969 to a maximum of
2,720 mg/1 on February 21, 1969.  Measured flows in the Cummins Parkway
drain varied from 0.0 to 47.9 cfs compared to 0.0 to 9.9 cfs for the
Thompson Avenue storm drain.  In the combined sewer systems, a maximum
chloride concentration of 866 mg/1 was found in the South Side Trunk
sewer on February 4, 1969.
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Henningson, Durham and Richardson also collected wintertime samples from
the Des Moines River and Raccoon River above and below the city of Des
Moines starting January 1969.  The report(43) concludes that chloride
levels in the river waters were significantly higher in the winter months
than in the summer.  In January and February, chlorides were around
30-50 mg/1 for the locations upstream of Des Moines, and the highest
result was 56 mg/1.  Downstream of Des Moines, the chlorides commonly
exceeded 56 mg/1 and the maximum level was 86 mg/1.  During the spring
and summer months, the chlorides throughout the area were below 20 mg/1,
but as stream flow diminished in the autumn, the chlorides increased to
between 20-30 mg/1.
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                              SECTION VII

                        SURFACE STREAMS, RIVERS
Various Rivers in the State of Maine

Hutchinson(44,45,46,47,48) analyzed seven major rivers in Maine for
sodium and chloride levels over the period 1965-1967.  These ions were
generally 1-2 mg/1 at the headwaters and increased to as high as
15-18 mg/1 at the mouths of the respective rivers.  Highest levels of
sodium and chloride were shown in the southern section of the State
where highway miles were greatest, but other factors also were present.
Based upon these data, Hutchinson concluded at least at that time, no
adverse effects of highway salting upon river water quality could be
shown.

Hutchinson sampled the Kenduskeag Stream in the Bangor, Maine area both
upstream and downstream of the city, together with two storm drains and
a brook entering into Kenduskeag Stream.  Also included in this study
was a culvert carrying surface drainage from one mile of Interstate
Highway 95.  The survey was conducted for 60 consecutive days from
March 1 to April 29, 1966.  The upstream waters of Kenduskeag Stream
contained sodium and chloride levels of 3.9 mg/1 and 6.5 mg/1, respec-
tively.  Downstream of the storm drains and the brook, the Kenduskeag
Stream through the center of the city showed average sodium and chloride
levels of 5.3 and 10.0 mg/1, respectively.  The two storm drains
contained runoff with average sodium content of 26.8-28.8 mg/1 and
average chlorides of 73.9-84.6 mg/1.  The highway culvert exhibited the
highest level of sodium and chloride with mean values of 168 mg/1 and
570 mg/1, respectively.  Hutchinson concludes since there was little
industrial pollution in the area, it appears safe to consider that "road
salt contamination" was significant in these waters.  Although it was
apparent that sodium and chloride levels in the Kenduskeag Stream are
definitely affected by surface drainage from the city of Bangor, the
salt concentrations downstream remain low because of considerable dilu-
tion in the stream(44,45,46).
Meadow Brook, Syracuse, New York

The surface waters of Meadow Brook watershed in southeastern Syracuse,
New York, have been studied by Hawkins(40) from October 1969 through
the present.  Meadow Brook drains about four square miles of suburban
Syracuse, described as approximately two-thirds developed land, which
receives heavy annual snowfall as well as moderate residential traffic.
From past results, Hawkins found a large variation in mineral content
of the Brook, particularly chloride concentrations.  From late-November
to mid-March, chlorides were usually in the range of 200-1,000 mg/1,
but frequently exceeded a few thousand mg/1.  For example, a sample in
December 1969 showed about 11,000 mg/1 chlorides.  Over the remaining
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months of the year, chlorides were relatively low and in the range of
30-150 mg/1.  Hawkins more or less concludes that:  1) salt runoff from
the watershed is discharged in several high concentration  surges during
the winter and melt season; 2) salt concentration in the stream is a
function of available snow and salt and the prevailing temperatures;
3) chlorides diminish through the spring and summer but still remain
suspiciously high, suggesting some retention in the watershed and the
contribution of this salt to summertime base flows; and 4) a close
correlation indeed exists between road salting and stream  chlorides(40).
Major Rivers in the United States

Effects of highway salts upon major rivers in the U.S. appear  small
compared to other sources.  Chloride content of major rivers are  rela-
tively low compared to wintertime road runoff and ditch drainage.
Unfortunately, adequate data does not exist on sodium and chloride
levels for most rivers of the northeast and north-central U.S.  Heavy
snowmelt will also coincide with the start of rising streams during
late winter and early spring, making it difficult to distinguish  road
salts.  Nevertheless from the limited data available on streams,  increas-
ing chloride trends are evident for some of the large rivers in the  U.S.
Highest salt loads are generally present in these streams from the end
of February to the end of May(5).

Hanes et. al., in their 1970 report for the Highway Research Board(5),
utilized chloride curves for major rivers in the U.S. based upon  Public
Health Service water quality monitoring data over the Water Years of
1958-1963.  The amounts of chlorides in terms of mg/1 and tons/day were
plotted for the Delaware River near Philadelphia; the Hudson River below
Poughkeepsie, N.Y.; the Mississippi River at East St. Louis, 111.; the
Missouri River at Kansas City, Kansas; the Ohio River at Cairo, Illinois;
and the Potomac River at Great Falls, Md.  Chloride concentrations in
these curves did not vary greatly throughout the year, and in  all but one
case were below 35 mg/1.  Only the Hudson River and the Ohio River showed
increase in chloride levels during the February-May period.  However, the
report concludes the chloride levels are clearly increasing from  year to
year in the Hudson River and the Delaware, and even though present levels
are low,..."this increase could be a potential danger"(5).  It is recog-
nized that other factors such as sea water intrusion and cyclic patterns
may be present in this 1958-1963 data.
 Sleepers  River  Basin, Vermont;  Hydrologic  Salt  Balance

 Kunkle(49)  provided annual  salt budgets  for  the Sleepers  River basin in
 northeastern  Vermont  from 1968-1970.  A  2.5  mile section  of U.S.  High-
 way  2  traverses one of  the  watersheds in this basin,  which receives heavy
 traffic and large  amounts of  deicing salt  in the wintertime.   The various
 watersheds  not  influenced by  the highway showed streamflow chloride levels
 of only 2-5 mg/1.  However, sampling stations downstream  of the highway
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were typically an order of magnitude higher.  Due  to high runoff  per  unit
area in the watersheds, excessive salt concentrations  in the watercourse
proximate to the highway were appreciably diluted  a few miles downstream.
Chloride levels were highest in the summertime baseflow of  the highway
watershed.  Some of the deicing salt apparently entered into the  soils
near the road and later appeared in the summer flows.  Individual seeps
sampled close to the highway showed chlorides in excess of  200 mg/1.

The Vermont study showed that stream salt concentrations were lowest  in
the springtime due to considerable dilution.  Nevertheless, during spring
thaws, much of the salt from the highway was being flushed  from the high-
way to the stream, and salt delivery rates  (in tons/day) were highest at
this time of the year.  On the other hand,  the control stations demon-
strated little seasonal fluctuation in salt delivery rates.  Sodium chlo-
ride yields for the control watersheds averaged about  7 tons/square mile/year,
Subsequent calculations for the highway watershed  yielded about 83 tons/year
of sodium chloride in excess of background  amounts.  From highway department
records, observations and other field data, Kunkle estimated that 65  to
100 tons salt were applied annually to the  highway section  in the watershed.
It therefore appears the large majority of  highway deicers  eventually en-
tered into the surface streams(49).

The older reports in the literature indicate that  about one-half  of deicing
salts applied onto highways are usually discharged with the runoff, and
about one-half is retained within the area.  However,  the Vermont study
given above, the results previously cited by the American Public  Works
Association for the Kennedy Expressway in Chicago  (see Section VI), and
likewise the assumptions made by 0'Conner and Mueller  in estimating road
salt inputs to the Great Lakes (see Section VIII), strongly imply that
the large majority of these salts over a sufficient period of time, may
find their way into downstream surface waters.  Additional  studies provid-
ing material balances over defined intervals of time and of sufficient
duration, would be extremely useful in assessing the fate and behavior
of deicing salts previously applied to roads and highways.  Such  studies
could also lead to a proper understanding and application of methods
whereby salt sensitive areas could be protected, and promising salt re-
covery/reuse techniques utilized.
Chloride Levels in Milwaukee Streams

High concentrations of chlorides in various river waters  in  the Milwaukee
area during mid-January 1969 were previously given  in  Section V of  this
report.
Oxygen Demand of Deicers

Schraufnagel, in discussing substitute deicing compounds,  describes  the
glycols and alcohols in particular, as having extremely high  biochemical
oxygen demand (BOD), ranging from 70 to 133 percent of the product
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weight(18).  In contrast, urea has a 5-day BOD:weight ratio of only  9
percent and sewage only 0.02 percent.  Schraufnagel makes the point  that
certain deicers, such as ethylene glycol, if released into a nearby
stream can exert tremendous demand on existing dissolved oxygen.   It is
indicated that one pound of deicing compound with a BODrweight ratio of
1.0, if discharged into a waterway having 7 mg/1 dissolved oxygen, will
utilize all the oxygen available in about 140,000 pounds (17,000 gallons)
of streamflow(18).
Dumping of Snow Into Nearby Streams and Water
Bodies; Chloride, Oil and Lead Content

Following the plowing, sanding and/or salting of streets and highways,
significant accumulations of snow, slush or ice are often collected into
receiving trucks and transferred to outlying areas for final disposal.
Frequently these large volumes of snow are deposited or dumped into the
nearby stream, into a bay or river (see Figure 18), or onto the banks of
a water supply reservoir.  Most cities indicate they have discontinued
such disposal practices.  Nevertheless, they continue to deposit this
snow onto areas lying within the flood plains or higher lands leading
directly into a waterway.  Realistically, the latter means of disposal
is no more acceptable than direct dumping into the stream.

Data is generally lacking on the chemical makeup of snowfall after becom-
ing impregnated with deicing salts; oils, greases and dirt from vehicular
traffic; and other urban wastes.  Data given previously in this report
show maximum chloride levels of up to 10,000 mg/1 in a typical snowbank
along the highway.  Studies in Stockholm, Sweden(50),indicate during their
normal winters, about 1,100,000 cubic yards (30 x 10  cubic feet) of snow
from city streets are dumped.  Unmelted snow from selected street loca-
tions in Stockholm were found to contain 2-105 mg/1 oils and 1-100 mg/1
metallic lead.  Median values were respectively, 21 and 18 mg/1.  The
oil and lead in snowfall were reported to be related in this study to
vehicular traffic, particularly the unburned gasoline and the components
of tetraethyl lead condensates spread onto the cold snow surfaces.  Addi-
tional samples of untouched snowfall from one of the Stockholm parks
interestingly enough showed as much as one mg/1 oil as well as traces
of lead.

The high lead content found in snowfall in Sweden is supported by recent
information from Columbus, Ohio(51).  Snow collected from streets in
Columbus, Ohio, contained "about 15 times more lead than the safe limit
set for drinking water by the Public Health Service."  Samples taken at
locations distant from city roads showed lower concentrations suggesting
that motor vehicle exhaust is a major factor contributing to this lead.
The best means of removal and ultimate disposal of excess snow, slush
and ice from urban centers, deserves careful attention and considerable
research in the future.
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                              SECTION VIII

                            FARM PONDS,  LAKES
 Farm Ponds-State  of  Maine
 Twenty-seven  farm ponds  located along various highways in Maine, were
 sampled  by  Hutchinson in April, July and August,  1966-1968.   The April
 samples  were  significantly higher in both sodium and chloride content
 compared to the  summer collections.   Sodium levels ranged from 1 to
 121 mg/1 with an average of 33 mg/1.   The chloride range was 1-490 mg/1,
 and average levels were  110 mg/1 for April and 80 mg/1 for August.  Nor-
 mal chloride  levels  for  farm ponds in this geographic area are 5-10 mg/1.
 It was concluded that road salts have significant seasonal influence on
 chloride content of  farm ponds, and  that repeated yearly salting is stead-
 ily increasing the salt  levels in some of these ponds(5,41,45,52).
The Great Lakes, Lake  Erie

Long-term studies of Lake Erie have  shown that  average  chloride  content
has increased  three-fold in  the  last 50  years,  from 7 mg/1  in 1910 to
about 23 mg/1  in 1964.  Although it  is reported that present  uses  are not
adversely affected, a  continued  rate of  chloride buildup  could cause  ser-
ious impairment of water uses in the future.  Highway salts are  estimated
to contribute  11 percent of  the  total annual  input  of chlorides  into  Lake
Erie waters(5,53).  Road salts entering  Lake  Erie on an annual basis  were
estimated by O'Conner  and Mueller(38) to be 750,000 tons  in 1960.   Similar
estimates of road salt inputs for Lake Superior,  Michigan,  Huron and
Ontario were respectively 91,000 tons; 438,000  tons; 198,000  tons, and
525,000 tons(38).
Wisconsin

The State of Wisconsin and other public authorities have maintained  a
long-term monitoring program on the quality of various  lake waters in
the Madison, Wisconsin area.  One of the smaller lakes  in  the  area is
Lake Wingra, which is spring-fed, but which also receives  runoff  from
nearby streets and urban lands.  Through 1940-1947, average chlorides
in Lake Wingra were 4-5 mg/1.  In March 1959, the chloride content of
the lake had increased to 18 mg/1, but in July of the same year the
chlorides had stabilized to between 9-11 mg/1 measured  from top to
bottom in the lake.  Concern was expressed when subsequent sampling  of
lake waters in the summer of 1965 showed chloride concentrations  of
41-43 mg/1.  Although existing water uses apparently are not affected
by current water quality, chlorides have increased four-fold since 1959
and eight-fold since the 1940-1947 period (9).
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Also in Wisconsin, samples taken in the winter of 1959 from Beaver  Dam
Lake at Cumberland, Wisconsin, showed a density stratification of
chlorides with lake depth.  The chloride concentration was 8 mg/1 near
the lake surface, and 33 mg/1 at the 15-foot depth near the lake bottom.
Schraufnagel suggests this chemical stratification is due to highway
runoff entering Beaver Dam Lake(9).
First Sister Lake, Ann Arbor, Michigan;
Salt-Induced Stratification

Judd in 1965-1968 studied the impact of highway salt runoff on First
Sister Lake, a small body of water surrounded by a residential subdivi-
sion, an interstate highway and other well-travelled roads in the Ann
Arbor, Michigan area(54).  Storm runoff from adjacent streets and roads
enters First Sister Lake mostly through storm sewers.  The lake  is
approximately 450 feet by 650 feet with a maximum depth of about 25
feet, and the lake has a single outlet used only for about 1-2 weeks
in the spring.

Judd found the salt flows moving through First Sister Lake have  the
tendency to sink to lower depths causing density stratification  of the
waters.  With normal snowfall and road salting, the levels of salt in
the lake create sufficient stratification to preclude complete wind
mixing of the lake in the spring.  Chloride concentrations at the
23-foot depth were around 150 mg/1 compared to 60-85 mg/1 in the sur-
face waters.  Through the summer, some of the salts eventually find
their way into the bottom muds, and lake stability.!/ is lowered  to
enable complete mixing of the waters in the fall months.  If salts had
not been absorbed into the bottom muds, it is speculated there would
be no lake overturn not only in the spring but also in the fall. This
stratification is associated with extended periods of low dissolved
oxygen in the deeper waters, and detrimental changes in animal and
plant life in the lake.  Even assuming previous fall overturn, Judd
indicates through 1967, the deeper zones of the lake were likely with-
out oxygen for some ten months, and the entire lake below the 10-foot
depth was virtually devoid of dissolved oxygen for about eight months(54),
Irondequoit Bay, Rochester, New York;
Salt-Induced Stratification

Recent studies by Dlment and Bubeck in 1969-1970 for  the  Irondequoit  Bay
drainage basin near Rochester, New York, show that  salt runoff  has
markedly affected the water quality within the Bay(57).   The  basin  has
a relatively dense population with total population around  210,000  persons.
Irondequoit Bay  is fed by  Irondequoit Creek and empties into  Lake Ontario
via one narrow channel.  The water body is approximately  3.7  miles  long
by 1 mile wide,  with average and maximum depths of  24 feet  and  75 feet,

T7"Stability"  of a lake  is defined by Schmidt(55,56), as  the  amount of
work required to mix the total body of water to uniform temperature with-
out adding or subtracting  heat.
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respectively.  During the winter of 1969-1970, highway salts were applied
to basin streets at the rate of 85,000 tons.  These deicers are reported
as the single major source of salt into the Bay.

Diment and Bubeck describe Irondequoit Bay as a striking example of  salt
accumulation.  Approximately two-thirds of the yearly salt input enters
the Bay from December through March.  For 1970, the average chlorides  in
the surface waters of the Bay were about 160 mg/1, compared to an average
of 320 mg/1 chlorides contained in the incoming wintertime flows, 1969-1970.
Except during fall overturn, chlorides in the bottom waters of the Bay
were 220 to 400 mg/1.  From January to November 1970, intense physical and
chemical stratification prevailed, and the bottom waters showed no more
than 1 mg/1 dissolved oxygen.  Overall results showed of the 85,000  tons
of deicing salts introduced in the basin, some 35,000 tons left in the
lake outflows.  Therefore, more than one-half of these salts were re-
tained in the soils and groundwaters of the basin or in the Bay muds(57).

Diment and Bubeck conclude that winter influx of salt into Irondequoit
Bay causes significant differential in vertical density, which is suffi-
cient to prevent the Bay waters from completely mixing in the spring.
During 1939-1940, the only previous period for which comparable data were
available, the Bay exhibited normal tendencies of a typical deep lake  in
a temperate continental climate with stratification and complete mixing
both in the spring and fall.  Apparently the lack of spring mixing is
not unusual for very small, deep lakes, but is rare for a lake as large
and shallow as Irondequoit Bay.  The above changes are not viewed with
serious alarm by the investigators, but nevertheless, salt runoff has
convincingly modified the characteristics of the Bay.  Similar conditions
could occur elsewhere.  The rising chloride levels also imply the need
for careful monitoring of water quality conditions in the Irondequoit  Bay
drainage basin, and that serious consideration be given to the local
distribution and storage of deicing salts in the groundwaters(57).
Possible Salt Stimulation of Algal Growths

A new development in salt pollution concerns the potential role of sodium
serving as a trace element toward stimulating excessive growth of blue-
green algae.  Recent data indicate in addition to nitrogen and phosphorous,
adequate amounts of sodium and potassium may also need to be present  for
the growth of blue-green algae.  Certain blue-green species may require
one of these monovalent elements, whereas other species may require both.
One reference states that sodium concentrations greater than 40 mg/1  may
be necessary for triggering undue growth of blue-greens.  Another refer-
ence infers that 5 mg/1 of sodium provides for optimum growth of Anabaena
cylindrica, which is common in nuisance algal blooms.  Further investi-
gation is essential on the suspected relationship between eutrophication
and sodium buildup from deicing salts(58,59).
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                              SECTION IX

                               WILDLIFE
Over the winter of 1958-1959, a number of wildlife mortalities in
Wisconsin were attributed to salt poisoning caused by highway deicing
chemicals(9).  Within a 40-mile radius of Madison, Wisconsin, cases of
salt poisoning were diagnosed in wild rabbits, pheasants, a quail and
a pigeon.  Although the gizzard contents of the dead quail were stained
blue with ferric ferrocyanide, which is a common additive in highway
salts, the additive was not implicated as the cause of death.  As part
of their follow-up studies, the State of Wisconsin experimentally induced
single doses of 3 grams sodium chloride into test animals including
adult pheasants and rabbits weighing 1100 to 1400 grams each (454 grams =
one pound).  This dosage generally produced death in the animals within
24 hours, and mortality was highest when water intake was restricted.
Heavy snows and cold weather in the winter of 1958-1959 likely contributed
to this problem by reducing food and drinking water available to the
animals, and in turn creating "salt hunger" conditions.  It should be
noted that the literature source for the above study does not provide
ample description on the particular test procedures used(9).  Hanes et.
al.,(5) also express some reservations concerning these results.  Animal
husbandry practices in the midwest and western U.S. often provide wild
animals such as deer with free access to "salt licks" in the wintertime.
Apparently this question has not been fully resolved.

Hanes et. al.,(5) consider ungulate animals being attracted onto highways
in their search for salt, to constitute a much greater hazard not only
to the animals, but to motorists alike.  In the State of Wisconsin,
approximately 120,000 deer are killed annually, the large majority by
hunters.  However, State personnel estimate that nearly 12,000 deer or
10 percent of the total, are killed along Wisconsin highways by motor-
ists (60).  The frequency of this type of accident appears much higher
in the wintertime when large amounts of deicing salts are left remaining
on the highway.
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                               SECTION X

                           DEICING ADDITIVES
Special substances may be added  to sodium chloride and calcium chloride
to reduce corrosion, or for reasons of better efficiency in handling  and
applying deicing salts.  Materials such as Prussian blue, sodium  ferro-
cyanide (yellow prussiate of soda), chromates, phosphates, etc.,  are
listed in the literature as available for use.  The manufacturer  recom-
mends these agents be added in the amounts of 0.5 to 2 pounds or  more,
per ton of deicing salt(5).
Ferric and Sodium Ferrocyanide, Anti-Caking Agents

The two most common additives to highway salts are ferric ferrocyanide
(Prussian blue) and sodium ferrocyanide, both used as anti-caking
agents.  Ferric ferrocyanide is relatively insoluble in water, and accord-
ing to various reports will not release cyanide upon acidification.
Laboratory tests by the Wisconsin State Laboratory found that blunt-nose
minnows do not appear adversely affected when placed into a 9600 mg/1
concentration of Prussian blue for 48 hours(9).

Sodium ferrocyanide, unlike Prussian blue, is soluble in water and will
liberate cyanide in the presence of sunlight.  The cyanide ions are far
more lethal to fish and aquatic life than the sodium ferrocyanide.  The
cyanide ion will react with hydrogen in water to form hydrogen cyanide.
The dissociation of hydrogen cyanide is pH-dependent.  At pH 7 or below,
only one percent of the hydrogen cyanide will exist as the cyanide ion,
whereas at pH 9, the cyanide ion will comprise 42 percent of the total(5).
Studies on sodium ferrocyanide show toxic levels for Daphnia magna at less
than 600 mg/1(61), and 540 mg/1(62).  A toxic threshold of 170 mg/1 sodium
ferrocyanide has been found for Polycelis nigra(63).  Subsequent tests
conducted by the Wisconsin State Laboratory determined that a 15.5 mg/1
solution of sodium ferrocyanide, if exposed to sunlight for 30 minutes,
would produce 3.8 mg/1 of cyanide.  With increased exposure time, this
level of cyanide remains fairly constant.  Since a similar solution of
sodium ferrocyanide in the dark produces relatively little cyanide in
solution, this reaction is considered light-sensitive, i.e., photochemi-
cally-induced(5,9).

Comparable test results may be obtained using potassium rather than
sodium ferrocyanide since chemical reactions of the two chemicals in
water are reported to be nearly alike(5,9).  Schraufnagel(9), in his
report, makes note of the work of Burdick and Lipschuetz in 1948(64)
on the toxicity of potassium ferrocyanide and potassium ferricyanide.
It was originally thought these two compounds were relatively innocuous
to fishlife.   However, Burdick and Lipschuetz found that sunlight
rapidly decomposed the potassium derivatives to produce cyanide ions
toxic to fishlife.  With very low light intensity or dark conditions,
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4,000 mg/1 potassium ferrocyanide was required to generate 0.3 to 0.6 mg/1
cyanide which killed 100 percent of the test fish in 48 hours.  In con-
trast, with direct sunlight, 0.36 to 0.48 mg/1 cyanide was generated by
only 2 mg/1 of either potassium ferrocyanide or potassium ferricyanide
in solution, sufficient to kill various fish within 60 to 90 minutes(5,64).
The potassium compounds as far as known, are not used as salt additives,
but should serve to predict similar effects of the sodium ferrocyanide
in receiving waters.

Schraufnagel(9,65) comments that cyanides are toxic to fishlife at con-
centrations of 0.1 to 0.3 mg/1.  The U.S. Public Health Service Drinking
Water Standards of 1962(66) state that levels of cyanide above 0.2 mg/1
would constitute grounds for rejection of a public water supply.  The
1969 U.S. Public Health Service "Manual for Evaluating Drinking Water
Supplies"(67) further indicates that cyanide in municipal supplies should
not exceed 0.01 mg/1.  However it should be noted this manual is primarily
intended as a guide in evaluating these systems and not as a requirement
for approval or rejection of any public water supply.  Pertinent data in
unpublished guidelines(68) also suggest the following objectives:  desir-
able and permissible cyanide limits in public water supplies - respec-
tively 0.01 mg/1 and 0.1 mg/1; and for body contact recreation, fisheries
use and farmstead supply - a limit of 0.02 mg/1 cyanide.  Numerical limits
for cyanide are among the lowest and most critical of all the trace ions
to be tolerated for various water uses.  The literature is fairly
generous in giving data on whole body dosages of cyanide and hydrogen
cyanide considered toxic to man(5,62,69,70,71,72),  and to domestic
animals(5,62,73).  Additional references are available on toxicity of
cyanides to fish, and effects of temperature, dissolved oxygen and
chlorination on varying toxicity(5,62,65,74,75,76,77,78,79,80) .

Schraufnagel(9) has calculated "if sodium ferrocyanide were used...at a
rate of 2 pounds per ton of salt and...the amount of cyanide released is
equal to about one-fourth the additive's concentration, an 800 mg/1 con-
centration of rock-salt deicer would present a hazard to fish life and
water supplies because of the accompanying cyanide.  This is equivalent
to about 500 mg/1 of chloride, a value which is frequently exceeded in
road runoff, but to our knowledge has not been exceeded in surface
waters..."  Chloride levels exceeding 500 mg/1 were however obtained
for the Kinnickinnic, Menomonee and Milwaukee River waters in January
1969 in the Milwaukee area, as previously cited in Section V of this
report.  Schraufnagel also estimates that between one-half to two-thirds
of all rock salt used for deicing in the State of Wisconsin is specially
treated with anti-cake agents.

Recent information(11) indicates that the amounts of sodium ferrocyanide
added to salt stocks have somewhat decreased over the past few years.
The salt industry as of May 1971, cites the figure of 0.5 pounds sodium
ferrocyanide ten-hydrate added per each ton of rock salt, although it
is thought  this figure does not necessarily apply to all deicing salts
sold across the country.  The industry contends that no environmental
hazards are caused by the cyanide additives.  Nevertheless, the conclu-
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sions and recommendations given  in  this  report  concerning  these  additives
are considered highly appropriate and valid, not only because  of the
serious nature of cyanides but also due  to an absence of field data  on
the prevailing level and fate of these additives in  the environment.
 Corrosion  Inhibitors

 Special additives are available  for reducing  the  levels of  corrosion
 and rusting associated with highway salts.  Unfortunately,  only
 fragmentary data exists on past  and present use of  these additives,
 their costs, and proven effectiveness in minimizing corrosion.   It is
 believed that past use of corrosion inhibitors has  been significant.
 Three products in particular have received greatest attention:
 a) a chromium-base inhibitor used in the 1950's but apparently later
 discontinued; b) a sodium hexametaphosphate product manufactured by
 Calgon, Incorporated; and c) a product  introduced by Cargill, Incorpor-
 ated around 1964, which consists of chromate  salts  mixed with an organic
 inhibitor, emulsifier and sodium chloride(5,9,81).
Chromate Additives Used As Rust  Inhibitors

In Michigan during the winter of 1955-1956, a chromium-base rust inhibi-
tor had been used with calcium chloride for highway deicing.  In one
area of Michigan, however, there was great concern because snowpiles
alongside the road were yellow in color.  Fortunately, local personnel
quickly recognized the possible danger of chromium entering into the
nearby groundwater supplies and stopped all further use of the chromium-
treated salt(82).  In other parts of the country on certain occasions,
streets and highways have also turned blue, green, or yellow following
heavy road salting.

The U.S. Public Health Service Drinking Water Standards of 1962(66) state
that a concentration of 0.05 mg/1 hexavalent chromium provides sufficient
grounds for rejection of a public water supply.  Pertinent data contained
in unpublished guidelines(68) also suggest the following objectives:
desirable and permissible hexavalent chromium limits in public water sup-
plies - respectively 0.02 mg/1 and 0.05 mg/1; for farmstead supply - a limit
of 0.05 mg/1; and for body contact recreation and fisheries use - a limit
of 1.0 mg/1.

Although relatively stringent limits have been placed on hexavalent
chromium, particularly for drinking water, the carcinogenic potential
of hexavalent chromium is good reason to preclude its entry into a
potable water supply(83).  Trivalent chromium generally is not con-
sidered physiologically harmful, and the U.S. Public Health Service
Standards do not place specific limits on this constituent.  However,
trivalent chromium has been occasionally found more toxic than the
hexavalent ion to some aquatic plants and animals including Daphnia
magna(65).
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Numerous references are given in the literature for effects of hexava-
lent and trivalent chromium on biological sewage treatment processes and
sludge digestion.  The trivalent form of chromium is fairly easily oxi-
dized to the hexavalent form, whereas the reaction may be reversed
under the influence of heat, presence of organic matter or reducing
agents.  Toxicity of chromium ions to bacteria is governed by many
variables.  Under aerobic conditions, the toxicity of the trivalent ion
is generally higher than hexavalent chromium.  In the absence of oxygen,
the oxidized form if present, is considered far more toxic to bacteria(65).

The Cargill report in describing its 1965-1967 studies(81), assigned toxi-
city ratings to each of the major ingredients found in its deicing product.
Since chromate salts comprised a small percent of the total product, the
manufacturer indicated that sodium chloride (major component in the
product) "is really the critical toxic ingredient in this formation and
not the chromate salts".  This report described studies conducted in
Winnipeg, Canada where 1-3 percent (10,000 to 30,000 mg/1) sodium chlo-
ride was found in puddles after highway salting.  Cargill calculated
"this would be equivalent to 40-120 mg/1 sodium chromate"(81).  Con-
siderable sampling was undertaken in the Minneapolis-St. Paul area of
storm sewer flows, streams and rivers principally during the winter of
1965-1966 and again in 1967.  Samples were analyzed for trivalent,
hexavalent and total chromium and chloride content.

From December 1965 to February 28, 1966, the consumption of Carguard
(Cargill) salt in Minneapolis was 13,258 tons.  Samples of December 29
taken of street runoff in Minetonka Village, Minneapolis, showed a salt
concentration of 1.1 percent (11,000 mg/1) together with 24 mg/1 of
sodium chromate.  From various sewers in the Minneapolis-St. Paul area,
many values of hexavalent chromium and trivalent chromium were reported
in the range of 0.3 - 0.8 mg/1; and maximum values were 1.7 mg/1 hexa-
valent chromium, 2.2 mg/1 trivalent chromium and 3.9 mg/1 total chromium.
These chromium concentrations were considerably above desired levels.
For surface water samples, Cargill indicated none exceeded 0.05 mg/1
hexavalent chromium.  The chloride results for wintertime sewage flows
in the Minneapolis-St. Paul area (presumably both storm and combined
sewers) showed high chloride concentrations as follows:  Bridal Veil
Falls Sewer (Minneapolis), January 22, 1967 - 2590 mg/1, February 24,
1966 - 3050 mg/1, February 28, 1966 - 1060 mg/1; Broadway Sewer (St.
Paul), February 8, 1966 - 2670 mg/1; and Smith West Sewer (St. Paul),
February 8, 1966 - 720 mg/1, January 22, 1967 - 2520 mg/1, March 20,
1967 - 1610 mg/1(81).

The Henningson, Durham and Richardson study recently conducted for the
FWQA on combined sewer overflows and stormwater runoff in the city of
Des Moines, Iowa, provided certain data on effects of highway salts on
street runoff(43).  Chloride results obtained from the HDR study are pre-
viously described in Section VI of this report.  Although considerable
highway salts were used in Des Moines during the winter of 1968-1969,
only a small quantity of chromium - treated salt was deployed over the
study area.  Various samples taken from two drainage systems containing
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combined sewage and storm water, showed that  total chromium content was
below 0.1 mg/1 in all but one sample.  The latter sample contained
0.13 mg/1 chromium.  It was presumed all chromium values in the Des Moines
report were given in terms of total chromium.  For two storm sewers,
specifically the Thompson Avenue and the 20th Street storm drains, street
runoff contained less than 0.2 mg/1 chromium  in all but one sample.  Only
within the Cummins Parkway storm system were  chromium levels significant.
Snowmelt runoff in this storm drain routinely showed chromium in the
range of 0.1 to 0.3 mg/1 during January-March 1969, and three samples
had chromium levels of 0.35, 0.88, and 1.21 mg/l(43).

Information recently provided by the Salt Institute(11) states that the
single reported supplier of chromium-treated  salt, has in the past few
months, discontinued the sale of its product.  The results given in this
report on the use of chromium additives with  road salt and the levels of
chromium found in the environment, nonetheless, are considered highly
pertinent.  These results reflect the fact that chromium additives have
been deployed over a long period of time and  probably were supplied from
many different sources.  The chromium-treated salt cited above was taken
off the market because cost overshadowed its  effectiveness as a corrosion
inhibitor, and not principally due to environmental considerations.  The
effects of past use of chromium additives may still be present in soils
and groundwaters, but more importantly, there is no guarantee that these
compounds are no longer being used and will not be used in the future.
Rather than discount the importance of chromium, environmentalists should
be aware that rapid changes are possible also in the deicing industry.
Such changes could lead to new products and additives, which in turn could
either minimize or further intensify the pollution problems caused by
highway deicing.
Phosphate Additives Used As Rust Inhibitors

Another corrosion inhibitor commonly mixed with highway salts is sodium
hexametaphosphate.  This type of rust preventative is probably best
exemplified by the product, Banox, manufactured by Calgon, Inc. which
contains sodium hexametaphosphate as the effective ingredient(5,9).
Schraufnagel(9) in 1966, indicated that Banox mixed with salt would
represent an additional cost of $3.00 to $4.50 per ton of salt.  Other
reports(5,9) emphasize this product may represent an effective nutrient
source and contribute to eutrophication in surface waters, particularly
lakes and ponds.  Sawyer in 1947(84) showed prolific growth of algae
in lakes when the average concentration of inorganic phosphorous was
greater than 0.01 mg/1, and Curry and Wilson(85) suggest that 0.01 mg/1
of phosphorous is the maximum value permitted without producing undesir-
able biological growths(5).  Schraufnagel calculates if this  additive
is mixed with salt at a one percent ratio, the resulting street runoff
will contain about one part of phosphate for each 200 parts of chloride.
Schraufnagel also speculates if all chlorides applied in Dane County,
Wisconsin during the winter of 1965-1966 had been so treated, the  total
phosphate would have been equivalent to the phosphate discharged by the
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Madison, Wisconsin sewage treatment plant over a two-month period of
time(9).

Smith(86) clearly points out the danger of salt additives in that they
may be extremely toxic, especially to fishlife, and produce a variety of
objectionable side effects such as encouraging algal growth.  Smith infers
that any chemical proposed for use as a salt additive should be very care-
fully evaluated for the extent of any and all detrimental effects.
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                               SECTION XI

        PUBLIC WATER SUPPLIES,  GROUNDWATER,  INDUSTRIAL WATER USES


 Public  Water Supplies

 Public  water supplies  in both  the States of Wisconsin and  New Jersey
 have  fairly low  chloride content(5).   Of 471 water supplies in Wisconsin,
 the average chloride level  is  13  mg/1 and the median  7 mg/1.   Sixty-six
 percent of the Wisconsin supplies show 10 mg/1 chlorides or less.   Of
 356 water sources  in New Jersey,  the  average chloride level is 15  mg/1
 and the median 9 mg/1.   Fifty-eight percent of the New Jersey supplies
 have  chlorides of  10 mg/1 or less.  For the two States, more than  80
 percent of the supplies  had less  than 21 mg/1 chlorides, and  more  than
 95 percent had less  than 51 mg/1  chlorides.   However,  even relatively
 low chlorides may  adversely affect certain  water uses.  In Springfield,
 Massachusetts, following the opening  of the Massachusetts  Turnpike in
 1958, a significant  chloride increase was experienced in the  city's
 water supply.  Prior to  1958,  chloride content was around  2.0 mg/1,
 which increased  to 12.4  mg/1 in 1966.   Although chlorides  were still
 low, a  large industrial  water  user in Springfield,  which requires  low
 electrical conductivity  in  its supply,  indicated difficulty with this
 water.  This municipal water supply thereby,  was considered far less
 desirable for industrial use purposes(4,87).


 Groundwater, Well  Supplies

 The Massachusetts  Legislative  Research Council Report(4) indicates in
 general, highway maintenance engineers  do not  believe road salts are an
 important cause  of groundwater pollution.   However, when there is  salt
 contamination of well  supplies, the engineers  usually place the blame
 on the  runoff from salt  storage piles  or  improper  drainage alongside
 the highway(5).  Salt contamination of  a  secondary water supply along
 the New York State Thruway  was successfully  corrected  by minor revision
 of a particular  highway  drainage  ditch(4,5).
Michigan

A 1963 Michigan study showed that roadside runoff containing highway
salts, in essence, represented contaminated recharge(82).  Roadside
wells within the intercepting shallow aquifer in Manistee County
receiving such recharge were found highly vulnerable to chloride
contamination.  One of these wells, 300 feet from a highway depart-
ment salt pile, contained 4,400 mg/1 chlorides.  In this case,
dissolved salt from the salt storage pile had flowed into a broken
section of storm sewer and moved into the groundwater aquifer(5,82).
Also in Michigan in Delta County, contamination of shallow parts of
the Black River Limestone was caused by salting practices of the
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Road Commission.  Construction of sheds and tarpaulin coverings were
suggested for the salt storage areas to minimize salt leaching and
percolation into the water table.
Wisconsin and Illinois

In Wisconsin, five wells were contaminated by salts leaching from a
sand-salt stockpile and the well waters ranged from 19 to 1,345 mg/1  in
chloride content.  The local aquifer normally contains less than 12 mg/1
chlorides(5,9).  Recently in Peoria, Illinois, the city salt storage
facility was discovered to be the source of serious chloride pollution
to industrial water-use wells along the Illinois River valley(88).
It was concluded that this pollution will probably continue for some
time even after the salt storage facility has been abandoned unless the
salt-saturated earth underlying the storage area is also removed.
Rigorous short-term corrective measures are suggested for this area,  but
nevertheless, it may require several years to purge excessive salts from
the aquifer(88).
New Hampshire

The New Hampshire State Highway Department started in 1953 to replace
roadside wells adversely affected by chlorides, and this program has
increased over the years with 37 wells being replaced in 1964, the last
year of reported data.  Some of the wells contained in excess of 3,500
mg/1 chlorides whereas these groundwaters are normally around 10 mg/1
chlorides(5).  Most of the problems have been associated with shallow-dug
wells and 90 percent of the replacement wells have been of drilled con-
struction.  It is reported elsewhere, that up to 1965, the State of New
Hampshire had replaced some 200 roadside wells at a total cost of more
than $200,000(18).
Maine

Throughout the State of Maine, from 1966-1968, Hutchinson conducted
analyses of 115 wells located along various State highways(44,45,52,89).
Samples were taken in April and July-August.  Normally sodium and
chloride levels are in the range of 3-4 mg/1, but wells adjacent to
highways showed average sodium and chlorides around 75 mg/1 and 160 mg/1,
respectively.  One well had 846 mg/1 sodium and 3,150 mg/1 chlorides.
Another well contained 343 mg/1 sodium and 1,163 mg/1 chlorides.   In
1967, about one-half of the wells near a salt-treated road exceeded the
chloride level of 250 mg/1.  Groundwaters in most cases showed higher
chlorides in April compared to summer, indicating a relatively quick
response in groundwaters following salt application.  It is noted  that
Hutchinson's contaminated wells were mainly shallow, hand-dug wells.
Drilled wells insulated with casing are far less susceptible to salt
intrusion.
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Hutchinson  in his  studies  in Maine,  furthermore  found  high  levels  of
salt  in  the snowpiles alongside highways pushed  by  snowplows  as much  as
20-30 feet  from  the edge of the pavement.  Maximum  sodium and chloride
concentrations within a typical snowbank were  713 mg/1 and  585 mg/1,
respectively.  At  one site, wind-blown  snow was  found  60  feet from the
edge  of  the pavement, and  also heavily  loaded  with  salt.  Based upon
these findings,  Hutchinson recommends that "private water supplies,
wells or ponds,  should not be located within a minimum distance of
40 feet  from highways because of possible contamination by  salt ions".
He also  suggests certain management  practices  can serve to  partially
alleviate the salt problem, e.g., providing intercepting  surface drains
at the edge of the roadway and chemical treatment of affected soils(44,
45,52,89).
Ohio

At Barbertown, Ohio in 1949-1950,  it was found  that groundwater on the
opposite side of the Tuscarawas River from a salt disposal area con-
tained more than 20,000 mg/1 calcium chloride caused by induced infil-
tration.  Groundwater resources could not be developed on either side
of the river, and consequently, Barbertown had  to close down its entire
municipal well field(90,91).
Connecticut

For the State of Connecticut, two cases of water supply contamination
caused by highway salts are described by Scheldt(92).  Tastes and odors
in one municipal water supply were duly noted and attributed to the
presence of sodium ferrocyanide  (an anti-caking agent) originating from
salt storage piles.  Recommendations were made that amounts of sodium
ferrocyanide mixed with the salt be reduced from 250 ppm to 50 ppm, and
that suitable covering be provided for the storage piles to minimize
salt penetration into the groundwater aquifer.  The other instance in-
volved contamination of groundwater from salt storage piles adversely
affecting the well supply serving four families.  Excessive salt content
not only affected taste and quality of the potable water supply but also
was reported responsible for corrosion damage to the plumbing and heating
systems.  Regarding drainage from salt storage piles, there should be no
question that such severe contamination of water supplies must be
stopped(92).
Massachusetts

The State of Massachusetts which deploys large amounts of highway  salts,
due to these deicing compounds, has experienced a wide range of  environ-
mental pollution problems.  During the winter of 1966-1967, approximately
170,000 tons of sodium chloride and calcium chloride were applied  to
9,000 miles of State highways and toll roads in Massachusetts(1).   These
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figures do not include deicing materials used by the City of Boston and
the various counties and towns in the State.

In 1964, the U.S. Geological Survey commenced groundwater sampling along
heavily travelled highways located within a 50-mile radius of Boston, Mas-
sachusetts.  Small diameter observation wells were sunk 19 to 60 feet
deep and located 15 to 30 feet off the highway.  The study, undertaken
in joint cooperation with the Massachusetts Department of Public Works,
at the present time comprises more than 40 wells situated within 6 test
areas.  The highways passing through the test areas include both relatively
new and old roadways.  The overall objective of the study is to trace the
spread of highway salts through roadside soils by means of long-term
measurement of vertical and lateral movements(19,93,94).  Tentative
findings show that a large percentage of the groundwaters are approaching
250 mg/1 chlorides, which is the upper limit recommended for public water
supplies.  The U.S.G.S. investigations, contrary to many previous studies,
show a relatively slow movement of salt through the unsaturated zone,
then through the groundwater.  In one case where the water table was only
2 feet below the ground surface, approximately 12 months lapsed before
the salt horizon reached the observation well only 30 feet from the
highway.  Other lapse times varied from a few months to a few years.
Peaks in chloride data generally occur in the period July to December.
From these results, as many as 70-80 discrete steps are perceived in
downward percolation of salt into the observation well zone.  Recharge
of groundwater by snow continues through the winter, although at reduced
rates compared to the rest of the year.  Chlorides are steadily increas-
ing each year.  Continuing studies planned beyond 1970 should further
define  the chloride curves, which could extend beyond the 250 mg/1
limit(19).

The Massachusetts Legislative Research Council in 1965(4) reported:
"It is well known that both well and surface supplies of drinking water
have been affected by increased use of salts".  In mid-1964, the Massa-
chusetts Department of Public Health alerted all water supply authorities
in the  State to the danger of chloride contamination and consequently
some water supplies were abandoned.  The Department of Public Health
described drainage originating from salt storage piles and street runoff
as two  important sources of hazard.  Accordingly, the State Department
of Public Works was instructed to cooperate with the Department of Public
Health  in efforts designed to minimize these conditions(4).

Specific cases of water supply contamination in Massachusetts merit our
attention.  The town of Becket in 1951 found the water in one of its
wells had drastically increased in chloride content to about 1,360 mg/1
whereas the other town wells showed a rise in chlorides to about 50 mg/1.
These adverse changes were attributed to a salt storage pile located up-
hill from the well field(95).  In recent years, the North Chelmsford
Water Commission, through action of the town selectmen, have threatened
court action to remove salt stored in a highway garage which was thought
to endanger the district well field.
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Private and public water supplies in the Weymouth, Braintree, Randolph,
Holbrook, Auburn and Springfield areas were among those believed  to be
affected by highway salts, in Massachusetts.  Large salt  storage  piles
located at Routes 128 and 28 in Randolph, and located alongside the Blue
Hill River, were suspected of introducing contamination into Great Pond,
which serves as water supply for Braintree, Randolph and  Holbrook.  Water
supplies in Tyngsboro and Charlton were similarly experiencing salt
increases, and two wells in Charlton were likely to be abandoned(96).
Also, in the general Boston area, snow removal and disposal practices are
cited as contributing to heavy salt content in the Mystic Lakes(97).

Early in 1970, the Massachusetts Commissioner of Public Health was re-
ported to have given a warning to all physicians and local health boards
regarding the care of patients on salt-free diets (specifically sodium-
free diets) within salt-affected communities(87).  Sodium chloride
increases had been recorded in the water supplies of 63 Massachusetts
communities at least in part due to highway salting and salt storage
piles.  Sodium intake must often be restricted for those persons  experienc-
ing chronic congestive heart disease, high blood pressure, renal  disease,
cirrhosis of the liver, and pregnancy(87).  The report indicates  that
persons in normal health will perceive no effects using these water supplies,
but adjustment may be necessary for salt-free patients including  possible
use of bottled water.  Many of these communities now have water containing
in excess of 20 milligrams salt per quart (21 mg/1), compared to  the upper
limits of 25-40 milligrams per quart (27-42 mg/1) that are being  prescribed
for many salt-free patients.  The Massachusetts findings are supported
by previous guidelines of the American Heart Association(5,98,99), which
for people on moderate or strict sodium diets, indicate maximum limits
of 20 mg/1 sodium permitted in drinking water.  The Massachusetts medical
alert specifically named the 63 communities so affected(87).
Industrial Water Supplies

On the subject of industrial water use, Schraufnagel(9,18) found that
chlorides have been responsible for the corrosion of various metals
including stainless steels.  Schraufnagel cites a previous recommendation
of the Ohio River Valley Water Sanitation Commission that monthly average
chloride concentrations in the Ohio River not be permitted to exceed 125
mg/1 in order to minimize corrosion of industrial structures.  The Ohio
River Valley Water Sanitation Commission further recommends that 250 mg/1
chlorides not be exceeded at any time to combat corrosion.  Schraufnagel
also cites an industry statement that "increasing the salinity average
above the then 40 to 50 mg/1, or lengthening the periods of high salinity,
would increase corrosion of all metals used in the handling system"(9,18).

Although McKee and Wolf in 1963(65), in their extensive review of the
literature, found that 50 mg/1 chloride generally would not be harmful
to industrial water users, they also advise that no "standard" chloride
level would be acceptable to meet the demands of all different industrial
processes.  McKee and Wolf summarize chloride tolerances for various
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Industries as follows:  food canning and freezing - 760 mg/1; carbonated
beverages, food equipment washing, and paper manufacturing (Kraft) -
200 to 250 mg/1; steel manufacturing - 175 mg/1; textiles, brewing,
and paper manufacturing (soda and sulfate pulp) - 60 to 100 mg/1; dairy
processing, photography and sugar production - 20 to 30 mg/1(5,65).
Other reviews on water quality needs for industry including chloride
limits also are available(100,101).
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                               SECTION XII

                         CORROSION OF VEHICLES
From the standpoint of the public,  there  is considerable controversy  as
to whether highway salts contribute  to automobile  corrosion.   Some  cri-
tics contend that all rusting on vehicles is due to highway salts.  On
the other extreme, the statement is  frequently made that salts have no
harmful effects whatsoever to the finish  on cars and trucks.  The real
situation probably lies between these two extremes.  Various changes
introduced by automotive manufacturers over the past ten years which
include electroplating; deep-dip priming;  special  paints particularly
the acrylic finishes; use of aluminum parts in place of chrome; under-
coating; and redesign of trouble-spots where rust  occurs, have appreci-
ably reduced this corrosion potential(4).  However, at the same time
the overall use of highway salts has increased significantly.  It is
extremely difficult to define potential and existing corrosion due  to
highway salts because of the lack of reliable and  conclusive data in
the general literature.
Cost Damages

Besides corrosion of vehicles, airborne salt crystals may be carried onto
structural steel, buildings, house sidings and other property alongside
streets and highways, causing appreciable corrosion damage to these
structures.  The amounts of airborne salt may comprise up to 10 percent
of the total salt spread during a given storm(4).  A rough order of
damage magnitude is given in a 1968 report for the Society of Automotive
Engineers which indicates "the private car owner pays for rust destruc-
tion at the rate of about $100 a year"(26).  Lockwood, et. al.,(6) express
little doubt that highway salts contribute substantially to corrosion
of vehicles.
How Corrosion Occurs

Various studies have been conducted concerning the corrosive effects of
highway salts on car underbodies and the outer decorative surfaces of
vehicles.  Corrosion commences when the outer paint finish is broken or
cracked so that water and/or brine solution comes in contact with the
underlying metal.  Once corrosion starts it can spread rapidly under the
paint film in any direction.  The outer finish is forced upward exposing
both rusted and new metal which hastens the corrosion process.  Breaks
in the painted surface are the result of flying gravel, stones, highway
debris; blows and scratches particularly on car doors; and poorly fit-
ting parts on a car, e.g., molding strips, trunk lids, etc.  Crevices
which tend to retain water and brine also make these areas susceptible
to attack.  Corrosion is caused by atmospheric oxygen combining with
exposed metals, especially iron and steel, in the presence of moisture
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to produce iron oxide, otherwise known as rust.  The literature points
out that salt and brine as such, do not cause corrosion(A).  Neverthe-
less, it is well known when the metal is exposed to salt water, the
electrolytic reaction converting the metal to its oxide will proceed
at a much faster rate compared to water alone(102).

The normal conditions under which an automobile must operate are condu-
cive to maximum potential corrosion of exposed metal surfaces.  During
the wintertime, vehicles are frequently exposed to salt spray, dirt,
grime, etc., and this material accumulates particularly on the underside
and lower parts of the car body.  Studies in Iowa show for normal appli-
cation of highway salts, about 50 percent of the salts are removed from
the roadway by traffic, 25 percent is carried off by surface water, and
about 12 percent leaches through the soil(103).  We do not know what
part of this 50 percent is retained on the car body.  Under such condi-
tions, salt and brine may be responsible for considerable damage to
automobiles.
Comparative Studies

Some of the earlier corrosion studies involved large numbers of CMC
cars located in various U. S. cities which were closely inspected for
corrosion damage under paint films and chrome surfaces.  These studies
generally showed the percentage of cars experiencing corrosion was
much higher in locations using highway salts, as compared to warm cli-
mate locations.  One such survey found that 58 percent of cars examined
in Detroit had corrosion along chrome moldings, whereas this ratio was
only 35 percent in Miami, Florida(4).

Another survey made of 14,000 cars in 44 States indicated where little
or no road salts were used, the chrome condition was judged good for
95.6 percent of the cars.  In salt application regions, the percentage
of cars with good chrome was only 80.4 percent.  The chrome trim on
cars is especially vulnerable to rusting since it is highly porous, and
moisture and oxygen may more readily penetrate the underlying steel.
Chrome is less important today, being partially replaced by aluminum(4).

A special corrosion study only recently completed by the American Public
Works Association, evaluates the effects of deicing salts and rust inhibi-
tors upon nine Falcon automobiles tested for up to three years in the
Minneapolis, Minnesota area(21).  Findings show that up to 50 percent of
vehicle corrosion can be attributed to deicing salts on streets and high-
ways.  Rust inhibitors under controlled use, especially the Carguard product
manufactured by Cargill, Inc., are found to reduce corrosion of bright
metal parts, but do not provide similar protectibn for sheet metal parts.
The APWA report contains recommendations on need for a) more comprehen-
sive purchase specifications by governmental authorities; b) post-assembly
corrosion protection; and c) closer examination of highway deicing pro-
cedures (21) .
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In 1964, various reports(4,104,105) indicated that corrosion of automobile
trim systems was increasing due to the greater use of calcium chloride
on U.S. highways.  Subsequent investigation(4) produced the following
findings:

     a.  At low humidity, calcium chloride is more severe than
         sodium chloride in its attack, but there is essentially
         no difference if the surfaces are continuously wetted.

     b.  Stainless steel is more susceptible to attack than
         other trim systems.

     c.  Corrosion can be alleviated by improving exterior
         trim systems, making salt products more alkaline,
         and by washing cars frequently during winter(4).
Mufflers, Tailpipes

The short life of automobile mufflers and tailpipes has frequently been
cited as a damaging consequence of using highway salts.  It has been
said that replacement of these underbody parts costs the Nation about
$500 million annually.  However, conflicting information has been sup-
plied by one automotive company official stating that muffler and tail-
pipe deterioration is the result of engine emission acids rather than
salts.  Likewise, there is diverging opinion as to whether industrial
and other air pollution may cause generalized corrosion in automobiles(4,
106).
Rust Inhibitors

The merits of adding rust inhibitors to road salts have not been satis-
factorily proved.  A committee attached to the Detroit Engineering
Society previously concluded the use of inhibtors is of doubtful value
in protecting the exterior finish of automobiles.  However, certain
agents may reduce the weight loss of metals susceptible to corrosion.
Comparison studies are open to question but the majority of results do
suggest that the car owner benefits little from the use of these inhibi-
tors (4).  Canadian researchers have similarly found that the large costs
for adding an inhibitor to road salts generally are not justified.  The
Canadian report concludes these inhibitors slow down, but do not eliminate
the corrosion of vehicles caused by highway salts(4).
Other Preventative Measures

The best rust prevention treatment recommended by automotive engineers
is frequent car washing.  The general literature also advises the car
owner that his best protection is frequent washing and periodic waxing.
However, more than one reference cites waxes, chrome lacquers and
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similarly applied coatings as possibly doing more harm than good because
the protective coating may serve to seal in moisture thereby promoting
corrosion.  Conflicting thoughts likewise are expressed concerning the
merits of undercoating, because in time, chipping and peeling of the
undercoat occurs.  The original car paint, if applied to the underside
of the car, may, because of its tighter bond, reduce the corrosion
potential compared to undercoating.  Regular car washing is relatively
effective not only in removing road salts, but also in minimizing dirt,
road grime, industrial contaminants, road tars, etc., all of which are
detrimental to car finish and appearance(4).
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                             SECTION XIII

              EFFECTS ON HIGHWAY  STRUCTURES AND PAVEMENTS
Review by Massachusetts Research Council and Findings of
U.S. Highway Research Board and Representative States

The 1964 study of the Massachusetts Legislative Research Council(4) gave
particular attention to a Symposium of the U.S. Highway Research Board
held in 1962, which considered effects of deicing chemicals on highway
structures(107).  The Board was primarily concerned with bridge floor and
deck deterioration in portland cement concrete structures.  The Symposium
noted that blame for public works damage in question could not be placed
solely on deicing agents and that the available data was inconclusive.
The evidence did indicate that concrete structure deterioration could be
at least partially attributed to inadequate field inspection and failure
to follow proper techniques in mixing, transporting, laying and curing
the concrete.  Air-entrained concrete introduced in the late-1940's and
which later gained widespread acceptance, did not meet the fullest ex-
pectations unless construction practices were rigidly controlled.  It was
emphasized that various concrete mixes, even air-entrained concrete, over
the first six months do not develop their maximum resistance.  If salts
are applied over this period of time, there could be significant struc-
ture damage.  Laboratory studies have also shown that sodium chloride and
calcium chloride may have damaging effects on concrete.  Defects caused
in bridge structures include hairline and larger cracks, splitting or
shelling out of the surface layer of the deck, aggregate popouts, scaling,
surface pitting, chipping, peeling, progressive deterioration from the
edges inward, i.e., raveling, and leaching of the deck, gutters, hub-
guards and sidewalks(4,107).

The State of Illinois made its recommendations to the Symposium as follows:
a) improving the quality of concrete used in structures and pavements;
b) improving drainage design for better removal of brine and abrasives
from bridge surfaces; c) more rigid control over construction practices;
d) better maintenance; and e) less corrosive ice-removal compounds.  On
the other hand, the State of Massachusetts did not find that salts were
detrimental to bituminous concrete pavements or bridge decks covered with
cement concrete(4,107).

Highway departments and others have used various materials and surface
treatments in order to protect concrete surfaces from damage by deicing
salts.  However, experience indicates such measures are usually unneces-
sary if concrete is properly laid.  The U.S. Bureau of Public Roads con-
ducted a series of tests which showed that surface protective coatings
are generally of little benefit in minimizing concrete scaling, although
in a few cases, certain admixtures are beneficial.  The Massachusetts
Research Council, in their review of the literature, describes two short-
comings in bridge maintenance which may significantly contribute to con-
crete damage:  a) failure to clear-away chemical-laden accumulations of
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snow and ice along gutter and sidewalk sections; and b) failure to remove
soil, debris and other obstructions from the gutters, causing poor drain-
age.  Standing salt water can saturate underlying concrete, lowering its
resistance to damage, and this water may also seep through construction
joints and cracks causing interior damage to the bridge deck(4,107).

Application of deicing salts to concrete roadways in the New York Thruway
system have caused few difficulties, but serious problems have been en-
countered with bridge structures.  In order to counteract progressive
deterioration of concrete bridge decks, a preventive and corrective
maintenance program was established.  Additionally, to minimize the
effects of salt brine and water passing through bridge expansion joints
onto the abutments and piers, the procedures for painting steel members
in the structure were modified(4,107).

The report by the State of Kansas to the Symposium gave evidence that
highway salting in Kansas is greatly accelerating the scaling of concrete
structures.  The chlorides also contribute to rusting of reinforcing
steel which leads to concrete spalling.  Recommendations were given that
all decks be sealed with a water repellent material and then carefully
covered with a bituminous coating.  It was further suggested that steel
and timber be waterproofed with paints, asphalts, resins, silicones or
equivalent(4,107,108).  Similar experiences in Ontario, Canada, however,
indicate that asphalt surfacing over concrete tends to trap considerable
salt onto  the surface of the concrete.  The salt solution not only pene-
trates under the asphalt at the curb zone but also enters into cracks in
the asphalt.  Excess moisture sealed in by the waterproof coating was
considered detrimental to the bridge decking.  The Ontario study concludes
that adequate drainage must be provided, and no surface coating can ade-
quately overcome defects in design, construction or materials which lead
to water and salt being trapped on the bridge decks(4,107).
Comments of Calcium Chloride Institute and Portland Cement Association

A 1961 report by the Calcium Chloride Institute(109) stresses suitable
precautions must be taken in using deicing chemicals and that scaling
of concrete attributed to salt "is not a chemical attack".  The
Institute infers that scaling will occur when concrete is less than
"ideal".  This study emphasizes chemicals should not be used on air-
entrained concrete less than 12 months old unless specific measures
are followed.  For non air-entrained concrete, chemicals should not be
applied for at least one year, and in the maximum case, up to four
years(4,107).  With deicing chemicals, the ability of the chlorides to
attract water, and their capability in depressing the freezing tempera-
ture of liquids, represent potential hazards to concrete.  Salt
application will increase the number of freeze-thaw cycles and raise
the level of water in the concrete which leads to scaling and spalling.
Another study conducted in Massachusetts concludes that highway salts
can penetrate the capillaries, particularly in non air-entrained concrete,
and cause disruption and scaling of the concrete material at an acceler-
ated rate(4,107).
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The Portland Cement Association correlates surface scaling of concrete
pavements with the increasing use of sodium chloride and calcium  chlo-
ride.  The severity of scaling is said to depend upon the amount  and
frequency of salts used.  The Portland Cement Association strongly
recommends air-entrained concrete where frost action and salt application
occur.  The Association cautions that concrete pavements may be damaged
by heavy salt applications, especially relatively new roadways.   Pave-
ments less than four years old are much more vulnerable than older high-
ways.  Protective treatments are advised in most cases particuarly for
concrete pavements less than four years old.  Without protective  treat-
ment, the Portland Cement Association recommends that heated abrasives
be substituted(4,107,110,lll).  The Massachusetts Legislative Research
Council Report specially notes New Jersey provisions, which prohibit
the use of salts within 500 feet of a bridge 50 feet or more in length(4).
Other Deicing Compounds

Concerning deicing compounds other than the chlorides, caution was ex-
pressed in a concrete industry trade journal as early as 1961, on the
corrosiveness of many of these chemicals to concrete.  Certain of the
agents were found to contain large amounts of ammonium nitrate.  These
materials are sold under trade names without reference to composition,
and also sold in small plastic bags being promoted for sidewalk and
driveway use.  Unfortunately, the harmful effects of the ammonium
compounds and some of the other agents to concrete surfaces, seem to
far outweigh their merits in melting ice(4,18,107,112).
Effects on Underground Utilities

Schraufnagel(18), based upon a fact-finding study by Hamman and Mantes(113),
describes the corrosive damage of deicing salts upon underground tele-
phone lines and water mains.  The Bell and Chicago Telephone Companies
previously noticed that corrosive failure of underground cables and
transformers was occurring in proximity of highway salting.  In Buffalo,
New York, the National Association of Corrosion Engineers surveyed
the chloride content of manhole waters at 25 locations over a three and
one-half year period.  Of 175 samples taken in Buffalo, 74 samples had
chloride levels in excess of 1,000 mg/1.  In Milwaukee, Wisconsin in 1965,
the Water Engineering Division, studying the chloride content of ground-
waters near buried water mains, found chlorides of 170-225 mg/1 near
streets routinely salted, compared to 10 mg/1 for groundwaters in unsalted
areas.  Concern was raised as to foreseeable corrosion damage to the water
distribution system.
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                              SECTION XIV

                  EFFECTS ON SOILS, VEGETATION, TREES
Deicing salts applied to roads and highways are eventually carried by
surface runoff into roadside ditches and receiving streams, or  these
salts will infiltrate into the soils bordering the highway.  Through
infiltration, deicing salts are carried into groundwaters, remain in
soil solution, or are absorbed by soil particles.  Soils may be
adversely affected as to their fertility and their ability to support
desirable plant growth.  Because of poor soil conditions, the uptake
of salt ions by trees and vegetation, and the toxic properties of these
ions, moderate to severe damage is frequently inflicted upon grasses,
vegetation, plants, shrubs, bushes and trees.  Exposure of plantings
is usually most severe in the highway median strip.

This section of the report reviews effects of highway salts upon road-
side soils, vegetation, and trees.  However, in contrast to previous
sections of the report where the literature was relatively sparse, there
are numerous reports in this area of study.  Keeping in mind the objec-
tives of this report, we have been quite selective in the particular
references used for judging effects of salts on soils and plant biota.
The materials presented in this section are broadly arranged into
discussion of:  a) general soil chemistry; b) nature and movement of
salts through soils; c) salt uptake by plants and correlative effects;
d) salt tolerance of individual species; and e) effects of salt spray
on vegetation.
Soil Chemistry, Salt Movement Through Soil Into Plants

Many researchers, particularly those in the western U.S., have studied
effects of salts on plants and the occurrence and movement of salts
through soils.  The problem can be viewed in many ways although total
soluble salt content (salinity), and the levels of specific ions are
of great importance.  Symptoms of injury in plants and trees include
advanced coloration of foliage, leaf scorch, defoliation, stunting,
and eventually, die-off.  Symptoms may however be similar whether due
to sodium or chloride, high salinity, or drought conditions.  Also,
because sodium and chloride salts in themselves give rise to salinity,
it is oftentimes difficult to determine the extent of damage caused by
each factor(114).

Salinity or total soluble salts cause interference with the mechanism
whereby a plant absorbs moisture from the soil.  Soil water enters the
plant root through a membrane across which an osmotic pressure differen-
tial is maintained.  The flow of water through the membrane is in the
direction of higher salt concentration and therefore, increasing salinity
in the soil makes it more difficult for water to be taken in by the
plant.  The sensitivity of a plant is related to the type of soil present,
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the soil "wilting" percent moisture, and amount of salinity per unit
weight of soil.  Besides short-term damage caused to plants by saline
soils, some data show that low salinities over extended periods can
cause cumulative damage in due time.  In general, other factors being
equal, plant growth will be retarded by increased salinity because of
increasing salt load or reduced soil water.  In similar context, when
salinities are raised, more water will be required, to be supplied by
rainfall or irrigation, in order to maintain previous plant growth.
Leaching of soluble salts from the soils, is inferred as an alternative
procedure(114).

The sodium, chloride, and calcium ions are of special significance when
deicing salts are used.  Chloride per se, is not reported to cause ad-
verse effects on soil characteristics, although it does add to salinity.
Chloride ions possess a negative ionic charge the same as that of soil
particles.  Consequently, chloride ions freely flow through soil parti-
cles compared to the cations such as sodium and calcium which are
absorbed onto soil particles or precipitated by soil reactions.  However,
high levels of chlorides do appear as pollutants in groundwater and as
toxicants taken in by plants.  Excessive chloride accumulates in the leaves
causing leaf burn, but also seems to locate in the twigs(52,114).

The sodium ion is important because it not only changes the character
of the soil but also exerts a toxic effect on various plants.  Cations
are absorbed onto soil particles and maintained in equilibrum with
cations in the surrounding soil water.  If sodium salts are applied to
the soil, the equilibrium is changed whereby sodium ions replace calcium
ions on the soil grains.  With loss of calcium, the soil may become less
fertile and also less permeable.  High sodium levels can cause dispersion
of collodial soil particles, which eventually leads to alkali soils
characterized by lack of aggregation and structure, and poor drainage
properties.  Sodium is often considered toxic to trees and other plants
with translocation to the leaves and twigs causing burning and browning.
Although thought to be generally non-essential to plant growth, sodium
can interfere with uptake of potassium, an essential plant element, and
even serve in its place(114,115).

Calcium is a commonly found element in soils and appears essential for
plant growth.  Calcium may be added to soil as lime or gypsum to replace
undesirable sodium ions and restore soil fertility.  However, excessive
calcium can cause high salinity and may be specifically toxic(114).

The 1963-1964 winter season was the first time the National Capital
Region of the National Park Service authorized the use of sodium
chloride on Park roads in the Washington, B.C. metropolitan area.
Various research included microscopic examination of Kentucky bluegrass
leaves and roots, and observations of damage to vegetation and trees
along approximately 70 miles of Park roads.  Although this study con-
ducted in 1964 did not reveal detectable injury to plant biota, the
results provided comparative background for significant salt damage
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experienced the following winters.  In his early 1964 studies, Thomas(116)
found the most important factors associated with sodium chloride injury
were:

     1)  Amount of salt applied
     2)  Amount of salt reaching vegetation, and retained
         and absorbed by the plants
     3)  Availability of water
     4)  Temperatures during plant growth
     5)  Wind velocities
     6)  Soil characteristics
     7)  Dormancy of plants and onset of plant growth
     8)  Plant tolerances and individual species sensitivities
     9)  Cumulative or long-term effects of salt

Salts reaching vegetation are reduced where curbing and storm sewers
are established.  Available rains may leach out excessive salts from
soils but Thomas from his review(116) indicates this rainfall in humid
regions must do more than merely saturate the soil in order to produce
adequate salt leaching.  Light rains appear to have little effect.
Sodium chloride, total soluble salts, particular soil types, and shallow
plants and soils will serve to intensify "drought" conditions.  It had
been previously recommended that total soluble salts in soils be main-
tained below 100 ppm, but as early as 1964, soluble salts adjacent to
salted parkways were already in the range of 1,860-2,580 ppm (1 ppm =
1 yg/g or 1 mg salt/kg soil).  It is extremely advantageous if salts
can be leached from the soils before active plant growth starts in the
spring.  For this reason, a late salt application around the beginning
of March may be much more harmful than a heavy mid-winter application.

Thomas(116), based upon his review, also points out that damaging effects
of salts may not become apparent for several years, that sub-lethal salt
doses may cause plants to become more generally susceptible to disease,
and that salt changes in soils and vegetation may more subtly, but more
importantly, be affecting entire natural ecosystems.

Prior and Berthouex(16,114) studied the movement and accumulation in
roadside soils of highway salts applied by the Connecticut State Highway
Department.  Soils were sampled at the surface, one, two and three foot
depths, and at distances 5, 25, 50 and 100 feet from the highway.  Soil
samples were analyzed for total soluble salts, chlorides and sodium.
Greatest salt concentrations were found near the highway and close to
the soil surface, as anticipated.  In a number of cases, salt was shown
as travelling more than 100 feet laterally from the highway, but the
predominant movement was downward.  Total soluble salts, sodium, and  to
a lesser degree, chlorides, were significantly higher within the soils
in January-February compared to the other months of the year.  This
seasonal difference was also noted in the soils 100 feet from the highway.
Salts were readily leached from the upper several feet of soil and by
April the majority of salts were displaced downward.  Salt concentrations
were reduced to minimal levels through the summer and fall before salt
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applications were due to be resumed the following winter.   Since all
data were collected in one year, no estimate is possible of salt
accumulations in successive years(114).
Wintertime Infiltration

The question of how much infiltration occurs in the wintertime  is  quite
important in predicting the portion of highway salt loads contained  in
highway drainage vs. that entering the soil horizon.  The majority of the
literature tends to indicate that infiltration will occur throughout the
year except when the ground is frozen.  During the winter, we may  there-
fore expect little or no infiltration, and snowmelt would largely  take
the form of surface runoff.  However, observations in Massachusetts  and
other locations indicate this may not be the case.  In the Boston  area,
long-term studies have shown that infiltration and groundwater  recharge
continue throughout the winter although at slower rates(19).  Prior(114)
in Connecticut, found almost normal infiltration occurring in forest
soils frozen to a depth of 4 inches.  Light textured soils allow for
greater infiltration during times of freeze.  Prior indicates even with
frozen ground conditions, at least some water and salt will infiltrate
into the roadside soils.
Salt Levels in Roadside Soils Along Maine Highways

Hutchinson extensively studied sodium and chloride levels in soils
adjacent to salted highways in Maine from mid-1965 through 1969.
Hutchinson selected his sampling sites on the Maine Turnpike and
Interstate 95.  Soils were collected at 6 and 18-inch depths, and in
5-foot increments from the edge of the road up to a distance of 45
feet.  A minimum of 12 borings was composited for each sample.  Samp-
ling sites were also established along a number of other major highways
in the State.  In this second series, samples were secured at discrete
distances of 0, 30 and 60-feet from the road embankment(115,117).

Different sections of Interstate 95 were opened in various years, and
Hutchinson was able to correlate sodium and chloride levels with the
number of years these roadside soils had received deicing salts.  One
section of roadway after a single winter demonstrated a five-fold
increase in sodium at the 6-inch soil depth near the edge of the high-
way.  Increases in sodium were shown at the 6-inch depth up to 30 feet
from the highway.  At the 18-inch soil depth, this increase was evident
over 10 feet lateral distance.  Background sodium values were generally
30-40 ppm (yg/g), compared to a maximum value of 235 ppm sodium found
after the one winter of salting.  Chloride background values were all
recorded as trace amounts.  After salting, chlorides at the 6-inch
soil depth varied from 30-174 ppm over the 45 feet of lateral distance.
At the 18-inch soil depth, chlorides ranged from 38-107 ppm(115,117).
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Four other sites on the Maine Turnpike and Interstate 95, which had
received yearly salting for 2,3,5 and 18 years, respectively, were also
sampled.  All soils in this study series were derived from marine sedi-
ments adding uniformity to the results obtained.  Compared to background,
the sites salted for 2 and 3 years, showed sodium increases in the 6-inch
deep soils of 4 to 8 fold near the edge of the highway.  Sodium content
was significantly high at both the 6 and 18-inch soil depths extending
outward some 30-35 feet from the highway.

The section of highway receiving salting over 18 winters indicated very
high sodium levels in the soils directly adjacent to the road.  High
sodium content prevailed over the entire 45 foot lateral distance
sampled.  Compared to the background levels of 30-40 ppm, the sodium
content averaged 333 ppm for all soil samples taken at the 6-inch
depth; the maximum value was 488 ppm for surface soils 5 feet from the
highway.  For all samples at the 18-inch depth, the average sodium
content was 218 ppm, with a maximum value of 307 ppm for the soils
5 feet off the roadway(115,117).

Chloride levels for the above four highway sites showed the same soil
relationships as sodium but quantitative results were lower since
chloride moves more rapidly through the soils.  With trace amounts of
chloride serving as background, the sites receiving 2 and 3 winters
of highway salting exhibited 46-100 ppm chlorides in the surface soils
next to the road, diminishing to 12-24 ppm in the surface soils 45
feet from the road.  The site with 18 winters of salting had 183-217 ppm
chlorides in the surface soils 5-15 feet from the roadway diminishing to
115-117 ppm in the outer periphery(115,117).

At other highway sites in the State of Maine sampled by Hutchinson,
(a total of 22 locations), the levels of salt ions in surface soils
exhibited wide variation, with sodium ranging from 14 to 1,056 ppm
and chlorides ranging from 8 to 768 ppm.  The various roadside soils
across the State, on the basis of being collected 0, 30, and 60 feet
from the highway, showed respective average sodium values of 281, 139
and 96 ppm.  Associated chloride values were respectively 116, 79, and
54 ppm.  Sodium and chloride content of soils immediately adjacent to
the highways were 6 and 115 times higher than are normal for soils in
the State of Maine.  Considering the width of highway right-of-ways,
it was concluded that private properties and soils were very much be-
ing affected by highway salting(46,89,117).

At one roadside location where the soils were examined in greater
detail, Hutchinson found that the cation exchange capacity of the Buxton
soil series present at this particular site was 23 percent saturated
with sodium cations.  In the western U.S., soils having a sodium satura-
tion greater than 15 percent are designated as "alkali" soils.  A number
of roadside soils in Maine may likewise be placed in this "undesirable"
classification.   In summarizing Hutchinson's findings, it is seen that
levels of both sodium and chloride ions in the soils along major highways
in Maine have increased markedly as a result of highway deicing.  It is
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clearly demonstrated that deicing ions have moved laterally at least 60
feet and downward at least 18 inches with time over which these roadways
were salted.  A strong correlation was shown between the consecutive num-
ber of years of salting at a given location vs. the increasing levels of
sodium and chloride ions in adjacent roadside soils.  The carry-over and
accumulation of salts within the soils from one year to the next was
strongly suggested.  Hutchinson also expresses the need to study soil
treatment measures using compounds such as calcium sulfate and calcium
carbonate in flushing excessive sodium from damaged soils.  These soil
treatments may be required only once every two or so years(46,89,115,117).
Chloride Content of Soils and Plants on National Park Grounds,
Washington, D.C.; Correlation with Plant Injury and Death

In continuation of the study on effects of salts on National Park lands
in Washington, D.C. during 1964, ensuing investigations were carried out
by Thomas and Bean in 1965(118), and Wester and Cohen in 1967(119).
Thomas(120) also reports upon a qualitative analytical method used to
determine "excessive" or "normal" amounts of chloride present in soils
and the roots of Kentucky bluegrass receiving highway salts.  In March
1965, extensive die-off of bluegrass sod was noted next to sidewalks
and roads in National Arlington Cemetery and within the parking lot of
the National Capital Regional Office Building.  In March-June 1965, samples
were collected of soils and plant roots for chloride analyses from the salt-
affected areas, and also from various parkways in and around Washington,
D.C.  Control samples were taken in areas not receiving salts.  The study
attempted to correlate the "vigor" of vegetation with the presence of
chlorides.  Unhealthy conditions included observation of dead, chlorotic
or stunted plants.

Thomas and Bean(118) found the time of the year at which tests are con-
ducted to be quite important.  For example, salt could kill the plant,
be leached out of the area, and not suspected or proved later as the
cause of death.  On the other hand, with adequate salt leaching there
could be subsequent plant recovery.  Also, salt uptake by the plant
could cause it to be slightly chlorotic, but it is not certain when and
if these plants would show significant damage.  However, another winter
of salting would likely aggrevate this condition.  Although observed
damage was confined mostly to areas proximate to road shoulders and
walkways, excessive chlorides were found in soils 20 feet from the edge
of the road.  Good correlations were established between the state of
health of bluegrass vs. ppm soluble salts in soils (break point of
843 ppm); and between excessive chlorides in soils vs. ppm soluble salts
in soils.  Qualitative (excessive) soil chlorides were considered a more
reliable indicator of salt injury and loss of plant vigor than the
measurement of chlorides in plant roots.  The authors conclude with the
increasing use of salts in the Washington, D.C. area, that decline and
death of vegetation will continue(118).
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Following the relatively severe winter of 1966-1967 in the Washington,
D.C. area during which 37 inches of snowfall occurred, Wester and
Cohen(119) found severe salt damage to vegetation.  The effects of
heavy wintertime salting were compounded by a serious lack of rainfall
in April, 1967 which provided little opportunity for natural leaching
of salts from the root zone.  Observed and recorded plant damage was
most prevalent in Kentucky bluegrass, California privet, Canadian
hemlock, sugar maple, American elm and Quebec linden.  Samples were
taken for qualitative levels of chlorides in plant leaves and quantita-
tive levels of chlorides in soils.  Both affected and non-affected areas
were sampled for comparative results.  Much of the damage was associated
with accumulations of salts previously deposited by snowplows and front-
end loaders.  Chloride concentrations of soils in non-salted areas varied
from 0.000 to 0.001 percent, compared to levels of 0.01 to 0.09 percent
for salted areas (note 0.01 percent = 100 ppm, and 0.1 percent = 1,000
ppm).  The high chloride content of 0.09 percent was derived from roadside
soils underlying a privet hedge in Fort Myer, Virginia in August 1967,
where almost all plants were killed.

At the Walter A. Reed Army Medical Center in Washington, D.C., severe
damage in 1967 was caused to a section of Canadian hemlock adjacent to
a parking lot and to street-side plantings of sugar maples.  There was
also some damage to turf caused by runoff from uphill salted areas.  The
maples showed symptoms of stunted growth, marginal leaf scorch, foliage
thinning, pre-season defoliation, sun-scald of bark and leaders because
of undue tree exposure, and eventual die-off.  Wester and Cohen(119)
classified their observations on plant damage into three categories:
moderate damage, severe damage, and complete kill.  There were no plants
within the non-salted areas falling into any of these categories.  How-
ever, the vegetation on salted land areas, depending upon the site, was
rated from 0-100 percent in each category.  The authors comment that any
salt damage may greatly shorten the life of affected trees; and shrubbery
and turf can be killed in a single season.  They suggest that salted
snow should be kept within street curbings rather than placed in prox-
imity to plants and vegetation.  Furthermore, potentially-affected areas
should be heavily watered in the early spring if at all possible(119).
Sodium and Chloride Content of Grasses, Salt Tolerances

Along Interstate 80 in Johnson County, Iowa, unsuccessful attempts were
made in 1964 and 1965 to establish turf in the roadside areas.  Salt
contamination was considered the major cause preventing establishment
of seedlings.  Studies by Roberts and Zybura(103,121) were designed to
evaluate salt tolerance and suitability of various coarse texture
grasses for roadside use in Iowa.  Soluble salt determinations  in soil
samples indicated salt levels sufficiently high to reduce grass growth
up to 10 feet from the road.  Greenhouse pot and field plot tests showed
salt tolerance was greatest for Kentucky 31 fescue, decreasing  through
slender wheatgrass, intermediate wheatgrass, western wheatgrass, followed
by other varieties.  The grasses exhibited increased foliar growth at
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sodium chloride levels up to 631 ppm, but it was noted that soil dis-
persal and deflocculation occurred at the 1,262 ppm salt level; and
above 1,000 ppm, injury to grasses became more evident. Unfortunately,
long-term effects of moderate salt levels on grasses were not determined.
Of all grasses tested, Kentucky 31 fescue not only had good sod and  root
development, but also showed best physiological and overall growth when
used in a salted roadside environment.

Verghese et. al.,(122) conducted several tests both in the field and the
greenhouse to determine effects of deicing salts on various grasses  used
along highways.  They found a close relationship between rates of salt
applications and the amounts of sodium and chloride ions in roadside
grasses.  Chloride accumulations within grasses were several times
higher than sodium.  Salt applications decreased the yield of all
grasses studied.  Of the various grasses, Kentucky 31 fescue showed
good adaption to reasonably high salt levels.  Nitrogen soil treatments
seemed to counteract decreasing grass yields due to sodium chloride,
but nitrogen also tends to increase the uptake rate of sodium and
chloride in tissues.  Other results indicate that potassium phosphate
may be effective in reducing salt injury to grasses, but phosphate
stimulates plant growth providing more surface area for salt absorption.
Other soil improvement measures include addition of soluble calcium
salts, gypsum, or anhydrous ammonia to the soil(5,46,117,123,124).
Gypsum is reported to be an effective and inexpensive amendment for
saline soils.
Salt Injury to Trees. St. Paul, Minnesota

French in the late 1950's(5,125), observed salt-injury symptoms of Amer-
ican elm and other species of trees along various city streets in
St. Paul, Minnesota, following winters of heavy road salting.  Tree
leaves turned yellow, then brown, generally coinciding with the start
of hot dry weather and this phenomena became more pronounced through
the summer.  French noticed that tree defoliation and serious injury
were more prominent on the side of the tree fronting the street.
Although soluble salts in the soils appeared to be below the danger
level, injured parts were shown to contain abnormal levels of sodium.
These findings were duplicated in greenhouse experiments when sodium
chloride - calcium chloride mixtures were applied to American elm
seedlings.
Sodium and Chloride Levels in Sugar Maples and Silver Maples in
New Hampshire, Massachusetts, Vermont and Connecticut;
Correlation with Injury and Death

Rich and LaCasse from various studies in New Hampshire determined that
sugar maples and other trees along a heavily-travelled and heavily-
salted highway were moderately to severely injured.  Trees within 30
feet of the highway were usually injured, whereas trees greater than
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30 feet away were almost always healthy.  Symptoms included leaf  scorch,
early coloration and defoliation, reduced growth, browning of  twigs  and
branches, and eventual die-off of severely-affected trees.  Injury could
not be correlated with size or age of tree, soil type, fertility, or
prevalence of parasites.  Foliage from affected trees showed abnormally
high sodium content and the sap from injured trees was high in soluble
salts.  Later studies in New Hampshire showed that maple trees along
salted State roads displayed considerable injury, whereas almost  no  in-
jury was observed for similar trees along unsalted town roads  in  the
same general area.  These investigations found that chloride content was
a somewhat better indicator than sodium for determining damage to foliage,
but in tree sap, sodium was the better indicator.  For the healthy,  mod-
erate, and severe injury classes, sodium levels in foliage were respec-
tively, 0.02, 0.03 and 0.17 percent.  Chloride levels were higher showing
0.06, 0.28 and 0.42 percent, respectively(126,127,128,129).

Rich and LaCasse(128) have repeatedly found of the various deciduous
trees, that maples are most prone to injury and damage caused by  highway
salts.  Kotheimer et. al.,(5,130) conducted studies in New Hampshire of
maple trees receiving highway salts compared to similar trees receiving
little or no salt.  Sugar maples were seen to be more susceptible to
highway salts than the red maples.  Kotheimer concluded that road salt
application was definitely associated with less vigorous and deteriorat-
ing maples alongside New Hampshire highways.  Westing(5,131) in his
review of sugar maple decline, notes that many causes may be responsible
for this decline including adverse environmental conditions, disease, or
completed life cycle.  Salt may only be one of these causes, albeit  an
important one.  Westing mentions symptoms such as reduced growth, loss of
coloration, marginal necrosis in leaves, twig and branch die-off, and
premature leaf loss.  Sixteen States in the northeast and north-central
U.S. have become concerned with this problem, but the sugar maple decline
has been particularly prevalent in the State of New Hampshire.

Additional studies have been undertaken by Holmes and Baker(132)  on
sugar maple decline in Massachusetts, and by Zelazny et. al.,(133) on
silver maple decline in Vermont.  Following extensive investigations
from 1961-1964, Holmes and Baker concluded that foliar chloride levels
in sugar maples could be correlated with injury levels, and salt  does
injure and even kills sugar maple trees.  Holmes and Baker take the
position that roads must be kept safe in the winter.  However, care
should be taken to minimize damage to maples by judicious use of  a salt
in sand mixture applied after plowing.  They make it equally clear that
more lavish use of salt will increase both foliar chloride uptake and
injury to sugar maples.  Salts may also affect the vulnerability  of  trees
to other injuries or disease, and these other agents may affect the  in-
tensity of salt injury.  Holmes and Baker observed minimal or no  injury
symptoms in the range of 0.05 to 0.6 percent foliar chlorides  (1  to  12
times normal); slight or moderate symtoms were present in the range  of
0.4 to 1.0 percent foliar chlorides; and severe symptoms were  experienced
above 1.0 percent chlorides.  It was moreover concluded that foliar
symptoms when correlated with chloride levels in excess of 0.3 percent
                                 - 93 -

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should not be attributed to factors other than salt.  Regarding foliar
sodium levels, these were shown to be much lower than chlorides.  Trees
with severe injury had foliar sodium from 0.004 to 0.053 percent; and
those with less severe symptoms had 0.0006 to 0.084 percent sodium(132).

Zelazny et. al.,(133) undertook studies in an area of extensive silver
maple decline in Vermont attributed to highway salts.  Heavy salt appli-
cations reached roadside soils and were consequently absorbed into  the
leaves and stems of nearby trees.  Chloride toxicity was judged more
critical than total soluble salts.  The test results indicated that
chloride levels of 0.20 percent in the leaves produced leaf scorch,
whereas chloride percentages in excess of 0.50 percent were correlated
with leaf scorch, defoliation and ultimate plant death.  Sodium levels
were much higher in damaged trees compared to healthy trees (respec-
tively, 0.005 - 0.146 percent vs. 0.002 - 0.016 percent in the leaves),
and thought to be one of the possible reasons for overall plant deterior-
ation.  The authors recommend that woody vegetation should be located
as far from the highway as possible, that plants be selected on the
basis of salt tolerance, and the highway drainage be diverted away  from
roadside vegetation(133).

Unpublished work by Button and Peaslee reported in the 1970 Highway
Research Board literature review(5,134), indicates that high levels of
sodium and chloride may be expected in trees exposed to highway drain-
age.  Observed symptoms included leaf-burn injury, decline in vigor,
and defoliation.  The leaves of sugar maple trees showing margin burns
contained around 5,000 ppm chlorides, and trees near die-off had around
9,000 ppm chlorides.  Low levels of highway salts applied over a suf-
ficiently long period of time could accumulate within the plant causing
serious injury and plant death.  The range of chlorides within the
leaves of damaged trees was 0.26 to 0.94 percent.  For healthy trees
these levels were 0.03 to 0.31 percent(5,135,136,137).

Allison from his observations on various species of plants, indicated in
1964 that chloride accumulations around 1-2 percent (i.e., 10,000-20,000
ppm) would cause marginal burn, leaf drop, twig dieback, and death of the
plant.  These chloride accumulations will occur when chlorides in soils
are in the approximate range of 700 to 1,500 ppm.  Sodium content of 0.05
percent or even less, also produces leaf burn and significant plant in-
Jury (5,138).
Salt Tolerance of Individual Plant Species; Fruit, Vegetable and
Fi«ld Crops, Grasses, Trees and Ornamentals

The subject of salt tolerance and variability between plant species  is
a most interesting one.  Salt tolerance of various plants has been
studied and classed with respect to:  1) relative plant yield on  saline
soils compared to non-saline soils; 2) plant yield on saline soils;  and
3) the ability of the plant to survive on saline soils.  The majority
of the Information developed on salt tolerance is based upon the  first

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and second criteria given above.  This is because most research on  salt
tolerance has been carried out in the arid and semi-arid regions of the
U.S., and within these areas crop yields have been of high importance.
Keeping in mind the third criteria is probably of greatest interest to
highway personnel, that is the ability of the crop to survive in saline
soils, information on salt tolerance can nevertheless be used as a  use-
ful guideline in selecting roadside plants and vegetation.  The data
presented in Tables V through IX below would appear to represent some
of the best and most concise information available.  Tables V, VI,  VII,
and VIII respectively, give the salt tolerance of various fruit crops,
vegetable crops, field crops, and grasses.  These tables are taken  from
the 1970 Highway Research Board literature review(5) but the original
source material is found in previous publications of the U.S. Department
of Agriculture.  Table IX gives the salt tolerance of trees and orna-
mentals taken from Zelazny, 1968(139).  Each table gives major plant
or major crop arranged according to whether the plant is salt tolerant;
moderately tolerant/sensitive; or sensitive.  Within each class, the
plants are listed in decreasing order of salt tolerance; however,
differences of 2 or 3 places in the columns may not be significant.
The discussion following gives further information on the salt tolerance
of ornamental shrubs and trees which is of particular interest to this
report.

Various researchers have studied the salt tolerance of ornamental trees
and shrubs.  Monk and Peterson(5,144) using one-year old seedlings,  clas-
sify 20 different species as follows:  1) Most Salt Tolerant - black
locust, honey locust, Russian olive, squaw bush, and tamarix; 2) Salt
Tolerant - Silvery buffalo berry, golden willow, ponderosa pine, and
green ash; 3) Moderately Tolerant - Japanese honeysuckle and eastern
red cedar; 4) Least Tolerant - Blue spruce, Douglas fir, black walnut,
little-leaf linden, barberry, winged euonymus, multiflora rose, spiraea,
and arctic blue willow.

Rudolfs(5,145) finds that oak has greatest salt tolerance, birch has
intermediate tolerance, and maple is most sensitive.  Zhemchuzhnikov(139)
concludes that trees with greatest salt tolerance are light-loving
species with a fair degree of drought resistance and usually located in
arid climates.  Hanes, et. al.,(5) also point out that vegetation not
subject to annual harvesting could, over time, accumulate sufficient
salt within the plants to cause serious damage.  This effect is important
when considering the tolerance of perennial woody plants.  Zelazny(139),
based upon an extensive literature review, has classified the salt
tolerance of 67 various trees and ornamentals as shown in Table IX.

We have previously described the three criteria determining the type
of salt tolerance data and plant classifications generally available.
Zelazny(139) with reference to these criteria does not believe high
yields are necessary, or even desired in some cases, for highway vegeta-
tion.  Rather it is desirable that roadside vegetation be maintained the
year around with minimum effort and cost, erosion be prevented, and the
roadside environment be aesthetically attractive.  Since the majority of
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salt tolerance data were developed in the arid U.S., we should compare
climate conditions of the western U.S. with that existing in the highway
salting regions of the northeast and north-central U.S.  Zelazny(139)
finds that arid and semi-arid areas usually experience high salt levels
and water shortage.  In the northeast and north-central States, the
climate is cooler and more humid, implying that toxicity of specific
salt ions is more important than water shortage.  Vegetation in the
western U.S. has also been exposed to saline conditions for thousands
of years which undoubtedly has created a natural selection of plants
to salt tolerance.  Such a selection has not occurred to as high a de-
gree in the eastern U.S.  It appears ironical that many plants capable
of tolerating high salt concentrations in the West are not able to with-
stand the cool, moist climate in the East(139).  Conversely, plants and
vegetation in the highway salting regions of the U.S. lacking this
natural selection, would appear to be significantly more sensitive to
salt injury.
Effects of Salt Spray on Vegetation and Roadside Environment

Two separate studies have described the effects of salt spray on vegeta-
tion alongside highways.  Where calcium chloride was sprayed on roads to
reduce dust, Strong(5,146) found there was frequent injury to roadside
trees particularly leaf scorch, and at times even tree die away.  With
small concentrations of calcium chloride, symptoms of leaf scorch and
needle burn could not be readily ascribed to salting as distinguished
from drought.  However, higher levels of calcium chloride produced more
rapid injury.  Direct application of calcium chloride and dust mixtures
to leaves did not appear to cause symptoms of leaf scorch, but rather
produced a brown spotting of the leaves.  Sauer(5,147) believes that
salt spray from highways may often be the major cause of roadside plant
injury rather than salt being absorbed from the soil.  Sauer observed
that certain portions of roadside plants which were directly behind
snow or beam barriers and thereby protected from the spray, were conse-
quently spared salt injury.

Following heavy snowstorms, motorists frequently perceive a salty
atmosphere prevailing along the highway.  This haze of airborne crystals
and dissolved salt stirred up by vehicular traffic will tenaciously
adhere to automobile windshields, increasing the opportunity for traffic
accidents.  A much higher potential also exists for accelerated corrosion
of automobile finish and metal parts.  It was estimated in Milwaukee
County, Wisconsin, that up to 10 percent of the highway salt on any one
day may become airborne, which could represent nearly 25 percent of the
total air pollution load normally prevailing in that County(26,60).
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                            TABLE V

               SALT TOLERANCE OF FRUIT  CROPS^-'
                        Moderately
 Tolerant                Tolerant                   Sensitive

Date palm               Pomegranate                 Pear
                        Fig                         Apple
                        Olive                       Orange
                        Grape                       Grapefruit
                        Cantaloup                   Prune
                                                    Plum
                                                    Almond
                                                    Apricot
                                                    Peach
                                                    Strawberry
                                                    Lemon
                                                    Avacado

ITOriginal Source, Bernstein, L., 1965(140)
                          TABLE VI

             SALT TOLERANCE OF VEGETABLE
                        Moderately
 Tolerant                Tolerant                   Sensitive

Garden beet             Tomato                      Radish
Kale                    Broccoli                    Celery
Asparagus               Cabbage                     Green  bean
Spinach                 Cauliflower
                        Lettuce
                        Sweet corn
                        Potato
                        Sweet potato-yam
                        Bell pepper
                        Carrot
                        Onion
                        Pea
                        Squash
                        Cucumber

2?Original Source, Bernstein, L., 1959(141)
                            - 97 -

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                               TABLE VII

                    SALT TOLERANCE OF FIELD CROPS-

                             Moderately
      Tolerant                Tolerant                   Sensitive

     Barley                  Rye                         Field  bean
     Sugar beet              Wheat
     Rape                    Oats
     Cotton                  Sorghum
                             Sorgo (sugar)
                             Soybean
                             Sesbania
                             Broadbean
                             Corn
                             Rice
                             Flax
                             Sunflower
                             Castorbean

     ~Tl  Original Source, Bernstein, L., 1960(142)
                              TABLE VIII
                                                         4/
             SALT TOLERANCE OF GRASSES AND FORAGE LEGUMES—

                               Moderately
   Tolerant                     Tolerant                 Sensitive

Alkali sacaton              White sweet clover       White dutch clover
Saltgrass                   Yellow sweet clover      Meadow  foxtail
Nuttall alkali-grass        Perennial ryegrass       Alsike  clover
Bermuda grass               Mountain brome           Red clover
Tall wheatgrass             Harding grass            Ladino  clover
Rhodes grass                Beardless wildrye        Burnet
Rescue grass                Strawberry clover
Canada wildrye              Dallis grass
Western wheatgrass          Sudan grass
Tall fescue                 Hubam clover
Barley                      Alfalfa
Birdsfoot trefoil           Rye
                            Wheat
                            Oats
                            Orchard grass
                            Blue gamma
                            Meadow fescue
                            Reed canary
                            Big trefoil
                            Smooth brome
                            Tall meadow oatgrass
                            Milkvetch
                            Sourclover

4?Original Source, Bernstein, L., 1958(143)~~~


                                 - 98 -

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                               TABLE IX
               SALT TOLERANCE OF TREES AND ORNAMENTALS-'
                                                       5/
   Tolerant

Common matrimony vine
Oleander
Bottlebrush
White acacia
English oak
Silver poplar
Gray poplar
Black locust
Honey locust
Osier willow
White poplar
Scotch elm
Russian olive
Squaw bush
Tamarix
Hawthorne
Red oak
White oak
Apricot
Mulberry
   Moderately
    Tolerant

Silver buffalo berry
Arbor vitae
Spreading juniper
Lantona
Golden willow
Ponderosa pine
Green ash
Eastern red cedar
Japanese honey suckle
Boxelder maple
Siberian crab
European black currant
Pyracantha
Pittosporum
Xylosma
Texas privet
Blue spruce
Douglas fir
Balsam fir
White spruce
Beech
Hard maple
Cotton wood
Aspen
Birch
    Poorly
   Tolerant

Black walnut
Little leaf linden
Barberry
Winged euonymus
Multiflora rose
Spiraea
Arctic blue willow
Viburnum
Pineapple guava
Rose
European hornbeam
European beech
Italian poplar
Black alder
Larch
Sycamore maple
Speckled aider
Lombardy poplar
Red maple
Sugar maple
Compact boxwood
Filbert
5/  From Zelazny, L., 1968(139)
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                              SECTION XV

                                SUMMARY
Current annual use of highway deicing compounds in the U.S. is estimated
around nine million tons of sodium chloride, one-third million tons of
calcium chloride, and eight million tons of abrasives.  About 40  States,
mostly in the northeast and north-central U.S., employ highway deicers.
"Bare-pavement" conditions for streets and highways in the wintertime
are considered necessary to adequately protect the lives and safety of
motorists using these roads.  The use of sodium chloride and calcium
chloride as deicers has increased rapidly over the past 15 years.  The
leading States in total use of highway salts are Pennsylvania, Ohio,
New York, Michigan and Minnesota.

Highway salting rates are usually in the range of 400 to 1,200 pounds
of salt per mile of roadway per application, and many roads and highways
in the U.S. may receive more than 20 tons salt per lane mile or more
than 100 tons per road mile over the winter season.  Snow-control equip-
ment includes tall-gate and hopper-type spreaders, trucks, front-end
loaders, snow blowers, plows, thermal melting systems, etc.  Considerable
wasting of highway deicing salts occurs because of excessive application,
misdirected spreading and general wintertime difficulties.

Salt storage is necessary for sustaining highway deicing operations,
but these facilities too frequently become a major contributing source
of groundwater and surface water salt contamination.  Salts are stored
unprotected in open areas, or placed in unused buildings, garages,
sheds, cribs, storage bins and upon elevated platforms or pallets.
Because of water supply contamination and desirability of better product
handling, many communities have turned to covering of salt piles, en-
closed structures, and diversion and collection of salt-laden drainage.

Street runoff from the melting of ice and snow mixed with chloride salts,
finds its way via combined sewers to the local sewage treatment plant,
and via storm sewers to nearby receiving streams.  Daily chloride loads
were shown to be 40 to 50 percent higher for winter months as compared
to summer months in municipal sewage at Milwaukee, Wisconsin.  During
days of heavy snow-melt, daily chloride loads were three-fold the normal
summertime loads.

Runoff samples collected from a downtown Chicago expressway in the winter
of 1967 showed chloride content from 11,000 to 25,000 mg/1.  It has been
calculated that 600 Ib. salt when applied to a one-mile section of road-
way 20 feet wide containing 0.2 inches of ice, will produce an initial
salt solution of 69,000 to 200,000 mg/1 in the temperature range  of
10 F - 25°F.  At Milwaukee on January 16, 1969, extremely high chloride
levels of 1,510 to 2,730 mg/1 were found in the Milwaukee, Menomonee  and
Kinnickinnic Rivers, believed directly attributable to deicing salts  enter-
ing these streams via snow melt.  The dumping of extremely large  amounts
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of accumulated snow and ice from streets and highways, either directly
or indirectly into nearby water bodies, could constitute a serious pollu-
tion problem.  These deposits have been shown to contain up to 10,000
mg/1 sodium chloride, 100 mg/1 oils, and 100 mg/1 lead.

A 1966-1968 survey of twenty-seven farm ponds along various highways in
the State of Maine showed that road salts have strong seasonal influence
on the chloride level of these waters, and that salt concentrations were
increasing yearly.  Density stratification of chlorides was observed in
Beaver Dam Lake at Cumberland, Wisconsin, in First Sister Lake near Ann
Arbor, Michigan, and Irondequoit Bay at Rochester, New York, all three
cases attributed to salt runoff from nearby streets entering these lakes.
Highway salts are also estimated to contribute 11 percent of the total
input of waste chlorides entering Lake Erie annually.  Sodium from road
salts entering streams and lakes may additionally serve to increase
existing levels of one of the monovalent ions essential for optimum
growth of blue-green algae, thereby stimulating nuisance algal blooms.

Special additives are present within most highway deicers sold today and
may create pollution problems more severe than caused by the chloride
salts.  Ferric ferrocyanide and sodium ferrocyanide are commonly used to
minimize caking of salt stocks.  Sodium ferrocyanide is quite soluble in
water and will generate cyanide in sunlight.  Tests by the State of
Wisconsin showed that a 15.5 mg/1 solution of sodium ferrocyanide pro-
duced 3.8 mg/1 cyanide after 30 minutes.  Levels of cyanide toxic to
fishlife range downward to 0.1 mg/1, but desired levels are sought as
low as 0.01 mg/1.  Maximum and desired levels of cyanide in public water
supplies range from 0.2 to 0.01 mg/1.

Chromate and phosphate additives have been used in highway deicers as
corrosion inhibitors.  As with cyanide, chromium is quite toxic, and
limits permitted in drinking water and other waters are quite low.  The
maximum amount of hexavalent chromium allowed in public water supplies
is 0.05 mg/1.  In the Minneapolis-St. Paul area, during the winter of
1965-1966, snow melt collections showed maximum values of 24 mg/1 sodium
chromate, 1.7 mg/1 hexavalent chromium, and 3.9 mg/1 total chromium.

Serious groundwater pollution has occurred in a number of locations, due
to heavy amounts of deicing salts applied onto highways and inadequate
protection given to salt storage areas.  The State of New Hampshire, up
to 1965, is reported to have replaced more than 200 roadside wells at a
total cost of more than $200,000, because these waters had been contam-
inated by highway salts.  Some of the wells exhibited chlorides in excess
of 3,500 mg/1.  In Manistee County, Michigan, a roadside well located
300 feet from a highway department salt storage pile, was found to contain
4,400 mg/1 chlorides.

Tastes and odors in a municipal water supply in Connecticut were ascribed
to sodium ferrocyanide originating from a salt storage pile.  Also in
Connecticut, a salt storage area was responsible for contaminating the
well water supply serving four families.  Within Massachusetts, salt
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increases have been noted In the water supplies of some 63 communities,
at least in part due to road salting and salt storage piles, and certain
water supplies have been abandoned.

Road salts not only promote vehicular corrosion, but additionally may
affect structural steel, house sidings, buildings and other property
alongside the highway.  It has been estimated that the private car owner
pays for corrosion in the amount of about $100 per year.  Frequent car
washing is still generally recommended as the best protection possible.

Deicers may cause appreciable damage to highway structures and pavements.
Concrete pavements and bridge floors and decks constructed of Portland
cement concrete show greatest susceptibility to salt attack.  Air-entrained
concrete is reported superior to non air-entrained concrete in its re-
sistance to salts.  Nevertheless, deicing chemicals should not generally
be applied even to air-entrained concrete for at least one year, after
it is poured.

Significant damage of roadside soils, vegetation and trees has been caused
by liberal application of highway salts.  Symptoms of injury in plants
and trees include leaf scorch, defoliation, stunting, and ultimately,
plant die-off.  Soil damage includes loss of fertility and permeability,
and dispersion of soil colloids, resulting in lack of aggregation and
poor internal drainage.  Many of the studies dealing with salt injury
and death of roadside trees have focused on sugar maple decline which
is occurring over a 16-State area, but mostly in the New England States.
Foliar (leaf) chloride levels in sugar maples have been correlated with
extent of injury, when in excess of 0.3 percent chlorides.

Included in this report are a series of tables giving relative salt
tolerance of various fruit crops, vegetable crops, field crops, grasses,
forage legumes, trees and ornamentals.  These data, are intended to
serve as approximate guidelines for highway authorities and others in
selecting roadside plants and vegetation.  It is believed that plants of
the northeast and north-central U.S. may be inherently more sensitive to
salt injury than has been previously thought.
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                              SECTION XVI

                            ACKNOWLEDGMENTS
The advice and assistance of the following persons and organizations who
contributed to this report are gratefully acknowledged:

Mr. Frank Wood of the Salt Institute, Alexandria, Virginia, who provided
the use of sketches of salt storage facilities and various other  informa-
tion for incorporation into this report.

The City of New York, New York and its Department of Sanitation;  the
City of Chicago, Illinois and its Bureau of Equipment Service; the  City
of Milwaukee, Wisconsin and its Department of Public Works, for their
cooperation in making available numerous photographs on deicing and snow
removal equipment and salt storage areas.

Mr. Clifford Risley and his staff of the Office of R&D, Great Lakes
Region, EPA, Chicago, Illinois, for their assistance in obtaining the
photographs from Chicago and Milwaukee.

Mr. J. R. Fitzpatrick of the Ontario Department of Highways for provid-
ing a series of photographs on the "Beehive" dome used for deicing
materials storage in the Province.

Mr. Raymond Leary, Director, and Mr. Lawrence Ernest of the Milwaukee
Sewerage Commission who supplied chloride data on the Milwaukee sewerage
system and other information for the Milwaukee area.

Mr. Ken Henries of the Wisconsin Division of Natural Resources, Milwaukee,
and Dr. Raymond Kipp of Marquette University, Milwaukee, for information
received on highway salting for Milwaukee and the State of Wisconsin.

Dr. F. E. Hutchinson of the University of Maine at Orono, who provided
detailed description and reports of his field investigations carried out
in Maine on soils, groundwater, farm ponds, and vegetation.

Also, the many individuals who supplied copies of published and unpublished
materials for incorporation into this document, and the many persons who
generously gave their time and helpful suggestions during review  of the
Interim Report on Highway Deicing previously released by the Edison Water
Quality Laboratory in December 1970.
                                 - 105 -

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                             SECTION XVII

                              REFERENCES
 1.  "Survey of Salt, Calcium Chloride and Abrasive Use  for  Street  and
     Highway De-Icing in the United States and in Canada for 1966-1967",
     The Salt Institute, 33 pp., Alexandria, Virginia, Date  not given.

 2.  "Snow and Ice Control - A Critical Look at the Critics", Dickinson,
     W. E., Paper appearing in the "Proceedings of the Symposium:
     Pollutants in the Roadside Environment", pp. 6-14,  University  of
     Connecticut, February 29, 1968.

 3.  Personal communication with The Salt Institute, Alexandria,
     Virginia, 1970.

 4.  "Legislative Research Council Report Relative to the Use and
     Effects of Highway De-icing Salts", the Commonwealth of
     Massachusetts, 80 pp., January 1965.

 5.  "Effects of Deicing Salts on Water Quality and Biota -  Literature
     Review and Recommended Research", Hanes, R. E., et. al., National
     Co-operative Highway Research Program Report 91, Virginia Poly-
     technic Institute and Highway Research Board, 70 pp., 1970.

 6.  "Snow Removal and Ice Control in Urban Areas, Research  Project
     No. 114, Volume I", Compiled and Edited by Lockwood, R. K.,
     American Public Works Association, 126 pp., August  1965.

 7.  "Snow Removal and Ice Control in Urban Areas, Research  Project
     No. 114, Vol. II", Compiled and Edited by Lockwood, R.  K.,
     American Public Works Association, 125 pp., June 1966.

 8.  "The Role of Deicing Salts in the Total Environment of  the Automo-
     bile", Wood, F. 0., Paper Presented at NACE Symposium,  18 pp.,
     March 2, 1970.

 9.  "Chlorides", Commission on Water Pollution, Schraufnagel, F. M.,
     20 pp., Madison, Wisconsin, 1965.

10.  "Complete Salting - Sanding Economic Study", Hopt,  R. L., 50 pp.,
     Maintenance Division, Idaho Department of Highways, Boise, Idaho,
     April 1971.

11.  Personal Communication with F. 0. Wood, Technical Director, The
     Salt Institute, Alexandria, Virginia, May 3, 1971.

12.  "Salt - The Universal Deicing Agent", Wood, F. 0.,  Paper Presented
     at Street Salting Urban Water Quality Workshop, SUNY Water Resources
     Center, Syracuse University, May 6, 1971, Syracuse, New York.
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13.  "The Encyclopedia of Oceanography", Encyclopedia of Earth Sciences
     Services, Volume I, Edited by Fairbridge, R. W., 1021 pp., Reinhold
     Publishing Company, New York, N.Y., 1966.

14.  "Chemical Oceanography 1", Edited by Riley, J. P- and Skirrow, G.,
     712 pp., Academic Press, London and New York, 1965.

15.  "The Chemistry and Fertility of Sea Waters", Harvey, H. W.,  240 pp.,
     Cambridge at the University Press, London and New York, 1963.

16.  "Salt Migration in Soil", Prior, G. A., Paper appearing in the
     "Proceedings of the Symposium:  Pollutants in the Roadside Environ-
     ment", pp. 15-23, University of Connecticut, February 29, 1968.

17.  Personal communication with F. E. Hutchinson, University of  Maine,
     Orono, Maine, May 1970.

18.  "Pollution Aspects Associated with Chemical Deicing", Schraufnagel,
     F. M., Paper appearing in the "Highway Research Record Report
     No. 193 on Environmental Considerations in the Use of Deicing
     Chemicals", pp. 22-33, Highway Research Board, Washington, D.C., 1967.

19.  Personal communication with U.S. Geological Survey, Federal
     Building, Boston, Massachusetts, May 1970.

20.  "Storing Road De-icing Salt", The Salt Institute, 16 pp.,
     Alexandria, Virginia, 1967.

21.  "Report Discusses Salt Corrosion", APWA Reporter, pp. 4,
     October 1970.

22.  "Mayor Sees Demonstration of New Salt Spreader", Article appear-
     ing in the New York Times, New York, N.Y., November 26, 1970.

23.  "Mayor Inspects Cleanup Arsenal", Article appearing in the
     New York Times, New York, N.Y., October 24, 1970.

24.  "Highway Research Record Report No. 193 on Environmental
     Considerations in the Use of Deicing Chemicals", Foreword,
     Highway Research Board, Washington, D.C., 1967.

25.  "What are the Problems", Greene, W. C., Paper appearing in
     the "Proceedings of the Symposium:  Pollutants in the Roadside
     Environment", pp. 1-5, University of Connecticut, February 29,
     1968.

26.  "What is Highway Salt Doing to Us?"  Newspaper article appearing
     in the Milwaukee Journal, May 4, 1970, Milwaukee, Wisconsin.

27.  "The Snowfighter's Salt Storage Handbook", 24 pp., The Salt
     Institute, Alexandria, Virginia, 1968.
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28.  "Beehives Protect Snow-Removal Salt and Prevent Water  Pollution",
     Fitzpatrick, J. R., American City, pp. 81-83,  September  1970.

29.  "Characterization, Treatment, and Disposal of  Urban  Stormwater",
     Weibel, S. R., et. al., Paper presented at the Third International
     Conference held in Munich, Germany, September  1966; Advances in
     Water Pollution Research, Vol I, pp. 329-352,  Published  by Water
     Pollution Control Federation and Port City Press,  Inc.,
     Baltimore, Maryland, 1967.

30.  "Air Chemistry and Radioactivity", Junge, C. E., et. al.,
     International Geophys. Series, j4_, 289, Academic Press,
     New York, 1963.

31.  "Salt Concentrations of Rainfall and Shallow Groundwater Across
     the Lower Rio Grande Valley", Fanning C. D. and Lyles, L.,
     Journal Geophys. Res. 69: pp. 599-604, 1964.

32.  "Amount of Rain Water Collected at Cirencester", Kinch,  E.,
     Journal Chem. Soc. (London), 77, 457, pp. 1271-1273, 1900.

33.  "Nitrogen and Chlorin in Rain and Snow", Knox, W.  K.,  Chemical
     News, 111 (2280): 61-62, 1915.

34.  "Nitrogen, Chlorin, and Sulfates in Rain and Snow", Artis, B.,
     Chemical News, 113 (2928): 3-5, 1916.

35.  "River Pollution. I. Chemical Analysis", Klein, L., Butterworths,
     London, England, 1959.

36.  "Chemistry for Sanitary Engineers", Sawyer, C. N., McGraw-Hill
     Book Co. Inc., New York, 1960.

37.  "Preventive Medicine and Hygiene", Rosenau, M. J., 6th Edition, D.
     Appleton Century Co., Inc., New York, 1935.

38.  "A Water Quality Model of Chlorides in The Great Lakes", 0'Conner,
     D. J., and Mueller, J. A., Proc. American Society  of Civil Engineers,
     Jour, of the Sanitary Engineering Division, 96, pp. 955-975, No. SA4,
     August 1970.

39.  Personal communication with members of the Milwaukee Sewerage
     Commission and personnel at the Jones Island sewage treatment
     plant, May 1970.

40.  "Street Salting and Water Quality in Meadow Brook, Syracuse, New
     York", Hawkins, R. H., Preliminary Draft Report Received from
     Author, of Paper Presented at Street Salting Urban Water Quality
     Workshop, SUNY Water Resources Center, Syracuse University,
     May 6, 1971, Syracuse, New York.
                                 - 109 -

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41.  "Effects on Winter Storm Runoff of Vegetation and as a Factor  in
     Stream Pollution", Sullivan, R. H., American Public Works
     Association, Paper presented at the Seventh Annual Snow  Conference,
     April 12, 1967, 6 pp., Milwaukee, Wisconsin.

42.  "Water Pollution Aspects of Urban Runoff", Final Report  on  the
     Causes and Remedies of Water Pollution from Surface Drainage
     of Urban Areas - Research Project No. 120, Contract No.  WA  66-23,
     conducted by the American Public Works Association for the
     Federal Water Quality Administration, 272 pp., January 1969.

43.  "Final Draft Report - Engineering Evaluation:  Rainfall-Runoff
     and Combined Sewer Overflow", FWQA Contract No. 14-12-402,
     Henningson, Durham and Richardson, Inc., March 1970.

44.  "Progress Report No. I, July 1, 1965 - June 30, 1966, The
     Influence of Salts Applied to Highways on the Levels of
     Sodium and Chloride Ions Present in Water and Soil Samples",
     Hutchinson, F. E., Project No. R1086-8, 22 pp., 1966.

45.  "Progress Report No. II, July 1, 1966 - June 30, 1967, The
     Influence of Salts Applied to Highways on the Levels of  Sodium
     and Chloride Ions Present in Water and Soil Samples", Hutchinson,
     F. E., Project No. R1086-8, 26 pp., 1967.

46.  "Project Completion Report, July 1965 - June 1969, The Influence
     of Salts Applied to Highways on the Levels of Sodium and Chloride
     Ions Present in Water and Soil Samples", Hutchinson, F.  E.,
     Project No. A-007-ME, 20 pp., June 1969.

47.  "Concentration of Nine Inorganic Ions in Maine Rivers",  Hutchinson,
     F. E., Research in the Life Sciences, pp. 8-11, Winter 1968.

48.  "Effect of Highway Salting on the Concentration of Sodium and
     Chloride in Rivers", Hutchinson, F. E., Research in the  Life
     Sciences, pp. 12-14, Winter 1968.

49.  "Effects of Road Salt on a Vermont Stream", Kunkle, S. H.,  Paper
     Presented at Street Salting Urban Water Quality Workshop, 7 pp.,
     SUNY Water Resources Center, Syracuse University. May 6, 1971,
     Syracuse, New York.

50.  "Physicochemical and Microbiological Properties of Urban Storm-
     Water Runoff", Soderlund, G., et. al., Paper Presented at Fifth
     International Water Pollution Research Conference, pp. 1-2/1 to
     1-21B, San Francisco, California, July-August 1970.

51.  "Snow Heavy With Lead", Newspaper Article Appearing in the  Daily
     News, Columbus, Ohio, April 15, 1971.
                                 - 110 -

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52.  "Effect of Highway Salting on the Concentration of Sodium and
     Chloride in Private Water Supplies", Hutchinson, F. E., Research
     in the Life Sciences, pp. 15-19, Fall 1969.

53.  "Chlorides in Lake Erie", Ownbey, C. R. and Kee, D. A., Tenth
     Conference Great Lakes Research, First Meeting International
     Association of Great Lakes Research, 14 pp., Toronto, Canada,
     April 1967.

54.  "Effect of Salt Runoff from Street Deicing on a Small Lake",
     Judd, J. H., Thesis Submission, 145 pp., University of
     Wisconsin, Madison, Wisconsin, 1969.

55.  "Uber Temperatur und Stabilitatsverhaltnisse von Seen",
     Schmidt, W., Geogr. Ann., 10, pp. 145-177, 1928.

56.  "A Treatise on Limnology, Volume I", Hutchinson, G. E.,
     John Wiley and Sons, Inc., Publishers, New York, N.Y., 1957.

57.  "Runoff of Deicing Salt:  Effect on Irondequoit Bay, Rochester,
     New York", Diment, W. H. and Bubeck, R. C., Paper Presented at
     Street Salting Urban Water Quality Workshop, 18 pp., SUNY Water
     Resources Center, Syracuse University, May 6, 1971, Syracuse,
     New York.

58.  Personal Communication with L. E. Reup, Technical Studies Branch,
     Division of Technical Support, National Field Investigations Center,
     U.S. Environmental Protection Agency, Cincinnati, Ohio, 1971.

59.  "Road Salt as a Polluting Element", Special Environmental Release
     No. 3, Sharp, R. W., Bureau of Sport Fisheries and Wildlife,
     U.S. Department of the Interior, Federal Building, Fort Snelling,
     Twin Cities, Minnesota, 55111, December 14, 1970.

60.  Personal communication with Members of the State of Wisconsin,
     Division of Natural Resources, Milwaukee, Wisconsin, May 1970.

61.  "The Apparent Thresholds of Toxicity of Daphnia magna for Chlorides
     of Various Metals when Added to Lake Erie Water", Anderson, B. G.,
     Trans. Amer. Fish. Soc., 78, pp. 96-113, 1948.

62.  "Report No. 3, Subcommittee on Toxicities, Metal Finishing
     Industries Action Committee", Ohio River Valley Water
     Sanitation Commission, 1950, Contained in "Water Quality
     Criteria", by McKee, J. E. and Wolf, H. W., 2nd Edition, State
     Water Quality Control Board, Sacramento, California, 1963.

63.  "A Study in the Relative Toxicity of Anions, with Polycelis nigra
     as the Test Animal", Jones, J. R. E., Journal Exp. Biol., 18,
     pp. 170-181, 1941.
                                 - Ill -

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64.   "Toxicity of Ferro-and Ferricyanide Solutions to Fish, and
     Determination of the Cause of Mortality", Burdick, G. E. and
     Lipschuetz, M., Trans. Amer. Fish. Soc., 78, pp. 192-202, 1948.

65.   "Water Quality Criteria", McKee, J. E. and Wolf, H. W., 2nd Edition,
     State Water Quality Control Board, Sacramento, California, 548 pp.,
     1963.

66.   "Public Health Service Drinking Water Standards - 1962", Public
     Health Service Publication No. 956, 61 pp., U.S. Department of
     Health, Education and Welfare, U.S. Government Printing Office,
     Washington, D.C., 1962.

67.   "Manual for Evaluating Drinking Water Supplies", A Manual of Prac-
     tice Recommended by the U.S. Public Health Service, 76 pp., U.S.
     Department of Health, Education and Welfare, Public Health Service,
     Environmental Control Administration, Cincinnati, Ohio, 1969.

68.   Materials in the Files of the Storm and Combined Sewer R&D
     Section, Edison Water Quality Laboratory, Federal Water
     Quality Administration, Edison, New Jersey, 1970.

69.   "Some Factors Influencing the Detoxication of Cyanides in
     Health and Disease", Bodansky, M. and Levy, M. D., Arch.
     Int. Med., 31, pp. 373-389, 1923.

70.   "Toxicologic Methods for Establishing Drinking Water Standards",
     Stokinger, H. E. and Woodward, R. L., Journal American Water
     Works Association, 50, pp. 515-529, 1958.

71.   "The Detection of Poisons in Public Water Supplies", Smith, 0. M.,
     Water Works Engineering, 97, pp 1293-1312, 1944.

72.   "The Merck Index, Edition 7", Stecher, P. G., Editor, Merck and Co.,
     Rahway, New Jersey, 1960.

73.   "Poisoning of Animals by Cyanides Present in Some Industrial
     Effluents", Clough, G. W., Vet. Rec., 13_, pp. 538, 1933.

74.   "Influence of Temperature and Oxygen Tension on the Toxicity
     of Poisons to Fish", Wuhrmann, K. and Woker, H., Proc. Inter.
     Assoc. Theoret. and Appl. Limnology, 12, pp. 795-801, 1953.

75.   "River Pollution - General and Chemical Effect", Lovett, M.,
     pp. 9-27, in "Treatment of Trade Waste Waters and Prevention
     of River Pollution", Issac, P. C. G., Ed., Bull. No. 10,
     Dept. of Civil Engineers, King's College, Newcastle-upon-Tyne,
     England, 312 pp., 1957.

76.   "Treatment and Disposal of Industrial Waste Waters", Southgate,
     B. A., Department of Scientific and Industrial Research,
     H. M. Stat. Office, London, England, 1948.
                                 - 112 -

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77.  "Water Pollution:  General Introduction", Southgate, B. A.,  Chem.
     and Ind., pp. 1194-1199, 1955.

78.  "Effects of Cyanide on Black Hills Trout", Karsten, A., Black
     Hills Eng., 22, pp. 145-174, 1934; Abstracts, Journal American
     Water Works Association, 23, 660, 1936.

79.  "The Effect on Fish of Effluents Containing Cyanide", Lehmann,  C.,
     L. F. Fischerei, 1926; Wass u. Abwass, 24, pp. 84, 1928; Abstracts,
     Journal American Water Works Association, 22, pp. 998, 1930.

80.  "Handbook of Toxicology", Spector, W. S., Technical Report
     No. 55-16, Wright Air Development Center, Air Research and
     Development Command, Wright-Patterson Air Force Base, Ohio,
     1955.

81.  "Toxicity and Pollution Study of Carguard Chemicals, 1965-1966",
     33 pp., Cargill, Incorporated, Minneapolis, Minnesota.

82.  "Ground Water Contamination and Legal Controls in Michigan",
     Deutsch, M., Water Supply Paper No. 1691, U.S. Geological
     Survey, U.S. Department of the Interior, 1963.

83.  "Standard Methods for the Examination of Water and Wastewater",
     12th Edition, Prepared by the American Public Health Association,
     the American Water Works Association, and the Water Pollution
     Control Federation, Boyd Printing Co., Inc., Albany, New York,
     1965.

84.  "Fertilization of Lakes by Agricultural and Urban Drainage",
     Sawyer, C. N., Journal Northeast Water Works Association,
     61, pp. 109-127, 1947.

85.  "Effect of Sewage - Borne Phosphorous on Algae", Curry, J., and
     Wilson, S., Sewage and Industrial Wastes Journal, 27, pp. 1262-1266,
     1955.

86.  "Progress Report on NCHRP Project 16-1; Effects of Deicing
     Compounds on Vegetation and Water Supplies", Smith, H. A., Paper
     presented at 54th Annual Meeting of the American Association of
     State Highway Officials, 7 pp., Minneapolis, Minnesota,
     December 5, 1968.

87.  "Salt Buildup in Drinking Water a Danger to Some Bay Staters",
     Newspaper Article appearing in the Boston Globe, Boston,
     Massachusetts, May 8, 1970.

88.  "Salt Piling - A Source of Water Supply Pollution", Walker, W.  H.,
     Pollution Engineering, 2_, 3*, pp. 30-33, July-August 1970.
                                 - 113 -

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 89.   "Progress  Report  III,  The Influence of Salts Applied to Highways
      on the Levels of  Sodium and Chloride Ions Present in Water and
      Soil  Samples", Hutchinson, F.  E., Project No. R1088-8, 28 pp.,
      1968.

 90.   "The  Groundwater  Resources of  Summit County, Ohio", Smith, R. D.,
      Ohio  Division of  Water, Bulletin No. 27, pp. 130, 1953.

 91.   "Movement  of Dissolved Salts in Groundwater Systems", Rahn, P. H.,
      Paper appearing in the "Proceedings of the Symposium:  Pollutants
      in the Roadside Environment",  pp. 36-45, University of Connecticut,
      February 29, 1968.

 92.   "Environmental Effect  of Highways", Scheldt, M. E., Journal of
      the Sanitary Engineering Division, Proceedings of the American
      Society of Civil  Engineers, 93, No. SA5, Paper No. 5509,
      pp. 17-25, October 1967.

 93.   "Side Effects of  Salting for Ice Control", Article appearing in
      American City, 80, pp. 33, August 1965.

 94.   "Salting Highways Could Contaminate Ground Water", Article
      appearing in Reclamation News, April 1965.

 95.   "Road Salt Blamed for  Souring  Water", Newspaper article appearing
      in the Boston Globe,  Boston, Massachusetts, April 1970.

 96.   "Do Road Salts Poison  Water Supplies?", Newspaper article appearing
      in the Boston Globe,  Boston, Massachusetts, 1968 or 1969.

 97.   "Alewife Brook Polluted", Article appearing in the Boston Globe,
      Boston, Massachusetts, May 1970.

 98.   "Your 500 - Milligram Sodium Diet", American Heart Association,
      55 pp., 1957.

 99.   "Your 1,000 - Milligram Sodium Diet", American Heart Association,
      55 pp., 1957.

100.   "Tolerable Salt Concentrations in Drinking Waters", Moore, E. W.,
      A Progress Report to  the Sub-committee on Water Supply of the
      Committee on Sanitary Engineering and Environment, 1950.

101.   "Manual on Industrial Water",  Spec. Tech. Pub. No. 148, American
      Society for Testing and Materials, Committee D-19 on Industrial
      Water, 336 pp., 1953.

102.   "Corrosion", Kallen,  H. P., Special Report, Power, pp. 73-108,
      December 1956.
                                 - 114 -

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103.  "Effect of Sodium Chloride on Grasses for Roadside Use",
      Roberts, E. C., and Zybura, E. L., Paper appearing in the
      "Highway Research Record Report No. 193 on Environmental
      Considerations in Use of Deicing Chemicals", pp.  35-42,
      Highway Research Board, Washington, D.C., 1967.

104.  Article appearing in Automotive Industries, February 1, 1964.

105.  Article appearing in Steel, March 2, 1964.

106.  "New Cars Resist Salt Corrosion", American City, August 1961.

107.  "U.S. Highway Research Board Bulletin No. 323", Washington, D.C.,
      1962.

108.  "Bridge Deck Deterioration and Repair Techniques", Delp, L. R.,
      AASHO Conference, Portland, Oregon, 1963.

109.  "Publication No. 98", Dickinson, W. E., National Ready Mixed
      Concrete Association, Washington, D.C., 1961.

110.  "The Elimination of Pavement Sealing By Use of Air Entraining
      Portland Cement", Portland Cement Association, Chicago, Illinois,
      HB 18.8.

111.  "Protection of Existing Concrete Pavements from Salt and Calcium
      Chloride", Portland Cement Association, Chicago, Illinois, HB 1-2.

112.  "Warning - Use the Right Deicer", Lerch, W., Modern Concrete,
      May 1962.

113.  "Corrosive Effects of Deicing Salts", Hamman, W. and Mantes, A. J.,
      Journal American Water Works Association, 58, 11, pp. 1457-1461,
      November 1966.

114.  "A Study of Salt Pollution of Soil by Highway Salting",
      Prior, G. A. and Berthouex, P. M., Paper appearing in the
      "Highway Research Record Report No. 193 on Environmental
      Considerations in Use of Deicing Chemicals", pp. 8-21,
      Highway Research Board, Washington, D.C., 1967.

115.  "The Relationship of Road Salt Applications to Sodium and Chloride
      Ion Levels in the Soil Bordering Major Highways", Hutchinson, F. E.,
      and Olson, B. E., Paper appearing in the "Highway Research Record
      Report No. 193 on Environmental Considerations in Use of Deicing
      Chemicals", pp. 1-7, Highway Research Board, Washington, D.C., 1967.

116.  "Notes on Winter Road Salting (Sodium Chloride) and Vegetation",
      Scientific Report No. 3, Thomas, L. K., Jr., 22 pp., National
      Capital Region, National Park Service, U.S. Department of the
      Interior, March 31, 1965.
                                 - 115 -

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117.  "The Relationship of Road Salt Applications to Sodium and  Chloride
      Ion Levels in the Soil Bordering Major Highways", Hutchinson,  F.  E.,
      Paper appearing in the "Proceedings of the Symposium:  Pollutants
      in the Roadside Environment", pp. 24-35, University of Connecticut,
      February 29, 1968.

118.  "Winter Rock Salt Injury to Turf (Poa pratensis L.)", Scientific
      Report No. 5, Thomas, L. K., Jr., and Bean, G. A., 22 pp.,
      National Capital Region, National Park Service, U.S. Department
      of the Interior, August 23, 1965.

119.  "Salt Damage to Vegetation in the Washington, D.C. Area During
      the 1966-1967 Winter", Wester, H. V. and Cohen, E. E., Reprint
      from Plant Disease Reporter, 52, 5, 5 pp., May 1968.

120.  "A Quantitative Microchemical Method for Determining Sodium Chloride
      Injury to Plants", Scientific Report No. 4, Thomas, L. K., Jr.,
      10 pp., National Capital Region, National Park Service, U.S.
      Department of the Interior, 1965.

121.  "Effect of De-icing Chemicals on Grassy Plants", Roberts, E. C.,
      Paper appearing in the "Proceedings of the Symposium:  Pollutants
      in the Roadside Environment", pp. 48-49, University of Connecticut,
      February 29, 1968.

122.  "Sodium Chloride Uptake and Distribution in Grasses as Influenced
      by Fertility Interaction and Complementary Anion Competition",
      Verghese, K. G., et. al., Unpublished Report, 15 pp., Virginia
      Polytechnic Institute, Research Division, Blacksburg, Virginia,
      1969.

123.  "Soil Salinity and Irrigation in the Soviet Union", Bower, C. A.,
      et. al., U.S. Department of Agriculture ARS Report of a Tech.
      Study Group, 41 pp., 1962.

124.  "Some Effects of Salt Water on Soil Fertility", Plice, M. J.,
      Soil Science Soc. Amer. Proc., 14,  pp. 275-278, 1949.

125.  "Boulevard Trees are Damaged by Salt Applied to Streets",
      French, D. W., Minnesota Farm and Home Science, XVI, 2, 9, 1959.

126.  "Maple Decline in New Hampshire":,  LaCasse, N. L., M. S.  Thesis,
      University of New Hampshire, 1963.

127.  "Maple Decline in New Hampshire", LaCasse, N. L. and Rich, A. E.,
      Phytopathology, 54, pp. 1071-1075,  1964.

128.  "Salt Injury to Roadside Trees", Rich, A. E. and LaCasse, N. L.,
      Forest Notes, Winter 1963-1964, 2-3.
                                 - 116 -

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129.  "Effect of Deicing Chemicals on Woody Plants", Rich, A. E.,
      Paper appearing in the "Proceedings of the Symposium:  Pollutants
      in the Roadside Environment", pp. 46-47, University of Connecticut,
      February 29, 1968.

130.  "Salt Injury to Roadside Trees - A Progress Report", Kotheimer, J.,
      Niblett, C., and Rich, A. E., Forest Notes, 85, 3-4, 1965.

131.  "Sugar Maple Decline:  An Evaluation", Westing, A. H., Econ,
      Botany, 20, 2, pp. 196, 212, 1966.

132.  "Salt Injury to Trees, II. Sodium and Chloride in Roadside
      Sugar Maples in Massachusetts", Holmes, F. W. and Baker, J. H.,
      Phytopathology, 56, 6, pp. 633-636, June 1966.

133.  "Effects of Deicing Salts on Roadside Soils and Vegetation, II.
      Effects on Silver Maples (Acre saccharinum L.)", Zelazny, L. W.,
      et. al., Unpublished Report, Virginia Polytechnic Institute,
      Research Division, Blacksburg, Virginia, 1970.

134.  Unpublished data from Connecticut State Highway Department,
      Department of Research and Development, and Connecticut
      Agricultural Experiment Station, Button, E. F., and Peaslee, D. E.,
      New Haven, Connecticut.

135.  "Influence of Rock Salt Used for Highway Ice Control on Natural
      Sugar Maples at One Location in Central Connecticut",
      Button, E. F., Report No. 3, Connecticut State Highway Department,
      1964.

136.  "Influence of Rock Salt, Salt Used for Highway Ice Control on
      Natural Sugar Maples at One Location in Central Connecticut",
      Button, E. F., Report No. 3A, Connecticut State Highway
      Department, 1964.

137.  "Ice Control Chlorides and Tree Damage", Button, E. F., Public
      Works, 93_, 3, p. 136, 1965.

138.  "Salinity in Relation to Irrigation", Allison, L. E., Advances
      in Agronomy, 16, pp. 139-180, 1964.

139.  "Salt Tolerance of Roadside Vegetation", Zelazny, L. W.,
      Paper appearing in the "Proceedings of the Symposium:  Pollutants
      in the Roadside Environment", pp. 50-56, University of Connecticut,
      February 29, 1968.

140.  "Salt Tolerance of Fruit Crops", Bernstein, L., U.S. Department
      of Agriculture, Agricultural Information Bulletin No. 292, 8 pp.,
      1965.
                                 - 117 -

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141.  "Salt Tolerance of Vegetable Crops in the West", Bernstein  L.,
      U.S. Department of Agriculture, Agricultural  Information
      Bulletin No. 205, 5 pp., 1959.

142.  "Salt Tolerance of Field Crops", Bernstein, L., U.S. Department
      of Agriculture, Agricultural Information Bulletin No.  217,  6  pp.,
      1960.

143.  "Salt Tolerance of Grasses and Forage Legumes", Bernstein,  L.,
      U.S. Department of Agriculture, Agricultural  Information
      Bulletin No. 194, 7 pp., 1958.

144.  "Tolerance of Some Trees and Shrubs to Saline Conditions",
      Monk, R. W., and Peterson, H. B., Proc. American Soc.  Hort. Sci.,
      81, pp. 556-561, 1962.

145.  "Influence of Sodium Chloride Upon the Physiological Changes
      of Living Trees", Rudolfs, W., Soil Science, £, pp. 397-425,
      1919.

146.  "A Study of Calcium Chloride Injury to Roadside Trees", Strong, F.  C.,
      Michigan Agr. Exp. Sta. Quart. Bull., 27, pp. 209-224, 1944.

147.  "Damage by De-icing Salts to Plantings Along the Federal Highways",
      Sauer, G., News Journal, German Plant Protective Service, 19, 6,
      1967.
        Additional Suggested Reading - Supplementary References


"Pollution Control Board Conducts Hearing on Salting of Streets", Oklahoma
Environmental Reporter, 12, Report No. 13, page 2, March 17, 1971.

"Rules on Salt Use Adopted", Newspaper Article Appearing in The Daily
Oklahoman, April 13, 1971.

"Snow Job", Newspaper Article Appearing in the Syracuse, New York Herald
Journal, Syracuse, New York, May 6, 1971.

"Maintenance Manual", Sections 5-290, 5-291, 5-292, 5-293 and 5-295,
respectively giving information and instructions on Snow Removal; Equip-
ment; Organization and Practice; Operating Snow Plows; and Ice and  Snow
Removal by Chloride Salts; Revision of July 1966, Idaho Department  of
Highways, Boise, Idaho.

"The Effect of Highway Salt on Water Quality in Selected Maine Waters",
Hutchinson, F. E., Paper Presented at Street Salting Urban Water Quality
Workshop, SUNY Water Resources Center, Syracuse University, May 6,  1971,
Syracuse, New York.
                                 - 118 -

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"Lake Stratification Caused by Runoff from Street Deicing", Judd,  J.  H.,
Water Research, 4^ 8, pp. 521-532, August 1970.

"Effects of De-icing Salts on Roadside Soils and Vegetation",  Zelazny,  L.  W.
and Blaser, R. E., Paper Appearing in "Highway Research Record No.  335,
Roadside Development and Maintenance", pp. 9-12, Highway Research  Board,
National Research Council, National Academy of Sciences - National  Academy
of Engineering, Washington, D.C., 1970.

"Sodium Chloride Uptake in Grasses as Influenced by Fertility  Interaction",
Verghese, K. G., et. al., Paper Appearing in "Highway Research Record
No. 335, Roadside Development and Maintenance", pp. 13-15, Highway  Research
Board, National Research Council, National Academy of Sciences - National
Academy of Engineering, Washington, D.C., 1970.

"Salt Tolerance of Trees and Shrubs to De-icing Salts", Hanes, R. E.,
et. al., Paper Appearing in "Highway Research Record No. 335,  Roadside
Development and Maintenance", pp. 16-18, Highway Research Board, National
Research Council, National Academy of Sciences - National Academy of
Engineering, Washington, D.C., 1970.

"Non-Chemical Methods of Snow and Ice Control on Highway Structures",
National Cooperative Highway Research Program Report 4, National Coopera-
tive Highway Research Program, Highway Research Board, National Research
Council, National Academy of Sciences - National Academy of Engineering,
Washington, D.C., Date Unknown.

"Protective Coatings to Prevent Deterioration of Concrete by De-icing
Chemicals", National Cooperative Highway Research Program Report 16,
National Cooperative Highway Research Program, Highway Research Board,
National Research Council, National Academy of Sciences - National
Academy of Engineering, Washington, D.C., Date Unknown.

"Economical and Effective De-icing Agents for Use on Highway Structures",
National Cooperative Highway Research Program Report 19, Boles, D.  B. and
Bortz, S., 19 pp., National Cooperative Highway Research Program, Highway
Research Board, National Research Council, National Academy of Sciences -
National Academy of Engineering, Washington, D.C., 1965.

"Methods For Reducing Corrosion of Reinforcing Steel", National Coopera-
tive Highway Research Program Report 23, National Cooperative  Highway
Research Program, Highway Research Board, National Research Council,
National Academy of Sciences - National Academy of Engineering, Washing-
ton, D.C., Date Unknown.

"Physical Factors Influencing Resistance of Concrete to De-icing Agents",
National Cooperative Highway Research Program Report 27, National  Coopera-
tive Highway Research Program, Highway Research Board, National Research
Council, National Academy of Sciences - National Academy of Engineering,
Washington, D.C., Date Unknown.
                                 - 119 -

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"Facts You Should Know About Effects of De-icing  Salt on  the  Environment
A Review of National Cooperative Highway Research Program Report  91",
16 pp, American Public Works Association Reporter, January 1971;  Reprint
Made Available by the Salt Institute, Alexandria, Virginia.

"Deicing With Salt - Some Pros and Cons", Pryzby, S. R.,  Public Works
Magazine, pp. 80,81,98, March 1971.

"Snow and Ice Removal and Ice Control Research",  Proceedings  of a Sympo-
sium held at Dartmouth College, Durham, New Hampshire, April  1970,
Highway Research Board Special Report No. 115, Highway Research Board,
Washington, D.C.

"Town Fights Road Salting to Protect Water Supply", Newspaper Article
Appearing in the Boston Globe, Boston, Mass., December 29,  1970.

"Effects of Winter Storm Water Runoff on Vegetation and as  a  Factor  in
Stream Pollution", Bugher, R. D., Paper Presented at the  Seventh  Annual
Snow Conference, 6 pp., Milwaukee, Wisconsin, 1967.

"Environmental Effects of Snow Removal and Ice Control Programs",
Smith, H. A., Paper Presented at the Eleventh Annual North American
Snow Conference, 16 pp., Chicago, Illinois, April 14, 1971.

"Vehicle Corrosion Caused by Deicing Salts - Evaluation of  the Effects
of Regular vs. Inhibited Salt on Motor Vehicles", American  Public Works
Association Special Report No. 34, American Public Works  Association
Research Foundation, APWA-SR-34, Chicago, Illinois, September 1970.

"Eleven Principles of Design", Society of Automotive Engineers J447A,
Date Unknown.

"Effect of an Inhibitor on the Corrosion Autobody Steel by  Deicing Salt",
Adair, T. H., Ontario Research Foundation, Report of Investigation
M-60110, 1961.

"Salt Corrosion of Automobiles", Joint ASM - AICE Seminar on  Corrosion,
University of Toledo, Toledo, Ohio, March 28, 1969.
                                 - 120 -

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
     11040 GKK 06/71
                             2.
                                                           3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
     Environmental  Impact of Highway Deicing
                                                           5. REPORT DATE
                                                           6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
     Edward Struzeski,  Jr.
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
     Storm  & Combined  Sewer  Section
     U, S.  Environmental Protection Aeencv
     Edison, N.J.  08817
                                   10. PROGRAM ELEMENT NO.

                                      IB C 611
                                   11. CONTRACT/GRANT NO.

                                     11040 GKK
 12. SPONSORING AGENCY NAME AND ADDRESS
     Municipal Environmental Research Laboratory
     Office of Research  and Development
     U.S. Environmental  Protection Agency
     Cincinnati, OH 45268
                                   13. TYPE OF REPORT AND PERIOD COVERED
                                     Reprint-Final  Report	
                                   14. SPONSORING AGENCY CODE

                                     EPA-ORD
 15. SUPPLEMENTARY NOTES
     PrQ.-ject Officer:
Edward Struzeski,. Jr.   201/548-3347x541 (8-342-7541)
 16. ABSTRACT
     Deicing agents for removal of ice and snow from highways  and streets are essential
     to wintertime road maintenance in most areas of the U.S.   Due to the ever-
     increasing use of highway deicing materials, there has been growing concern as  to
     environmental effects  resulting from these practices.  This Stat-of-the-Art report
     reviews the available  information on methods, equipment and materials used for
     snow and ice removal;  chlorides found in rainfall and municipal sewage during the
     winter; salt runoff from streets and highways; deicing compounds found in surface
     streams, public water  supplies, groundwater, farm ponds and lakes;  special addi-
     tives incorporated into  deicing agents; vehicular corrosion and deterioration of
     highway structures and pavements; and effects on roadside soils, vegetation and
     trees.  It is concluded  that highway deicing can cause injury and damage across a
     wide environmental spectrum.  Recommendations describe future research, develop-
     ment and demonstration efforts necessary to assess and reduce the adverse impact
     of highway deicing.  This report was prepared by the Storm and Combined Sewer
     Section, Wastewater Research Division,  MERL, (formerly the Edison Water Quality
     Laboratory), Edison, NJ.
17.
                               KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                             b.lDENTIFIERS/OPEN ENDED TERMS
                                                   COSATI Field/Group
     additives
     chlorides
     concrete durability
     corrosion
     deicers
     economic analysis
     ice control
   public water serv.
   runoff
   snows torms
   sodium
   toxic tolerances
   water pollution
environmental damages
groundwater  contamination
salt storage
urban runoff
vehicular  corrosion
wintertime highway runoff
13 B
18. DISTRIBUTION STATEMENT
    RELEASE TO PUBLIC
                      19. SECURITY CLASS (ThisReport)
                      UNCLASSIFIED
                                                 21. NO. OF PAGES
                                              20. SECURITY CLASS (Thispage)

                                              UNCLASSIFIED	
                                                                         22. PRICE
EPA Form 2220-1 (9-73)
                                            121
                                                               •4USGPO: 1976 — 657-695/5444 Region 5-11

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Continued from inside front cover....
11022 — 08/67

11023 — 09/67

11020 — 12/67

11023 — 05/68

11031 — 08/68
11030 DNS 01/69
11020 DIH 06/69
11020 DES 06/69
11020 — 06/69
11020 EXV 07/69

11020 DIG 08/69
11023 DPI 08/69
11020 DGZ 10/69
11020 EKO 10/69
11020 — 10/69
11024 FKN 11/69

11020 DWF 12/69
11000 — 01/70

11020 FKI 01/70

11024 DOK 02/70
11023 FDD 03/70

11024 DMS 05/70

11023 EVO 06/70
11024 — 06/70
11034 FKL 07/70
11022 DMU 07/70
11024 EJC 07/70

11020 — 08/70
11022 DMU 08/70

11023 — 08/70
11023 FIX 08/70
11024 EXF 08/70
Phase I - Feasibility of a Periodic Flushing System for
Combined Sewer Cleaning
Demonstrate Feasibility of the Use of Ultrasonic Filtration
in Treating the Overflows from Combined and/or Storm Sewers
Problems of Combined Sewer Facilities and Overflows, 1967
(WP-20-11)
Feasibility of a Stabilization-Retention Basin in Lake Erie
at Cleveland, Ohio
The Beneficial Use of Storm Water
Water Pollution Aspects of Urban Runoff, (WP-20-15)
Improved Sealants for Infiltration Control, (WP-20-18)
Selected Urban Storm Water Runoff Abstracts, (WP-20-21)
Sewer Infiltration Reduction by Zone Pumping, (DAST-9)
Strainer/Filter Treatment of Combined Sewer Overflows,
(WP-20-16)
Polymers for Sewer Flow Control, (WP-20-22)
Rapid-Flow Filter for Sewer Overflows
Design of a Combined Sewer Fluidic Regulator, (DAST-13)
Combined Sewer Separation Using Pressure Sewers, (ORD-4)
Crazed Resin Filtration of Combined Sewer Overflows, (DAST-4)
Stream Pollution and Abatement from Combined Sewer Overflows •
Bucyrus, Ohio, (DAST-32)
Control of Pollution by Underwater Storage
Storm and Combined Sewer Demonstration Projects -
January 1970
Dissolved Air Flotation Treatment of Combined Sewer
Overflows, (WP-20-17)
Proposed Combined Sewer Control by Electrode Potential
Rotary Vibratory Fine Screening of Combined Sewer Overflows,
(DAST-5)
Engineering Investigation of Sewer Overflow Problem -
Roanoke, Virginia
Microstraining and Disinfection of Combined Sewer Overflows
Combined Sewer Overflow Abatement Technology
Storm Water Pollution from Urban Land Activity
Combined Sewer Regulator Overflow Facilities
Selected Urban Storm Water Abstracts, July 1968 -
June 1970
Combined Sewer Overflow Seminar Papers
Combined Sewer Regulation and Management - A Manual of
Practice
Retention Basin Control of Combined Sewer Overflows
Conceptual  Engineering Report - Kingman Lake Project
Combined Sewer Overflow Abatement Alternatives -
Washington, D.C.

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