EPA-R2-73-257
MAY 1973 Environmental Protection Technology Series
Water Pollution
and Associated Effects
from Street Salting
National Environmental Research Center
Office of Research and Monitoring
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
U. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
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EPA-R2-73-257
May 1973
WATER POLLUTION AND ASSOCIATED EFFECTS
FROM STREET SALTING
By
Richard Field, Chief
Storm and Combined Sewer Technology Branch
Edison Water Quality Research Laboratory
National Environmental Research Center - Cinn.
Edison, New Jersey
Edmund J. Struzeski, Jr.
Staff Assistant to the Director of Technology Programs
Division of Field Investigations
National Field Investigations Center
Denver, Colorado
Hugh E. Masters and Anthony N. Tafuri
Staff Engineers
Storm and Combined Sewer Technology Branch
Env.lv •"- Agency
Li:- -
National Environmental Research, Center
U. S. Environmental Protection Agency
Cincinnati, Ohio 45268
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402
Price 85 cents domestic postpaid or 60 cents GPO Bookstore
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EPA Review Notice
This report has been reviewed by the Office of Research
and Monitoring, EPA, and approved for publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation
for use.
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ABSTRACT
This report comprises a state-of-the-art review of highway deicing
practices and associated environmental effects.
The bare pavement policy has resulted in a great increase in the use
of deicing salts, in many cases replacing the abrasives previously used.
However, no conclusive evidence has been found to substantiate that salt
usage makes winter travel safer.
Besides chemical melting, various methods for anti-icing/deicing
are available or have been conceived (external and in-slab thermal melt-
ing systems; mobile thermal "snow melters"; compressed air or high speed
fluid streams in conjunction with snowplow blades or sweepers; snow/ice
adhesion reducing [hydrophobic/icephobic] substances; improved vehicular
and/or tire design) which may become more prominent in the future especi-
ally when communities realize that a price must be paid to alleviate the
environmental effects of wintertime salting.
Salt storage facilities often become a major contributing source of
local groundwater and surface water contamination and vegetation damage.
Coverage and proper drainage of salt piles is becoming more prevalent,
but there has not been an adequate acceptance of approved practices and
a proper recognition of pollutional problems associated with this mater-
ial storage. Types of enclosed structures are illustrated, and cost con-
siderations given.
High chloride concentration levels have been found in roadway runoff.
The special additives in deicing salts may create more severe pollutional
problems than the chloride salts. Many roadside wells, due to contamina-
tion by salt laden runoff, have had to be replaced in such snow belt
states as New Hampshire, Maine, and Massachusetts. Widespread damage
of roadside soils and vegetation has been observed in areas of liberal
salt usage.
Areas of future research are also indicated in this report.
111
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TABLE OP CONTENTS
Page
ABSTRACT
FIGURES
TABLES
ACKNOWLEDGEMENT
ill
vi
viii
ix
SECTION
I CONCLUSIONS 1
II RECOMMENDATIONS 3
Resulting EPA Projects 3
Additional Needs 6
III INTRODUCTION 9
IV USE OF DEICING COMPOUNDS 11
V CHLORIDE SALT REDUCTION POSSIBILITIES 17
VI SALT STORAGE 19
VII ENVIRONMENTAL EFFECTS FROM DEICING COMPOUNDS 27
Runoff/ Sewage and Surface Streams 27
Farm Ponds and Lakes 29
Deicing Additives 29
Ground and Surface Water Supply Contamination 31
Vehicular and Roadway Damage 34
Soil, Vegetation and Trees 34
VIII REFERENCES 41
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FIGURES
Figure Title Page
1 Twin-disc salt spreader with tail-gate screens 16
(placed inside truck body) to prevent salt
lumps from reaching feeder ports
2 New design salt spreader with screen grid over 16
top to preclude salt lumps
3 Open salt storage pile, downtown Chicago, Illinois 20
4 Open salt storage pile, Milwaukee, Wisconsin, 20
estimated quantity 41,000 tons
5 Moving salt by front-end loader inside enclosed 21
storage structure
6 Covered salt stockpile located adjacent to the 21
Maumee River in Toledo, Ohio
7 Salt storage - Approximate construction cost 22
$3 to $5 per Ton of capacity
8 Salt storage - Approximate construction cost 22
$3 to $5 per Ton of capacity
9 Salt storage - Approximate construction cost 22
$3 to $5 per Ton of capacity
10 Salt storage - Approximate construction cost 23
$50 to $75 per Ton of capacity
11 Salt storage - Approximate construction cost 23
$50 to $75 per Ton of capacity
12 Salt storage - Approximate construction cost 23
$50 to $75 per Ton of capacity
13 Salt storage - Approximate construction cost 23
$50 to $75 per Ton of capacity
14 Salt storage - Approximate construction cost 24
$15 to $20 per Ton of capacity
15 Salt storage - Approximate construction cost 24
$10 to $30 per Ton of capacity
VI
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16 Salt storage - Approximate construction cost 24
$20 to $30 per Ton of capacity
17 Salt storage crib 25
18 Salt storage shelter 25
19 Salt storage building 25
20 The "Beehive" - Salt storage structure; note 26
air vents at top
21 The "Beehive" - Method of loading; first stage 26
by truck and dozer
22 The "Beehive" - Method of loading; second stage 26
by conveyor
23 Dumping snow into nearby waterway 30
24 Chloride concentration of wells in the Burling- 32
ton, Massachusetts Area, 1963-1971
25 Relatively healthy sugar maples photographed 35
1960, Route 17, Durham-Middletown Line, Conn.
26 Same trees as above - those on left exhibiting 35
salt damage, photographed 1965
27 Closeup of sugar maples exhibiting pronounced 36
damage, Route 17, Durham-Middletown Line, Conn.
28 Healthy (right) vs. damaged sugar maple leaves 36
(left), from right and left side of Route 17,
respectively, Durham-Middletown Line, Conn.
VII
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TABLES
Table Title Page
I Conclusions (Abbreviated Listing) 2
II Chloride Salt Reduction Possibilities 4
(Abbreviated Listing)
III Recommendations (Abbreviated Listing) 8
IV Reported Use (Tons) of Sodium Chloride, Calcium 12
Chloride and Abrasives by States and Regions in
the United States, Winter of 1966-1967.
V High Chloride Values in Runoff 28
VI Special River Sampling, Milwaukee Sewerage Com- 28
mission, January 16, 1969
VII Salt Tolerance of Fruit Crops 37
VIII Salt Tolerance of Vegetable Crops 38
IX Salt Tolerance of Field Crops 38
X Salt Tolerance of Grasses and Forage Legumes 39
XI Salt Tolerance of Trees and Ornamentals 40
Vlll
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ACKNOWLEDGEMENTS
The authors express appreciation to Ms. Pauline Weigel, Staff
Assistant, Storm and Combined Sewer Technology Branch, National
Environmental Research Center-Cinn., EPA, Edison, New Jersey, for
her cooperation and assistance in editing.
IX
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SECTION I
CONCLUSIONS-^
Some of the more pertinent conclusions drawn from the study are as
follows: (Table I presents a synoptic version)
1. Highway salts can cause injury and damage across a wide environ-
mental spectrum, and these effects although not yet evident in certain
areas of the country, may appear in the future.
2. Practically all highway authorities in the U.S. believe that
ice and snow must be removed quickly from roads and highways, and that
"bare pavement" conditions are necessary, often resulting in excessive
salt application. Conclusive evidence is needed to substantiate using
salt to make winter travel safer.
3. Salt storage sites are persistent and frequent sources of ground
and surface water contamination, and vegetation damage.
4. The special additives found in road deicers provoke great con-
cern because of their severe latent toxic properties and other potential
side effects. Significantly, little is known as to their fate and dis-
position. Field investigations must provide considerably more data to
determine safe levels when using these additives.
5. A sufficient number of incidents and detailed studies have been
described to show the adverse impact of deicing salts to water supplies
and receiving waters.
6. In less severe cases of salt intrusion into public water sup-
plies, salt-free patients have been cautioned to change their potable
water source.
7. Deicing salts are found in high concentrations in highway runoff.
8. Surveillance data are needed to clearly define the many influences
of deicing salts upon the environment.
9. The majority of in-depth studies support the finding that deic-
ing salts are a major factor in vehicular corrosion and roadway damage.
The literature also indicates that rust inhibiting additives do not pro-
duce results to justify their continued use. It is further noted that
deicers may attack and cause damage to telephone cables, water distribu-
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tion lines, and other utilities adjacent to streets and highways.
10. There is little doubt that road deicers can disturb a healthy
balance in soils, trees, and other vegetation comprising the roadside
environment.
TABLE I
CONCLUSIONS
(ABBREVIATED LISTING)
1. SALTS CAN CREATE VARIOUS ENVIRONMENTAL PROBLEMS
2. "BARE-PAVEMENT" IS GENERAL PHILOSOPHY EXCESSIVE
APPLICATION USUALLY RESULTS
3. STORAGE SITES CAN CAUSE POLLUTION
4. DEICING ADDITIVES INCREASE PROBLEMS
5. HIGH SALT CONCENTRATIONS FOUND IN HIGHWAY SNOWMELT
6. SALTS CAN CONTAMINATE WATER SUPPLIES AND RECEIVING WATERS
7. SALTS CAN BE DETRIMENTAL TO HEALTH
8. SALT MONITORING IS NEEDED
9. SALTS INCREASE CORROSION
10. SALTS CAN DAMAGE VEGETATION
I/ Selected from a more comprehensive listing of conclusions contained
in the Edison Water Quality Research Laboratory report(3).
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SECTION II
RECOMMENDATIONS—
Resulting EPA Projects
Two major projects have been instituted and sponsored by the U.S.
Environmental Protection Agency's Office of Research and Monitoring
which were based on recommendations from the state-of-the-art survey on
the environmental impacts of highway deicing.
One of these projects, recently completed, involved a search for
new technology in snow and ice control by Abt Associates, Inc. (1) .
This work has covered the alternate concepts as highlighted by Table II.
It revealed that many studies have been made on ice adhesion in general
and that a few experiments have been performed on ice releasing agents
for aircraft and vessel exteriors, and outdoor mechanical equipment.
However, little has been done to directly investigate the use of such
agents on pavement. The search indicated the high potential of using a
hydrophobic or icephobic (water or ice repellant) substance for ice con-
trol and further recommended that development be sought.
Recognizing the importance of this recommendation, EPA prepared a
request for proposal (RFP). The product of this KFP will be a study to
develop a hydrophobic or icephobic substance which can be used to reduce
the adhesion of ice or hard packed snow on pavements. This study will
evaluate the relative merits of using these substances, once determined,
as an alternate to salt. The study will be undertaken from the point of
view of finding an economical hydrophobic anti-icing/deicing agent which
can be placed on or within pavement surfaces and that would not have
irreversible harmful effects on the environment. While this approach is
novel, it is potentially the most valuable alternative.
Another study which is also being considered, as a result of recom-
mendations from the Abt Project, aims to carefully evaluate the environ-
mental and economic impacts of the continued use of deicing compounds in
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a more proper perspective.
TABLE II
CHLORIDE SALT REDUCTION POSSIBILITIES
(ABBREVIATED LISTING)
1. EXTERNAL/IN-SLAB THERMAL MELTING
2. STATIONARY/MOBILE MELTERS
3. SUBSTITUTE DEICING COMPOUNDS
4. COMPRESSED AIR TYPE SNOWPLOW
5. ADHESION REDUCING PAVEMENT MATERIALS
6. SOLAR ENERGY STORING PAVEMENT SUBSTANCES
7. ELECTROMAGNETIC ICE SHATTERERS
8. IMPROVED DRAINAGE, ENHANCING RUNOFF, ACCIDENT
REDUCTION, AND SNOWMELT CONTROL/TREATMENT
9. SALT RETRIEVAL/TREATMENT
10. IMPROVED TIRE/VEHICULAR DESIGN
The second, and larger project(2) will provide the following:
1. A Deicer Users Manual, to describe snow and ice removal practices
and the best systems of applying deicing chemicals to streets and highways.
(Several highway agencies and the salt industry are known to have various
instructional material that are principally directed to operational per-
formance. The best data in this area will be incorporated into the Manual.
Pollution of the surrounding environment and potential in cost savings do
not warrant excessive saltings, and the Deicer Users Manual will give
utmost priority to environmental protection.) More specifically, the
manual will include:
a. Absolute minimum amounts of deicing chemicals necessary to
maintain safe traffic flows;
b. Critical points or placement of application;
c. Higher degree of instrumentation, improved calibration, and
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increased reliability of existing and new deicing equipment;
d. Incorporation of applicable weather detection, prediction,
and warning systems as a basis for projecting manpower, equipment, and
material requirements for combatting winter storms more efficiently and
effectively;
e. Proper maintenance and repair schedules;
f. Methods of salt spreading to optimize operational and man-
power efficiencies;
g. A rating test(s) for materials and methods;
h. Suggested prime systems and alternatives;
i. Canadian, European, and British practices as they may apply;
and
j. Model codes or ordinances for using deicing compounds.
2. A Manual of Design and Recommended Practices for Storage Facil-
ities and Methods of Handling Deicing Materials Throughout Storage. (Al-
though 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 with the de-
icing materials often stockpiled unprotected in open areas, and too freq-
uently these sites have become chronic sources of ground and surface
water pollution.) This Manual will 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 shielded
structures;
d. Adequate foundation and footing;
e. Sequence and timing of materials delivery;
f. Alternative methods for preventing caking of salt materials
including physical, mechanical, and chemical techniques; and
g. Drainage requirements for all storage sites including those
of salt manufacturers.
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The aforementioned Deicer Users and Storage Manuals will include
important information necessary for policy making and management.
3. An evaluation of the pollutional magnitude from continued prac-
tices of removing and dumping the enormous quantities of snow from streets
and highways into nearby water bodies or onto water supply watersheds.
Particular studies will be undertaken to:
a. Determine the characteristics and quantities of the snow now
being disposed of in several selected locations within the snowbelt states;
b. Identify the areas and specific locations where the snow is
being disposed of (such as, water bodies and water supply watersheds);
c. Monitor the depository, before and after dumping, for time
effects, unit pollutant loads, and any other detrimental effects upon it
from the melted snow;
d. Summarize the toxic materials found in the snow from the
various snow dump test sites;
e. Develop model codes or regulations for the practice of snow
dumping;
f. Forecast what effect technological advances are expected to
have upon the future snow accumulations in the previously selected loca-
tions of investigation. (New snow disposal practices will be compared
from an economic and technical standpoint); and
g. Develop recommendations for specific changes in existing
snow removal practices that are considered environmentally unacceptable.
Present program work plans anticipate relating feasible project recom-
mendations for deicer alternatives into full-scale, municipal demonstra-
tion (s) .
Additional Needs
In addition to the present work being carried out, the following
are recommended: (Table III presents a synoptic version of these recom-
mendations)
1. Foster increased recognition of the problem at various govern-
mental levels which would include accelerated training, environmental
impact awareness, and demonstration of optimum procedures and techniques
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in wintertime deicing.
2. Carry forth detailed studies both in the laboratory and field
on the various toxic and nutrient additives mixed with deicing materials
so as to determine their potential hazards and safe levels of use.
3. Initiate a program for obtaining base-line data on long-term
environmental changes that may be taking place due to the increasing
use of deicing chemicals. Data are especially needed on deicing chem-
icals in surface and groundwaters; in selected soils and vegetation; and
the deterioration levels prevailing among salt-affected vehicular traffic,
highway pavements and structures, and underground utilities.
4. Consideration be given by the various governmental authorities
in roadway design to reduce deicing requirements, and enhance the con-
trol, collection, and treatment of ensuing salt runoff.
5. 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.
Evaluation of the pollutional impact of marine salts should be made as
soon as possible.
6. Information be compiled and disseminated, and in other cases
developed, on best selection of roadside plantings, and the various
remedial measures for restoring roadside soils and vegetation damaged
by deicing chemicals.
7. Findings of past studies dealing with vehicular corrosion, dete-
rioration of highway pavements, structures, and utilities, potentially
caused by road deicers, be made readily available for further study and
use.
8. Various suppliers and users of highway deicers investigate and
present information on the merits and demerits of various substitute
materials that may be used in place of the common chloride salts. A
major objective is to identify those deicers having high efficiency and
demonstrating minimum side effects.
9. Conduct studies to determine the use of deicing salts with re-
gard to the purpose for which they are intended, i.e., making winter
driving safer.
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TABLE III
RECOMMENDATIONS
(ABBREVIATED LISTING)
1. FOSTER PROBLEM RECOGNITION AND ALLEVIATION METHODS
2. INVESTIGATE TOXIC ADDITIVE EFFECTS
3. ESTABLISH ENVIRONMENTAL BASE-LINE DATA
4. REDUCE SALT POLLUTION BY IMPROVED HIGHWAY DESIGN
5. FURTHER INVESTIGATE MARINE SALT IMPACTS
6. IMPROVE ROADSIDE CONDITIONS
— Better Plant Selection
— Soil and Vegetation Restoration
7. FURTHER EVALUATE VEHICULAR AND ROADSIDE CORROSION
8. FURTHER INVESTIGATE SALT SUBSTITUTES
9. SUBSTANTIATE THAT SALT USAGE MAKES WINTER TRAVEL SAFER
I/ Selected from a more comprehensive listing of recommendations contained
in the Edison Water Quality Research Laboratory report(3).
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SECTION III
INTRODUCTION
Salt contamination in runoff is generated by storm events. Accord-
ingly, countermeasures for this form of pollution are being investigated
by the U.S. Environmental Protection Agency's Storm and Combined Sewer
Pollution Control Research, Development, and Demonstration Program.
This report comprises a state-of-the-art review of highway deicing
practices and associated environmental effects, and offers a critical
summary of the available information on:
1. Methods, equipment, and materials used for snow and ice removal;
2. Chlorides found in rainfall and municipal sewage during the
winter;
3. Salt runoff from streets and highways;
4. Deicing compounds found in surface streams, public water sup-
plies, groundwater, farm ponds, and lakes;
5. Special nutritious or toxic additives incorporated into deic-
ing agents;
6. Vehicular corrosion and deterioration of highway structures and
pavements attributable to salting; and
7. Effects of deicing compounds on roadside soils, vegetation and
trees.
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SECTION IV
USE OF DEICING COMPOUNDS
It has been found from a study(3) that the current annual use of high-
way deicers is approximately 9 to 10 million tons of sodium chloride, 0.3
million tons of calcium chloride, and about 11 million tons of abra-
sives (3-5). Reported amounts of these materials deployed for highway
deicing by individual States and Regions during the winter of 1966-1967
are presented in Table IV. Twenty-one states in the eastern and north-
central sectors of the country use more than 90 percent of all chloride
compound deicers. Leading States in deicer use are Pennsylvania, Ohio,
New York, Michigan and Minnesota. It is noted that 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
this State alone has probably exceeded 2.3 million tons.
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. As a result, the use of deicing salts has
greatly increased and in many cases has replaced the abrasives previously
used. Unfortunately, the more damaging chlorides are more efficient in
melting snow and ice, won't be blown off the road as easily by wind and
traffic, require less application time, and are less costly both in appli-
cation 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(6); whereas chemical deicers directly
attack and melt the ice and packed snow surfaces. The salt dissolves the
ice and most importantly, causes a break in the tight bonding of ice to
pavement. Chemicals also prevent the formation of new ice. The result-
ing salt residue is then readily washed off the pavement.
Marine salts have shown to be comparable in cost/effectiveness to
rock salt and are receiving use for highway deicing(6). These salts are
probably being sold separately or mixed together with commercial rock
11
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TABLE IV
REPORTED USE (TONS) OF SODIUM CHLORIDE, CALCIUM CHLORIDE,
AND ABRASIVES BY STATES AND REGIONS IN THE UNITED STATES,
WINTER OF 1966-1967^—•
STATE
SODIUM
CHLORIDE
CALCIUM
CHLORIDE
ABRASIVES
EASTERN STATES
Maine
New Hamsphire
Vermont
Massachusetts
Connecticut
Rhode Island
New York
Pennsylvania
New Jersey
Delaware
Maryland
Virginia
99,000
118,000
89,000
190,000
101,000
47,000
472,000
592,000
51,000
7,000
132,000
77,000
1,000
-
1,000
6,000
3,000
1,000
5,000
45,000
6,000
1,000
1,000
22,000
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
1,975,000
92,000
4,455,000
NORTH-CENTRAL STATES
Ohio
West Virginia
Kentucky
Indiana
Illinois
Michigan
Wisconsin
Minnesota
North Dakota
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
43,000
230,000
-
77,000
60,000
6,000
102,000
84,000
13,000
2,146,000
63,000
615,000
SOUTHERN STATES
Arkansas
Tennessee
North Carolina
Mississippi
Alabama
Georgia
South Carolina
Louisiana
Florida
1,000
17,000
2,000
75,000
18,000
2,000
75,000
12
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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—
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
2,000
3,000
2,000
1,000
8,000
165,000
291,000
31,000
36,000
6,000
150,000
291,000
2,000
1, OOP
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(4).
b/ Represents data by all governmental authorities reporting within
each State.
£/ Overall values given in Table IV 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 tons abrasives.
13
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salt amounting to hundreds of thousands of tons annually. It is known
that the major constituents in sea water approximate 30.5% sodium, 55.1%
chlorides, 3.7% magnesium, 7.7% sulfates, 1.2% calcium, 1.1% potassium,
0.2% bromides, and 0.4% bicarbonates and carbonates(7-9). Although com-
merical marine salts exclude impurities to a large extent, information
on product composition is not readily available. Further marine salt
data are definitely required on composition; comparative deicing effi-
ciency; and significantly, the potential consequences of sulfates, mag-
nesium, potassium and other available constituents possibly contributing
to environmental pollution.
Highway salting rates are generally in the range of 400 to 1,200
pounds of salt per mile of highway, per application(10-12). Over the
winter season, many roads and highways in the U.S. may receive more than
20 tons of salt per lane mile, or more than 100 tons per road mile.
Considerable wasting of highway deicers undoubtedly occurs because
of excessive application, misdirected spreading, and general wintertime
difficulties. In some cases, salts are applied as soon as or even before
snow occurs, based upon weather forecast probability. It is believed that
there have been frequent instances where highway salts were used but no
snow followed.
Environmental problems are minimized by deploying chemicals as spar-
ingly as possible to maintain "bare-pavement" conditions. 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(15) indicates several chal-
lenges presented by previous research findings, one being to improve
present maintenance practices 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(16) cites the viewpoint of the Bureau of Public
Roads that improper calibration of salt spreaders is extremely common.
This along with improper operation of equipment leads to excessive salt
application rates, which not only increases over-all costs but also con-
14
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tributes to the damage of vegetation and water supplies/ and the dete-
rioration of concrete pavement and structures. In Ontario, it is claimed
$1 million per year is saved by better application of highway salts(16).
Over recent years salt use in the State of Maine is reported to have been
reduced some 30,000 tons annually due to improved practices(11). Greene
estimates operational savings of several million dollars per year are
possible Nation-wide without reducing the quality of wintertime road
maintenance(16). 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, frequent calibration, increased reliance and improvement of
salt metering instrumentation, education and awareness through the ranks
particularly at the working level, concerted effort and increased train-
ing carried forth at the state highway department level, and due con-
sideration to environmental protection.
Various types of snow-control equipment are used, two of which are
shown in Figures 1 and 2. These figures show the use of screen grids in
salt spreaders for precluding problems with salt lumps. Other new salt
spreader designs include "electronically-controlled" 10-wheel vehicles,
capable of distributing 14 cubic yards of salt before reloading(13,14).
We should not neglect the possible use of sweepers as a substitute for
snow plows to alleviate pavement damage. This snow removal mechanism
could also allow direct snow pick-up as opposed to just pushing it aside.
15
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FIGURE 1
Twin-disc salt spreader with tail-gate
screens (placed inside truck body) to prevent
salt lumps from reaching feeder ports
FIGURE 2
New design salt spreader with screen
grid over top to preclude salt lumps
16
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SECTION V
CHLORIDE SALT REDUCTION POSSIBILITIES
Besides chemical melting, various methods for deicing are available
or have been conceived which may become more prominent in the future
especially when communities realize that a price must be paid to alle-
viate the pollutional effects of wintertime salting. Some of these
methods are:
1. External and in-slab thermal melting systems;
2. Stationary (or pit) and mobile thermal "snow melters";
3. Substitute deicing compounds;
4. Compressed air or high speed fluid streams in conjunction with
snowplow blade or sweepers to loosen pavement bond and lift snow;
5. Snow adhesion reducing substances in pavement;
6. Pavement substances that store and release solar energy for
melting;
7. Electromagnetic energy to shatter ice;
8. Road and drainage design modifications to enhance runoff, reduce
wintertime accidents, and capture snowmelt for treatment or control;
9. Salt retrieval or treatment possibly enhanced by the addition
of chelating agents; and
10. Improved tire or vehicular design to reduce deicer requirements.
Although it is recongized that power, maintenance, and chemical costs for
the above systems are high when compared to rock salt, municipalities,
such as Burlington, Massachusetts have expressed(17) a deep willingness
to explore and demonstrate new methods regardless of cost. Burlington
has recently suspended roadway salting practices when a study(17-19) in-
dicated that their well water chloride concentrations could exceed the
recommended limit of 250 mg/l(20,21) if salting was continued. It should
also be pointed out that experience, operational data, and knowledge of
environmental effects are lacking for the substitute chemical deicers.
17
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SECTION VI
SALT STORAGE
Salt storage is needed for sustaining highway deicing operations,
but too frequently these facilities, which concentrate great quantities
of salt, become a major contributing source of local ground and surface
water salt contamination. Because of water supply contamination, desir-
ability of better product handling, and aesthetic improvements, many
communities have turned to covering of salt piles, enclosed structures,
and the diversion of collection of salt-laden drainage(22,23) . Typical
open salt storage areas in Chicago and Milwaukee are shown in Figures 3
and 4. Figures 5 and 6 illustrate covered salt stockpiles in New York
City and Toledo, Ohio, which again from a water pollution control stand-
point, are highly preferred over open storage.
Example sketches of the types of salt storage facilities most fre-
quently used in the United States are illustrated in Figures 7 to 19. It
is noted that construction costs as given for these storage facilities
were prepared around 1965, and are undoubtedly somewhat below current
estimates. 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.
Fitzpatrick(24) of the Ontario Department of Highways has described
a dome-like structure or "beehive", as shown in Figure 20, which is 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.
The structure has a 100 foot base diameter and is 50 feet high. Trucks,
front-end loaders and other equipment, as shown by Figures 21 and 22, can
easily move about the structure for loading and unloading thus alleviating
the pollution effects from spillage in open areas. Costs are reported
around $5.00-$6.00 per ton of sand-salt mixture stored (approximately
equal to $3.50 per square foot of floor area)(24).
19
-------
FIGURE 3
Open salt storage pile, downtown Chicago, 111
Courtesy of city of
Chicago, Illinois
FIGURE 4
Open salt storage pile, Milwaukee, Wis,
estimated quantity 41,000 tons
20
-------
FIGURE 5
g Sa]t by f™nt-end loader
enclosed storage structure
FIGURE 6
u S2U stockPHe located adjacent
the Maumee River in Toledo, Ohio
21
-------
FIGURE 7
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 4" by 4"
wood sills. It will hold approximately a 40-ton minimum
carload of bulk salt.
FIGURE 8
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 9
Approx. Construction Cost $3 to $5 per ton of capacity
f P "• COflfuCA rio
Courtesy of the
Salt Institute,
Alexandria, Va.
Open bin storage like this is favored by many Ohio communities,
and the dimensions shown here are given to scale. The roof
has a 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.
22
-------
FIGURE 10
FIGURE 11
Approx. Construction Cost
$50 to $75 per ton of capacity
Approx. Construction Cost
$50 to $75 per ton of capacity
D
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 10, except that a vertical chain
and bucket elevator is used.
FIGURE 12
FIGURE 13
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 12
follows the contour of the hill.
23
Courtesy of the
Salt Institute,
Alexandria, Va.
-------
FIGURE 14
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 4" 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 15
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 16
Approx. Construction Cost $20 to $30 per ton of capacity
This piling arrangement, similar to that in Figure 14 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.
24
Courtesy of the
Salt Institute,
Alexandria, Va
-------
FIGURE 17
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 18
Salt Storage Shelter
Umbrella structure protects material from weather
Panel on both sides keeps salt from collect-
ing around posts.
Courtesy of the
Salt Institute,
Alexandria, Va.
FIGURE 19
Salt Storage Building
Tie corner posts of storage buildings together with
underground galvanized cables with turnbuckles.
25
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The "Beehive" -
Method of loading;
first stage by
truck and dozer
FIGURE 20
The "Beehive" -
Salt Storage Structure;
note air vents at top
FIGURE 22
The "Beehive" -
Method of loading;
second stage by
conveyor
26
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SECTION VII
ENVIRONMENTAL EFFECTS FROM DEICING COMPOUNDS
Runoff, Sewage, and Surface streams
Street runoff from the melting of ice and snow mixed with chloride
salts, finds its way via combined and sanitary sewers to the local sewage
treatment plant and then to the streams; and also via storm sewers to
nearby receiving waters. 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(12,25). During days of heavy snow-melt,
daily chloride loads were three-fold the normal summertime loads. Cal-
culations (10) show that 600 pounds of salt when applied to a one-mile
section of roadway 20 feet wide containing 0.2 inches of ice, will pro-
o
duce an initial salt solution of 69,000 (at 10 F) mg/1 to 200,000 (at
25 F) mg/1. Street runoff samples collected from a downtown Chicago ex-
pressway in the winter of 1967 showed chloride contents from 11,000 to
25,000 mg/l(26,27). Table V illustrates some high chloride concentration
values found in runoff.
At Milwaukee, on January 16, 1969, extremely high chloride levels of
1,510 to 2,730 mg/1 found in the Milwaukee, Menomonee, and Kinnickinnic
Rivers, were believed directly attributable to deicing salts entering
these streams from highway snow melt(23). Table VI contains the Milwaukee
results. Meadow Brook in Syracuse, New York contained chloride concentra-
tions usually in the range of 200 to 1,000 mg/1, but frequently exceeded
a few thousand mg/1(29). For example, a sample in December showed about
11,000 mg/1 chlorides in the Meadow Brook watershed(27). From the limited
data available on streams, increasing chloride trends are evident for
some large rivers in the U.S.(10). Wintertime highway runoff eventually
running into freshwater streams and natural or man-made lakes or ponding
areas may have adverse effects upon water life in the future(10,24).
The dumping of extremely large amounts of accumulated snow and ice
from streets and highways, either directly or indirectly into nearby water
27
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TABLE V
Location
Chippewa Falls,
Wise.
Madison, Wise.
Lake Monona
Wise.
Chicago, 111.
Des Moines, Iowa
HIGH CHLORIDE VALUES IN RUNOFF
Chlorides
Source
Highway
Street
Snow Pile
Date (mg/1)
Reference
1956-1957 10,250 Schraufnagel (12)
1956-1957 3,275 Schraufnagel (12)
1956-1957 1,130 Schraufnagel (12)
JFK Express- 1966-1967 25,100 Schraufnagel (26,27)
way
Cummins Pkwy. 1958-1969 2,720 Henningson, et al. (28)
Storm Drain
TABLE VI
SPECIAL RIVER SAMPLING, MILWAUKEE SEWERAGE COMMISSION,
January 16, 1969^-
Location
Kinnickinnic River at
Chase Avenue
Menomonee River at 13th St.
and Muskego
Menomonee River at 70th and
Honey Creek Pkwy.
Milwaukee River at Silver
Spring Road
Milwaukee River at Port
Washington Road
Water
Temperature( C)
10.0
10.5
5.0
4.0
6.5
Chlorides (mg/1)
2,005
200
2,730
2,680
1,510
a/ Records received from the Milwaukee Sewerage Commission, May 1970(25)
28
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bodies could constitute a serious pollution problem. These deposits have
been shown(30) to contain up to 10,000 mg/1 sodium chloride, 100 mg/1 oils,
and 100 mg/1 lead. The latter two constituents attributable to automotive
exhaust. Figure 23 shows a dumping operation.
Farm Ponds and Lakes
Effects of highway salts upon farm ponds and as a cause of induced
stratification in lakes have been described by various investigators. 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 in-
creasing yearly(10,26,31,32). Density stratification of chlorides was
observed in Beaver Dam Lake at Cumberland, Wisconsin(12); in First Sister
Lake near Ann Arbor, Michigan(33); and Irondequoit Bay at Rochester, New
York(34), all three cases attributed to salt runoff from nearby streets
entering these lakes. It has also been estimated that highway salts con-
tribute 11 percent of the total input of waste chlorides entering Lake
Erie annually(10,35). Sodium from road salts entering streams and lakes
may additionally serve to increase existing levels of one of the mono-
valent ions essential for optimum growth of blue-green algae, thereby
stimulating nuisance algal blooms(36,37).
Recent investigations(38) have brought attention to the hazardous
potential of sodium and calcium ion exchange with mercury tied up in
bottom muds. This could release highly toxic mercury to the overlying
fresh waters. Undoubtedly other poisonous heavy metals can also be re-
leased in this manner.
Deicing Additives
Special additives present within much of the highway salts sold today
may create pollutional problems(39) even more severe than caused by the
chloride salts(40). Ferric ferrocyanide and sodium ferrocyanide are com-
monly used to minimize the caking of salt stocks(12). The sodium form
29
-------
FIGURE 23
Dumping snow into nearby waterway
30
-------
in particular, is quite soluble in water, and will generate cyanide in
the presence of sunlight(10). Tests by the State of Wisconsin showed that
15.5 mg/1 of the sodium salt can produce 3.8 mg/1 cyanide after 30 min-
utes (10,12). Maximum levels of cyanide allowed in public water supplies
range from 0.2 to 0.1 mg/1(20,41). Chromate and nutritious phosphate(10,
12) additives are used in deicers as corrosion inhibitors(10,12,40). As
with cyanide, chromium is a highly toxic ion(40), and limits permitted in
drinking and other waters are in the same low range(20,41). During the
winter of 1965-1966 in the Minneapolis-St. Paul area, snow melt samples
showed maximum levels of 24 mg/1 sodium chromate, 1.7 mg/1 hexavalent
chromium, and 3.9 mg/1 total chromium(40).
Ground and Surface Water Supply Contamination
Serious groundwater pollution has occurred in many locations due to
the heavy application of salts onto highways and inadequate protection
given to salt storage areas(6,10,17-19,31,32,42-56). The State of New
Hampshire up to 1965, is reported to have replaced more than 200 road-
side wells, due to contamination by road salts. Some of these wells had
contained in excess of 3,500 mg/1 chlorides(10,49). 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(10,43). Tastes
and odors in domestic water supplies in Connecticut have been traced to
chlorides and sodium ferrocyanide originating from salt storage areas(51).
Within Massachusetts, salt increases have been noted in the water supplies
of some 63 communities(19,42,57), and various supplies have been abandoned
at least in part due to road salting and salt storage piles(17-19,42,50,
52,53,57).
The previously cited Town of Burlington,-^Massachusetts conducted a
study(17,18) indicating area wells are becoming .increasingly high in
chlorides as shown in Figure 24. If this chloride concentration were to
increase at the rate shown, water supplied by these Burlington wells could
soon exceed the upper limit of 250 mg/1 chloride established by the U.S.
Public Health Service(20), a condition which could possibly force closing
31
-------
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O
a-
00
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o
O"
to
vO
o
"fr
o
00
o
o
CM
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o
o
10
-c c
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o
u
LU
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LU
U
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FIGURE 24
32
-------
of wells. It should be emphasized that a desirable concentration of
chlorides is considered to be 25 mg/1 or less(21) and that the American
Heart Association(10,19,58,59) recommends water containing more than 20-22
mg/1 of sodium (59 mg/1 sodium chloride) should not be used when patients
are on diets with an intake of sodium restricted to less than 1,000 mg/
day(59). The normal adult intake of sodium is about 4,000 mg/day(10).
Other specific cases of water supply contamination in Massachusetts
merit 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 attributable to a salt storage pile located uphill from the well(54).
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 in-
creases, and two wells in Charlton were likely to be abandoned(55). Also,
in the general Boston area, snow removal and disposal practices are cited
as- contributing to heavy salt content in the Mystic Lakes(56).
On the subject of industrial water use, Schraufnagel(12,49) found
that chlorides have been responsible for the corrosion of various metals
including stainless steels. Schraufnagel also cites an industry state-
ment 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". McKee and Wolf in 1963(60), in
their extensive review of the literature summarized chloride tolerances
for various 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;
and dairy processing, photography and sugar production - 20 to 30 mg/1(10,
60). Other reviews on water quality needs for industry including chloride
limits are also available(61,62).
33
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Vehicular and Roadway Damage
Road salts not only promote vehicular corrosion, but may also affect
structural steel, house sidings, and other property(6,49,63-73). It has
been previously estimated that the private car owner pays for corrosion
in the amount of about $100 per year(65). Deicers may cause appreciable
damage to highway structures and pavements, particularly those constructed
of Portland cement(6,69,70). Even though air-entrained concrete is re-
ported superior to non air-entrained concrete in its resistance to salts,
it is preferrable that neither form be exposed to road salts for at least
one year, after being poured(6,69,70). Detrimental effects from deicing
salts have been reported(49,73) on various underground utilities, such
as cables and water mains.
Soil, Vegetation, and Trees
Widespread damage of roadside soils, vegetation, and trees has been
observed where there has been liberal application of road salts(10,32,46,
74-109). Most studies dealing with plant injury and death have focused
on the sugar maple decline(10,87-93,95-98,109) which has occurred over a
16-State area, mostly in the New England States. Figures 25 through 28
resulting from a study conducted by the Connecticut State Highway Depart-
ment (95-98,109) show the progressive deterioration of sugar maples and
associated leaf damage. Figure 25 taken in 1960 depicts the condition of
sugar maples on two sides of a road where longitudinal drainage is from
right to left. Figure 26 depicts the condition of these maples five years
later. Leaf margin burn, limb die-back, and varying degrees of defolia-
tion are pronounced on the trees on the left receiving the impact from
salt-laden drainage. These effects are more readily illustrated by Fig-
ures 27 and 28. The tree in Figure 27 on the left side of the roadway
shows severe stages of deterioration, and the leaves in Figure 28 demon-
strate severe leaf-margin burn. It is important to realize here, in
general that until the 1960's, highway maintenance departments princip-
ally relied on abrasives as opposed to salt(3).
34
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FIGURE 25
Relatively healthy Sugar Maples,
Photographed 1960, Route 17, Durham-
Mi ddletown line, Conn.
FIGURE 26
Same trees as above - those on
left exhibiting salt damage
photographed 1965
Courtesy of E. F. Butto
State of Conn. Dept. o-
Transportation
35
-------
FIGURE 27
Close-up of Sugar Maple exhibiting
pronounced damage, Route 17,
Durham-Middietown line, Conn.
FIGURE 28
Healthy (right) vs.
Maple leaves, from
side of Route 17,
Durham-Middletown
damaged Sugar
right and left
respectively,
line, Conn.
Courtesy of E. F. Button,
State of Conn. Dept. of
Transportation
36
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Tables VII through XI give relative salt tolerances of various fruit
crops, vegetable crops, field crops, grasses, forage legumes, trees, and
ornamentals. It is hoped that this information may be used by highway
authorities and others in selecting roadside plants and vegetation.
TABLE VII
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
I/ Original Source, Bernstein, L., 1965(101)
37
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TABLE VIII
2/
SALT TOLERANCE OF VEGETABLE CROPS—
Moderately
Tolerant Tolerant Sensitive
Garden beet Tomato Radish
Kale Broccoli Celery
Asparagus Cabbage Green bean
Spinach Caulifower
Lettuce
Sweet corn
Potato
Sweet potato-yam
Bell pepper
Carrot
Onion
Pea
Squash
Cucumber
2/ Original Source, Bernstein, L., 1959(102).
TABLE IX
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
3/ Orignial Source, Bernstein, L., 1960(103)
38
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TABLE X
4/
SALT TOLERANCE OF GRASSES AND FORAGE LEGUMES-
Tolerant
Alkali sacaton
Saltgrass
Nuttall alkali-grass
Bermuda grass
Tall wheatgrass
Rhodes grass
Rescue grass
Canada wildrye
Western wheatgrass
Tall fescue
Barley
Birdsfoot trefoil
Moderately
Tolerant
Sensitive
White sweet clover White dutch clover
Yellow sweet clover Meadow foxtail
Perennial ryegrass Alsike clover
Mountain brome Red clover
Harding grass Ladino clover
Beardless wildrye Burnet
Strawberry clover
Dallis grass
Sudan grass
Hubam clover
Alfalfa
Rye
Wheat
Oats
Orchard grass
Blue gamma
Meadow fescue
Reed canary
Big trefoil
Smooth brome
Tall meadow oatgrass
Milvetch
Sourclover
4/ Original Source, Bernstein, L., 1958(104)
39
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TABLE XI
5/
SALT TOLERANCE OF TREES AND ORNAMENTALS—
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
Cotton wood
Aspen
Birch
Poorly
Tolerant
Black walnut
Little leaf linden
Barberry
Winged euonymus
Multiflora rose
Spiraea
Artie blue willow
Viburnum
Pineapple guava
Rose
European hornbeam
European beech
Italian poplar
Black alder
Larch
Sycamore maple
Speckled alder
Lombardy poplar
Red maple
Sugar maple
Compact boxwood
Filbert
5/ From Zelazny, L., 1968(100).
40
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SECTION VIII
REFERENCES
1. "Highway Snow and Ice Control: A Search for Innovative Tech-
nological Alternatives", EPA Contract No. 68-01-0706, Abt Assoc.,
Inc., Reports for EPA (1972).
2. "Study of the Environmental Impact of Highway Deicing", EPA Con-
tract No. 68-03-0154, Arthur D. Little, Inc. (1972).
3. "Environmental Impact of Highway Deicing", 11040 GKK 06/71, Storm
and Combined Sewer Technology Branch, Edison Water Quality Research
Laboratory, EPA (June 1971).
4. "Survey of Salt, Calcium Chloride and Abrasive Use for Street and
Highway Deicing in the United States and in Canada for 1966-1967",
The Salt Institute, Alexandria, Virginia (date not given).
5. "Survey of Salt Calcium Chloride and Abrasive Use in the United
States and Canada for 1969-1970", The Salt Institute, Alexandria,
Virginia (date not given).
6. "Legislative Research Council Report Relative to the Use and Effects
of Highway Deicing Salts", The Commonwealth of Massachusetts (Jan-
uary 1965).
7. "The Encyclopedia of Oceanography", Encyclopedia of Earth Sciences
by Fairbridge, R.W., Reinhold Publishing Company, New York, N.Y.
(1966).
8. "Chemical Oceanography 1", Edited by Riley, J.P. and S. Kirrow, G.,
Academic Press, London and New York (1965).
9. Harvey, H.W., "The Chemistry and Fertility of Sea Waters", Cambridge
at the University Press, London and New York (1963).
10. Hanes, R.E., et. al., "Effects of Deicing Salts on Water Quality
and Biota-Literature Review and Recommended Research", National Co-
operative Highway Research Program Report 91, Virginia Polytechnic
Institute and Highway Research Board (1970).
11. Hutchinson, F.E., Personal communication (May 1970).
12. Schraufnagel, F.M., "Chlorides", Commission on Water Pollution,
Madison, Wisconsin (1965).
41
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13. "Mayor Sees Demonstration of New Salt Spreader", New York Times
newspaper article (November 26, 1970) .
14. "Mayor Inspects Cleanup Arsenal", New York Times newspaper article
(October 24, 1970).
15. "Highway Research Record Report No. 193 on Environmental Considera-
tions in the Use of Deicing Chemicals", Foreword, Highway Research
Board, Washington, D.C. (1967).
16. Greene, W.C., "What are the Problems", Paper presented at the Univer-
sity of Connecticut Symposium - Pollutants in the Roadside Environ-
ment (February 29, 1968).
17. Burling, Jr., William H., Personal communications (August 1972).
18. "Salt Contamination of Existing Well Supplies", Whitman and Howard,
Inc., Report for Town of Burlington, Mass. (October 1971).
19. Huling, E.E., and Hollocher, T.C., "Groundwater Contamination by Road
Salt: Steady-State Concentrations in East Central Massachusetts",
Science, 176, 288 (April 21, 1972).
20. "Public Health Service Drinking Water Standards - 1962", Public Health
Service Publication No. 956, U.S. Department of Health, Education and
Welfare, U.S. Government Printing Office, Washington, D.C. (1962) .
21. "Water Quality Criteria", National Technical Advisory Committee to
the Secretary of the Interior, Washington, D.C. (1968) .
22. "Storing Road Deicing Salt", The Salt Institute, Alexandria, Virginia
(1967).
23. "The Snowfighter's Salt Storage Handbook", The Salt Institute, Alex-
andria, Virginia (1968).
24. Fitzpatrick, J.R., "Beehives Protect Snow-Removal Salt and Prevent
Water Pollution", American City (September 1970).
25.. Members of the Milwaukee Sewerage Commission and Jones Island sewage
treatment plant personnel, Personal communication (May 1970).
26. Sullivan, R.H., "Effects on Winter Storm Runoff of Vegetation and as
a Factor in Stream Pollution", Paper presented at the Seventh Annual
Snow Conference, Milwaukee, Wisconsin (April 12, 1967).
27. "Water Pollution Aspects of Urban Runoff", 11030 DNS 01/69, Contract
No. WA 66-23, American Public Works Association, Report for U.S. EPA
(January 1969).
42
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28. "Rainfall-Runoff and Combined Sewer Overflow", Contract No. 14-12-402,
Henningson, Durham and Richardson, Inc., Final Draft Report for U.S.
EPA (March 1970).
29. Hawkins, R.H., "Street Salting and Water Quality in Meadow Brook,
Syracuse, New York", Paper presented at the Street Salting Urban
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30. Soderlund, G., et. al., "Physicochemical and Microbiological Proper-
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31. Hutchinson, F.E., "The Influence of Salts Applied to Highways on the
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1967).
32. Hutchinson, F.E., "Effect of Highway Salting on the Concentration of
Sodium and Chloride in Private Water Supplies", Research in the Life
Sciences (Fall 1969).
33. Judd, J.H., "Effect of Salt Runoff from Street Deicing on a Small
Lake", Thesis submission - University of Wisconsin, Madison, Wiscon-
sin (1969).
34. Diment, W.H. and Bubeck, R.C., "Runoff of Deicing Salt: Effect on
Irondequoit Bay, Rochester, New York", Paper presented at the Street
Salting Urban Water Quality Workshop, SUNY Water Resources Center,
Syracuse University, Syracuse, N.Y. (May 6, 1971).
35. Ownbey, C.R. and Kee, D.A., "Chlorides in Lake Erie", Tenth Con-
ference Great Lakes Research, First Meeting International Associa-
tion of Great Lakes Research, Toronto, Canada (April 1967).
36. Keup, L.E., Personal communication (1971).
37. Sharp, R.W., "Road Salt as a Polluting Element", Special Environ-
mental Release No. 3, Bureau of Sport Fisheries and Wildlife, U.S.
Department of Interior (December 14, 1970).
38. Feick, G., et. al., "Release of Mercury from Contaminated Freshwater
Sediments by the Runoff of Road Deicing Salt", Science, 175, 1142
(March 10, 1972).
39. Smith, H.A., "Progress Report on NCHRP Project 16-1; Effects of
Deicing Compounds on Vegetation and Water Supplies", Paper pre-
sented at the 54th Annual Meeting of the American Association of
State Highway Officials, Minneapolis, Minnesota (December 5, 1968).
43
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40. "Toxicity and Pollution Study of Carguard Chemicals, 1965-1966",
Cargill, Inc., Minneapolis, Minnesota.
41. Materials in the Files of the Storm and Combined Sewer Technology
Branch, Edison Water Quality Research Laboratory, U.S. EPA (1970).
42. "Salt Buildup in Drinking Water a Danger to Some Bay Staters",
Boston Globe newspaper article (May 8, 1970).
43. Deutsch, M., "Ground Water Contamination and Legal Controls in Michi-
igan", Water Supply Paper No. 1691, USGS (1963).
44. Walker, W.H., "Salt Piling - A Source of Water Supply Pollution",
Pollution Engineering, 2_, 3 (July-August 1970).
45. Hutchinson, F.E., "The Influence of Salts Applied to Highways on the
Levels of Sodium and Chloride Ions Present in Water and Soil Samples",
Project No. R1086-8, Progress Report No. I (July 1, 1965-June 30,
1966).
46. Hutchinson, F.E., "The Influence of Sodium and Chloride Ions Present
in Water and Soil Samples", Project No. R1088-8, Progress Report No.
Ill (1968).
47. Smith, R.D., "The Groundwater Resources of Summit County, Ohio",
Ohio Division of Water, Bulletin No. 27 (1953).
48. Rahn, P.H., "Movement of Dissolved Salts in Groundwater Systems",
Paper presented at the University of Connecticut Symposium-Pollutants
in the Roadside Environment (February 29, 1968).
49. Schraufnagel, F.M., "Pollution Aspects Associated with Chemical
Deicing", Highway Research Record Report No. 193, HRB, Washington,
D.C. (1967).
50. U.S. Geological Survey, Personal communication (May 1970).
51. Scheldt, M.E., "Environmental Effects of Highways", Journal of the
Sanitary Engineering Division, Proceedings of the American Society
of Civil Engineers, 93, No. SA5, Paper No. 5509 (October 1967).
52. "Side Effects of Salting for Ice Control", American City, 80,
(August 1965).
53. "Salting Highways Could Contaminate Ground Water", Reclamation News
(April 1965) .
54. "Road Salt Blamed for Souring Water", Boston Globe newspaper article
(April 1970) .
44
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55. "Do Road Salts Poison Water Supplies?", Boston Globe newspaper
article (1968 or 1969).
56. "Alewife Brook Polluted", Boston Globe newspaper article (May 1970).
57. "The Massachusetts Department of Public Health last year warned 62
communities in the Bay State that the sodium content in their drink-
ing water was high enough to pose a health hazard to people on low
salt diets", Boston Globe newspaper article, Section 1, p. 2, (Aug-
ust 1, 1971).
58. "Your 500-Milligram Sodium Diet", The American Heart Association
(1957).
59. "Your 1000-Milligram Sodium Diet", The American Heart Association
(1957) .
60. McKee, J.E., and Wolf, H.W., "Water Quality Criteria", Second
Edition, State Water Quality Control Board, Sacramento, Calif.
(1963) .
61. Moore, E.W., "Tolerable Salt Concentrations in Drinking Waters",
Progress Report to the Sub-committee on Water Supply of the Com-
mittee on Sanitary Engineering and Environment (1950).
62. "Manual on Industrial Water", Spec. Tech. Pub. No. 148, ASTM,
Committee D-19 on Industrial Water (1953).
63. Lockwood, R.K., "Snow Removal and Ice Control in Urban Areas",
Research Project No. 114, Volume I, American Public Works Associa-
tion (August 1965).
64. Kallen, H.P., "Corrosion", Special Report, Power (December 1956).
65. "What is Highway Salt Doing to Us?", Milwaukee Journal newspaper
article (May 4, 1970).
66. "Report Discusses Salt Corrosion", APWA Reporter (October 1970).
67. Article appearing in Automotive Industries (February 1, 1964).
68. Article appearing in Steel (March 2, 1964).
69. "U.S. Highway Research Board Bulletin No. 323", Washington, D.C.
(1962).
70. Dickinson, W.E., "Publication No. 98", National Ready Mixed Con-
crete Association, Washington, D.C. (1961).
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71. "The Elimination of Pavement Sealing By Use of Air Entraining
Portland Cement", HB 18.8, Portland Cement Association, Chicago,
Illinois.
72. "Protection of Existing Concrete Pavements from Salt and Calcium
Chloride", HB 1-2, Portland Cement Assoication, Chicago, 111.
73. Hamman, W. and Mantes, A.J., "Corrosive Effects of Deicing Salts",
Journal American Water Works Association, 58, 11 (November 1966) .
74. Hutchinson, F.E., "The Influence of Salts Applied to Highways on
the Levels of Sodium and Chloride Ions Present in Water and Soil
Samples", Project No. A-007-ME, Project Completion Report (July
1965-June 1969).
75. Roberts, E.G., and Zybura, E.L., "Effect of Sodium Chloride on
Grasses for Roadside Use", Highway Research Record Report No.
193, HRB, Washington, D.C. (1967).
76. Prior, G.A., "Salt Migration in Soil", Paper presented at the
University of Connecticut Symposium - Pollutants in the Roadside
Environment (February 29, 1968).
77. Prior, G.A. and Berthouex, P.M., "A Study of Salt Pollution of
Soil by Highway Salting", Highway Research Record Report No.
193, HRB, Washington, D.C. (1967).
78. Hutchinson, F.E. and Olson, B.E., "The Relationship of Road Salt
Applications to Sodium and Chloride Ion Levels in the Soil Border-
ing Major Highways", Highway Research Record Report No. 193, HRB,
Washington, D.C. (1967).
79. Thomas Jr., L.K., "Notes on Winter Road Salting (Sodium Chloride)
and Vegetation", Scientific Report No. 3, National Park Service
(March 31, 1965).
80. Hutchinson, F.E., "The Relationship of Road Salt Applications to
Sodium and Chloride Ion Levels in the Soil Bordering Major High-
ways", Paper presented at the University of Connecticut Symposium -
Pollutants in the Roadside Environment (February 29, 1968).
81. Thomas Jr., L,K., and Bean, G.A., "Winter Rock Salt Injury to
Turf (Poa pratenais L.)", Scientific Report No. 5, National Park
Service (August 23, 1965).
82. Wester, H.V. and Cohen, E.E., "Salt Damage to Vegetation in the
Washington, D.C. Area During the 1966-1967 Winter", Plant Disease
Reporter, 52, 5 (May 1968).
46
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83. Thomas Jr., L.K., "A Quantitative Microchemical Method for Deter-
mining Sodium Chloride Injury to Plants", Scientific Report No.
4, National Park Service (1965).
84. Roberts, E.G., "Effect of Deicing Chemicals on Grassy Plants",
Paper presented at the University of Connecticut Symposium -
Pollutants in the Roadside Environment (February 29, 1968).
85. Verghese, K.G., et. al., "Sodium Chloride Uptake and Distribution
in Grasses as Influenced by Fertility Interaction and Complementary
Anion Competition", Unpublished Report, Virginia Polytechnic
Institute (1969).
86. French, D.W., "Boulevard Trees are Damaged by Salt Applied to
Streets", Minnesota Farm and Home Science, XVI, 2, 9 (1959).
87. LaCasse, N.L., "Maple Decline in New Hampshire", M.S. Thesis,
University of New Hampshire (1963).
88. LaCasse, N.L., and Rich, A.E., "Maple Decline in New Hampshire",
Phytopathology, 54 (1964) .
89. Rich, A.E., and LaCasse, N.L., "Salt Injury to Roadside Trees",
Forest Notes (Winter 1963-1964).
90. Rich, A.E., "Effect of Deicing Chemicals on Woody Plants", Paper
presented at the University of Connecticut Symposium - Pollutants
in the Roadside Environment (February 29, 1968).
91. Kotheimer, J., Niblett, C., and Rich, A.E., "Salt Injury to Road-
side Trees - A Progress Report", Forest Notes, 85, 3-4 (1965).
92. Westing, A.H., "Sugar Maple Decline: An Evaluation", Botany,
20_, 2 (1966) .
93. Holmes, F.W. and Baker, J.H., "Salt Injury to Trees, II. Sodium
and Chloride in Roadside Sugar Maples in Massachusetts", Phyto-
pathology, 56, 6 (June 1966).
94. Zelazny, L.W., et. al., "Effects of Deicing Salts on Roadside
Soils and Vegetation, II. Effects on Silver Maples (Acre sac-
charinum L.)", Unpublished Report, Virginia Polytechnic Institute
(1970).
95. Button, E.F. and Peaslee, D.E., Unpublished data from Connecticut
State Highway Department, Department of Research and Development
and Connecticut Agricultural Experiment Station.
96. Button, E.F., "Influence of Rock Salt Used for Highway Ice Control
on Natural Sugar Maples at One Location in Central Connecticut",
Report No. 3, Connecticut State Highway Department (1964).
47
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97. Button, E.F., "Influence of Rock Salt, Salt Used for Highway Ice
Control on Natural Sugar Maples at One Location in Central Connect-
icut", Report No. 3A, Connecticut State Highway Department (1964).
98. Button, E.F., "Ice Control Chlorides and Tree Damage", Public
Works, 93_, 3 (1965).
99. Allison, L.E., "Salinity in Relation to Irrigation", Advances in
Agronomy, 16 (1964).
100. Zelazny, L.W., "Salt Tolerance of Roadside Vegetation", Paper pre-
sented at the University of Connecticut Symposium - Pollutants
in the Roadside Environment (February 29, 1968).
101. Berstein, L. "Salt Tolerance of Fruit Crops", Department of
Agriculture Bulletin No. 292 (1965).
102. Bernstein, L., "Salt Tolerance of Vegetable Crops in the West",
Department of Agriculture Bulletin No. 205 (1959).
103. Bernstein, L., "Salt Tolerance of Field Crops", Department of
Agriculture Bulletin No. 217 (1960).
104. Bernstein, L., "Salt Tolerance of Grasses and Forage Legumes",
Department of Agriculture Bulletin No. 194 (1958) .
105. Monk, R.W., and Peterson, H.B., "Tolerance of Some Trees and
Shrubs to Saline Conditions", Proc. American Soc. Hort. Sci., 81
(1962) .
106. Rudolfs, W., "Influence of Sodium Chloride Upon the Physiological
Changes of Living Trees", Soil Science 8^ (1919).
107. Strong, F.C., "A Study of Calcium Chloride Injury to Roadside
Trees", Michigan Agr. Exp. Sta. Quart. Bull., 27^ (1944).
108. Sauer, G., "Damage by Deicing Salts to Plantings Along the Federal
Highways", News Journal, German Plant Protective Service, 19, 6
(1967).
109. Button, E.F., Personal communication (August 1972).
48
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
/. Report No,
EPA-R2-
73-257
w
Water Pollution and Associated Effects from
Street Salting
5. Kepor' J' : ors gnvironmentaj damages, hydrophobic substances, highway deicing, groundwater
contamination, plant tolerances, public water supplies, salt storage, vehicular
corrosion, water pollution effects, wintertime highway runoff, snow removal
practices.
i~b. Identifiers Stormwater Runoff
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
US DEPARTMENT OF THE INTERIOR
WASHINGTON. D C 2O24O
Richard Field
USEPA/EWQRL, Edison, New Jersey 08817
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