SALT WATER INTRUSION
IN THE UNITED STATES
Robert S. Kerr Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74820
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EPA-600/8-77-011
July 1977
SALT WATER INTRUSION IN
THE UNITED STATES
by
Bob D. Newport
Ground Water Research Branch
Robert S. Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
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DISCLAIMER
This report has been reviewed by the Robert S. Kerr Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publication.
Mention of trade names or commercial products does not constitute endorsement
or recommendation for use.
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FOREWORD
The Environmental Protection Agency was established to coordinate
administration of the major Federal programs designed to protect the
quality of our environment.
An important part of the Agency's effort involves the search for
information about environmental problems, management techniques, and new
technologies through which optimum use of the Nation's land and water
resources can be assured and the threat pollution poses to the welfare
of the American people can be minimized.
EPA's Office of Research and Development conducts this search through
a nationwide network of research facilities.
As one of these facilities, the Robert S. Kerr Environmental Research
Laboratory is responsible for the management of programs to: (a) investi-
gate the nature, transport, fate, and management of pollutants in ground
water; (b) develop and demonstrate methods for treating wastewaters with
soil and other natural systems; (c) develop and demonstrate pollution con-
trol technologies for irrigation return flows; (d) develop and demonstrate
pollution control technologies for animal production wastes; (e) develop
and demonstrate technologies to prevent, control or abate pollution from
the petroleum refining and petrochemical industries; and (f) develop and
demonstrate technologies to manage pollution resulting from combinations
of industrial wastewaters or industrial/municipal wastewaters.
This report contributes to the knowledge essential if the EPA is to
meet the requirements of environmental laws that it establish and enforce
pollution control standards which are reasonable, cost effective, and
provide adequate protection for the American public.
William C. Galegar
Director
m
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ABSTRACT
Salt water intrusion, from one or more sources outlined in this report,
has resulted in degradation of subsurface fresh water aquifers in 43 states.
Numerous case histories delineating current problems exist, providing adequate
documentation of the seriousness of salt water intrusion.
Waste from municipal and industrial sources entering natural streams or
reservoirs are responsible for the more visible types of pollution; their
detection is rapid, their source can usually be identified, and their elimin-
ation will result in rapid natural improvement of water quality. In contrast,
the clandestine movement of salt water through a fresh water aquifer continues,
defying early detection, concealing its origin, and creating long-term prob-
lems with expensive remedies.
IV
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CONTENTS
Foreword iii
Abstract iv
Acknowledgment vi
INTRODUCTION 1
General 1
Ground-Water Use 1
Potential Problem Areas 1
Ground-Water Pollution 2
MECHANISMS OF INTRUSION 10
Reversal or Reduction of Gradient 10
Destruction of Natural Barriers 10
Disposal of Waste Saline Water 10
Oil Production 12
CONTROL TECHNOLOGY 13
CURRENT CONTROL EFFORTS 14
BIBLIOGRAPHY 27
REFERENCES 30
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ACKNOWLEDGMENT
The need for this report was conceived by Mr. Edmond P. Lomasney,
Regional Representative, Office of Research & Development, EPA Region IV,
Atlanta, Georgia. He guided its development to conform with the needs of
that Region.
Since its original preparation in January 1975, this report has been
widely accepted and acclaimed, as can be shown by the continued and increasing
requests for copies. The Robert S. Kerr Environmental Research Laboratory
acknowledges with appreciation such favorable response which has resulted in
this publication of "Salt Water Intrusion in the United States."
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INTRODUCTION
GENERAL
The earth, concealing a lense of fresh water, was uniquely designed so
man, requiring fresh water could exist. Then man, in his impatient pursuit
of progress, created a demand on this resource exceeding the supply plus
natural recharge. Where salt and fresh water zones are hydraulically connected,
salt water intrudes as fresh water levels decrease thereby destroying the
potability of the aquifer. In areas where subsurface reservoirs thus defied
destruction, contaminants have been injected into them, exemplifying man's
continuing disregard for his environment.
Contaminated ground-water reservoirs are not visible, give off no odor,
and are not associated with fish kills; consequently, it has been difficult
to generate interest in water pollution in the subsurface environment. Slow
but sure, degradation of ground water continues while the seriousness of
aquifer pollution has often been downgraded by environmentalists and policy
makers who have directed their efforts to the more sensational forms of
pollution.
GROUND-WATER USE
Conservative estimates indicate that subsurface water supplies 50 percent
of the national population and 95 percent of the rural population. Some states
depend on ground water for over 85 percent of their public water supply while
20 percent of the total United States water demands are met by subsurface
supplies.
POTENTIAL PROBLEM AREAS
The U. S. Public Health Service in 1962 placed the limit on public drink-
ing water supply at 500 ppm dissolved solids. Approximately two-thirds of
the conterminous United States is underlain by aquifers known to produce water
containing at least 1,000 ppm dissolved solids, and beneath most of these
aquifers are zones containing mineralized water of 10,000 ppm and above.
Areas contained in the remaining one-third are believed to contain mineralized
water, but verification by well drilling has not been completed. Mineralized
water, the majority of which is of the sodium chloride type, situated under
or adjacent to most fresh water aquifers, constitutes a potential problem of
salt water encroachment into fresh-water aquifers throughout the United States.
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GROUND-WATER POLLUTION
In an effort to determine the magnitude of the problem of salt water
intrusion, the American Society of Civil Engineers prepared a report in
1969 (1). From questionnaires sent to all 50 states, 43 indicated problems
with salt water intrusion. Condensed from a table in this report is a summary
of the types of salt water intrusion problems and number of states affected.
Number of States
Affected Type of Salt Water Intrusion
27 Lateral intrusion caused by
excessive pumping
11 Vertical intrusion caused by
excessive pumping
8 Improper disposal of oil field
brines
6 Intrusion caused by faulty well
casings
5 Surface infiltration
5 Layers of salt water in thick
limestone formations
2 Vertical intrusion caused by
dredging
2 Irrigation return flow
In this report, it was noted that the most acute problems were associated
with metropolitan areas along the coast. In most of these areas, fresh water
aquifers are hydraulically connected to the ocean or brackish waters of estu-
aries (Figure 1). Heavy demands on subsurface water supplies in large metro-
politan areas or industrial complexes are generally responsible for fresh
water aquifer contamination. When fresh water is extracted at a rate greater
than natural recharge, salt water intrudes up-dip contaminating wells inland
from the coast.
While salt water encroachment in inland areas affects fewer people than
coastal intrusion, salinity problems from a number of man-made and natural
sources are widespread, directly affecting 22 inland states. Problems in
inland areas have received relatively little publicity although they are
almost as numerous as coastal incidences of intrusion.
Salt water intrusion is characterized by movement of saline water into
a fresh water aquifer through hydrodynamic changes of the system usually
caused by man. Salt water and fresh water often share the same formation.
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THE ENCROACHMENT OF SALT WATER INTO FRESH
Recharge Area
of water in wells (piezometric surface)
Figure 1. Idealized cross-sectional diagram showing relationships between salt water and fresh water
where coastal artesian aquifer crops out beneath the sea at some depth. This might be almost anywhere
along the Atlantic Coast from Long Island, N.Y., to Florida, along the Gulf Coast from Florida to Mexico,
or along parts of the Pacific Coast. Similar hydrologic conditions occur on some of the Hawaiian islands
and elsewhere. The artesian aquifer crops out inland from the shore where it is recharged by rain. In
this area the aquifer has a free air-water contact (water table). Downdip the aquifer is covered by
relatively impermeable clay, and the confined (artesian) water rises higher than the top of the aquifer.
The level at which it stands in wells defines the piezometric surface. Note abrupt fall of the piezo-
metric surface between wells 3 and 4, because well 4 ends in the zone of contact with salt water (3).
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hydraulically connected yet delicately separated by the physical difference of
specific gravity. Fresh water being less dense will occupy the upper reaches
of a formation, retaining its identity if undisturbed (Figures 2 and 3).
Few incidences of salt water intrusion can be attributed to natural
phenomena. Man's activities, primarily pumping more water from an aquifer
than can be naturally replenished, are responsible for destroying the hydraulic
continuity between fresh and saline waters.
Intrusion problems, created by excessive demands on subsurface reservoirs,
are further complicated by natural or man-made avenues for salt water movement.
Faults (Figure 4), unconformities (Figure 5), improper oil exploration
(Figure 6), canal construction (Figure 7), and channel dredging all provide
areas of possible communication. In many cases, the causes of salt water
intrusion are interrelated, complicating their indentification and delaying
their remedies.
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Water
H1
r^i
^
i
1
^"V*
Figure 2. Three diagrams showing the relation of salt water to fresh water,
according to the Ghyben-Herzberg principle. (A) Small, open-bottomed tube
containing fresh water is placed in salt water and sand of larger container.
Sand is indicated in diagram by stippling. Fresh water is free to move out
but does not move beyond a point of balance with heavier salt water. Fresh
water stands above salt water. (C) U-tube contains fresh water in left-hand
side and salt water in right-hand side. As in (A), the fresh water stands
higher than the salt water, 41 units high to 40 units high. (B) Idealized
cross section of permeable island in sea. Here rain water has seeped into
the sand and produced a lens of fresh water that has depressed the heavier
ocean water. The fresh-water lens floats in and on the salt water much as
an iceberg floats on the ocean with most its mass submerged. Periodic rains
replenish the fresh-water lens (3).
Land Surface
- •
WateraDle
\r ondfresh-woter inter
freshwater and salt-woter interfac
with r\ o recnotae
fresh-water and salt-water interface
with uniform recharge
Figure 3. Idealized cross section showing interface relations between fresh
water and salt water in a uniformly permeable aquifer. Two streams cut the
land surface; and in times of sufficient rainfall when the water table is high,
they intersect the water table and drain away the ground water. This condition
is shown by the water table line A-A. Given no recharge, the water table sinks
C-C. Salt water below the fresh water
as shown by line B-B, and the fresh water
indicated by the arrows. Salt water below
below the reach of the streams, line
reacts for the condition of recharge
above flows downward and outward, as
the fresh water reacts for the condition of no recharge, as shown in line D-D (3)
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KiTSilS^»rJ?Vl'W-t* I '„»'
AQUIFER
AQUICLUDE
POSSIBLE MOVEMENT OF
FIGURE 4 - SCHEMATIC DIAGRAM SHOWING CONNECTION OF AQUIFERS THROUGH FAULTS
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UNCONFORMITY -
- AQUIFER(WATER BEARING)
AQUICLUDE(IMPERMEABLE)
POSSIBLE MOVEMENT OF WATER
FIGURE 5- SCHEMATIC DIAGRAM SHOWING CONNECTION OF AQUIFERS THROUGH UNCONFORMITIES
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00
BRINE-DISPOSAL
WELL
I
A
Land
ABANDONED WELLS
I I
WITH CASING NO CASING
B C
WATER-SUPPLY
WELL
I
D
Surfoce
WATER-SUPPLY
WELL
I
E
Casing rusted;
failure or
absence of
cement
V
Well not
plugged or
improperly
plugged
X
CONFINING ROCKS(Low permeability)^
INTERVENING ROCKS
"Casing rusted*,failure or
absence of cement
FIGURE 6 - SCHEMATIC DIAGRAM SHOWING HOW SALT WATER MIGHT ENTER A FRESH-WATER
AQUIFER THROUGH ABANDONED WELLS
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SW
FeetQ Wei I Field
Miami
Canal
Point of NE
stagnation
(A)
80
Theoretical lines of
ground-water flow
IOO-'- Floridan Aqulclude
SW
Well Fiefd
Miami
Canal
Point of NE
stognotlon
r- "• — Waterjable__'.
(B)
Theoretical lines of
yound-woter flow
100-'— Floridan Aquiclude
SW
*«H Field
20
60
80
Miami
.Canal.
Point of
stagnation
(C)
•Water Table"
\
40- ^Biscovne "!*"^ ~lf*' L-L-r^\\\S' ,'J^ '
• it * • ^*^ • • ^^^^0 ^^r + J
.Aquifer , •'. l_^. ' * _•
»Theoretical lines of
_ground-water flow
IOO-1— Floridan Aquiclude
SW
Feet
Miami
Canal
Point of NE
stagnation
Floridan Aquiclude
Canal contains only fresh
water and because of pumping
nearby stands higher than
adjacent water table. Water
moves from canal into aquifer
toward well field, to left
side of illustration.
Salt water moves into canal
and leaks out of sides and
bottom of channel, the
greatest concentration of
salty water at first being
immediately under the canal.
Fresh water has replaced salty
water in canal and salt water
in Biscayne aquifer is now cut
off from its source. It sinks
to base of aquifer and creates
a salt water mound having high-
est chloride at bottom of mound.
Mound moves to southwest, in
direction of the local ground-
water gradient.
(D) Flattened out and greatly diluted
mound of salty water has moved
into well field where it will
be removed with municipal water.
Theoretical lines of
ground-water flow
DENSITY OF STIPPLING REPRESENTS
DEGREE OF SALINITY
Figure 7. A diagrammatic cross section illustrating
salt-water encroachment by canal water in Miami, Florida (3),
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MECHANISMS OF INTRUSION
REVERSAL OR REDUCTION OF GRADIENT
Salt water intrusion of- this type while occurring in inland areas is most
common along the coast of the United States. Potential salt water intrusion
exists in all areas where fresh and salt water share the same aquifers separated
normally by natural equilibrium.
Under natural conditions along the coast, subsurface fresh water will flow
from elevated land areas to the ocean (Figure 1). Similar flow patterns exist
in inland areas associated with estuaries or salt-bearing streams (Figure 8).
Normally, sufficient pressure exists in the fresh water aquifer to counteract
the tendency of salt water to move inland or laterally from streams or estuaries.
As fresh water levels are lowered by excessive pumping, a cone of depression
is formed, reversing the gradient and allowing salt water to enter original
fresh water zones.
DESTRUCTION OF NATURAL BARRIERS
Removing material of low permeability while dredging coastal waterways has
resulted in salt water infiltrating into fresh water aquifers. Similar prob-
lems have been created by the construction of new coastal waterways which
expose permeable materials, transverse fault zones, or other natural barriers.
Oil exploration or deep mining practices which breach the confining layer
between fresh and salt water aquifers provide additional avenues for intru-
sion. Salt water zones once penetrated can travel up or down poorly cemented,
broken, or deteriorated well casings or within mining shafts to fresh water
zones.
DISPOSAL OF WASTE SALINE WATER
There are several techniques of brine disposal which can result in the
contamination of fresh surface or underground water. Saline wastes discharged
to a stream or an unlined evaporation pit has the potential of infiltrating
into a fresh water zone. Subsurface disposal of pollutants, especially salt
water, have created serious problems inland as well as in coastal areas.
Since these disposal wells penetrate zones of both fresh and salt water
(Figure 6), problems occur when injection wells constructed in old fields,
where abandoned wells have been improperly plugged, permit direct communica-
tion between the injection zone and the fresh water aquifer. In some areas,
the structural consistency of the intervening zone separating the fresh from
the saline formation is inadequate due to natural fracturing, thus permitting
vertical intrusion.
10
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-..-..*• **\ V
/ /Soli'Water \ \^
Lond Surface
a>
•• • .• • •...•.•. • • • ••-.->
'• • '/.•.'•', -Solt Water \.'.'. ' ' •
Fresh Water
Figure 8. This diagram shows the ground-water conditions near a coastal stream
that carries salty water in its channel. The arrows indicate the direction of
ground-water flow. Salt water underlies the stream channel as a trapezoidal
prism. (A) Movement under natural conditions before pumping takes place.
(B) Movement during pumping of ground water. A cone of depression surrounds
each pumped well, the water table is depressed, and salty water encroaches
into the aquifer (3).
11
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OIL PRODUCTION
Salt water intrusion affecting the inland part of the United States is
largely due to oil exploration. In search of oil and gas in the United States
over one million holes have been drilled which penetrate both fresh and salt
water formations; these holes represent an equal number of communication possi-
bilities which could adversely affect ground water. Documented cases of
ground-water pollution from exploration activities lend credence to the fact
that, when there are a million chances for failure, failure will occur.
In 1963, the Texas Water Pollution Control Board conservatively estimated
that for every gallon of oil produced, 2.4 gallons of salt water was recovered.
In 1970, 3.5 x 10 barrels of oil was produced in the United States; these
figures will provide an indication of the magnitude of the problem of brine
disposal. With the recent threefold increase in the price of crude oil,
secondary recovery operations utilizing the salt water injection technique
have been drastically increased. This type of production, in addition to a
general increase in the national production, will increase the water-oil ratio
of produced fluids possibly one order of magnitude.
Various states have enacted laws and published guidelines to prevent
pollution from oil exploration and production. Properly followed, these would
adequately control pollution from current activities; however, the administra-
tion and enforcement of these laws are inadequate in many areas. Compounding
the problem associated with this industry is the lack of technology necessary
to locate polluting wells which have been improperly plugged or abandoned.
Legal responsibility for these wells drilled over the past 50 years cannot be
determined, thus the burden of correcting the problem is on the state or land-
owner.
Salt water intrusion from past or present oil and gas exploration and
production creates serious social, economical, and legal problems similar in
many respects to aquifer contamination from other sources.
12
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CONTROL TECHNOLOGY
Current technology has failed to provide a means of early detection of
salt water intrusion into potable aquifers. Case histories are very similar.
Supply wells which had for years produced fresh water for domestic, industrial,
or agricultural purposes suddenly turn salty. Detection in most cases occurs
after several miles of a fresh water aquifer has been severely contaminated.
The economic feasibility of aquifer reclamation in many cases does not exist.
The ground-water resource must therefore be abandoned and a search for surface
water supply initiated.
Domestic, agricultural, and public water supplies of entire cities have
been destroyed by the various types of salt water intrusion. Multimillion-
dollar reclamation projects, funded by taxes or revenue bonds, can be developed
by metropolitan areas affected. This avenue of relief does not exist in rural
areas since domestic or agricultural supply wells constitute a considerable
investment for rural families, the loss of which results in financial chaos.
Abandoned rural homes and productive farmlands provide adequate testimony to
this fact.
13
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CURRENT CONTROL EFFORTS
Major efforts directed at controlling salt water intrusion are now under-
way primarily along the East and West Coast and the Gulf of Mexico. Several
successful projects are now in operation while others are still in the planning
or observation stages.
For example, salt water intrusion detected in the mid-1940's in the Los
Angeles area has been reversed. This was accomplished by the injection of
fresh water through a line of wells paralleling the coast, thus forming a
mound of fresh water, acting as a barrier against sea water intrusion.
While analyzing water from three new wells near Terre Haute, Indiana, in
1955, it was discovered that the chloride was 550 ppm. Normal concentration
of this aquifer had been about 16 ppm. A local study by the Indiana Department
of Conservation and the U. S. Geological Survey identified the problem as an
unplugged oil test hole 2,000 feet from the supply wells. To remedy this
problem, the oil test hole was properly plugged and in an effort to evacuate
the salt water from the fresh water aquifer, pumping of the supply wells was
initiated in August 1956. By October 1958, after intermittent pumping of
7,000 hours at 800 gpm, the chloride concentration in the aquifer (14 to 62
ppm) was approaching normal.
These two successful control methods exemplify the current efforts under-
way and were selected to indicate the time and funding necessary to control
or reverse salt water intrusion.
Listed below is a brief summary, outlining the various types of salt
water intrusion problems and current options of control.
Lateral Intrusion Caused by Excessive Pumping (Coastal and Inland Areas)
(1) Reduce pumping
(2) Relocate wells
(a) Move wells inland
(b) Disperse wells to eliminate areas of intense pumping
(3) Directly recharge aquifer
(4) Fresh water recharge into wells paralleling the coast, forming
a hydraulic barrier
(5) Create a trough parallel to the coast by evacuating encroaching
salt water from wells
14
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Vertical Intrusion
(1) Reduce pumping
(2) Disperse wells to eliminate areas of intense pumping
(3) Drill scavenger wells to evacuate salt water, thus reducing the
pressure on the salt water zone
Improper Disposal of Oil Field Brine
(1) Eliminate surface disposal
(2) Regulate subsurface disposal
(a) Select proper receptive formations
(b) Use sound engineering techniques
(c) Locate and properly plug abandoned wells in injection area
Intrusion Caused by Broken or Corroded Well Casings
(1) Locate and plug faulty wells
Surface Infiltration
(1) Eliminate source and prevent reoccurrences
Layers of Salt Water Existing in Thick Fresh Water Formations
(1) No remedy; well may be relocated, if feasible
The above outline of current treatment methods used in controlling salt
water intrusion is stated briefly. All methods listed have been used with
varying degrees of success. The following Table 1 lists in abbreviated form
the location, encroachment problem, treatment utilized and results of treat-
ment application throughout the United States. For detailed information
concerning a particular area of interest, local authorities should be contacted,
15
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TABLE 1.--REPRESENTATIVE EXAMPLES OF SALTWATER INTRUSION
(1)
Location
(1)
ALABAMA
Mobile-Gulf Coast
Marango County-
Coastal Plain
ALASKA
Yakutat area-
Gulf of Alaska
Cook Inlet area-
Anchorage
ARIZONA
ARKANSAS
Various
Eastern
Nature of problem
(2)
Lateral intrusion from
Mobile River caused
by intensive pumping
Upward flow of saline
water within a fault
Lateral intrusion from
the ocean on a narrow
sand spit when pumping
\J\J 1 I *_ *_- L< 1 V «—
measures
taken
(3J
Pumping curtailed;
deeper wells for
fresh water
Well field moved
to safer loca-
tion
Installed shallow
infi Itration
gallary to skim
from a 70-ft vertical fresh water from
well (Ghyben-Herzberg the lens over-
principle)
lying sea water
l
Potential of lateral None
intrusion from the
ocean caused by in-
tensive pumping
No known examples.
i
Potential contamin- ' State requires
ation from oil field casing or plug-
brines leaking into ging of wells
fresh water aquifers
Lateral movement of ' None
saline water because
of pumping
1
Outlook
(4)
Status quo for
shallow aquifer
Unknown
Okay if demand
does not exceed
supply
Present contam-
ination at Fire
Island; hazard
to Anchorage
well field;
monitoring wells
to be installed
Under control
Unknown, depends
upon all factors
in hydro! ogic
system; study
proposed
16
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TABLE 1.--CONTINUED
(1)
(2)
(3)
(4)
Southern
CALIFORNIA
Ventura County-
Oxnard Plain
Santa Clara
County
Los Angeles
County-West
Coast Basin
COLORADO
Denver Arsenal
CONNECTICUT
New Haven and
Bridgeport
Lateral salt water in-
trusion caused by
updip migration re-
sulting from pumping
Lateral intrusion from
ocean caused by in-
tensive pumping
Lateral intrusion from
San Francisco Bay
caused by intensive
pumping
Lateral intrusion from
ocean caused by in-
tensive pumping
Surface infiltration
and lateral movement
of industrial wastes
caused contamination
of adjacent aquifers
Lateral intrusion from
tidewater in harbors
caused by intensive
pumping
None
Experimental fa-
cilities in oper-
ation for control
with a pumping
trough by State
Department of
Water Resources
and United Water
Conservation
District
Pumping curtailed;
recharging aqui-
fer artificially
Intrusion stopped
with a fresh
water pressure
barrier; pumping
rates stabilized
Industrial wastes
moved to deep
disposal well;
well injection
correlates with
increased earth-
quake activity
Pumping relo-
cated landward;
alternate sup-
plies used
Gradual local
encroachment
Economic pressure
wilI force
solution;exper-
imental work is
continuing
Managed ground-
water basin
Continued oper-
ation of barrier
by Los Angeles
County Flood
Control District
and management
of the ground-
water basin
Controversy
Further pumping
curtailment and
greater use of
alternate sup-
plies
17
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TABLE 1.--CONTINUED
(2)
(3)
(4)
DELAWARE
Coastline and
Delaware River
FLORIDA
Dade and Broward
Counties-Miami
Pinellas County-
St. Petersburg
Cocoa Beach-
Cape Canaveral
Hendry County-
Southwest
Florida
Lateral intrusion from
tidal water in Dela-
ware River and Bay
and from ocean caused
by intensive pumping
and dredging of imper-
meable soils
Infiltration of tidal
water from canals
constructed to drain
inland areas and to
lower water table
Lateral intrusion from
ocean and Tampa Bay
into thick limestone
aquifers caused by
intensive pumping
Upward movement of
residual salt water
within thick lime-
stone aquifer caused
by intensive pumping
Localized upward move-
ment of residual salt
water into thick lime-
stone aquifer caused
by intensive pumping
and broken or corroded
well casings
Pumping relocated
landward
Canal construc-
tion controlled;
installed canal
salinity control
structures to
keep out sea
water and to
raise level of
fresh water
Pumping reduced
Pumping curtail-
ment will be
necessary. Re-
plenishment by
injecting surface
water is being
considered
Stopped pumping
to the area
Continued
intrusion;
further pumping
curtaiIment
Continued manage-
ment of factors
affecting water
supply; contin-
ued surveillance
and studies
Investigation and
management effort
underway
Pumping limited
to available
supply
No change
18
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TABLE 1.--CONTINUED
(2)
(3)
(4)
GEORGIA
Savannah area
Brunswick
HAWAII
Oahu
IDAHO
ILLINOIS
INDIANA
Various
Mt. Vernon-West
Franklin
Potential lateral
intrusion from ocean
into limestone aqui-
fer resulting from
massive cone of
depression caused
by intensive pumping
Wells encounter layers
of residual salt water
in thick limestone
aquifers
None yet because
intrusion has
not reached
large produc-
tion wells
None reported
Potential lateral
intrusion from
ocean where pumping
is too deep or
excessive
Leaky wells con-
trolled; pumping
limited to
amount of
recharge, and
locations chosen
carefully
No known examples
Brine disposal
Suspected lateral or
upward movement of
saline water
Brine disposal
Upward (?) flow of sa-
linewater through
fault zones into
fresh-water aquifers
owing to pumping
State control
State control
None
Major pumping
curtailment;
continuing co-
operative
investigations
Pumping from se-
lected zones
only; amount of
pumping probably
will have to be
controlled;
continued co-
operative inves-
tigations
Continued manage-
ment by Board of
Water Supply;
City and County
of Honolulu;
permanent oper-
ation of moni-
toring wells;
continued
studies to
maximize safe
production
Generally good
Bleak; abandon-
ment of wells
necessary
19
-------
TABLE 1.—CONTINUED
(1)
(2)
(3)
(4)
IOWA
KANSAS
Various
Various
Various
KENTUCKY
LOUISIANA
Baton Rouge
Vermilion River
area
MAINE
Potential updip migra-
tion of saline water
within thick aquifers
owing to intensive
pumping
Brine disposal
Potential infiltration
of saline streamflow
Salt mine waste
disposal
Discharge of oil field
brines into streams
and subsequent infil-
tration
Lateral movement of
residual saline water
(or possibly indus-
trial waste) into
water supply well
field owing to
intensive pumping
Lateral intrusion of
tidal water from Ver-
milion River during
low-flow periods into
producing aquifer
No known examples
None
State Board of
Health controls
None
Disposal within
mined out areas
State controls
None yet
Reduced pumping
Localized prob-
lems only (?)
Controlled
Trouble;possible
control of
saline water
sources
Controlled
Gradual improve-
ment
Reduced pumping-
supplementary
water supply;
continuing
intensive
studies
River salinity
control struc-
ture proposed
20
-------
TABLE '1.--CONTINUED
(1)
(2)
(3)
(4)
MARYLAND
Baltimore and
Sparrow Point
MASSACHUSETTS
Provincetown,
Scituate
and Somerset
MICHIGAN
Various
MINNESOTA
Northwest
MISSISSIPPI
Pascagoula area
Lateral and vertical
intrusion from tidal
estuary of Patapsco
River into producing
aquifers; problem was
aggravated by harbor
dredging, which im-
proved exposure of
permeable materials,
and by leaky and
broken well casings,
which conducted saline
water to deeper found-
ations
Minor lateral intrusion
from ocean and salt
water marshes in
shallow aquifers be-
cause of heavy
pumping
Upward intrusion of sa-
line water from deep
bedrock into producing
glacial aquifers owing
to pumping; sometimes
aggravated by heavy
pumping and/or leaky
or broken well casings
Upward intrusion of
saline water from
deep bedrock into
producing glacial
aquifers caused by
pumping
Pascagoula Formation
is subject to intru-
sion of salt water
moving updip from the
Gulf of Mexico
Little; reduction
in pumping
None
Reduced pumping
and alternate
water supply
Reduced pumping
None
Continuing
intrusion;
addi tional
abandonment of
wells; develop-
ment or alter-
nate supplies
Continuing local
problem
Continued problem
requiring ad-
justed pumping
pattern or
alternate water
supply
Use of alternate
supplies
No problems yet;
cooperative
monitoring
program underway
21
-------
TABLE 1.—CONTINUED
(1)
(2)
(3)
(4)
MISSOURI
Various
MONTANA
Various
NEBRASKA
Northeast
East
NEVADA
and
NEW HAMPSHIRE
Portsmouth
Various
NEW JERSEY
Newark-Passaic
River, Sayreville
Raritan River,
Camden-Delaware
River
Potential upward intru-
sion into producing
aquifers from deep,
saline aquifers, if
pumping draft becomes
too heavy
Brine disposal and
leaky wells in saline
formations
Potential upward intru-
sion into producing
aquifers from deep,
saline aquifers
No known examples;
however, an inherent
potential for lateral
movement of saline
groundwater
Minor lateral intru-
sion from tidal water
in Piscataqua River
Possible contamina-
tion by highway
salt: This is a
potential problem
in many States, but
apparently was not
considered a salt
water intrusion
problem by most
respondents
Later, intrusion from
tidal estuaries into
producing aquifers,
aggravated by inten-
sive pumping, harbor
and canal dredging,
and the disposal of
industrial and muni-
cipal wastes
State laws
None
Unknown
Pumping relocated;
use of alternate
supplies
Good, because
problem recog-
nized
Trouble, com-
pliance checks
inadequate
Not serious
Continuing
problem
Alternate deicing
methods when
problem becomes
serious; studies
underway
Serious, until
control measures
established;
studies are
continuing
22
-------
TABLE 1.--CONTINUED
(1)
Atlantic City-
Cape May
NEW MEXICO
Various
NEW YORK
Long Island
NORTH CAROLINA
Wilmington
New Bern
NORTH DAKOTA
Red River Valley
OHIO
MusKingum River
Basin
Various
OKLAHOMA
Various
(2}
Lateral intrusion from
ocean and Raritan and
Delaware Bays owing to
pumping
Upward intrusion into
producing aquifers
from deep, saline bed-
rock formations be-
cause of heavy pumping
Lateral intrusion from
ocean into producing
aquifers caused by
heavy pumping and re-
duced natural recharge
Lateral intrusion from
tidal estuaries into
shallow producing aq-
uifers owing to heavy
pumping
Upward intrusion into
producing aquifers
from deep, saline bed-
rock formations due
to pumpi ng
Industrial waste from
chemical plants
Oil orine disposal
Potential infiltration
of oil field brines
(3)
Pumping moved
landward
Principally re-
location of
pumping wells
Artificial re-
charge of storm
runoff; reduced
pumping; use of
alternate sup-
plies; Experi-
ments with re-
claimed water
injection by
USGS and Nassau
County underway
Use of alternate
supplies
None
Self-regulation
by industry
Regulation by
State
State-controlled
standards for
deep disposal
wells
(4)
Continued
intrusion
Grim
Continuing intru-
sion; additional
control measures
and artificial
recharge; inten-
sive studies
are continuing
Unknown
Not good;
studies under-
way
Good
Good
Problems prob-
ably not
increasing
23
-------
TABLE 1.— CONTINUED
(1)
(2J
(3)
(4)
OREGON
PENNSYLVANIA
Philadelphia
RHODE ISLAND
Providence
Warren
SOUTH CAROLINA
Paris Island
Beaufort area
SOUTH DAKOTA
Black Hills
Various
TENNESSEE
No known examples
Lateral intrusion of
shallow aquifer by
tidal water from
Delaware River and
by infiltration of
industrial and muni-
cipal wastes, aggra-
vated by heavy
pumping and harbor
dredging
Lateral intrusion of
glacial outwash aqui-
fers from tidal estu-
aries and ocean caused
by pumping
Heavy pumping in lime-
stone aquifers causes
upward and downward
intrusion from layered
saline aquifers
Lateral intrusion from
ocean into shallow,
producing aquifer
owing to pumping
Potential updip intru-
sion of saline water
into producing aquifer
because of increased
pumping
Localized upward in-
trusion into produc-
ing aquifers from
deep, saline form-
ations owing to
pumping
No known examples
Using alternate
supplies
Continued intru-
sion until
control mea-
sures instituted
Stopped pumping
Pumping reduced
Develop inland
groundwater
supplies;
artificial
recharge in
coastal areas
possible
Limited pumping
only
None yet
Pumping curtail-
ment may be
necessary
None
24
-------
TABLE 1.—CONTINUED
(1)
13)
(4)
TEXAS
Galveston-Texas
City
UTAH
Great Salt Lake
area
Western
VERMONT
VIRGINIA
Newport News
Cape Charles
WASHINGTON
Tacoma area
Grant County
WEST VIRGINIA
Upward and/or down-
ward intrusion of
residual saline water
into producing aqui-
fers because of heavy
pumping
Potential lateral intru
si on from lake into
producing aquifers be-
cause of heavy pumping
Potential upward and/
or lateral intrusion
of saline waters into
producing aquifers;
also, an increase in
salinity of ground-
water from irrigation
return flow
No known examples
Contaminated wells;
could be intrusion
of seawater or re-
sidual saline water
Lateral intrusion from
ocean owing to pumping
Lateral intrusion into
producing aquifer from
vicinity of saline
lakes because of
pumping
No known examples;
however, an inherent
potential for move-
ment of residual
saline water
Pumping moved
inland; surface
supplies devel-
oped; desalting
being considered
None yet
Continuing
problems
None
May be serious
Conditions
getting worse
Unknown
Not known
Wells moved
inland
None
Continued
intrusion
25
-------
TABLE 1.--CONTINUED
(1)
12)
(3)
14)
WISCONSIN
Various
Various
WYOMING
Various
Various
Lateral intrusion of
saline water because
of heavy pumping
Cannery waste disposal
Mixing of fresh and
saline water by
intrusion through
old oil wells
Salinity increasing
in groundwater
because of irrigation
return flow
None
State control
None
None
Not generally
serious
Serious, if
control not
effective
Localized
problems
Minor problems
26
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BIBLIOGRAPHY
This report presents only a brief assessment of salt water intrusion
problems, their remedies and potential areas of concern. For this reason, the
following references are provided which hopefully answers the most detailed
questions.
1. Alcorn, I. W. Salt Water Injection Systems. Oil Weekly, 110(13). 1943.
2. American Society of Civil Engineers. Salt Water Intrusion in the United
States. Jour. Hydraulics Div., Amer. Soc. of Civil Engineers, pp. 1651-1669.
September 1969.
3. Banks, H. 0., R. C. Richter, J. J. Coe, J. W. McPartland, and R. Kretsinger.
Artificial Recharge in California. Amer. Soc. of Civil Engineers Meeting,
Austin, Texas. September 8, 1954.
4. Barksdale, H.C., et al. The Ground-Water Supplies of Middlesex County,
New Jersey. New Jersey Water Policy Comm. Spec. Rept. 8, 169 pp. 1943.
5. Bauman, Paul. The Hydraulics of Ground Water Mounds. Proceedings of
1963 Biannual Conference on Ground Water Recharge and Ground Water Basin
Management. 1963.
6. Bonderson, P. R. Quality Aspects of Waste Water Reclamation. Jour, of
the Sanitary Engineering Division, Proceedings ASCE. October 1964.
7. Bruington, A. E. Control of Sea-Water Intrusion in a Ground-Water Aquifer.
Ground Water, 7(3):9-14. 1964.
8. Bureau of Mines. Minerals Yearbook 1969. U.S. Bureau of Mines. 1971.
9. Brashears, M. L., Jr. Artificial Recharge of Ground Water on Long Island,
New York. Econ. Geology, 41(5):503-516. 1946.
10. California Department of Water Resources. Sea-Water Intrusion: Aquitards
in the Coastal Ground Water Basin of Oxnard Plain, Ventura County. Bulletin
63-4, 569 pp. 1971.
11. California Department of Water Resources. Sea Water Intrusion: Morro Bay
Area, San Luis Obispo County. Bulletin 63-6, 104 pp. 1972.
27
-------
12. Cohen, P., and G. E. Kimmel. Status of Salt-Water Encroachment in 1969
in Southern Nassau and Southeastern Queens Counties, Long Island, New York.
Geological Survey Research 1970. U. S. Geological Survey Prof. Paper
700-D, pp. D281-D286. 1970.
13. Counts, Harlan B., and Ellis Donsky. Salt-Water Encroachment bieology
and Ground-Water Resources of Savannah Area Georgia and South Carolina.
Geological Survey Water Supply Paper 1611, 100 pp. 1963.
14. Feth, J. H., et al. Preliminary Map of the Conterminous United States
Showing Depth to and Quality of Shallowest Ground Water Containing More
Than 1,000 ppm Dissolved Solids. U. S. Geological Survey. Hydrol.
Invest. Atlas HA-100, 31 pp. 1965.
15. Feth, J. H. Saline Groundwater Resources of the United States. Water
Resources Research, 6(5):1454-1457. October 1970.
16. Gabrysch, R. K., Gene D. McAdoo, and C. W. Bonnet. Records of Water
Level Measurement in Wells in Galveston County, Texas 1894-1969. Texas
Water Development Board. December 1970.
17. Garcia-Bengochea, Jose I., and Robert 0. Vernon. Deep Well Disposal of
Waste Waters in Saline Aquifers of South Florida. Water Resources Research,
6(5):1464-1470.
18. Geleynse, M., and A. R. Barringer. Recent Progress in Remote Sensing
with Audio and Radio Frequency Pulses. Proceedings of the Third Symposium
on Remote Sensing of Environment, University of Michigan. 1965.
19. Gregg, D. 0. Protective Pumping to Reduce Aquifer Pollution, Glynn
County, Georgia. Ground Water, 9(5):21-29. 1971.
20. Hughes, R. V., and R. J. Pfister. Advantages of Brines in Secondary
Recovery. AIME Trans. Petroleum Div., 170. 1947.
21. Johnson, A. H. Ground-Water Recharge on Long Island. Amer. Water Works
Assoc. Jour., 40(11):1159-1166. 1948.
22. Kohout, F. A. Reorientation of our Saline Water Resources Thinking.
Water Resources Research, 6(5):1442-1447. October 1970.
23. Kinsman, Frank. Some Fundamentals in Non-Contact Electromagnetic Sensing
for Geoscience Purposes. Proceedings of the Third Symposium on Remote
Sensing of Environment, University of Michigan. 1965.
24. Los Angeles County Flood Control District. Report on Required Facilities
for Replenishing and Protecting Ground Water Reserves in the Central and
West Coast Ground Water Basins, Part 1, Montebello Farebay Recharge Project,
West Coast Basin Barrier Project, Los Angeles. 1961.
28
-------
25. Lusczynski, Norbert J., and Wolfgang V. Swarzenski. Fresh and Salty
Ground Water in Long Island, New York. Jour. Hydraulics Div., Proceedings
of the American Society of Civil Engineers, 88(HY4):173-194. July 1962.
26. McGuiness, G. L. The Role of Ground Water in the National Water Situation.
Geological Survey Water Supply Paper 1800, p. 1121. 1963.
27. Parker, Gerald G. The Encroachment of Salt Water into Fresh. Water,
Yearbook of Agriculture 1955, pp. 615-635. 1955.
28. Petitt, Ben M., Jr., and Allen G. Winslow. Geology and Water Resources
of Galveston County, Texas. Geological Survey Water Supply Paper 1416,
155 pp. 1957.
29. Rhea, A. A., and E. B. Miller, Jr. Disposal of Salt Water in the East
Texas Field. AIME Petroleum Technology, TP 1151. 1940.
30. Schmidt, Ludwig, and J. M. Devin. The Disposal of Oil Field Brines.
U. S. Bureau of Mines Report of Investigations, RI 2945. 1929.
31. Stringfield, V. T. Artesian Water in the Florida Pennisula. U. S.
Geological.Survey Water Supply Paper 773-C, 115-195 pp. 1936.
32. Texas Water Commission Ground Water and Electronic Data Processing
Division and Texas Water Pollution Control Board. A Statistical Analysis
of Data on Oil Field Brine Production and Disposal in Texas for the
Year 1961 From an Inventory Conducted by the Texas Railroad Commission.
February 1963.
33. Warner, Don L. Regulatory Aspects of Liquid Waste Injection into
Saline Aquifers. Water Resources Research, 6(5):1458-1463. October
1970.
34. Winslow, A. G., and L. R. Kister. Saline Water Resources of Texas.
U. S. Geological Survey Water Supply Paper 1365, 105 pp. 1956.
29
-------
REFERENCES
1. Task Committee on Saltwater Intrusion of the Committee on Ground-Water
Hydrology of the Hydraulics Division. Saltwater Intrusion in the United
States. Jour, of the Hydraulics Div., Proceedingsof the American Society
of Civil Engineers, 95(HY5):1651-I669. September 1969.
2. Feth, J. H., and others. Preliminary Map of the Conterminous United
States Showing Depth to and Quality of the Shallowest Ground Water
Containining More than 1,000 Parts Per Million Dissolved Solids.
U.S. Geological Survey Hydrologic Investigations Atlas HA-199. 1965.
3. Parker, Gerald G. The Encroachment of Salt Water into Fresh. Water,
Yearbook of Agriculture 1955, 615-635 pp. 1955.
30
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE ANDSUBTITLE
SALT WATER INTRUSION IN THE UNITED STATES
5. REPORT DATE
July 1977 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
Bob D. Newport
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Robert S. Kerr Environmental Research Lab.
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74820
- Ada,OK
10. PROGRAM ELEMENT NO.
1BA609
11. CONTRACT/GRANT NO.
N/A
12. SPONSORING AGENCY NAME AND ADDRESS
Same as above.
13. TYPE OF REPORT AND PERIOD COVERED
Special
14. SPONSORING AGENCY CODE
EPA/600/15
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Salt water intrusion, from one or more sources outlined in this report,
has resulted in degradation of subsurface fresh water aquifers in 43 States.
Numerous case histories delineating current problems exist, providing adequate
documentation of the seriousness of salt water intrusion.
Waste from municipal and industrial sources entering natural streams or
reservoirs are responsible for the more visible types of pollution; their
detection is rapid, their source can usually be identified, and their elimina-
tion will result in rapid natural improvement of water quality. In contrast,
the clandestine movement of salt water through a fresh water aquifer continues,
defying early detection, concealing its origin, and creating long-term problems
with expensive remedies.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Ground Water, Salt Water Intrusion
United States
13B
08H
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
37
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
31
•ft U.S. GOVERNMENT PRINTING OFFICE: 1977-757-056/6503 Region No. 5-11
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