ALL ABOUT WATER : the Blue Planet
Life came into being in this water. As living things became more complex and
specialized, they left the sea for the land, taking water with them as the major part
of their bodies. On the Planet Earth, water is life.
A philosopher observed that the proper study of mankind is man; the water
chemist paraphrases this: "The proper study of water is the water molecule." The
formula for water—H2O—by itself tells us only its composition and molecular
weight. It does nothing to explain the remarkable properties that result from its
unique molecular arrangement (see Figure 1.1). Two hydrogen atoms are located
105° apart, adjacent to the oxygen atom, so that the molecule is asymmetrical,
positively charged on the hydrogen side and negatively charged on the oxygen
side. For this reason, water is said to be dipolar. This causes the molecules to
agglomerate, the hydrogen of one molecule attracting the oxygen of a neighboring
molecule. The linking of molecules resulting from this attractive force is called
hydrogen bonding,
One of the consequences of hydrogen bonding is that molecules OfH2O cannot
leave the surface of a body of water as readily as they could without this intermolecular
attraction. The energy required to rupture the hydrogen bond and liberate
a molecule of H2O to form vapor is much greater than for other common
chemical compounds. Because of this fact, the water vapor—steam—has a high
energy content and is an effective medium for transferring energy in industrial
plant operations, buildings, and homes.
Water also releases more heat upon freezing than do other compounds. Furthermore,
for each incremental change in temperature, water absorbs or releases
more heat—i.e., has great heat capacity—than many substances, so it is an effective
heat transfer medium.
The freezing of water is unusual compared to other liquids. Hydrogen bonding
produces a crystal arrangement that causes ice to expand beyond its original liquid
volume so that its density is less than that of the liquid and the ice floats. If
this were not the case, lakes would freeze from the bottom up, and life as we know
it could not exist.
Water is often called the universal solvent. Water molecules in contact with a
crystal orient themselves to neutralize the attractive forces between the ions in
the crystal structure. The liberated ions are then hydrated by these water molecules
as shown in Figure 1.4, preventing them from recombining and recrystalizing.
This solvency and hydration effect is shown quantitatively by water's relatively
high dielectric constant.
WATER SOURCES AND USES
Water has moved in ceaseless migration across the face of the earth since earliest
time. Well-established currents such as the Gulf Stream and the Humboldt current
continuously circulate in the seas, regulating the earth's climate and providing
sustenance for the fisheries on which much of the world's population relies.
Where stopped by land barricades, the sea, refusing to be held back completely,
releases its water as vapor to condense and fall somewhere inland as rain to attack
the land barrier. This continual evaporation and condensation is the hydrologic
cycle.
Over the U.S. mainland, rainfall averages approximately 4250 X 109 gal/day
Of this, about two-thirds returns to the atmosphere through
evaporation directly from the surface of lakes and rivers and transpiration from
plant foliage. This leaves approximately 1250 X 109 gal/day (0.46 X 1010 m3/day)
to flow across or through the earth to return to the sea (Table 2.1). Although
municipal usage of water seems a small fraction of this great volume, per capita
consumption of water in the United States is very high—100 to 200 gal/day (0.38
to 0.76 m3/day), probably because potable water is relatively inexpensive ($0.50
to $1.50 per 1000 gal). In Europe, municipal water costs are generally much higher, and per capita water consumption is only 25 to 35% of that in the United
States. The cost of water for irrigation, the largest water use in the United States,
is usually less than 10% of the cost of potable water, raising questions as to priorities
in resources and the effectiveness of the national water policy.
Abundant supplies of water attracted the American colonists to settlements
along rivers. Their waterfalls became the principal sources of power for early
industry. Along the eastern seaboard, river waters were of excellent quality, ideal
for textile and paper manufacture. As the frontiers moved inland, settlers found that the salinity of the streams became higher, particularly where long rivers
flowed over relatively soluble rock formations.
Figures 2. Ia and b compare the chemical properties of some of the major rivers
in the United States. Table 2.2 shows how water quality, using Colorado River
data, is influenced from the headwaters to the discharge to the sea. The quality of
such rivers is affected by rainfall, the geological nature of the watershed, conditions
of evaporation, seasonal changes in stream flow, and by activities of human
society. As an example of the latter, in column D of Figure 2. \a, the low alkalinity
relative to total dissolved solids is attributed to industrial discharges upstream,
chiefly from coal mines and steel mills. [These analyses date from the era prior to the existence of the Environmental Protection Agency (EPA).] Water quality is
affected by municipal sewage, even in the absence of industrial waste discharges,
which typically shows an increase in total dissolved solids of 50 mg/L from water INTAKE TO OUTFALL.
It is not the province of this text to include orientation in geology, but a few
basic facts about minerals can be helpful to understanding water chemistry. Of
the elements of the earth's crust most readily soluble in water, calcium is the most
prominent (Chapter 4), and the increase in hardness of the Colorado River in its It is not journey to the sea (Table 2.2) is caused by the dissolution of calcareous (calciumbearing)
rock. The principal mineral contributing calcium to water is limestone
(CaCO3), an alkaline compound, and its source is the shells or skeletons of aquatic
organisms (from tiny polyps to clams and larger shellfish) deposited in the bottom of prehistoric seas and forced into a new shape by the pressure and heat of succeeding
geological periods. The dissolution of limestone makes water alkaline.
Some areas were never submerged beneath prehistoric seas of recent geological
eras and therefore have had no contact with limestone. Some portions of the immense Orinoco basin of Venezuela, a water-rich jungle, are in this category.
Some rivers there contact chiefly siliceous rock, such as flint, quartz, and sandstone.
The decaying vegetation produces humic acid, and in the absence of alkaline
limestone, the acidity of the soils and rivers there creates an environment hostile to humans and the kinds of plants and animals they depend on for sustenance.
(An analysis of the Caroni River illustrating this condition is given in Figure
2. Ic.) Lakes suffering the effects of acid rain are usually in basins lacking limestone,
often overlaid with soils high in humus; these lakes lack the alkaline reserve
needed to neutralize the acidity of the rainwater runoff.
A variety of analyses of river waters from countries other than the United
States are shown in Figure 2.1c. Rivers flowing through drainage basins having
dense vegetation and substantial rainfall are generally rather highly colored the
world over, as shown by columns A through H. In Venezuela and Brazil, the mineralization of the highly colored Caroni and Amazon rivers is limited by
the nature of the lithosphere, especially the absence of limestone, and the heavy
rainfall. (The Amazon drains such an enormous, rain-drenched area that it discharges
about 20% of the worldwide flow of freshwater to the oceans.) The influence
of municipal and industrial use of river water in adding to its mineral con-tent is shown in columns I and J (the Dee River in southwest Great Britain) and
columns P and Q (rivers of Spain seriously affected by a high degree of reuse and
lack of dilution during the May-to-October drought).
EFFECTS OF RAINFALL
The sudden dilution of a river by heavy rainfall can be a disruptive factor in a
water treatment plant. The location of a river water intake should be carefully
chosen with this problem in mind. In the operation of a treatment plant, it is
common practice to adjust the chemical dosages according to effluent water quality.
However, there are many water supplies so variable that it is necessary to base
changes in chemical treatment on raw water characteristics, rather than on finished
water quality. This imposes a hardship on the treatment plant operators,
requiring their constant attention to analysis and control.
Tides create another important influence on surface water quality in that they
slow, or actually reverse, normal river flow. This is particularly pronounced during
periods of low rainfall. The change in water quality between high and low tide
sometimes justifies the installation of raw water supply reservoirs to receive water
at low tide when the river flows unimpeded and quality is at its best. Plants so
equipped stop pumping at high tide when saline bay waters move upstream into
the upper channel. An example of the effect of tides and seasonal runoff is given
in Table 2.3, showing the enormous variations in the Delaware River near Wilmington,
Delaware.
OTHER SEASONAL CHANGES
Another characteristic of surface waters is seasonal temperature changes. This
complicates treatment, particularly affecting the coagulation process in the winter.
Low temperatures also create problems with air-binding of filters due to the
increased solubility of gases and higher water viscosity. This binding causes pressure
drop through the filter beds to increase, releasing gas and disrupting flow.
Another effect of temperature change occurs in water-cooled systems of industrial
plants where heat exchange equipment is usually designed for the least favorable
condition—the higher summer temperatures of surface waters. In winter,
when the temperature is low, the flow must often be restricted to prevent overcooling.
Lower water velocities may allow silting in heat transfer equipment,
which can lead to corrosion and to pressure loss when higher cooling rates are
needed.
Because rivers are warmer in the summer, designers take this into account in
most water-dependent systems. But a complication arises in that many wastewaters
contain heat from plant processes, and this added heat compounds the
natural rise of the summer, sometimes producing an effluent warm enough to create
an unhealthy condition for aquatic life. Pollution discharges not only add to
the heat load of the river, but they usually also add to the oxygen demand and
may have a pronounced influence on the oxygen content of the river water.
When pollutants are biodegradable, bacterial activity in the stream increases
with pollution load, tending to reduce the dissolved oxygen level in the stream,
(see Chapter 5), but there are offsetting factors. The principal one is the presence
of algae in the stream; algae will produce oxygen by photosynthesis in daylight—often causing supersaturation on bright, sunny days—with a falloffat night as the
process is restricted. This diurnal cycle affects not only dissolved oxygen, but also
carbon dioxide, and thus pH. This can have a strong influence on the coagulation
of a water supply in municipal and industrial water treatment plants.
It is unusual to find high levels of dissolved iron in surface waters, except
where the water supply is highly colored and has a relatively low pH. In this case,
the iron usually is complexed by the organic matter causing the color. An exception
to this would be where there is acid mine drainage into the river; in this case,
the iron is introduced into the water in the reduced (ferrous) condition and a lack
of dissolved oxygen prevents its oxidation to the less soluble ferric state.
When a river is dammed, the water quality may be considerably different from
that of the flowing stream. The impoundment behind the dam then takes on the
characteristics of a lake. In deep impoundments, it is common to find stratification, with oxygen depletion in the bottom, stagnant zone, and development of
significant levels of iron and manganese in the bottom water, even though the
surface remains free of these heavy metals. Concentration gradients are sometimes
found in impounded lakes, indicated by an increase in conductivity with
depth. For example, Lake Mead, the impoundment of the Colorado River above
Hoover Dam on the Nevada-Arizona border, has a conductivity of 900 ^S at the
surface; at 50 ft of depth, this figure begins to increase, reaching 1150 ^S at 300 ft
where it levels off; at the bottom—about 460 ft—the conductivity abruptly
increases to almost 1500 /uS.
From flowing streams and rivers, water may diffuse into underground aquifers
when the surrounding water table is low; or, water may feed into the river from
these aquifers when the water table is high. This, too, influences chemical composition,
particularly iron and manganese in certain streams.
In the impoundment of major rivers, such as the Columbia, the Colorado, and
those in the Tennessee Valley system, the mineral content of the lakes behind the
dams is similar to that in the river, as would be expected. On the other hand,
natural or artificial impoundment of streams in smaller watershed areas of abundant
rainfall produces water supplies of very low mineral content. This accounts
for the excellent quality of such municipal waters as Greenville, South Carolina,
New York City, and Boston, as shown by Figure 2.2.
WHERE RIVER MEETS OCEAN
The quality of water in estuaries where rivers meet the sea is unpredictable,
depending on river flow, tidal conditions, the size of the basin or bay, and the
presence or absence of land formations that restrict the flow to the sea. In large
basins, such as Albemarle Sound on the east coast, the water, although saline, is
of relatively uniform composition because of mixing of the shallow water by
wind; but in smaller bays, the quality will change with the tides and the flow of
the river. It is one of the miracles of nature that aquatic life adapts to these
changes and flourishes in such tidal areas.
Many of the major rivers of the world finally reach the ocean through deltas,
which have some of the characteristics of an estuary. In many instances, the flow
of these rivers is so great that the dilution of the ocean can be measured for miles
out to sea. Some plants have used the brackish waters of tidal basins as cooling
tower makeup, since the water is low enough in dissolved solids to be concentrated
by evaporation without severe scaling problems, just as fresh waters are.The use of brackish water for this purpose permits installation of much smaller
pipelines than would be needed if once-through cooling were practiced. One
example is a chemical plant on the island of Trinidad, which is able to use water
from the bay side of the island as cooling tower makeup. This water is diluted
enough by the immense flow of the Orinoco River so that its salinity is lower than
typical ocean water, permitting it to concentrate by evaporation without causing
scale problems.
Out at sea, where surface waters have become part of the circulation system,
the composition of the ocean water is remarkably uniform, as shown in Table 2.4.
There are, of course, local changes in salinity, as mentioned earlier, caused by
upwelling of subsurface waters into the ocean, the flow of mighty rivers into the
sea, or the melting of glaciers and the polar ice caps. Even though it isn't usable
by land animals, sea water is a valuable source of water for industry and is widely
used for cooling.
LAKES AS RESERVOIRS
Lakes are a major source of fresh water. They are of particular significance in
North America, where Canada and the United States share, in the Great Lakes
Basin, what is usually considered to be the largest freshwater supply in the world.
In the Soviet Union, a single body of water, Lake Baikal in Siberia, contains about
the same volume of fresh water as the entire Great Lakes system, 5500 mi3 (2.3
X 104 km3). Lake Baikal is about 5000 ft (1525 m) deep, with a surface area of
about 11,000 mi2 (2.8 X 106 ha), compared with 95,000 mi2 for the Great Lakes.
Together, the Great Lakes and Lake Baikal contain 40% of the world's presently
available fresh water. In addition to sharing the Great Lakes with the United
States, Canada is dotted with countless smaller lakes, carved by ice-age glaciers,
holding another 15% of the presently available fresh water of the world.
Of the Great Lakes, Lake Superior is the largest, with a total area of about
32,000 mi2 and a maximum depth of approximately 1300 ft. It is also "the different
lake," with a significantly lower dissolved solids content than the other Great
Lakes due to differences in geologic formations of the lake bed and to temperature
(Figure 2.3). The analyses of Lake Michigan and Lake Erie are shown in Figure
2.3. Even though these two lakes are different in configuration, area, and depth,
their chemical compositions are similar. This concentration of mineral matter is
maintained fairly uniformly until the water of the Great Lakes is finally discharged
from Lake Ontario into the St. Lawrence River.
The composition of lake water changes seasonally and sometimes even daily
with weather conditions. Although the major dissolved mineral constituents may
not be greatly affected by seasons and weather, such factors as dissolved oxygen,
temperature, suspended solids, turbidity, and carbon dioxide will change because
of biological activity. Another factor that creates change is the seasonal turnover
that occurs in most lakes in the United States during the spring and fall.
All About Water ( PART TWO )
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SEASONAL TURNOVER
An excellent classification of lakes is given in The Microscopy of Drinking Water
by Whipple and Fair. Using as their basis for categorizing lakes the nature of the thermocline (temperature barrier) at different times of the year, they have defined
three types of lakes: polar, temperate, and tropical, with those in the United States
being chiefly in the second category.
In temperate lakes over 200 ft (60 m) deep (first order), the bottom water is at
the temperature of maximum density, 39.20F (40C), year round. After the ice
cover thaws in spring, the surface water gradually warms from 32 to 39.20F (O to
40C), within which temperature range its density increases; vertical circulation
commences as the surface reaches the bottom water temperature. After this spring
turnover, the surface rises above 39.20F and its density decreases as it continues
to warm through the summer. The temperature gradient in the summer is illustrated
by Figure 2.4.
The fall and winter cooling again reduces the surface temperature to its maximum
density, and the fall turnover occurs.
During the period of summer stagnation, vertical circulation is induced by
wind, but this force is not strong enough to cause mixing of the bottom water, the
hypolimnion. A similar turnover occurs in lakes of the second order, in the approximate
range of 25 to 200 ft (7.5 to 60 m) deep. In the second-order lake, the bottom
temperature changes measurably but is never far from that of maximum density.
Figure 2.6 illustrates surface and bottom temperatures of a 60-ft-deep lake, with
turnover occurring at the points where the temperature curves cross.
In lakes of less than about 25 ft deep (third order), vertical circulation is
induced almost exclusively by wind action, rather than density differences, so that
there is little difference between surface and bottom temperatures.
An understanding of these characteristics of lakes is necessary to properly
locate water intakes and discharges. It aids in anticipating the changes in water
treatment needed to meet changes in composition caused by turnover and windinduced
circulation.
Another characteristic of lake waters, usually seasonal and related to biological activity, is taste and odor. Except where these may be introduced by wastewater
discharges, they are usually attributed to organic matter, such as essential oils produced
by the algae growth.
SUBSURFACE WATER
Underground reservoirs constitute a major source of fresh water. In terms of storage
capacity, underground aquifers worldwide contain over 90% of the total fresh
water available for man's use (Figure 2.7). Much of this is too deep to be exploited
economically. In the United States, where the Great Lakes contain such a large
More than 97% of the earth's water is in
the oceans. All the rivers of the world contain only 0.02% of the world's total water. (There is some dispute among experts on the exact quantity ofgroundwater.) (From ''Water of the World," U.S.Dept. of the Interior/Geological Survey.)
volume of fresh water, the proportion of surface water to groundwater is much
higher. But even here, it is estimated that at least 50% of total available freshwater
storage is in underground aquifers (Figure 2.8).
Over 60 bgd (2600 m3/s) of water is withdrawn from wells for irrigation of the
U.S. mainland (Figure 2.9). This well water usage is almost twice the total water underused
by municipalities throughout the United States. Over 80% of the municipalities
in the United States depend on well water, although less than 30% of the
total volume of water treated for municipal use is from this source. The largest well field in the United States supplies 72 mgd (3.1 m3/s) to the city
of Tacoma. Industry draws approximately 12 bdg (520 m3/s) from wells.
WELL WATERS CONSTANT
Underground water usually moves
very slowly. Its flow is measured in feet
per year; compare this with surface
streams, where velocities are in the
feet-per-second range. Because of this
slow movement, the composition of
any one well is usually quite constant.
Although shallow wells may vary seasonally
in temperature, most wells are
also constant in temperature, usually in
the range of 50 to 6O0F (10 to 160C).
Since the water has passed through
miles of porous rock formation, it is
invariably clear if the well has been
properly developed to keep fine sand from entering the casing.
Since the composition is related to the chemistry of the geological formations
through which the water has passed, waters from wells drilled into different strata
have different characteristics. Some aquifers are so large that they may cover several
states in total area, and wells drilled into that particular aquifer produce water
of similar composition. For that reason, with good geological information it is
possible to make some generalizations about the composition of well waters in
different parts of the United States. Selected analyses are shown in Figure 2.10.
As water filters through the ground, soil organisms consume dissolved oxygen
and produce carbon dioxide, one of the principal corrosive agents in dissolving
the minerals from geological structures. It is common to find iron and manganese
in waters that are devoid of oxygen if they have been in contact with iron-bearing
minerals. Shallow wells containing oxygen are generally free of iron.
Extensive records on the composition of well waters are available from the
U.S. Geological Survey and also from most state agencies regulating the use of
water as a natural resource. Most well drillers also have records of subsurface
supplies, including both chemical composition and water yield.
The water produced with oil, called connate water or oil-field brine, is unique
and creates unusual problems in handling and treatment for reuse or disposal. It
is usually more concentrated than seawater, often exceeding 100,000 mg/L in total
salinity; this fact and the reduction in temperature and pressure as the brine travels
upward from great depths cause difficult problems of scale and corrosion control.
Several analyses are shown by Table 2.5.
In many areas of the country, particularly the west and southwest, under ground water is being mined. This mining has resulted in net loss of water, which
has steadily reduced the level of the water table and has contributed to land subsidence.
In some areas, such as Long Island, heavy withdrawal has resulted in
intrusion of seawater inland. Here, underground injection of highly treated wastewater
is being practiced to provide an intermediate barrier to hold back the saltwater
from the freshwater wells. Injection water of this kind must be free of pollution,
since the pollution of an underground aquifer can be very serious, so much
time being required to displace the pollutant once it has gotten into the aquifer.
Augmentation of a groundwater source by artificial recharge has also been
practiced where a nearby source of surface water has been available for this purpose.
The aquifer becomes, in effect, a storage reservoir. As an example, an industrial
plant in southern New Jersey had for many years relied on wells for plant use. A long period of drought in the 1960s so drastically reduced the water table
that the plant faced a water supply crisis. An injection well was constructed to
recharge the aquifer from the Delaware River at times of optimum quality, permitting
the plant to continue using existing pumping facilities. The city of Los
Angeles reclaims storm water and segregated wastewater of selected quality by
gravity recharge of underground reservoir from water collected by the Los Angeles
River. The natural riverbed has been paved with concrete to prevent haphazard
loss of collected water to the ground, and a collapsible dam has been constructed
at the river's end. Collected waters are spread over the old, natural river delta for
percolation through the original gravel riverbed into the underground reservoirs.
During a heavy storm, the dam is momentarily and deliberately collapsed to flush
out collected solids, then reinflated. This arrangement provides for recovery of
most of the storm water in this arid metropolis.
SOURCES AND PRACTICES IN OTHER COUNTRIES
Just as in the United States, water resources in other countries are characterized
in quantity and quality by rainfall, the nature of the lithosphere, residence time
in contact with soluble minerals, and social and industrial influences.
Often, the well waters of Mexico are high in silica content, like well waters of
the southwestern United States. The surface waters of northern Spain, where
annual rainfall is approximately 60 in, are like waters of the Pacific northwest,
while the arid sections of that country produce waters of much higher salinity, as
in the southwestern United States. Almost 75% of Spain, the central Meseta plateau,
receives less than 18 in of annual rainfall; the Guadalquivir River, which
originates in the plateau, is as still as a mill pond for 6 months of drought, while
evaporation, groundwater flow, and wastewater discharges raise its salinity.
Well waters of central Europe are like those of the U.S. midwest and are as
variable in quality based on location, the nature of the geological formations the
water has passed through, and depth. An analysis of an industrial well outside
Vienna is shown in Figure 2.1Oc. A well water analysis from a refinery on the
Adriatic coast of Yugoslovia is unusual in its low sulfate and chloride level, a low
ratio of magnesium to calcium, and a low silica level. The Ilova River in the same
area also has a low concentration of sulfate and chloride relative to total dissolved
solids. It is obvious from these and other analyses in this chapter that prediction
of a water analysis is not possible and that, throughout the world, each source is
unique.
Practices of storing water resources vary from place to place, much dependent
on land values. In the Netherlands, where recovery of land from the sea is a slow
and costly process, advantage has been taken even of sand dunes as storage reservoirs
for water. A water source of growing importance is sewage, both domestic
and industrial. Reuse of municipal sewage by industry is no longer a rarity; each
instance presents unique problems, but the need for water in arid places has given
economic incentive to practical solutions. In the United States, reuse of domestic
sewage as barrier water, as described earlier, is the only example where a small
flow of treated sewage may eventually return to potable wells. But in South Africa,
where the total amount of available water is only 20 bgd—almost equally divided
between irrigation and all other uses—research has been conducted on direct
return of a portion of highly treated sewage to municipal water plant intakes. The
city of Windhoek in Namibia has practiced such recycle for over a decade; this
may become a growing practice as South Africa prepares to offset a 5% deficit in
natural water supplies facing it in the year 2000.
THREATS TO WATER SOURCES: THE EFFECTS OF
ACIDIC RAINFALL
The oxides of sulfur and nitrogen discharged from utility stations, ore smelters,
and internal combustion engines—in diesel locomotives, automobiles, and
trucks—react with water in the atmosphere to form sulfuric and nitric acids.
These acidify the rainfall downwind from industrial populous areas. The pH profile
(see Chapter 4 for an explanation of pH and acidity) of rainfall over the
United States is shown in Figure 2.11. A similar pattern prevails over Europe,
where the acidity has affected most prominently the Scandanavian countries.
If the lakes and reservoirs receiving this rainfall are already low in natural alkalinity,
as results from the absence of limestone in the area, they may be swamped
by the acid rainfall, resulting in an acidic lake water. This condition can lead to a
sterile aquatic environment unless the acidity is neutralized by application of
lime, soda ash, or other alkalies. In general, the lakes and reservoirs affected by
acid rain are contained in basins having a granite bedrock. These waters have
little alkalinity, as shown by Figure 2.2, and are themselves quite corrosive even
without the added input of acidic rain. Water supplies having such low buffer
capacity will always be vulnerable to the influence of human activity, and as water
sources they are invariably temperamental. In the United States, the major contributor
(45%) to the estimated production of 25 million tons per year of nitrogen
oxides is transportation; the major contributor (65%) of the estimated 29 million
tons per year of sulfur oxides is the electric utility industry. These inputs suggest
that lakes having a historical background alkalinity of less than about 20 ppm are
vulnerable to the ravages of acid rain. Preliminary findings in New York state show
that liming such lakes may effectively protect their ecology. However, even
though the water sources may someday be protected in this fashion, the acidity
of the rainfall itself will need correction for protection of soil, trees and plants,
crops, and concrete and steel structures. It is one of our major pollution problems.
Table 2.1 lists the distribution of the water resources of the United States and
the rates of withdrawal and consumption. That portion of this fresh water used
by industry, not including utility cooling water.
THREATS TO WATER SOURCES: THE EFFECTS Of LANDFILL LEACHATE ON GROUNDWATER QUALITY
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The random disposal of both domestic (municipal) and industrial wastes as solids
and packaged liquids on dumps or landfill areas has proceeded uncontrolled and
unchallenged for many years. In industrialized countries, the enormity of the risk
this has created for goundwater contamination has only recently come to light as
a major environmental issue.
In the United States, the Environmental Protection Agency is identifying
hundreds of major sites that must be cleared, decontaminated, and restored to a
nonhazardous status. Many of these sites owe their hazardous nature to the presence
of toxic chemicals, usually leaking from damaged or partially drained shipping
drums. Obviously, the great varieties of drummed chemicals means that
each site has its own peculiarities. Water-soluble materials are usually carried into
the soil by storm water. In some cases, soil bacteria may digest organic chemicals
with a high BODiCOD ratio. In the aerobic zone, the by-product is mostly CO2;
if the leachate reaches the anaerobic zone, the by-products are ammonia, CO2,
methane, and residual nondigestible organic materials.In many cases, the soil adsorbs some toxic substances like PCBs and DDT
until saturated, and then these materials continue downward until they reach and
contaminate the water table. The soil must then be decontaminated.
Figure 2.13 shows the analysis of leachate from a test well sample taken below
a municipal landfill; its character is essentially that of an anaerobically digested
sewage. In this particular case, the leachate has gathered in an aquifer directly
above the municipality's drinking water source, separated by a clay layer. To
eliminate this potential threat to the potable supply, the municipality must withdraw
the leachate and treat it for use as industrial water and cycle it to extinction
in an evaporative cooling tower and sidestream demineralizing system.
It is always difficult to plan such a treatment system. Special procedures are
required for sampling, and samples from different cores show different analyses.
Once pumping has commenced, it may be that the quality will slowly improve,
but that depends on the volume and shape of the leachate reservoir, rainfall, and
the shape of the cone of depression at the withdrawal well.
Most common people use ordinary raw water,commonly taken from land for their pool, or from National /government /state own water company. But ,the last study from Jakarta health Dept senior officer, stated water from land or state own water company still has more harm residu due to unhealthy environment.
If that water for drinking ,they have to be boiled, and if they used for swimming pool,they have to be treated by high performance water purification then sterilized with UV Sterylizer , to avoid harm particel such heavy metal polutant and E-Colly bacteria.
Environment Issue about water treatment plant in Indonesia.
The sudden dilution of a river by heavy rainfall can be a disruptive factor in a water treatment plant. The location of a river water intake should be carefully chosen with this problem in mind. In the operation of a treatment plant, it is common practice to adjust the chemical dosages according to effluent water quality. However, there are many water supplies so variable that it is necessary to base changes in chemical treatment on raw water characteristics, rather than on finished water quality. This imposes a hardship on the treatment plant operators, requiring their constant attention to analysis and control. Tides create another important influence on surface water quality in that they slow, or actually reverse, normal river flow. This is particularly pronounced during periods of low rainfall. The change in water quality between high and low tide sometimes justifies the installation of raw water supply reservoirs to receive water at low tide when the river flows unimpeded and quality is at its best. Plants so equipped stop pumping at high tide when saline bay waters move upstream into the upper channel.
The oxides of sulfur and nitrogen discharged from utility stations, ore smelters,
and internal combustion engines—in diesel locomotives, automobiles, and trucks—react with water in the atmosphere to form sulfuric and nitric acids. These acidify the rainfall downwind from industrial populous areas. A similar pattern prevails over Asia, where the acidity has affected most prominently the asian countries. If the lakes and reservoirs receiving this rainfall are already low in natural alkalinity, as results from the absence of limestone in the area, they may be swamped by the acid rainfall, resulting in an acidic lake water. This condition can lead to a sterile aquatic environment unless the acidity is neutralized by application of lime, soda ash, or other alkalies. In general, the lakes and reservoirs affected by acid rain are contained in basins having a granite bedrock. These waters have little alkalinity, and are themselves quite corrosive even without the added input of acidic rain. Water supplies having such low buffer capacity will always be vulnerable to the influence of human activity, and as water sources they are invariably temperamental. In the Indonesia, the major contributor (45%) to the estimated production of 0,5 million tons per year of nitrogen oxides is transportation; the major contributor (65%) of the estimated 0,39 million tons per year of sulfur oxides is the electric utility industry. These inputs suggest that lakes having a historical background alkalinity of less than about 20 ppm are vulnerable to the ravages of acid rain. Preliminary findings in Jakarta show that liming such lakes may effectively protect their ecology. However, even though the water sources may someday be protected in this fashion, the acidity of the rainfall itself will need correction for protection of soil, trees and plants, crops, and concrete and steel structures. It is one of our major pollution problems. That portion of this fresh water used by industry, not including utility cooling water. The random disposal of both domestic (municipal) and industrial wastes as solids and packaged liquids on dumps or landfill areas has proceeded uncontrolled and unchallenged for many years. In industrialized countries, the enormity of the risk this has created for goundwater contamination has only recently come to light as a major environmental issue. In Indonesia,WALHI - Wahana Lingkungan Hidup Indonesia-a NGO specialized in
the Environmental Protection Agency is identifying hundreds of major sites that must be cleared, decontaminated, and restored to a nonhazardous status. Many of these sites owe their hazardous nature to the presence of toxic chemicals, usually leaking from damaged or partially drained shipping drums. Obviously, the great varieties of drummed chemicals means that each site has its own peculiarities. Water-soluble materials are usually carried into the soil by storm water. In some cases, soil bacteria may digest organic chemicals with a high BODiCOD ratio. In the aerobic zone, the by-product is mostly CO2; if the leachate reaches the anaerobic zone, the by-products are ammonia, CO2, methane, and residual nondigestible organic materials.In many cases, the soil adsorbs some toxic substances like PCBs and DDT until saturated, and then these materials continue downward until they reach and contaminate the water table. The soil must then be decontaminated. Its character is essentially that of an anaerobically digested
sewage. In this particular case, the leachate has gathered in an aquifer directly above the municipality's drinking water source, separated by a clay layer. To eliminate this potential threat to the potable supply, the municipality must withdraw the leachate and treat it for use as industrial water and cycle it to extinction in an evaporative cooling tower and sidestream demineralizing system. It is always difficult to plan such a treatment system. Special procedures are required for sampling, and samples from different cores show different analyses. Once pumping has commenced, it may be that the quality will slowly improve, but that depends on the volume and shape of the leachate reservoir, rainfall, and the shape of the cone of depression at the withdrawal well.
Because of that, today, many poeple who care about healthy, they start to use mountain fresh water specially from Highland area.
As we do, we produce high quality water from natural resourcess from Gunung Pancar,located in Sentul Highland, south of Jakarta Capital. This area still free from environment destruction or poluted with industrial waste.
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