Amanda BertinoRyan CrawfordPeter KwiecienEmily Mei

NRC 576: Water Resources Management and PolicyDecember 10, 2014

Desalination

Introduction :

Desalination refers to the process that removes salt and other minerals from saline water.

Globally, desalination is very important because it allows people to produce fresh, clean water

for human consumption or irrigation. It is one of the few rainfall-independent sources of fresh

water. Desalination is and may become important in some parts of the world where other popular

sources of water such as ground water, water recycling, and water conservation are not

accessible or have been exhausted. The objectives for our paper are to understand environmental

and economical impacts and possible consequences of desalination in order to provide fresh

drinkable water for an exponentially increasing population.

Saline water accounts for 97% of the Earth’s available water so having the ability to turn

that water into safe drinking water and of other different qualities would be able to positively

affect many countries and regions that have very dry ecosystems. Depending on the use of water,

the degree of quality of the water is different depending on its final use. However, a huge

limiting factor for the widespread use of desalination is that it is very expensive. Not only does

the desalination process itself require a high-energy consumption but also the technology and

plants needed to perform the desalination process are also very expensive. Despite these

expenses, countries in very dry ecosystems such as Australia, and the Middle East (primarily

UAE and Israel) are investing more money into desalination (USGS 2014). See figure 1, below.

Figure 1: This map shows the locations of the major desalination plants around the world. 53.4% of the world’s desalination plants are in the Middle East and 17% are in the United States.

The main process of desalination that is currently being used is reverse osmosis

technology. Reverse osmosis is the process by which the solvent (salt) is filtered out of a solution

of high concentration to a solution of low concentration using a semi-permeable membrane

(USGS 2013). See figure 2, below.

Figure 2: This picture explains the reverse osmosis process for desalinating saltwater. The salt water travels through the membrane near the outer sides of the fiberglass pressure vessel. It is pushed through the semipermeable membrane towards the center of the pressure vessel and finally a porous layer that lets the freshwater through, but not the brine. The brine and other components of the salty concentrate exits out one smaller pipe near the sides of the pressure vessel and the desalinated water exits via a pipe in the center of the pressure vessel.

Objectives:

In our study we plan to understand environmental and economical impacts and possible

consequences of desalination in order to provide fresh drinkable water for an exponentially

increasing population. Our study areas are the United States, focusing on California, and The

United Arab Emirates. Then we will develop strategies—both technological and policy solutions,

for an comprehensive understanding of the economic and environmental effects of desalination.

Results—Economic Impacts:

When considering the use of desalination for clean drinking water, the two biggest

implications are the economics and the environmental impacts. The economic impacts of

desalination are the most important factor to begin with. The cost of desalinating seawater is

more expensive than other sources but in many dry ecosystems, other alternatives are no longer

an option. In many dry countries, climate change is causing them to get even drier and where

once there was enough water now there is not. In 2013, the average cost of water ranged from

0.50 to 1.0 USD/cubic metre (USGS 2014), while in many developing countries with water

shortages, it can cost them up to 5 USD/cubic metre. Factors that determine the costs for

desalination include facility costs, location, where they are getting the saline water from, labor

costs, energy required, financing, and salt disposal (USGS 2014).

As desalination becomes more popular (USGS 2013), the per cubic metre cost in falling.

Currently there are more than 14,000 desalination plants in operation worldwide producing

several billion gallons of water per day (USGS 2014). This accounts for less than 1% of total

world consumption (USGS 2014). A big limiting factor for the use of desalination is the initial

cost of building a desalination facility (Laîné 2000). Desalination plants are costly to build, but

large facilities are more efficient and cost effective than small plants, but that means a much

larger initial investment that some countries may not be able to afford (Laîné 2000). Many

factors decide just how costly a desalination plant will be such as salinity of the source, cost of

fossil fuels, materials used to construct the plant, and turbidity of the water (USGS 2014). The

economic constraints of some countries will inhibit them from having desalination facility but as

the price of water continues to rise, the initial cost of a desalination plant might be outweighed

by the benefits of having an alternative source of safe drinking water.

Results—Environmental Impacts:

Having desalination plants may be an alternative to providing fresh drinkable water for

communities, but there are controversial issues that come along with the process. Processes of

desalination and the plants do not only have economical impacts, but also environmental impacts

that are unique to desalination. Desalination provides fresh water to those who need it on land,

but to the ecosystem it is taken from, it puts a large strain on the habitat. For desalination to

work, large pipes intake water from the source of salt water (i.e. the ocean, salt water seas, or salt

water rivers.) These pipes pull in large amounts of water, displacing the normal level of water

seen in the environment, but more importantly is that the flow rate of the intake of these pipes

harms organisms in the environment. The intake process can cause harm organisms by

impingement and entrainment to many aquatic organisms due to the intake of the large quantities

of seawater (Latteman and Höpner 2008). Many organisms may get pulled into these pipes into

the plant where they are killed by the strong forces acted upon them and unable to escape the

current (Fuentes-Bargues 2014). Larger organisms can still be pulled up to the screens covering

the pipes, harming them and potentially trapping them there. The inflow of water also has the

potential of harming and affecting large populations of aquatic organisms such as shellfish

because the intake process pulls in eggs of many species, which in turn can affect the population

numbers in the species that live in the ecosystem (Fuentes-Bargues 2014).

Other factors that raise the potential environmental risks are how the plant operates and

its outflow processes. In order to desalinate water to make it drinkable by humans, there are a

series of filtrations and chemicals that are needed. The reject streams of desalination plants

produce large quantities of concentrates due to the chemicals used for the filtration, treatment,

and cleaning processes (Latteman and Höpner 2008). These chemicals are contained within the

facility, but run the risk through any failures of leaking out of the plant into the environment. A

breach in the plant leading to contamination of the water source could result in damage to the

ecosystem and harm populations of the wildlife that lives there. The outflow processes also have

a harmful byproduct, brine (Fuentes-Bargues 2014). Brine is highly concentrated salt water that

is the byproduct of desalination. Brine is also is much denser per liter, and during the outflow

process this brine is pumped back into the water source. Due to the density of brine, it sinks to

the bottom of the ecosystem before it goes back into solution, and while still so concentrated it

can cause damage to the environment and to organisms that come in contact with it (Fuentes-

Bargues 2014).

To minimize the harm to the environment, knowing the location and the type of

technology that is going to be used to build desalination plants are key. Even if minimizing the

machinery used and having the perfect location, there will still be adverse impacts that directly or

indirectly take a toll on the environment.

The adverse impacts of desalination are great in both during the construction period and

the operation period of the plants. A major aspect of the impact of desalination is the land use

that goes toward building the plant. The land that was once an undisturbed ecosystem is now

permanently damaged (Sadhwani et al. 2005). After the construction of the plant, marine and

terrestrial wildlife are going to be impacted because in order to build the plant, vegetation will be

removed for space therefore, disturbing the terrestrial ecosystem (Fuentes-Bargues 2014).

Having machinery being used and construction being built in the habitats and ecosystems

where organisms live will have a huge impact on wildlife. The movement of wildlife will be

affected. For many species, the desalination plant will be an obstacle and may block their path to

finding resources. This includes the flight path of birds since power lines from the plant are in

the way; there is a higher chance of collision and electrocution of bird species. Also, during the

operation of desalination plants, the noise pollution of the process is also going to cause a

disturbance and cause excess strain to nearby organisms (Fuentes-Bargues 2014). Other causes

that may put strain on nearby habitats is the use of machinery because the earthmoving works

can generate an increase of suspended solids and turbidity of the water. This can lead to an

increase in accidental releases of dangerous products such as oil from the machines (Fuentes-

Bargues 2014). The earthmoving works can also cause a disturbance in the air quality because it

can cause an excess of dust emissions and other air pollutants into the environment (Fuentes-

Bargues 2014).

Finding alternatives to safe drinking water, such as desalination, also have adverse

impacts. There is an indirect effect of desalination plants, which is the amount of energy that is

being used to run the plants (Sadhwani et al. 2005). Great amounts of energy is going to be used

in order to run these desalination plants therefore causing more pollution the environment

because it takes fossil fuels and the burning of oil (Sadhwani et al. 2005). During the process of

running the plants there can be spillage and leakage over the land. There may also be fuel that

remains from the processes of desalination. (Fuentes-Bargues 2014). This resulting pollution can

contaminate other nearby water sources and ecosystems.

The land that is used to build the plant is being stripped and the possible ecosystems there

are being disrupted. This includes the marine ecosystems as well because outgoing and incoming

pipes will be used for the intake and outflow of water and possible waste. One of the key

concerns of desalination is the concentrate and chemical discharges such as the dumping of

excess salt waste back into the water source and other water bodies (Latteman and Höpner 2008).

This will potentially raise the salinity that may harm organisms sensitive to high salinity levels

and have adverse impacts on the functioning of the ecosystem overall (Latteman and Höpner

2008). An example of this are the meadows of little Neptune grass Cymodocea nodosa and a

green seaweed known as Caulerpa prolifera (Fuentes-Bargues 2014). The rise of salinity in the

water causes stress, which may be fatal. Also, damage to underwater ecosystems such as

underwater meadows of Neptune grass or Mediterranean tape weed causes regression, which

prevents further development of enrichment of the ecosystem. (Fuentes-Bargues 2014).

Case Studies:

The countries we focused on for our case studies were the United States and United Arab

Emirates. These two countries differ in their reasons of use, economic impacts, and

environmental impacts.

The United Arab Emirates uses desalination as a way to obtain water to supply small

communities in Oman. Often acquired through groundwater, unlike in the United States, much of

the groundwater is brackish there, meaning it is salt-water ground reserves. Using these

desalination plants is essential to many communities for fresh water. Private companies who

provide their own funding to build and operate the facilities own current desalination plants in

the United Arab Emirates. Many of these private owners have tried varied desalination waste

management methods. Such methods include dumping in small bores in the ground to evaporate,

ocean/beach disposal, and lining small evaporation ponds and leaving waste there. But due to

high year round solar activity, much of the power on their grid comes from solar power, and

powers these plants. The world's largest desalination plant is the Jebel Ali Desalination Plant in

the United Arab Emirates, producing 640,000 m3 of water per day.

Within the United States we are focusing in on the desalination plants in Lower

California where frequent dry spells leave much of the coast without enough water to supply for

the rapidly growing demand of major coastal cities. Currently California has seventeen

desalination plants built or being planned (CA Department of Water Resources 2014), see Figure

3, below. The largest desalination plant in California is going to be built in Carlsbad in 2016 and

is expected to produce 50 million gallons of fresh water a day to approximately 110,000

customers in San Diego County. This planned plant is expected to cost close to one billion

dollars (Boxall 2013). California is currently facing water shortages after three years of below

average rainfall and in order to keep with the public drinking water demand (Santa Barbara

Public Works 2014). Support from the public was unanimous (Boxall 2013).

Figure 3: Built and proposed sites of current and future desalination plants in California, USA.

Desalination is often not feasible because more energy is required to produce water from

desalination than any other water supply or demand-management option in California (Wolff and

Cohen 2004). Some negative environmental impacts that desalination could have on California

are impingement and entrainment of marine organisms (York and Foster 2005). Future and

continuing research is needed to fully understand the impacts on desalination and then how to

best manage and reduce environmental impacts. In the face of climate change and an uncertain

future, desalination offers both advantages and disadvantages that have promoted California to

the expensive steps towards planning new desalination plants in order to secure that the state can

keep up with future water demands.

Methods—Integrated Water Resources Management:

We created an integrated water resources plan for California as example of a potential

solution to the global water shortage. In the next twenty to thirty years, California faces the very

real problem of not being able to supply its population with fresh clean water. With populations

growing, and fresh water sources being depleted and not recharged like groundwater aquifers,

California is going to be in a tough spot to supply water essential to its future residents. One of

the only viable options that can solve this problem is the installation and implementation of

desalination facilities. Desalination can provide the state with all of its fresh water needs, by

tapping into the saltwater of the oceans, or taking from the brackish groundwater, desalination

holds the power to convert these otherwise undrinkable sources into viable drinking options to

the community.

Desalination is not without its drawbacks, and the state of California will feel the side

effects of such a solution. Desalination is one of the most expensive forms of obtaining fresh

water. It is highly fuel intensive, and such a cost will be seen in the water bills of consumers.

Fuels often used by plants are fossil fuel based, causing its own pollution, along with a bi

product of brine, which would need a solution of how to deal with it. It has ecological impacts on

its surrounding area, such as noise pollution and stress on underwater habitats, as well as

beachfronts being turned into facilities, areas locals hold very dearly. Such issues can be handled

with all of the appropriate stakeholders in mind using Integrated Water Resource Management, a

method that promotes the use of coordination and management of water, land, and other

resources to benefit the economic and social needs of a community without sacrificing

ecosystem.

Access to clean drinking water is a human right. Without reliable access to clean drinking

water, the people of California will face an uncertain future. As populations in coastal

communities continue to experience large populations increases, an integrated approach to

dealing with drought is urgently needed. A proper enabling environment “ensures the rights and

assets of all stakeholders (individuals as well as public and private sector organizations and

companies, women as well as men, the poor as well as the better off), and protects public assets

such as intrinsic environmental values” (TOOLBOX 2013). Institutional roles utilize the design

and implementation of public policies for sustainable water investments and management that

elicit the support of all sections of society. Management instruments are necessary to utilize

instruments that better suit California in 20 to 30 years, considering the existing social and

political consensus, available resources, and geographical, social and economic contexts. In

order to best meet the needs of all, an integrated approach to dealing with water shortage in

California is needed.

Important aspects of the integrated approach that need to be addressed are policies and

incentive structures. Creating effective policies will manage relative environmental, economic

and social values of water; as well as assigning responsibilities to the various public and private

actors including basin organizations.

In order to be more manageable of our water resources, we need to be able to implement

a framework of policies, to be able to maintain and to be able update them depending on the

water resources’ scarcity. Having institutional roles, such as state and non-state organizations

take part in helping to create, implement and maintain a framework of policies are going to result

in an improvement in governance. The governance is very important when dealing with

shortages of resources, especially with water. For there to be a good governance, there needs to

be policies set that are tailored to the local characteristics and concerns of each community.

Policies that can be implemented to do this and to get communities to reduce the water

use can be to have penalties such as fines for the overuse of water for unnecessary use. The

government can also start to take into account how much water people are using in each

community and then manage the amount used. A way for communities to communicate with

each other and to manage the water resource is to have community meetings. Governmental and

non-governmental organizations should attend so that this way, they can resolve possible issues

and all be on common ground with each other. Spreading awareness of the shortage of water is

also a major component of saving a resource. Letting people know that there are alternatives,

such as desalination, in order to provide more water for the future is important but at the same

time, communities need to be educated about the process of desalination and its pros and cons.

Being able to educate people about the limited amount of water that is available is crucial to the

conservation of water because people are going to learn that there are severe consequences that

come with shortages of the public good possibly even with alternatives such as desalination. This

can be achieved by having this topic being taught to students in school, especially at an early age

so that communities can be more sustainable. Having non-state actors such as private sector

actors, non-governmental organizations, etc. educating communities on how to become more

prominent in managing water, allocating resources and organizing service provision will be even

more effective if both these become policies. Luckily, this stage is already in its adulthood and

many more people are becoming more aware of the water scarcity issue.

When the Global Water Partnership begins the planning process for Integrated Water

Resources Management, they start with national agencies. There is a four-step process that the

IWRM uses. The first step is finding out what the issues are. They also figure out how much of

an impact the issue will cause and how often the issue will happen (TOOLBOX 2013). Second,

they brainstorm management solutions starting at a local level, then the basin level, and then

national level. Some management solutions include water monitoring, water allocation, and

discharge regulation (TOOLBOX 2013). Next, they find institutional capabilities, starting local

and working up. The capabilities are influenced by factors like financial resources and the

efficiency of institutional structures. Lastly, strategies are created to help improve the weak

spots. The scale at this point can go from a small local level all the way up to an international

level (TOOLBOX 2013). Although this plan was created specifically for California, a similar

plan can be created for the United Arab Emirates following the same principal strategy.

Conclusion :

Desalination is the process of converting saline water that is undrinkable into fresh clean

drinking water that can be used for consumer, irrigation, agriculture, and various other purposes.

In order to be able to do this, processes such as reverse osmosis (RO) is currently being used. RO

deals with the removing of the salt by filtering it through a semi-permanent membrane called

Memstill to lower the concentration of salt to an acceptable level. To be able to do this in the first

place, we need to build desalination plants in many areas of the world. These actions though, can

lead to future implications on the environment and the economy. Possible questions are going to

arise may be where can we build the plants, what are we going to do with the waste and most

importantly, how much is this going to cost. Because of the great amounts of energy that is

needed to run the plants and the waste it produces, there are going to economical and

environmental impacts. The costs that are going to incurred by the plant and process itself is

going to be a problem for the economy especially in countries that are lacking freshwater and

don’t have enough funding. Also, for areas that are not near bodies of water or near plants, it is

going to cost more for them to get the desalinated water compared to areas that are closer in

distance. This leads to the possible environmental impacts because not only is the desalinated

water is going to be transported, but also the waste. Environmental impacts can include leakage

of waste, which can pose threats to nearby ecosystems and harming organisms. During the time

when the plants are being run, the intake of salt water by pipes can have detrimental effects on

populations of species, possibly having a large decrease of individuals in that species. This puts

an excess strain on ecosystems and species. Especially if the species is already endangered-- in

the event that this happens, extinction is going to become a major concern.

In the incorporation of desalination plants, there are methods to follow to make the future

process of the plant and its impact on the residents minimal. Partial power of the plant being

generated by on site or nearby solar farms can help supply power for desalination at peak hours

while not producing carbon emissions while doing so. Desalination is know to be fuel intensive,

so any alternative fuel sources will benefit the local community and help mitigate effects on the

surrounding ecosystem. Grid management can also prove to be beneficial if that the grid only

utilizes desalinated water when necessary, and depend on other water options if available. Using

desalination to provide for only peak hours where other sources cannot provide for will keep

costs low, and keep the fuel use of the plant down, as well as brine production.

There are many questions still unanswered about desalination plants and their effects.

Future research and planning questions related to desalination can include questions such as:

what is going to be done with the brine left over after the desalination process? Are deep well

injections of brine a financially feasible way of getting rid of the brine? Does it have any

environmental effects? Should evaporation ponds continue to be used or should the money used

for constructing them be used for newer, more modern forms of desalination? Should

desalination plants continue to be built near oceans? Is it feasible to build desalination plants

inland? Is it worth pumping salt water inland to desalinate it? The questions mentioned above are

just a few of the many problems that need to be addressed and solved in the near future.

References :

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Bucket. Los Angeles Times. Retrieved September 13, 2014.

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http://www.water.ca.gov/desalination/.

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Through Cooling at California’s Coastal Power Plants. California Energy Commission.