Civil Engineering Report: Non-Potable Water Supply for Coal Mines

This civil engineering report investigates non-potable water supply options for the coal mining industry, focusing on the critical need for a consistent water supply in Australia. The report explores two primary options: direct water supply from rivers and the recycling of stormwater, emphasizing the significance of Life Cycle Cost (LCC) analysis in determining the most cost-effective and sustainable solution. It provides an overview of the coal mining industry's water usage, highlighting the importance of non-potable water and the benefits of recycled water and stormwater. The report includes a literature review, discussing the characteristics and advantages of recycled water and stormwater, such as reduced water bills, industrial symbiosis, and environmental sustainability. It concludes with a recommendation for the use of recycled stormwater as a more economically viable and environmentally friendly option, aligning with modern sustainability initiatives. The report covers various applications of non-potable water within the mining operations, including dewatering, dust suppression, and equipment cooling, underscoring the need for efficient water management practices.

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NON-POTABLE WATER SUPPLY OPTIONS TO A COAL MINE INDUSTRY
ACKNOWLEDGEMENTS
The preparation of this thesis is a demanding task that calls for maximum dedication and
cooperation from various significant people and institutions. Listing all of them might be
impossible. First and foremost I thank the Almighty God for having granted me the life and
energy to enable me get to this far. May power and glory go back to Him who dwells above. I
would like to also thank my supervisor(s) who dedicated a lot of the quality time and
perseverance towards the preparation of this thesis proposal. I am equally humbled to thank them
sincerely for every positive immediate responses, guidance and encouragement that has seen me
get to this level of this task this time. May I also thank the University as well for their faithful
commitment and moral support.

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ABSTRACT
Coal mines in Australia require a steady and continuous supply of non-portable water in order to
continuously run. The supply can be done using two options: supplying the water directly using
pipes from the river or recycling of stormwater. The choice of an option between the two
depends on the Life Cycle Cost analysis that would help in determining which of the options id
cost effective both for now and in the future. Life Cycle Costing is a tool for economic analysis
that can be used to help with making of choice between the two available alternatives in order to
select an alternative that is having an impact on the pending costs as well as the future costs.
Through life-cycle costing, a comparison is made on the initial options of investments and then
identification on the least cost alternatives is done for the stipulated period of time. This research
paper presents Life Cycle Costing analysis of the two supply options in which it is concluded
that supply no-portable water from recycled stormwater is a more economically viable options as
well as incorporating the modern initiative of sustainability. This option is thus recommended for
realization.

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CHAPTER 1: INTRODUCTION
Background of the Study
The use of water as one of the elements in the coal mining industry is very fundamental and
comes in features that are similar to the application of water in several other industrial uses. This
use comes with distinctive features that make it worth and meaningful to take into consideration
and further detail the use of water in the coal mining industry (Dhillon, 2013, p.128). Most of the
water finds its uses in the arid and semi-arid areas where scarcity of water is a common
phenomenon but also include a few regions in which the users of this resource face competition
from agriculture and urban centers.
The coal mining sector has the capability to be the largest consumer of water as well as a key
supplier of the same resource. Water supply to the coal mining industry is in most cases
independent and does not rely on the regulations from the different authorities that are mandated
with the supply of water utilities. A lot of the water is extracted for use in dewatering the mines
or at other times used as a by-product from extraction (Gheisari, 2009, p.128). When in the form
of a by-product, the water can be acid and be containing toxic quantities of metals or any other
possible pollutant ants. Such waster is costly discharged to the environment during which
controls are imposed on its quality to ensure the impact on the environment and the human as
well as animal life is kept under check.
The demand for coal products is constantly on the increase as the population of the world grows
and expands on a daily basis. The world's population is rapidly increasing and more and more
people are finding their ways into the cities in search of better and improved living towards
leading to an increase in the demand for coal and other minerals in Australia. An exponential

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increase and growth in the rate of production of Australian coal and other products have been
witnessed since the 1950s with the production of coal in the sector having been estimated as
doubled between 1994 and 2008 (Jin, 2017, p.230). An increase in the production, as well as a
decline in the quality of the ores of the mineral, result in continuing access to water a crucial
business imperative to the coal mining industry in Australia.
Introduction
The use of water by the coal mining industry has been recorded to be stable according to
information from the Australian Bureau of Statistics, (ABS). ABS and other research further
suggest that there has been efficiency in the use of water in the coal mining industry with quality
improvements recorded since 1994. The recently experienced exponential growth in the product
can be encountered by a subsequent dramatic improvement in the efficiency so as to maintain the
steady flow. Water has various uses in the as far as operations activities in the coal mining
industry are concerned. Among the operational activities in which water is a fundamental aspect
include:
 Dewatering mines
 Transportation of ore and wastes in suspension and slurries
 Separation of materials physically such as centrifugal separation
 Washing equipment
 Dust suppression in mineral processing as well as around roads and conveyors
 Separation of the mineral through the use of chemical processes
 Cooling the systems around power generation

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CHAPTER 2: LITERATURE REVIEW
Non-potable Water Supply Options to the Coal Mines
Non-potable water is water that has not undergone proper examination treated and hence not got
the approval from the necessary authorities as being safe and usable for consumption.
Accessibility to the reliable and sufficient source of water is a very important requirement for
coal mines. This is as well applicable to those mines which do not wash their products as they
need water in the management of dust, human consumption, drilling among other several uses.
Research and findings establish that to the tune of 200L of water are consumed for every tonne
of coal that is produced, and this value may be higher or lower depending on the prevailing
circumstances of production of the mineral (Lavappa, 2017, p.266). The change of the clean and
safe water to dirty which then calls for management from the mine systems and storages
culminate into extra costs.
Types of non-potable water
 Recycled water
 Stormwater
 Greywater
 Groundwater
 Water from lakes and rivers

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Recycled water
This is water that has been and then once again supplied for reuse in treated or untreated form.
Recycled water may be extracted from sewage which includes wastewater treatment plants or
process water streams (Singh, 2017, p.271). Recycled water is beneficial for such purposes as
replenishing of groundwater basin, toilet flushing, landscape irrigation and most important
industrial processes. To the tune of about 8% of the municipal wastewater is currently reclaimed
by the United States which a highly insignificant amount is thereby leaving room for many
improvements. Recycled water for industrial purposes comes along with numerous benefits to
the coal mining industry. Recycling or reclaiming water on the site or from a region that is close
to the site serves to reduce the energy that is required in moving water long distances or even
pumping the water from an aquifer. Most of the application and operation activities that require
water in coal mining don not require clean and safe water. The use of recycled water for such
purposes lower the amount of energy that is needed to treat the water before it is used.
The use of recycled water also comes with cost-saving befits which are influenced by the quality
of the water that is required (Sompura, 2017, p.320). A need for high-quality water results in
high treatment cost. Environmental sustainability is a well one of the benefits associated with
recycled water. Through the use of recycled water, water is not extracted and hence removed
from the ecosystem in which it is needed by the living organisms for the purposes of their
survival. Still, the use of recycled water lowers discharges of waterways and water pollution.
Recycled water is used in numerous ways in the industrial processes and operational activities
including:

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 Cooling processes for example cooling of the industrial towers in which the water is used
in cooling down the towers and in the process evaporate. Attention should be given to the
buildup of minerals as well as biological growth in the towers when recycled water is
used as the cooling agent.
 Water boiler in where the water has to be pre-treated in the same way as conventional
portable water. In this application, consideration is given to scale buildup which may
result in corrosion of the water boilers. Upon proper and extensive analysis, recycled
water is very effective for use in boilers.
Recycled water has numerous benefits ranging from financial to environmental. Depending on
the industrial needs that require being met, it is not possible to manage all these needs instead a
great number of them can be achieved. This notwithstanding, reclaiming as much water as is
attainable is a tremendous step in conserving the environment as well as lowering the expenses
in a company.
Advantages of Recycled Water
 Reduces water bills
 Lowers costs through industrial symbiosis i.e. reuse of by-products, sharing management
of utilities and sharing ancillary services (Office, 2017, p.170)
 Reduces the volume of water being used
 Reduces the amount of wastewater generated as there are no wastes
Disadvantages
 Requires relatively high financial investment
 Requires high trust level between industries

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 Requires in-depth and extensive knowledge and information on the quality of water for
reuse
 Requires modifications of the existing operations so as to accommodate direct reuse as
well as treat-and-reuse
Stormwater
This is runoff from the roofs, driveways, roads as well as other hard surfaces. Stormwater
collection and treatment for the purposes of reuse is rapidly increasing making the water
available for use in a variety of applications among them industrial purposes. Stormwater can be
used in the coal mining industry for cooling of the tower feed water or process water. Various
systems are available that can be used in controlling, measuring capturing and delivering
harvested stormwater that is treated in line with the intended uses (Galar, 2017, p.207).
Similarly, there are automated controllers that make it possible to complete the system control to
complex and sophisticated systems from simple ones. These controllers are also able to data log
the parameters of the system as well as the quantity of water that has been processed. In so
doing, it becomes possible to calculate the return-on-investment savings.
Reuse of stormwater in the coal mining industries also has an impact in reducing the load on
wastewater treatment plants. Economic and environmental sense is made through the installation
of a system for harvesting stormwater. This system offers to pay itself once installed in a period
of not more than two years.
Benefits of Stormwater
Ease of maintenance: Harvesting of stormwater enables better utilization of the available energy
resources. The cost of installation and operation of a stormwater harvesting system is less than

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that of setting up a system of pumping or purifying water. Maintenance of the harvesting system
as well calls for little demand and energy which enables the use of the water in numerous
substantial ways without necessarily being purified.
Reduction of water bills: Stormwater collected from the stormwater harvesting system can be
used for numerous operational activities in the industries. For the coal mining industry, this leads
to a significant reduction in the utility bill. Still, harvesting of stormwater in the industry ensures
the provision of the required amount of water for numerous operations to move on smoothly
without having the nearby water sources depleted (Rommerskirchen, 2009, p.190). Stormwater
harvesting also serves to reduce the burden of soil erosion in the various geographical areas
which gives the land an opportunity to once again thrive. This waster can also use kept in
cisterns where it can be used when there is an acute shortage of the resource.
Reduces floods and soil erosion: The collection of water during rainy seasons in large tanks
helps in prevention of floods in low lying areas. Still, it is also vital in the reduction of soil
erosion and pollution of surface water with fertilizers and other organic chemicals from
rainwater run-off. The overall impact is cleaner ponds, lakes, and rivers.
Reduces demand for groundwater: The demand for water is ever on the increase following the
rapid and exponential increase in the human population across the globe. This results in
extraction of groundwater by residential colonies and industries for use in meeting their daily
demands for water. In so doing, the groundwater reservoirs have been depleted leading to a
tremendous reduction in the levels of groundwater in some areas leading to acute water scarcity
(Tiwari, 2016, p.162).
Disadvantages of stormwater

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Initial high cost: Depending on the level of technology and the size of the system, stormwater
harvesting may prove to be a costly investment for an industry. It also takes quite some time,
approximately 12 years to recover the cost which is also a factor in the amount of rainfall and the
complication of the systems installed.
Unpredictable rainfall: Prediction of rainfall is quite a challenge and at the time the region in
which the mines are located may experience little if no rains at all which would, in turn, limit the
supply of stormwater. Relying purely on rainfall for the water needs of an industry is not
advisable especially in areas where the amount of rainfall experienced is limited. Stormwater
harvesting is suitable in regions that experience heavy and plenty of rainfall (Tiwari, 2016,
p.262).
Regular Maintenance: Stormwater harvesting systems are prone to algae growth, lizards, rodents,
insects, and mosquitoes and thus require regular maintenance. Without proper maintenance,
these harvesting systems may form breeding grounds for such animals among others.
Storage Limits: Collection and storage facilities may be to some extent a restriction on how
much stormwater can be used. During long rains when a region experiences heavy downpours,
the collection and storage systems may not be able to contain all the stormwater and this some of
them might end up in rivers and drains.
Life Cycle Costing Analysis of the Supply Options
Two alternatives are availed for use in the supply of water to the coal mines: direct supply from a
river and recycling of the wastewater generated from the industry. Life Cycle Costing is a tool

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for economic analysis that can be used to help with making of choice between the two available
alternatives in order to select an alternative that is having an impact on the pending costs as well
as the future costs (Ang, 2007, p.207). Through life-cycle costing, a comparison is made on the
initial options of investments and then identification on the least cost alternatives is done for the
stipulated period of time. For the case of this, a choice is to be made between the two available
alternatives of supplying water to the coal mine. The decision is arrived at after analysis has been
done on the economic implications of each of the alternatives and hence the least cost-effective
alternative identified.
Diagram for rainfall supply in Queensland in 2015
The supply of water to the coal mine from the river directly would involve such costs as the
purchase of the supply pipes, labor costs, maintenance costs, electricity costs, costs of purchasing
water storage tanks, electricity costs, equipment cost including a power generator, water pumps
and supply motors among other equipment. Other costs will include life insurance cost, life risk
cost.