Brian Bozzo
Gerard Hubert
Pat Sweeney
Michael Newman
Midterm Report
I. Introduction
A. Water problem on Global Scale
The objective of this project is to design and implement and water system for
Nicaraguan communities. The system will focus on Hierba Buena and Piedras Blancas
but ideally can be incorporated in any community with a source at a high elevation. The
project focuses on designing a system that incorporates a UV purification system run by a
generator to insure the people a constant and clean source of water. The details of the
design will be elaborated on later in the report.
The necessity for clean water and the benefits this system could provide are
extraordinary. The problems caused by water in Waslala’s communities and all over the
world are devastating. The combination of water and sanitation issues continues to cause
problems on a global scale. Today, 2.6 billion people lack basic sanitation facilities.
Over 1 billion people are without access to safe water and are forced to use unsafe
resources on a daily basis. In the developing world this equates to 5 out of 10 people
without proper sanitation, and 2 out of every 10 without drinking water. These startling
numbers lead to numerous health issues and continue to hamper national and economic
development in suffering nations.
The water and sanitation problems spread across the world and have many serious
repercussions. The first and most significant effect is the related diseases that result.
Diseases include intestinal worms, trachoma, schistosomiasis, cholera, guinea worm,
malaria, typhoid, hepatitis A, and diarrhea. Taking a closer look at these diseases, the
influence a clean source of water would have in their reduction is significant. Studies
have shown that adequate water supplies would reduce Trachoma by 25% and reduce the
schistosomiasis infection rate by 77%. Of the above mentioned diseases the most serious
is diarrhea. Diarrhea leads to physical and mental stunts in children and lowers the
immunity against all other diseases leading to high mortality rates. Figures show diarrhea
is responsible for 1.8 million deaths a year. The majority of these diseases are found in
children, who suffer most from these health problems.
The problems caused by water extend beyond diseases. Poor school attendance
and performance is directly linked. The common and necessary chore of fetching water
keeps most girls out of school. Diseases also contribute to the poor attendance. Farmers
are often less productive as a result of illness. The water problem continually weakens
economic development and growth.
B. Waslala
The Water for Waslala organization defines Waslala as a perfect “microcosm of
the greater world problem”. Waslala located in the mountainous region of central
Nicaragua has a population of 40, 000 people and suffers from extreme poverty. 70% of
the population is unemployed with the majority of men working as farmers. Statistics
show that an estimated 90% of the population lives in poverty. None of the 85
communities have electricity or access to proper health care. The education system is
Waslala reaches an estimated 2nd grade level, and many people see education and
impractical and unnecessary.
A main reason and a continuing problem for Waslala is their water situation.
Two thirds of Waslala’s population currently does not have access to clean water. As
discussed on a global level, the lack of water continually hurts the growth and
development of Waslala. Our experience in Waslala, allowed us witness these hardships
first hand. We hope and see the potential to successfully implement our design. We can
only hope that our small contribution can help improve a community’s lifestyle and
relieve their hardship. The rest of our report discusses background information on water
systems and details the specifics of our design.
II. Background and State of the Art
Nicaragua has had international agencies working in the country for relief and aid
steadily. A major organization with projects in Nicaragua currently and in the past is the
Global Water Partnership (GWP). GWP is involved extensively throughout the world,
more specifically in developing nations. Many of the organizations working in Nicaragua
have similar goals and agendas, however, we found GWP to have an extensive and
thorough outline for their missions which encompass the goals of many other similar
organizations. Thus, we will now discuss GWP for it provides a great example for what
organizations are doing for the people of Nicaragua. The main goal of the organization is
to promote integration and management of water for a community and the world as a
whole. Integrated water resource management (IWRM) is the main focus in achieving
this goal.
IWRM deals mainly with efficiency in various forms. There are four types of
efficiencies laid out by the GWP and they are: technical, productive, product-choice, and
allocative. Technical efficiency is concerned with the overall output and input of a
system. Productive efficiency is closely related to technical efficiency; however, it is
more of an economic concern. Inputs and outputs are viewed in terms of value rather than
strictly quantity. A major concern that is present in Waslala would be product-choice
efficiency. This is how the goods and services accommodate what the consumer wants
and is willing to pay for. According to GWP, generally the technical personnel make all
the decisions. These may not be desirable to the community at large. Such a case has
happened before when designing tap stands, delivery systems, distribution, among other
concerns. Therefore, it is important for the community to have a strong voice in the
decision making process. Finally, the last major efficiency that the GWP lists is
allocative, which is the allocation of water to users for drinking, agriculture, by region or
home, etc. It is important for all of these four topics to be considered when implementing
a water system in any community, because increasing efficiency will always benefit those
who are using the system.
Two easy ways to increase efficiency is through changes in user behavior and
improving the infrastructure and technology. User behavior can be controlled through
social and economic means, as well as regulatory instruments and personnel. The
infrastructure is incredibly important because by cutting losses, allowing user control of
the system to match demands, and recycling the water, more water will be available if
managed properly. Land management, which is a major problem in Nicaragua, is also of
great concern, this will be discussed in further detail later.
GWP is determined to educate Nicaraguans on all these matters, and are currently
doing so. It is invaluable to teach people how to help themselves so they may make the
most of their given situation. GWP not only helps with water systems, but the problems
that interfere with success of those waters systems.
The Canadian International Development Agency (CIDA) is also involved in
Nicaragua. They have a plan in action to develop sub-watershed areas in northern
Nicaragua. CIDA helps areas based on many credentials, some of which are: socioeconomic indicators, the capacity of local governments and affiliates, and the presence of
existing projects. Three of the main goals from this project are governance,
environmental and private sector development (PSD), and health.
The first goal of governance will allow these systems to be used properly and in
service for a long time. One way of doing this is improving the service delivery.
However, in order to achieve this there must be plans to manage finances and operations
by the community. Such management will depend largely on the community needs.
Improving management also will affect the development of the environment and private
sector. Protecting the environment is crucial with these projects, and CIDA understands,
because degradation puts the water systems and people at severe risk. A growing problem
in Nicaragua is deforestation due to the need for wood and grazing land. CIDA plans to
attack this problem with agroforestry. Agroforestry combats problems such as erosion,
retention of soil moisture, and evaporation by planting trees on the same plots as
agricultural crops. The trees provide shade helping with evaporation and water retention.
The rooted trees also play a large role in hindering erosion. At the same time these trees
can be fruit bearing to provide additional food, or repeatedly cut down and replanted to
provide wood for fuel. Finally, CIDA is working with Swiss agencies for water supply
and sanitation (WSS). All of this effort would be fruitless if the people still become sick
from the water that is being delivered to them. By filtering and purifying the water less
people will be sick and overall health will improve.
The United States is involved in Nicaragua as well. The United States
Environmental Protection Agency (USEPA) has had influence in the past on Nicaraguan
water demands. The USEPA worked with the United States Agency for International
Development (USAID), the Pan-American Health Organization (PAHO), MINSA, CIRA,
and ENACAL after the devastation of Hurricane Mitch in 1998. Source water protection
was deemed by ENACAL (a Nicaraguan agency) as crucial after the hurricane. This was
part of an initiative to promote sanitation, safe drinking water, and source water
protection in Central America. As well as the USEPA and USAID the United States
Center for Disease Control (USCDC) is involved in Nicaragua and safe drinking water
efforts throughout the world. The USCDC has publications listing contaminants,
indicators, treatment, and many other topics crucial to the development of safe drinking
water.
Among other agencies many schools such as Villanova bring students to areas of
Nicaragua to understand and address the issues involved with water and health.
Additionally, many private organizations such as grupo fenix and Christian Engineers in
Development address power, water, health, and wellness concerns in Nicaragua.
The work done for our project will directly be related to everything previously
discussed. The ideals and teachings of these societies and agencies will be crucial in the
implementation and overall design of our water system. Not only will we be providing
water to a community which does not have a system currently, but that water will be safe
to drink from the tap. Our system will incorporate sand filtration to clear the water of
debris and suspended solids, as well as an ultra-violet (UV) purification system that will
kill harmful bacteria and pathogens. The energy for this purification will be provided by
an electric generator using the waters own kinetic energy to create the electricity
necessary. Therefore, the community will have water to use easing their lives and
allowing them to pursue other endeavors which currently they do not have time for.
Children will have this water at their school. Significant increase in health will be seen
due to the purification and treatment of this water.
The system we design will help the effectiveness of Water for Waslala (WFW)
because it will be accomplish the goals that the organization initially set forth. These
goals will be reached in a manner that is far superior to the current water systems for not
only will the community have water, but the water will be safe to use and drink. By
utilizing the high pressure head a generator can power the UV purification process.
Therefore, the people benefiting from this system will be in a far better situation than
their counterparts.
Furthermore, this project will benefit the world as a whole because now any
community with proper funds, head, and flow can use our project as a template for
designing a similar water system. The specifics will be discussed at length later; however,
people will be able to learn and expand on our ideas and hopefully create and even better
and more efficient water system. One does not create from nothing. We have used the
current and past technology to design our system, and someday other students or
professionals may very well use our design to create their own. Therefore, benefiting not
only Waslala or Nicaragua, but any area in need of safe drinking water development.
B. Design objectives and parameters
1.) Primary Design Objectives
Our critical design objectives can be broken down into three subcategories;
Power, purification / filtration, and water system. Each category is met with specific
design parameters based solely on initial research and non – experimental data. As a note
of caution one must realize that prior to laboratory testing all numbers, figures and
measurements are estimations based on similar projects and projected environments.
With this said each subcategory will now be further examined.
Power – From strictly a power delivery stand point our design must incorporate a
generator capable of supplying adequate power to the U.V. Purification element. Typical
U.V. purifications systems run on 120 V / 60 Hz alternating current. These values include
both industrial purification systems and those geared towards a more commercial or
residential use. It is extremely important to realize the simplicity and practicality that is
behind the micro-hydro generator. Not only is this system basic, on both a design and
implementation level, it is also low maintenance and economically feasible. The latter
two of these statements will be addressed in more detail below, in the secondary
objective section, Section III.B.2. Typical micro-hydro generators are composed of a
turbine, alternator and power storage device (most traditionally a set or series of batteries)
which operate in sequence to generate electrical current. For our 120 V/60 Hz power
specification needed to operate the U.V. Purifier, an inverter – battery combination could
be implemented. This addition would convert stored, low voltage, DC electricity in the
batteries, to 120 V AC electricity through the use of an inverter. Several advantages result
from this additional design parameter. “First, the battery system allows the user to store
energy and expend it, if needed, in short powerful bursts (like a washing machine starting
the spin cycle). The batteries will allow substantially more energy for short periods than a
turbine is producing, as long as the battery and inverter are designed to handle the load.
Second, DC charging means that precise control of alternator speed is not needed, as is
required for 60 Hz AC output. This saves thousands of dollars on control equipment.”1
The question for adequate power supply therefore solely depends on the
geography and setup of the generators environment. The communities for which we are
designing this project are characterized as low flow / high head systems. Pelton wheel
turbines are extremely cost effective and sufficient for these particular environments. The
Pelton-equipped Harris turbine is another option which meets the low flow high head
constraints. Though specific turbines will be analyzed in much greater detail as this
project progresses, basic number charts indicate a more than adequate power supply.
Using an elevation of roughly 100 meters and a flow of 0.3
L
Gal
, or nearly 4.75
,
sec
min
between 120 and 160 watts of power can be outputted. This should be more than
sufficient for our design needs.
Purification - Power is simply a necessity to drive the main component of our
design project, the Ultra Violet Purification System. We have set a series of standards and
water quality benchmarks that will greatly reduce, if not eliminate, the water born illness
1
Real Goods © 2006, Gaiam.com, Inc. “Hydroelectricity”
discussed earlier in this report. Specifications are based on the efficiency and
effectiveness of the U.V. purification method, as well as initial filtration elements.
Perhaps the greatest concern in the entire purification process begins at the water source.
Murky or unclear water cannot be purified using ultra violet light. The emissive
ultraviolet waves cannot penetrate beyond the particles suspended within the water and
therefore cannot kill the potential viruses and bacteria within. To eliminate this problem
water entering the system must adhere to strict clarity standards. T.S.S. or total suspended
solids and water turbidity are two parameters which measure the amount of visible
impurities in the water. To reduce these values we plan on implementing a rock and sand
bed filter at the initial water source. This type of filtration is common to most if not all
Water for Waslala systems and simply filters out debris and sediment in the water.
Through rock and sand bed filtering 90% of T.S.S. and 50% of turbidity are removed.
The resultant water is clear enough for ultraviolet purification and therefore capable of
being used in our proposed design.
DLR is a leading manufacturer of commercial, residential and industrial
Ultraviolet water purifiers. They offer systems that are capable of handling both small
and mid-sized flow projects. Many of their smaller U.V. purifiers are perfect for the
remote Nicaraguan community setting. These systems can handle the needed quantity and
flow rate of water as well as adhere to the high quality water standards we have set.
These standards include and are not limited to the removal of, bacteria, micro organisms,
water-born and non-water-born viruses and fecal chloroforms. The following excerpt
from American Water and Air Incorporated further explains the extent of the DLR
ultraviolet water purification system.
“Every UV water purification system is designed to deliver a dose greater than 40
mJ/cm² in accordance with public health recommendations and pending regulations, so
the water will always be safely and effectively disinfected! UV radiation with 253.7
nanometer wavelength is extremely effective in killing microorganisms such as bacteria
(E. coli), viruses (poliovirus, influenza, hepatitis), protozoan cysts (Cryptosporidium,
Giardia Lamblia), yeasts and molds. UV in this range targets the DNA of the microbial
contaminants and renders them non-viable.”2
Essentially all the problematic contaminants and water born illnesses present in the
Nicaragua community will be eliminated. Another important quality of these DLR
systems is the company’s strict adherence to the NSF Standard 55 Class A certification
program. This level of water purification is on par with U.S. and Canadian standards and
well exceeds those present in Nicaragua.
Water System – Our final objectives are those associated with the basic water
design and supply system. These values are based on both hypothetical future system
implementations and those values recorded during our visit to Nicaragua in the spring of
2006. We plan on supplying between 80 liters per person per day to members of the
Hierba Buena community and 100 liters per person per day to the Piedras Blancas II
community. This water will of course be pure to the standards mentioned above and be
available to the local church, school and individual community member’s houses or water
collection sites.
2.) Secondary Design Objectives
In addition to those objectives stated above we have selected several other
secondary considerations and requirements for our design project. These include cost
limitation and feasibility models, system maintenance needs for both the generator and
U.V. purifier, and the possibility of harnessing excessive electricity production for other
community use. Each of these will now be analyzed in further detail.
2
American Air and Water, Inc. “DLR Commercial / Residential UV Water Purifiers” © 2005 - 2006
B. Design Parameters
2. Secondary Design Objectives
Cost- Since we are dealing with impoverished communities, the financial responsibilities
of the system are ours to consider. It is important that we spend enough money to
implement a sufficient, reliable system that will accommodate all of our primary
objectives, but maintain a realistic budget that can be supplied by and managed by our
design team. If we are considering flow rates averaging at about half a liter per second,
then we must make sure we select an ultraviolet purifier that will be able to accommodate
flows at this speed. An example of an acceptable selection would be the Purguard UV
A2 Water Purifier. This piece kills microorganisms and other bacteria with an efficiency
of 99%, and can accommodate flow rates up to thirteen gallons per minute. The cost is
relatively inexpensive at approximately five hundred dollars per unit, and it meets all the
requirements presented by our primary objectives. A product description can be found at
http://www.air-n-water.com/product/A2.html. Generators are the most expensive piece
of equipment necessary for this design, and can exceed the price of the purifier by two or
three times depending on the specifications. Aquair retails the Aquair Hydro DC
Generator which is capable of producing 2.4 kilowatt hours per day from any fast moving
water supply. This generator would fulfill our needs and cost about one thousand dollars.
It can be purchased through the following website:
http://www.bitterrootsolar.com/hydro/aquair.htm.
An
economical mechanical supplier site that would be an effective resource can be found at
http://www.powersourcing.com/se/microhydrogenerators.htm . The average cost of one
inch diameter piping for six meters of length is approximately sixteen dollars. For a
system like herba Buena, our estimated pipe length would be twelve hundred meters, but
I would add an additional two hundred meters to that to accommodate for turns. So the
average cost of the piping required for this system would be approximately four thousand
dollars. The cost of cement is approximately fifty dollars for a ninety pound bag, and the
average storage tank for our system would have a minimum capacity of four thousand
gallons. The estimated cost of this storage tank would be approximately one thousand
dollars. Considering all of these factors and adding an extra thousand dollars to the total
to accommodate for unforeseen costs, I would estimate our total cost of this designed
system to be around seventy five hundred dollars. We would have to receive funding
from the university to afford the implementation of this design. If necessary, a proposal
could be created and presented to different corporations to fundraise the remainder of the
money needed.
Maintenance- Another important consideration of the design process is the maintenance
of the implemented system. Since the citizens of these towns will be responsible for
conditioning the water system, we need to make sure the maintenance is relatively simple
and inexpensive. A proper instruction should be prepared and presented in a communal
meeting so that the people will be informed of the proper conditioning required to
maintain a functioning system. A twenty five watt replacement bulb for the types of
purifiers in consideration would cost the town approximately fifty dollars to purchase,
and proper installation would be required. I would recommend including a bypass in our
design to make the cleaning of the generator and changing of the ultraviolet bulb easier
for the town. The website futurepundit.com states that a monthly cleansing of the
purifier’s casing is recommended to optimize purifying efficiency, and that a simple and
affordable liquid dish washing soap is ideal for the process. Aquair suggests that their
generators receive a biannual lubrication. The filtration bed at the source should prevent
any large debris from getting tangled in the generator’s propeller, an annual cleanout of
the casing would also be optimal.
Excess Power- With the additional power being generated by the flow, there are
several possibilities to further benefit the community. Depending on the amount of
surplus power, we might be able to provide the school with electricity. This however
depends on the type of generator we decide to use, which brings us back to financial
limitations. If it is economically feasible, the possibility of supplying one or more
buildings of importance with electricity could be a realistic goal of our design. This of
course, would require further research and a broader analysis of the required electrical
system that would result. Although at this point this goal remains a secondary concern
for our system, its potential to benefit the citizens of these communities makes it a
worthwhile consideration.
III. Problem Statement and Design Objectives
A. Detailed Project Definition
The need for potable water systems in Hierba Buena and Piedras Blancas #2 is a
severe social issue. The deficiency of such an essential commodity burdens the citizens
of these towns with serious health concerns that pose a legitimate threat to their youth. It
was our personal interaction with the people of these communities that has motivated us
to design a system that will provide them with an effective solution to their problem. Our
proposed system will incorporate the primary aspect of water supply as well as the
principles of pressure dissipation, water purification, and source filtration. All of these
aspects are closely related and our system will not only deliver running water to the
community, but also harness the unused power of the flow to operate an ultra-violet
purification unit. The system will provide water for the schools and churches of these
communities and simultaneously offer every individual house the ability to tap into a
strategically placed spigot for their own personal use. Beyond mere delivery, pressure
dissipation is an important aspect of the design process. Any elevation difference of one
hundred meters or more can cause an excessive pressure in the pipes that threatens the
performance of the system. Since this issue was present in both surveyed regions, the use
of break pressure tanks would normally be necessary in the design of both systems. Our
design incorporates an adaptation to this issue which implements a generator immediately
before the reservoir tank. This generator will not only dissipate the static and dynamic
pressure heads, but use the energy of this dissipated pressure to power an ultraviolet
purification device. This method of water purification necessitates a rapid sand bed unit
for water filtration to eliminate large source contaminants before the water enters the
system. It is necessary for all of these aspects to be thoroughly analyzed, since each is
dependent on the others.
B. Community Specifics
Our group was responsible for surveying three towns, each with its own
specific needs and aspirations. However, since the community of Piedras Blancas #1
opted to use an alternative means of water delivery that had been previously established,
we are only considering implementing our system in Hierba Buenas, and Piedras Blancas
#2. We first analyzed the community of Hierba Buenas, where the total population was
two hundred and fifty people. This community had forty four households and seventy
two students to accommodate. The flow rate measured at the prospective source for this
community was approximately .3 liters per second; however this only considered one of
the available springs. We estimated that after excavation, the source could produce three
or four times this flow rate. The final estimated flow rate for this source used for
consideration was 0.9 liters per second, which we deemed sufficient for the community.
With this source alone, it would be possible to provide each member of the community
with one hundred liters of available water per day. The community was extremely
organized and united behind the construcion of this system and the citizens were
extremely cooperative and helpful. In Piedras Blancas #2, the demand was much smaller.
This community only consisted of seven households and had a total population of forty
nine citizens. There were fifty students attending class in their school, ten of which lived
in the community itself. The flow rate produced by their available stream was .5 seconds
per liter. This flow rate would provide the community with approximately thirty seven
thousand two hundred liters of water per day, which would far exceed the community’s
needs. An important consideration in this community would be the purity of the water
being used, since it was surface water it would be of less quality than that of a spring.
This further justifies the need for our purification system in the community. The
community was not as organized as the others we visited, but this is not to say the need is
any less. With a little more organization and cooperation, the people of Piedras Blancas
#2 may be appropriate candidates for an effective water distribution and purification
system that will far surpass their needs.