**Improving and Evaluating the UV Tube**

**for use in Mexico**

Presented for (ERG 291/E298) Design for Sustainable Communities Class

University of California Berkeley

May 2006

Esha Datta

Jorge Hernandez

Kate Ming

Sintana Vergara

**Executive Summary**

Lack of access to safe drinking water is a world crisis affecting more
than 1.1 billion people according to the World Health Organization (WHO
2000). Without access to proper sanitation, water can be contaminated
with fecal matter containing pathogens. Drinking contaminated water
causes the deaths of 1.8 million people every year (WHO 2000), and leads
to many illnesses including diarrhea, cholera, and giardia, which can
cause death, especially in children. People and governments have
designed varying systems to disinfect water. From straining cloths to
remove particulate matter to centralized systems, water treatment
facilities have been implemented worldwide. However, these latter
systems are expensive, difficult to implement and hard to maintain in
developing countries. An alternative to these centralized systems are
Point of Use (POU) disinfection systems. These systems are smaller scale
and allow users to disinfect water either in their homes or community
immediately before use.

The UV-tube is a POU water treatment technology investigated, tested,
and promoted by students and researchers at the University of California
Berkeley. It is a system that uses ultra-violet (UV-C) light to
deactivate pathogens in water. After several design iterations, lab
tests, and field studies, the UV-tube has proved to be a viable option
for water purification in poor areas. An extended pilot study in Baja
California Sur in the summer of 2005, showed that the UV tube, dubbed
AquatUVo, successfully disinfects water, and that people use it
effectively and correctly. Other results from the Berkeley led project
suggest that several aspects of the design could be improved to better
fit the needs of people in Baja California Sur. Various alterations to
the unit were suggested to make the design more user-friendly, such as
moving the outlet drain and the window to view the light.

As part of the Spring 2006 Design for Sustainable Communities class at
UC Berkeley, we have developed a new design for the system that
addressed these concerns. In order to get feedback on the new design,
two Mexican families near the San Francisco Bay Area were chosen for a
pilot study. They used the new UV-tube for two weeks and were
interviewed on their perceptions of the product. They offered general
suggestions ranging from aesthetics to specific design issues. These
suggestions were examined and will be taken into account for the next
design. Over the summer, we will create and implement a new design while
in Baja.

**Project Background**

According to the World Health Organization, approximately 1.1 billion
people worldwide lack access to a clean water supply. These conditions
lead to 1.8 million deaths due to diarrheal diseases from waterborne
pathogens, of which 90% are children under the age of 5 (WHO). This
world health issue is dire and has invoked many solutions. There are two
types of solutions in use centralized decontamination, followed by
distribution to people, and Point of Use (POU) treatment. The former
system has several challenges in its application in financially
constrained countries. One main drawback is recontamination of water
throughout the distribution network. For water to remain disinfected by
the time it reaches the end user, the distribution network must have
residual ways to keep pathogens from infiltrating into the network, such
as chlorine. Preventive measures to ensure against recontamination
require prohibitive high maintenance costs for developing countries.
Additionally, high costs associated with the construction of centralized
treatment plants and distribution systems prohibit their use in
underdeveloped nations (Mintz 2001; Reiff 1996). For example, according
to the Inter-American Development Bank, central water projects in Mexico
cost nearly \$700 per family served for infrastructure alone (BID 1998).
The maintenance requirements for centralized systems are often unmet for
both rural and urban setting due to social, economic, and institutional
reasons (Mackintosh 2003; Mintz 1995).

A good alternative for resource-constrained and rural communities is POU
water purification systems. As opposed to cleaning the water at the
source and then distributing it throughout a complex system of pipes to
the end user, POU systems provide individuals and communities with the
capability to treat water themselves. This eliminates the issue of
expensive construction and maintenance of a centralized system and gives
users control over maintenance and usage. For POU water treatment
options to be successful, the technology must be affordable, culturally
acceptable, easy to operate, provide safe water storage to avoid
recontamination, and be accompanied with hygiene educational programs
and materials to motivate and promote behavioral changes (Mintz 2001,
Wright 2004). To minimize cost, ease maintenance, promote environmental
sustainability, and reduce risk of dependence on long supply chains, all
POU units should be constructed utilizing locally available resources.
Currently, boiling and adding chlorine bleach or tablets are the most
common POU methods. Their limitations reduce their sustainability and
viability in developing countries; boiling water is time- consuming and
resource intensive while chlorine alters the taste of water and requires
complicated dosing procedures.

# **Project History**

In 1999 Berkeley's Renewable and Appropriate Energy Laboratory (RAEL)
launched the UV-tube project, a POU system, to address the growing need
for an effective method for water borne pathogen inactivation in
underserved communities. The UV-tube offers an effective alternative to
boiling water and complicated chlorine dosing for drinking water
treatment. The UV-tube uses ultra-violet light to deactivate pathogens.
The UV-Tube design incorporates a germicidal UV bulb suspended over
water in a horizontal tube or covered trough**.** The water enters at
one end through an inlet in the top of the tube, and then flows along
the bottom (beneath the germicidal bulb) until it reaches an outlet at
the opposite end, where it exits. The height of the outlet sets the
depth of the water in the tube and regulates the hydraulic retention
time. Because the UV-Tube does not require water pressure to operate, it
may be connected directly to a faucet or filled with a funnel and
bucket. Different tube sizes and geometries are possible, because
various germicidal bulb sizes are available. Stainless-steel sheets,
galvanized gutter, copper sheet, pottery, ferro cement, PVC pipe, and
ABS pipe prototypes have been used as construction materials.

The system's constraints include the need for electricity and reduced
effectiveness in turbid water. Initially, the project faced other
limitations that were specific to the manner in which UV disinfection
systems were manufactured for commercial markets, including their high
initial costs, high maintenance requirements, and dependence on
vertically integrated supply chains. All of these limitations were
addressed through a series of design test iterations. By 2003, Berkeley
researchers had developed a low-cost and user-friendly system that could
be built and distributed using locally available resources. The key
difference between this new UV-tube system and the commercial systems is
that the bulb is placed above the water instead of being submerged (as
shown in figure 2). This UV-tube characteristic was adopted from a
system developed by Dr. Ashok Gadgil, a scientist at the Lawrence
Berkeley National Laboratory.

The UV tube as a POU has many advantages over commercial systems and
other UV-disinfection units that make them ideal for use in developing
regions. First, UV-tubes are easy to use and can be constructed from
common, low cost materials available in developing areas. Other small UV
disinfection units on the market cost between US\$300 and US\$1000, a
price too high for POU use in developing countries. Depending on the
design and region of implementation, the cost of household and communal
UV tube ranges from US\$30 to US\$100. With an operational flow of 5
liters per minute, UV tubes meet users' needs for effective, fast, and
reliable water disinfection, without changing the taste of the water.
They have less environmental impact than most methods of obtaining safe
drinking water. Finally, UV tubes are a community-level solution to the
problem of contaminated drinking water. They can be built and sold by
local entrepreneurs or built and maintained by those wanting to sell
treated water, and evaluated by users who provide feedback on the
design.

![](media/image1.jpeg){width="3.3229166666666665in" height="1.78125in"}

Figure 1: Schematic of different UV systems

**Figure 2: Basic working concept of UV-Tube Design**

The UV-tube has been tested both in the field and in the lab. The
inactivation effectiveness of the UV tube was tested against the
bacteria *E. coli* and the MS2. The tests showed that the design
delivered twice as much dosage required by NSF/ANSI standard 55 for
commercial UV systems. The design has been field tested in several
locations and improvements have been made from conclusions drawn from
the field studies. In January 2003, a version of the UV-tube named "el
tUVo" was implemented in a community in Morelos, Mexico. In
collaboration with the Mexican Institute of water Technology (IMTA),
students conducted a small-scale pilot study involving 18 families in
two communities.

Working together with staff from Consejo Nacional de Fomento Educativo
(CONAFE), students documented water quality and its relation to health
in 25 rural communities across the state of Baja California Sur (BCS) in
the summer of 2004. According to the project results, more than 50% of
the water sources sampled had presence of *E. coli,* indicating fecal
contamination of the water*.* These results coincide with the high rates
of diarrheal diseases that were found in the area. Students also
documented water practices in the region and found that residents were
interested in options to disinfect water at the household level.

This knowledge motivated students to design a new iteration of the
UV-tube for a pilot project specific to BCS. In the summer of 2005, a
team of students implemented the latest UV-tube (AquatUVo) design in two
communities in BCS. These students installed 30 AquatUVos in homes and
monitored them over an 8 week time period. Participants were interviewed
at the end of the study to better understand their use and perception of
the AquatUVos. They were then asked questions addressing the usability
of the device, willingness to pay for the technology, and their
perceptions of its usefulness.

**Characteristics of Targeted Communities**

The current UV-tube iteration is designed to meet the needs of small
rural communities in Baja California Sur (BCS). The terrain and cultural
landscape of BCS make it a good candidate for UV-tube installations.
Baja California Sur is a predominantly rural state in Mexico with a
tenth of the state's population living in communities of 500 people or
less. Only 5% of the total population lives in one of the three cities:
Ciudad Constitución (pop. 36,000) in the north, La Paz (pop. 162,000) in
the middle, and Los Cabos (pop. 70,000) in the south ([INEGI
2000]{.mark}) Since the state is predominantly rural, a centralized
water distribution system is not a viable option; POU treatment options
offer good alternatives. When the option was presented to them, people
showed interest in POU systems. Generally speaking, individual families
collect drinking water from wells or springs, and carry it home to be
stored in large container, out of which the family takes its drinking
water. Some of the wells are used by many community members, while
others are used by only one family; few families purchase water. BCS
residents tend to be wealthier than residents of other Mexican regions
because the state has a higher amount of people who own land. Therefore,
they have higher disposable incomes, with which to buy devices such as
the AquatUVo. These communities also have reliable access to
electricity, facilitated by governmental subsidies towards supplying
solar panels in rural communities.

#### Current Project Goals

The UV-tube project has been handed down through generations of UCB
students. Many new designs have been developed, refined, and tested in
the laboratory and field. Consequently, the UV-Tube has become a design
concept, rather than a single design. As part of the Energy and
Resources Group course "Design for Sustainable Communities (ERG 291)",
we have implemented improvements to the design of the AquaUVO based on
results from the pilot study in the summer of 2005.

######## 

![](media/image2.jpeg){width="2.3751968503937007in"
height="0.8547244094488189in"}![](media/image3.jpeg){width="1.6251968503937009in"
height="1.4618110236220472in"}![](media/image4.jpeg){width="2.4507874015748032in"
height="1.8381889763779529in"}![](media/image5.jpeg){width="1.5318897637795275in"
height="1.8429133858267717in"}![](media/image6.jpeg){width="1.588976377952756in"
height="3.35748031496063in"}

**Figure 3: Previous Iterations of UV Tube Design**

Over the course of the spring semester, the goal was to implement design
improvements on the previous bucket and steel sheet metal design concept
as pictured in Figure 3. The UV Tube Team identified several areas on
the current design that were in need of improvement as recommended by
previous users from the pilot study. Figure 4 shows that the current
placement of the drain tube can be confused with the clean water outlet,
given their close proximity. Additionally, the window that acts as an
indicator for the UV lamp during the disinfection process has been
perceived to be too small and in an awkward location. Figure 3 also
shows several versions of the UV tube installed in the field in Mexico
and their individual application and usage location. Note that some
tubes are placed on uneven (non-level) surfaces such as a stool,
dresser, sink countertop, wooden crates and even bolted to a cement
block wall. In this configuration, the UV-tube can be placed in a
variety of spaces in a household. Although this allows the system
flexibility to meet the space of the house, it invites misuse. Without
being fixed to a surface, the UV tube can be placed on an uneven surface
or tilted in a way that water flows faster than the optimum maximum flow
of 5 liters per minute This action can reduce the detention time of the
water in the device to less than that required to effectively deactivate
pathogens. In addition, if the tube is not level, water may contact the
UV lamp inside the tube and sediment deposits can grow on the surface,
over time blocking much of the beneficial UV light. Creating an
all-inclusive user-friendly design would eliminate this problem as well
as create the appearance of a central space for water disinfection. The
best option for addressing all of these issues was to create a small
table to house the AquatUVo and all its components.

![](media/image7.jpeg){width="2.5458333333333334in"
height="2.033333333333333in"} ![](media/image8.jpeg){width="2.7in"
height="2.025in"}

**Figure 4: Previous Iterations of UV Tube Design**

This new table-based design is built on the idea concept of simplicity,
and incorporates the following design guidelines: **minimization of
materials, ease of manufacturing, intuitive design, level surfaces,
compactness, attractiveness, sturdiness/durability, and most importantly
low cost**. Figure 5 shows CAD drawings of the UV tube and table that
allowed the group to virtually modify the design. The dimensions of the
table or tube were modified frequently to best design for material
minimization and optimal dimensions. Note that the tube is now strapped
level to the bottom surface of the table top.

![](media/image9.jpeg){width="2.5805555555555557in"
height="1.9652777777777777in"}
![](media/image10.jpeg){width="2.5909722222222222in"
height="1.9736111111111112in"}

**Figure 5: Working CAD Drawings of UV Tube and Table**

> The major design modifications to the current bucket and tube based
> design are shown in figure 5. Three support beams were added for
> stability, leaving one side open for the *garaffon* (large clean water
> storage bottles used in Baja California) access. The **placement of
> the drain** was changed to the back end of the tube to prevent users
> from confusing it with the clean water outlet as shown in figure 3. An
> **in-line ground fault circuit interrupter** (GFCI) was added for
> safety to prevent electrical shock and equipment damage in case the
> tube ever became clogged and overflowed with water. The location of
> the **indicator light** window was moved from the front of the tube
> (as seen in figure 3), to the rear so that it is slightly protruding
> out of the tabletop near the bucket water inlet. In addition, the
> window was also made larger. Window location was chosen based on the
> idea that the user will find it easier to check if the light is on
> before opening the water release valve on the bucket before they begin
> disinfection. Other minor modifications include grounding the UV tube,
> using a three pronged plug to allow for a GFCI, and adding an **on/off
> switch** for convenience.

![](media/image2.wmf)

**Figure 5: Major Design Improvements to UV Tube**

There were a few lessons learned from the challenges/obstacles faced
during the course of creating this new design. Perhaps the largest
challenge was spending a disproportionate amount of time focusing on the
design and construction the table ourselves, rather than having a
professional carpenter build them quickly. Early on, effort should have
been focused on making the UV Tube modifications and sending it out to
be tested in the field to gain valuable user feedback. Another challenge
was obtaining the different components to build three UV Tubes in one
centralized hardware store. The parts had to be purchased at multiple
locations. Finally, the UV Tube team met to build three tubes: two for
the pilot installation and one for personal use/test. Troubleshooting of
two of the three tubes during the construction process proved
challenging (see figure 6).

![](media/image3.jpeg){width="2.751388888888889in"
height="2.063888888888889in"}

**Figure 6: Team Members Troubleshooting and Building 3 UV
Tubes/Tables**

[]{.mark}

The next steps in designing the UV tube are to analyze the user feedback
and see how to implement suggestions in a future design of the tube.

##### Implementation

To assess our new design, the group sought the input of those who would
be using the AquatUVo in the end: community members in Mexico. Its
user-friendliness, convenience and design specifications were developed
with the end-user in mind, so they are in effect the experts who can
tell how effective the system is, and what should be modified. However,
since we are all full-time students at UC Berkeley, traveling to the
final end user was not feasible, so the end-user was approximated by
choosing Northern California families with strong ties to Mexico.
Systems were installed in two homes to allow the families to use it for
two weeks and report their suggestions upon the groups return.

***Criteria***

A household was identified in the agricultural area of Santa Rosa,
California that was willing to participate in the study. From there, the
group traveled door-to-door in the neighborhood, trying to recruit other
families to pilot test the new AquatUVo. In determining which families
to include in the study, we looked for the following characteristics:

-   At least one generation born and raised in Mexico

-   Family with close ties (friends and family) in Mexico

-   Willingness to participate

-   (preferred) Families procuring drinking water from wells

-   (preferred) Families that face a water quality problem

The recruitment process consisted of describing our project's goals to
tweak the design of a Point Of Use water treatment technology to improve
access to clean drinking water in Mexico and assessing the ability of
the families to meet our criteria. After talking to several families, we
selected two families for our pilot study.

***Family Profiles***

The first family included in our study meets the profile of the "first
adopter." This family was our initial contact in the community; they
were suggested to us directly by a member of the Mexican Consulate as a
family that would likely participate in a study like ours. Six people
lived in the home; 2 parents and 4 children, the eldest of which was 18
and preparing to go to college. Spanish and English were spoken in the
household; the children answered the phone in English. The parents were
teachers and had lived in the US for about 30 years. They still had many
family members in Mexico, and visit very frequently. Drinking water was
obtained from a well behind their house, but came into the home after
passing through a filter, through pipes. The family's current water
practices included filtering all their water from the faucet through a
Brita filter. They were very enthusiastic about this project, and
willing to do anything they could to help out with our project.

The second family consisted of an elder couple and their grandchild.
They lived on a ranch, owned by the company that employed the male of
the household. The father figure was a laborer, and the mother figure
worked at home. They had been in the US for over 30 years, had family in
Mexico whom they visited sporadically, and spoke Spanish in the home.
The family's water also came in piped, from wells on the property.
However, many of them complained that the tap water tasted like
chlorine, so they had been buying large containers of bottled water.
This family was also very willing to participate in our study, not
because of immediate benefits they would reap, but for the possibility
of helping people in Mexico.

***Pilot Installation***

We returned to each household, one week after recruiting them for our
project, and brought one AquatUVo for each home. In each home, we asked
them where they thought the system would be most convenient, and in both
cases, it was placed in the kitchen, near the sink and an electrical
outlet. We reiterated the purpose of our project, described how the
AquatUVo disinfects water (and what it does and does not change about
the water), and demonstrated how to use the system. We also distributed
laminated instructions for use, which both families later affixed to the
wall near the system. Most importantly, we told them the role that they
would play in our project by participating in this pilot study. We asked
them to use the AquatUVo every day for two weeks --for all their
drinking water needs -- and told them we would return to ask them
detailed questions, to get their opinions and suggestions for
improvements on the system.

*Interviews*

We conducted one interview at each home, primarily to the male of the
household, who was, in both cases, our primary contact in the home. The
interviewers asked the following types of questions:

-   General feedback on system

-   Tested the user on knowledge of how the system works

-   Specific design-focused questions on how to improve/change certain
    aspects of the system

-   Demographic information

The interviews were conducted in Spanish. One member of the group asked
questions, another took notes, while the rest of the group observed and
made additional comments or asked questions at the end. For a list of
questions, and notes on the answers provided, please see Attachment A.

# **Relevance of Pilot Study**

In order to analyze the results from our pilot study, we must be certain
of its relevancy. Because our end users live in Mexico and are
unavailable to us, we found a reasonable approximation of the end user
in the Bay Area. We chose to follow a user-centered design approach
rather than a technology-based approach, and thus are more interested in
finding similarities in culture than similarities in water issues. We
recognized that the families we chose to interview did not have any real
need for a new water treatment system. Our aim was rather to find a
population to sample from that was as culturally similar as possible to
the rural communities in Baja California Sur, Mexico. With this
emphasis, we were to gain insight on the cultural subtleties and context
for the UV tube. In consideration of the similarities and differences
listed above, we believe that our pilot test is a good approximation of
our end user. When making decisions concerning the design of the UV
tube, we must keep in mind these points so that we can accurately meet
the needs of the end-user.

In many ways, the families that we interviewed were very similar to our
end users. The UV tube users in BCS, Mexico mostly live in very rural
areas. The majority of the population lives away from the cities in
underdeveloped areas of Baja. The communities are very small, and often
home to less than five hundred people. The families that we interviewed
both lived in a fairly rural community near the vineyards and Santa
Rosa. The houses were located in the middle of the vineyards far from
neighboring homes. The families we chose for the pilot study still
retained close ties to Mexico. Both families were originally from
Mexico. The interviews were conducted in Spanish and our test subjects
seemed most at ease in their native language. In addition, the second
generation also seemed very much at ease speaking Spanish, suggesting
close ties to Mexican heritage and minimal assimilation. In addition,
both families indicated that they still had many family members still
living in Mexico and whom they visited often. The families that we chose
to interview were willing to participate in this project because they
believed that they could help their own people in Mexico. Both of the
families referred to specific communities that they felt would benefit
from the use of the UV tube. These communities were places where either
they themselves or their friends had lived. The family members told
anecdotal stories about the contamination of the water sources in these
areas.

While the family members came close to approximating our end user, there
were still many key differences. The test families we interviewed
clearly have a very different motivation for using the UV tube than our
end users. They did not have any real need of a new water treatment
system since their water was already very clean. Though their water came
from wells, they primarily drank bottled water or filtered water. Their
enthusiasm for participating in the study came from their eagerness to
make a difference and help their own people in Mexico. Because of this
difference, it is possible that the test families might have overlooked
factors of use that would come from a real need for clean water. Our end
users in rural BCS live in small houses and have much lower incomes. In
contrast, the families we interviewed seemed to be of a higher
socioeconomic class. Their houses were one story tall and seemed
slightly larger than a typical house in Mexico. They often had some
expensive items in their houses, such as a treadmill and a large screen
TV. This difference could provide some discrepancy when we are trying to
gain information for determining the appropriate costs and space
limitations in a house in rural Mexico. While our test families may have
similar origins to our end users, they are somewhat removed from Mexico.
One family we interviewed had come to the United States in 1978 and the
other had immigrated in 1971. Since the families are not recent
immigrants, it is possible that the Mexico that they remember is
somewhat different from reality and that the opinions and viewpoints
they express would not mirror those of today's population of rural
Mexico.

# **Key Recommendations**

Both families were very pleased with their system, and when initially
asked if they would change anything, they responded that they would
change nothing. However, when we asked more specific questions about
particular aspects of the design, they did give us more feedback.

## 

## Altering Indicator Window

Both families believed that the indicator window was not visible enough.
They suggested making it bigger to allow for more light through. Another
concern was raised addressing its location. We had originally placed the
window near the valve, expecting that people could check to see whether
the light was on before they turned the valve to allow water to flow
into the tube from the bucket. From our response, it seems as though
people would prefer the window to be placed closer to the on/off switch
so that the user could check that the light was on right after you
turned on the switch. We must determine whether the benefits of moving
the light outweigh the costs; it may be that if we move it, many will
suggest that it should be moved back.

***Improving Aesthetics***

Both families indicated that the aesthetics of the system could be
improved to provide a more finished and modern look. Specific
suggestions included painting the table and replacing the bucket with a
container similar to the *garrafon*. In addition, participants suggested
that the table could be made out of a different material than wood, such
as modern looking plastics, since the wood could possibly warp if it got
wet. Another solution is to provide a protective and decorative plastic
table cloth that would cover the system.

***Adding a Filter***

One of the most interesting findings from the interviews was the way in
which water treatment systems were viewed. The families understood water
treatment to be the physical removal of contaminants such as
particulates or insects. Though we had explained that the system worked
through UV light, they continued to refer to the apparatus as a filter.
After we had explained that the UV light killed the bacteria, one
participant expressed concern that the remains of the dead bacteria
would still be in the water, maintaining its polluted quality. From this
observation, we realized that it might be beneficial to incorporate a
rudimentary filter, such as a piece of cloth for the water to flow
through. This might provide peace of mind to the users and increase the
likelihood of adoption in rural Mexican communities.

***Changing the Outlet***

Our original design of the table had the mouth of the *garrafon* placed
as close to the outlet as possible, while still allowing the user to
slide the *garrafon* in and out from underneath the table. During the
installations, we discovered that this distance still provided problems,
as a little bit of water still spilled out along the outside. To
temporarily fix this problem for our test users, we provided a smaller
sliding tube. This tube remained up when the *garrafon* was inserted and
then came down once the water started to flow. While this solved the
problem of water spillage, it also introduced the possibility of more
contamination since users would touch the sliding tube with their hands.
The next design iteration should include a better solution to this
problem, such as a flexible hose outlet.

***Facilitating Transport of Water***

The most inconvenient part of using the UV tube system seemed to be
transporting the dirty water into the bucket in preparation to be
cleaned. One participant noted that it would be helpful if there was a
way in which piped water flowed directly into the bucket.

***Adding a Protective Cover***

One participant expressed a concern about the amount of dust in rural
Mexico. This dust could settle into the open bucket of water and any
crevices, contaminating the water further. To solve this problem, it
would be advisable to use a protective cover over the bucket and any
other open water containers to prevent dust from settling.

***Setting Appropriate Costs***

An important factor to consider during implementation in Mexico is
setting appropriate costs for the UV tube system. We asked both families
how much they thought a family in Mexico would be able to pay for this
system. They indicated that while city dwellers would be able to pay
much more than those who lived on the ranches and needed it most. One
participant remarked that some families have difficulty paying for
shoes, much less a water treatment device. While we were unable to pin
down an exact cost, both families seemed to believe that US\$40 was an
acceptable cost for the system.

# **Future Work**

This summer, work on the improved UV tube design will continue in BCS,
Mexico. Three members of our team will be traveling to Mexico to
continue with this project. One of the main tasks we will pursue will be
adapting materials of our current design to those materials available in
Mexico. Even in the Bay Area, we had difficulty finding all of the
components of the UV tube and had to search several different hardware
stores. We are unsure which components are readily available at a
typical hardware store in rural Mexico. In addition, we don't know the
standard type and size of certain components. While many of the
components are sold in English units in the United States, they are sold
in metric units in Mexico. After determining which materials are
available in Mexico, we must adapt our design to accommodate available
resources. Additionally, we would like to incorporate a rudimentary
filter into the UV tube design. This will increase performance and make
people in rural Mexico more likely to adopt the system. While in Mexico,
we will conduct another study to test the new design in households in
rural BCS, California. We will conduct interviews with our true end
users to gain further insight on how successful our design is and learn
of further modifications that we can implement. The next step will be to
consider plans for large scale dissemination in Mexico. We will consider
if any modifications should be made to the design to make it easier to
manufacture on a large scale. In addition, we will work on an
appropriate business plan for determining cost, how to distribute the
systems, and how to spread the word about this new technology.

In addition, we will work on establishing a needs assessment
methodology, in order to determine where in Mexico the UV tube is an
appropriate technology, and where it is not. Appropriate here means that
it is culturally acceptable, technically effective in removing bacteria
and viruses from the source water, and economically feasible for people
to purchase. For places where the UV tube is not appropriate, we will
work on determining what other options for water treatment are feasible.

**References**

BID. 1998. *Programa para la sostenibilidad de los servicios de agua
potable y saneamiento en comunidades rurales*. Banco Interamericano de
Desarrollo, ME-0150.

INEGI. 2000. *Xii censo general de población y vivienda 2000*. Instituto
Nacional de Estadística Geografía e Informática.

Mackintosh, G. and C. Colvin. 2003. Failure of rural schemes in south
africa to provide potable water. *Environmental Geology* 44, no. 1:
101-105.

Mintz, E., J. Bartram, P. Lochery, and M. Wegelin. 2001. Not just a drop
in the bucket: Expanding access to point-of-use water treatment systems.
*American Journal of Public Health* 91, no. 10: 1565-1570.

Reiff, F. M., M. Roses, L. Venczel, R. Quick, and V. M. Witt. 1996.
Low-cost safe water for the world: A practical interim solution.
*Journal of Public Health Policy* 17, no. 4: 389-408.

World Health Organization (WHO). 2000. *Global water supply and
sanitation assessment 2000 report*. Accessed 12/3/05.

Wright, J., S. Gundry, and R. Conroy. 2004. Household drinking water in
developing countries: A systematic review of microbiological
contamination between source and point-of-use. *Tropical Medicine &
International Health* 9, no. 1: 106-117.

**Attachment A**

***Sample Interview Form:***

**household aquatuvo use form**

Quisiéramos hacerles algunas preguntas relacionadas con el uso del
AquatUVo. Para nosotros es muy importante que nos respondan las cosas
como son. Nosotros no los vamos a juzgar de ninguna forma, solo estamos
interesados en aprender como se usa el AquatUVo en las casas para poder
realizar las mejorías necesarias. ¿Les parece bien? ¿Entonces, podemos
hacerles unas breves preguntas?

+---+----+------------------------------------------------------------+
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+---+----+------------------------------------------------------------+
| * | ** | **Comments**                                               |
| * | St |                                                            |
| \ | ep |                                                            |
| # | ** |                                                            |
| * |    |                                                            |
| * |    |                                                            |
+---+----+------------------------------------------------------------+
|   |    | Washed Hands                                               |
+---+----+------------------------------------------------------------+
|   |    | Use regular little cups of water to fill bucket from sink  |
|   |    | (though usually fills it up with a hose)                   |
+---+----+------------------------------------------------------------+
|   |    | Carried bucket back on top of table and inserted hose      |
+---+----+------------------------------------------------------------+
|   |    | Placed garaffon under table and inserted adaptor to outlet |
|   |    | spout.                                                     |
+---+----+------------------------------------------------------------+
|   |    | Turned switch on                                           |
+---+----+------------------------------------------------------------+
|   |    | checked light                                              |
+---+----+------------------------------------------------------------+
|   |    | opened bucket valve                                        |
+---+----+------------------------------------------------------------+
|   |    | Once filled lifted the garafon to the top of the UV tube   |
|   |    | table                                                      |
+---+----+------------------------------------------------------------+
|   |    | Placed the PVC outlet adptor in the opening of the tube so |
|   |    | the kids would not loose it.                               |
+---+----+------------------------------------------------------------+
|   |    |                                                            |
+---+----+------------------------------------------------------------+
|   |    |                                                            |
+---+----+------------------------------------------------------------+
|   |    |                                                            |
+---+----+------------------------------------------------------------+
|   |    |                                                            |
+---+----+------------------------------------------------------------+
|   |    |                                                            |
+---+----+------------------------------------------------------------+

+-------------------------------------------------------+------+------+
| # TEST OF HOW IT WORKS                                |      |      |
+-------------------------------------------------------+------+------+
| 1\. ¿Tiene un idea en general de cómo funciona el     |      |      |
| AquatUVo? - Yes (good that we are getting feed back   |      |      |
| to implement improvements for rural communities)      |      |      |
+-------------------------------------------------------+------+------+
|                                                       |      |      |
+-------------------------------------------------------+------+------+
| 2\. ¿Sabe para que es el tubo de drenaje? Thinks the  | **   | No   |
| water that has to come out                            | Si** |      |
+-------------------------------------------------------+------+------+
| 3\. ¿Nos puede mostrar como se usa el AquatUVo? yes   |      |      |
+-------------------------------------------------------+------+------+

+-------------------------------------------------------+------+------+
| **GENERAL REACTION**                                  |      |      |
+-------------------------------------------------------+------+------+
| 1\. ¿Cree que el AquatUVo beneficiaría alguna persona | **   | No   |
| o comunidad que usted conoce en Mexico?               | Si** |      |
+-------------------------------------------------------+------+------+
|                                                       |      |      |
+-------------------------------------------------------+------+------+
| 2\. ¿Usted recomendería el AquatUVo? A quien?         | **   | No   |
|                                                       | Si** |      |
+-------------------------------------------------------+------+------+
| "Mi gente" (mexicanos)                                |      |      |
+-------------------------------------------------------+------+------+
| 3\. ¿Que piensan sus familiares del AquatUVo? (have   |      |      |
| they used it?) A tenido visitas que le han comentado  |      |      |
| algo del AquatUVo? Que han dicho?                     |      |      |
+-------------------------------------------------------+------+------+
| They think that it's good 1st day of instillation     |      |      |
| thought it was good. Good because it killed all       |      |      |
| pathogens. Oregon Relative even wanted on to take     |      |      |
| back with him to Oregon.                              |      |      |
+-------------------------------------------------------+------+------+
|                                                       |      |      |
+-------------------------------------------------------+------+------+
| **USER FRIENDLINESS**                                 |      |      |
+-------------------------------------------------------+------+------+
| 1\. ¿Si le ha funcionado el AquatUVo? ¿Ha tenido      |      |      |
| algún problema?                                       |      |      |
+-------------------------------------------------------+------+------+
| Light didn't go on for 2 days                         |      |      |
+-------------------------------------------------------+------+------+
| 2\. ¿Le cambiaría algo para hacer el AquatUVo más     |      |      |
| facil de utilizar?                                    |      |      |
+-------------------------------------------------------+------+------+
| tubing on bucket to inlet was bent use better tubing, |      |      |
| a way to connect a water source hose to the UV tube   |      |      |
| so you don't have to remove the bucket and make it    |      |      |
| easier to use.                                        |      |      |
+-------------------------------------------------------+------+------+
| 3\. ¿Qué le gusta más del sistema?                    |      |      |
| Everything...really likes the idea.                   |      |      |
+-------------------------------------------------------+------+------+
| 4\. ¿Cuales aspectos no le gustó del sistema? NIcer   |      |      |
| looking table. Not well made sand and Paint it. Use   |      |      |
| plastics instead of Wood. Not everyone will have      |      |      |
| enough Money to buy Wood                              |      |      |
+-------------------------------------------------------+------+------+
| 5\. ¿Era cómoda la altura de la mesa? Yes a kid could | Si   | No   |
| even use it.                                          |      |      |
+-------------------------------------------------------+------+------+
| 6\. ¿Preferiría que fuera más alta? Más baja? NO good |      |      |
| size                                                  |      |      |
+-------------------------------------------------------+------+------+
| 7\. ¿Le gustó cómo sale el agua del AquatUVo? It      | **   | No   |
| doesn't drip                                          | Si** |      |
+-------------------------------------------------------+------+------+
| 8\. ¿Cuando desinfectaba el agua, se le mojo el piso? | Si   | **   |
|                                                       |      | No** |
+-------------------------------------------------------+------+------+
| 9\. ¿Tiene alguna recomendación para que esto no      |      |      |
| pase? Qué cambiaría?                                  |      |      |
+-------------------------------------------------------+------+------+
|                                                       |      |      |
+-------------------------------------------------------+------+------+
| 10\. ¿Es el drenaje conveniente de usar? Drained two  | Si   | No   |
| times easy to use                                     |      |      |
+-------------------------------------------------------+------+------+
| 11\. ¿Es la luz indicadora facil de ver?              | **   | No   |
|                                                       | Si** |      |
+-------------------------------------------------------+------+------+
| 12\. Le cambiaría la localización de la luz? Dónde la |      |      |
| pondría? Bigger Light hole (Light hard to see) move   |      |      |
| next to switch                                        |      |      |
+-------------------------------------------------------+------+------+
| 13\. En alguna ocasión, se le ha olvidado prender la  | Si   | **   |
| luz antes de abrir la corriente del agua?             |      | No** |
+-------------------------------------------------------+------+------+
| 14\. Le parece que el "switch"de la luz este situada  | Si   | **   |
| en un lugar obvio? Hay un mejor lugar para el         |      | No** |
| switch"?                                              |      |      |
+-------------------------------------------------------+------+------+
| **SPACE/ AESTHETICS**                                 |      |      |
+-------------------------------------------------------+------+------+
| 1\. ¿Le gusta el tamano del sistema? Se le hace       | **   | No   |
| apropriado el tamano del sistema para una casa en     | Si** |      |
| Mexico? Tomaría demasiado espacio en una casa         |      |      |
| Mexicana?                                             |      |      |
+-------------------------------------------------------+------+------+
| 2\. ¿Hay un lugar mas conveniente para el sistema en  |      |      |
| su casa? Likes where it is                            |      |      |
+-------------------------------------------------------+------+------+
|                                                       |      |      |
+-------------------------------------------------------+------+------+
| 3\. Si le cambiaría algo estético al AquatUVo, qué    |      |      |
| sería? (Ejemplos: color, material, forma\...)         |      |      |
+-------------------------------------------------------+------+------+
| Already discussed                                     |      |      |
+-------------------------------------------------------+------+------+
| # BUILDING                                            |      |      |
+-------------------------------------------------------+------+------+
| 1\. ¿Cree usted que sus familiares en Mexico podrían  | **   | No   |
| construir un sistema como este?                       | Sí** |      |
+-------------------------------------------------------+------+------+
| 2\. ¿Cree que sus familiares en Mexico construirian   | Sí   | No   |
| un sistema como este? (went off Topic)                |      |      |
+-------------------------------------------------------+------+------+
| **COST**                                              |      |      |
+-------------------------------------------------------+------+------+
| 1\. Cree que sus familiares pagarían \$100 por este   | Sí   | **   |
| AquatUVo? People in the city could afford this        |      | No** |
+-------------------------------------------------------+------+------+
| 2\. \$80?                                             | Sí   | **   |
|                                                       |      | No** |
+-------------------------------------------------------+------+------+
| 3\. \$60? Could prob sell some animal/ live stock to  | Sí   | **   |
| buy it.                                               |      | No** |
+-------------------------------------------------------+------+------+
| 4\. \$40? Poor familias don't even have Money to buy  | **   | No   |
| shoes for their kids so need unit to be cheap.        | Sí** |      |
+-------------------------------------------------------+------+------+
| **DETAILS OF USING UV TUBE**                          |      |      |
+-------------------------------------------------------+------+------+
| 1\. Cuantas personas utilizaron el AquatUVo? Just him |      |      |
+-------------------------------------------------------+------+------+
| 2\. Quien lo sabe usar? Just him                      |      |      |
+-------------------------------------------------------+------+------+
|                                                       |      |      |
+-------------------------------------------------------+------+------+
| 3\. ¿En Mexico, en su opinion, quien principalmente   |      |      |
| usaría el AquatUVo? Just him                          |      |      |
+-------------------------------------------------------+------+------+
| 4\. ¿Con qué frecuencia usó el sistema, durante estas |      |      |
| dos semanas? Once a day                               |      |      |
+-------------------------------------------------------+------+------+
| 5\. ¿Qué cantidad de agua desinfectó a la vez? ½      |      |      |
| garaffon                                              |      |      |
+-------------------------------------------------------+------+------+
| 6\. ¿Uso su familia todo el agua que fue desinfectada | Si   | **   |
| por el AquatUVo? NO (check for bold si or no)         |      | No** |
+-------------------------------------------------------+------+------+
| 7\. ¿Cuáles eran los usos del agua desinfectada?      |      |      |
| (beber, lavar platos, regar plantas\...) uses it to   |      |      |
| cook beans and for drinking...wife only drinks        |      |      |
| sparklets water...she doesn't like the chlorine taste |      |      |
+-------------------------------------------------------+------+------+
|                                                       |      |      |
+-------------------------------------------------------+------+------+
| 8\. ¿Cuánto tiempo le tomó desinfectar el agua cada   |      |      |
| vez que usó el AquatUVo? 10 min                       |      |      |
+-------------------------------------------------------+------+------+
| 9\. ¿Usó alguna vez el tubo de drenaje para sacar     | **   | No   |
| todo el agua del AquatUVo?                            | Si** |      |
+-------------------------------------------------------+------+------+

+-------------------------------------------------------+--------------+
| # COMMUNITY/ RELEVANCE                                |              |
+-------------------------------------------------------+--------------+
| 1\. ¿Hace cuanto vive en los Estados Unidos? Since    |              |
| 1961                                                  |              |
+-------------------------------------------------------+--------------+
| 2\. ¿Tiene parientes en Mexico? Con cuanta frecuencia |              |
| los visita? Sister in México uncles he's from baja    |              |
+-------------------------------------------------------+--------------+
|                                                       |              |
+-------------------------------------------------------+--------------+
| 3\. ¿Cuantas personas viven en su domicilio? 3 wife   |              |
| him and a kid                                         |              |
+-------------------------------------------------------+--------------+

Side notes

Would like to change the design. He doesn't think it takes too much time
to clean water.

He would like to see the design change to a fancier version. He think
the bucket is ugly would like it to use 2 garaffones one inserted on top
like a regular water cooler (upside down) He likes the fancy look of the
blue garaffon.

Thinks It's good we are getting feed back

When Light did not go on he tried using a new extension cord then called
the group

Has a sister in baja

In Mexico just drank right out of natural water source with animal
excrement's

Would like to give it to someone who needs it more with more family
members with children.

He felt bad because the thought that we thought he didn't like it when
he asked us to take it back

Maniadero city in baja where his sister lives and 4 uncles and a few
cousins.

Use a sliding scale to have people to pay for system.