Effects of Water Storage and Irrigation on Human Vulnerability to Disease
Understanding the relationship between science and society in public health policy
A research project submitted to the Urban Studies and Planning Program
University of California at San Diego
Zee K. Sa
USP187
zsa@ucsd.edu
February 19,2011
Abstract
Research suggests that there are new microbial diseases(pathogenic) in
water storage and system facilities. An increasing number of researchers
characterize the situation as a public health policy issue that requires changes to
existing water policies. The study examined and evaluated water policy in the San
Diego Basin 9 plan for water sheds, Safe Drinking Waters Act, Clean Waters Act,
Title 22 of the California Code of Regulations, and the World Health
Organizations Guidelines for Drinking Water Quality. The study’s aim was to
improve the public health by promoting safer, cleaner, water systems by
understanding different water regulations and examine the efficiency of the use of
chemical treatments to clean water and promote the public health. The research
consisted of data collection from different water systems and regulations they
abide by, the level of chemical treatment used such as chlorination, level of
fluoride used if any, interviews and data collected from different water system
sites. The result shows that most water systems follow similar regulations to
manage their water systems and the type of chemical treatment used is similar but
the use of fluoridation differs between system depending on number of service
each system provides. The research includes the comparative study of different
water systems in San Diego County such as the Small Drinking water program,
Environmental Protection Agency Drinking Waters and the San Diego Regional
Water Quality Control Board relying on interviews and data obtained to assess
their similarities and differences. The result obtained demonstrates that the water
regulations these water systems abide by acts as a prevention of potential
outbreaks from water borne diseases but there has been no policy or awareness on
the potential health issues that can arise from chemical by products resulting from
the excessive amount of chemical treatments used in these water systems.
Key Terms: Public Health, Water systems, Community, County of San Diego, Basin Plan
Introduction
Global changes have had a major impact on vector borne diseases, including malaria,
dengue fever, infections by other arboviruses and many others that have been observed for the
past few years. Global changes encompass a wide range of factors including climate change and
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variability, land use, water storage and irrigation, and human population. In addition to vector
borne diseases, climate change has also have a huge affect on infectious, water-related disease.
This research is focused primarily on the effects of water storage and system on human
vulnerability to disease. The research will provide strong facts and evidence, which will better
define the different water management practices that follow water policy regulation to promote
clean and safe water for the community. The goal of the research is to find more solutions to
prevent potential water borne diseases that results from contaminated water and excessive
amount of chemical treatments to promote better public health.
It seeks to examine the guidelines and regulations that water systems abide by and the
different approaches to potential outbreaks between water systems in hope to find ways to
decrease the human vulnerability to diseases resulting from water contaminations. A significant
proportion of diseases are caused by “classical” water related pathogens. Several studies have
proven that water related diseases not only remain the leading cause of morbidity and mortality
worldwide, but the disease is expanding and outbreaks of microbial disease are increasing.
Cholera is a disease that comes from a water related pathogen. Similarly, water related vector
borne diseases have emerged over the years.
Many studies have also shown that the most deadly vector borne disease, malaria, kills
over 1.2 million people annually.1 Dengue fever is the world’s fastest growing vector borne
disease. Both these diseases are transmitted by mosquitoes. Standing water sites, or any sort of
water site, are common breeding grounds for mosquitoes. The mosquitoes lay their eggs and
mature into biting adults that can spread disease. Poorly constructed water storage and system
sites contribute to the widespread disease, as these water sites serve as the source of drinking
Emerging issues in water and infectious disease, ” World Health Organization, 2003,
http://www.who.int/water_sanitation_health/emerging/emerging.pdf
1
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water for many communities but also serve as potential breeding and nesting sites for
mosquitoes. Therefore, water storage and systems needs the water to be clean and safe for the
public.
The WHO (World Health Organization) has an integrated vector management team who
works side by side with managers in health, agriculture, water resources and land use to examine
the local eco-setting of disease vectors and disease transmission patterns. The WHO also
provides the main guidelines for better drinking water quality known as the Water Safety Plan.
These guidelines are compiled from data obtained from many water systems in the United States
to provide an efficient strategy and plan for better drinking water quality.
As mentioned earlier, IVM works with managers in water resources due to the potential
major effects that water storage and system can have on human vulnerability to disease. This
research focuses on the Water Quality Control Plan for the San Diego Basin for water sheds,
WHO water quality guidelines and also the Clean Water Act, Safe Drinking Water Act (SDWA)
and Title 22 of the California Code of Regulations (CCR) for drinking water systems within the
San Diego County. The methodology is to examine the different water systems and the
regulations they abide by. In addition, we obtained the data for level of chemical treatments such
as chlorine and fluoride each system use in their water to find better solutions to promote safe,
clean water for the public and eliminate all potential diseases that can arise from contaminated
water or potential diseases that results from the excessive use of chemical treatments.
Literature Review
Water is an essential source for human survival. Access to clean and safe water is a
fundamental human need and therefore it is a human right. Contaminated water is a major issue
worldwide. It jeopardizes the health and social well being of all humankind. Infectious water-
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related diseases have been increasing over the years and there are numbers of newly discovered
pathogens that have challenged water companies and the public health sectors. For these reasons,
there are many regulations to keep water storage facilities and systems as clean as possible. The
main issue is massive water storage facilities can have pathogens and these microorganisms are
associated with diseases such as malaria, dengue fever, cholera, typhoid and also emerging
diseases such as Acquired Immunodeficiency Syndrome (AIDS) , Ebola and most recently Sever
Acute Respiratory Syndrome( SARS). 2 Previously, a multitude of research and projects have
been carried out to learn more about these water related pathogens. It is important to understand
the effects of water storage and systems on the human vulnerability to disease.
Water related pathogens have been around since the early 1900s. In fact, gastrointestinal
infections were the third leading cause of death in the United States during this time. 3 Over the
decades, the general use of drinking water chlorination paired with antibiotic therapy decreased
the numbers of deaths from water borne infectious diseases (WBID). One study estimated the
annual incidence for WBID, primarily focusing on gastrointestinal infections relative to drinking
water in the US. The research was conducted by the International Association of Hydrological
Sciences in collaboration with CDC (Center of Disease Control). Surveillance was conducted on
drinking water for contamination with pathogens and it showed disease incident rates had
decreased over the years.4
“Emerging issues in water and infectious disease, ” World Health Organization, 2003,
http://www.who.int/water_sanitation_health/emerging/emerging.pdf
2
Morris, Robert. Levin, Ronnie. “Estimating the incidence of waterborne infectious disease related to drinking
water in the United States,” International Association of Hydrological Sciences, September 1994,
http://iahs.info/redbooks/a233/iahs_233_0075.pdf
3
Morris, Robert. Levin, Ronnie. “Estimating the incidence of waterborne infectious disease related to drinking
water in the United States,” International Association of Hydrological Sciences, September 1994,
http://iahs.info/redbooks/a233/iahs_233_0075.pdf
4
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An outbreak of drinking water related to WBID is defined as “an incident in which two or
more persons experience a similar illness after consumption or use of water intended for drinking
and epidemiologic evidence implicates the water as source of illness”.5 Results have shown that
many diseases are reportable and data on the research was obtained from the CDC. It was duly
noted that the approaches have limitations and the complexity of estimating the rates of
incidence and outbreaks requires the use of all available information from the collaborative
organizations. The CDC research study’s primary goal of the water treatment was the elimination
of mortality from infectious disease and the goal was largely achieved by more strict regulation
and surveillance of drinking water, which prevented the outbreak before it occurred. However,
excessive level of chemical treatments in water created another issue of potential cancer resulting
from the high level of chemicals used but no evidence on human population have been found to
show these cancerous results from high level of chemical uses in water systems.
Several studies have shown that water related diseases remains relatively high worldwide.
In addition, water related vector borne pathogens have been emerging over the past 20 years.6
This is likely due to the spread of drug resistance parasites such as malaria and of insecticideresistant vectors. The changing environment, in addition to intensified water resource
development and demographic change have created conditions where vector borne disease can
gain fortification. Water storages and system have their pros and cons. The pros of water
storages are that it contributes substantially to food security and economic progress. The cons
are based on the fact that it creates new breeding sites and enhances human-vector contacts due
Morris. “Estimating the incidence of waterborne infectious disease...” International Association of Hydrological
Sciences, Sept. 1994, http://iahs.info/redbooks/a233/iahs_233_0075.pdf
5
“Emerging Infectious Diseases,” World Health Organizations.
http://www.who.int/water_sanitation_health/emerging/emerging.pdf
6
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to ecological and demographic changes. 7 For example, surface irrigation is mainly used for the
flooding of crops, which creates temporary shallow water bodies, the ideal breeding sites for
malaria carrying mosquitoes. Mosquito-borne diseases are the two leading causes of illness and
death in the tropics and subtropics.
There are many approaches to monitor potential vector borne diseases. The first and
primary approach is to keep surveillances on ideal breeding sites for these vectors. The World
Health Organization has an Integrated Vector Management (IVM) team that collaborates with
managers in health, agriculture, and water resources to examine the local eco-setting of disease
vector and disease transmission patterns and then systematically design and periodically update
strategies and action plans.8 The IVM have used many systems such as the geographical
information systems to map out the distribution of mosquito species, breeding sites, and
transmission of diseases. These information help IVM plan strategically to eliminate breeding
sites in an “environmentally friendly” vector control methods in their framework and prevent
further outbreaks of the mosquito-borne diseases.
Water storage and system have a major effect on the human vulnerability to disease.
Regulation and surveillance to promote clean and safe water in water development projects
requires up to date information and strategies due to the ever changing environment and some
chemical by products are formed from treatments to clean water systems can lead to other health
issues. The important fact is pathogens have become more resistant to these chemicals and vector
“Effect of irrigation and large dams on the burden of malaria,” World Health Organizations, 2005,
http://www.who.int/water_sanitation_health/resources/stiliteraturerev/en/index.html
7
“Principles of integrated vector management,” World Health Organizations, 2010,
http://www.who.int/heli/risks/vectors/malariacontrol/en/index2.html
8
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borne disease has gained a stronghold due to the changing climate. Furthermore, chemical by
products are formed from water treatments that lead to disinfection by product(DBPs) which
causes cancer and other toxic effects in experimental animals. The main objective is to examine
the different regulations that exist and review the different water management practices and
strategies used to eliminate and prevent pathogen infested waters and find a solution to prevent
any disinfection by products that results from chemical treatments used in the water systems. The
purpose of this thesis is to elaborate the information and data results found from the research of
the different water management practice in San Diego in hope for better water policy to regulate
the levels of chemical treatment used in water systems to prevent chemical by products that can
lead to DBPs and push for the use of fluoridation in water systems to promote better public
health. The thesis will also discuss the existing water policy regulations to prevent the spread of
pathogens, vector borne diseases and potential outbreaks in water resources. A well known
policy known as the Clean Water Act (CWA) is the cornerstone of surface water quality
protection in the United States. The Clean Water Act establishes the basic structure for
regulating discharges of pollutants into the waters of the United States and regulating quality
standards for surface waters. 9 The main objective is to promote clean and safe water for the
general public health and decrease the human vulnerability to water borne infectious diseases.
Research Strategy
The main research is on the effects of water storage and system on the human
vulnerability to disease. This basic research was conducted in San Diego County. The research
has examined the different regulations and the level of contaminants if any within the water of
the water management practices in San Diego. Moreover, the research has collected data of the
9
“Summary of the Clean Water Act,” EPA, 2011, http://www.epa.gov/lawsregs/laws/cwa.html
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different levels of chlorine used in the water systems and data from research organizations on the
levels of chemical treatments that may lead to DBPs that can result in cancer. The data of the
levels of chemical treatment are collected to analyze the levels of chemical treatments used in
water systems but also to find the maximum level of chemical treatment to be used in water
system. The purpose is to eliminate potential chemical by products that can form from excessive
levels of chemical treatments that can lead to DBPs and may cause other health problems for the
community.
The research was primarily focused on the San Diego County due to the readily available
access to information and different organizations and programs within the region. Furthermore,
San Diego has a stable climate that eliminated any external affects on the study that was being
conducted in comparison to the previous studies that have been done. These have variable
climate changes that made their studies much harder to carry out and external effects such as
climate change can give inaccurate data. The data obtained from interviews with professionals
who works within the water systems regarding the practices and techniques used to keep their
water safe and clean are more accurate due to the elimination of the external effect of variable
climate change. Climate change can be a problem for water systems and storage because water
are more easily contaminated which means regulations and practices to keep the water clean
becomes more difficult and this may require higher levels of chemical treatments to clean the
water if contaminated. The research studied the effectiveness of the regulations that the San
Diego County Water districts follow to promote and maintain cleaner and safer water.
The research was primarily focused on the water regulations based off the Water Quality
Control Plan for the San Diego Basin 9, commonly known as the Basin Plan. This plan is for the
water sheds within the San Diego region. The strategy of water management for vector control
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was obtained from the County of San Diego Vector Control Program. The San Diego County
Vector Control Program (VCP) is a branch within the County of San Diego- Department of
Environmental Health. Similar to the World Health Organization’s Integral Vector Management
program, San Diego County’s VCP monitors and control vectors and the diseases they carry.
This program has been reducing and controlling mosquitoes and other vectors since the 1930s.
San Diego was a good place to conduct the research to find the different techniques and
level of chlorination that water management practices used to prevent any potential outbreaks
because it is the first county that found the mosquito born disease, West Nile Virus (WNV) in
2003. Due to this fact, it is commonly known that San Diego have potential breeding sites for
mosquitoes and can potentially be more prone to other diseases that are mosquito born such as
malaria and dengue fever.
Moreover, San Diego County was a good place to conduct the research because it was
more accessible to obtain additional data and information if needed. Interviews were conducted
with staffs that work within the different water systems in San Diego County. The staff at the
County of San Diego VCP was very friendly and was willing to answer any questions and
provide any additional data that are needed to do the research. However, interviews were hard to
find due to the lack of response from the different water system company. More then 10 requests
were sent out to different water systems within San Diego in a month but only 4 people
responded within the time increment. For this reason, the data collected from interviews were
limited and not like we hoped for.
Most of the other data and information collected are available through the water system
programs which can be obtained online. The Water Quality Control Plan for the San Diego Basin
9 shows the policy regulations and plan for better water quality conditions and its main priorities
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is in the San Diego Region. There is a San Diego Water Board’s Basin Plan Team who seem
very dedicated to the project and have a lot of information relative to the regulation updates of
the Basin plans. They review these regulations every 3 years so all the policies and requirements
will be up to date to keep the water safe and clean. Moreover, they have information regarding
the different water management practices and their efficiency in following regulations.
The main strategy to approach this research topic of the effects of water storage and
system on the human vulnerability to disease required the knowledge of water regulation and
water management practices in maintaining and sustaining clean, safe water. We had to learn and
collect the information on how the water companies plan to keep up with the regulations and deal
with contamination if necessary to prevent any potential outbreaks. It was also essential to learn
how the Water Basin Plan team’s and the Vector Control program’s strategies address an
outbreak as well as their plan on facing a potentially unknown water born infectious disease. In
addition, we had learned from Centers of Disease Control (CDC) that the use of excessive levels
of chemical treatment may also lead to health problems that result from chemical by products.
Chemical by products lead to disinfectant by product (DBPs) which can result in toxic and
cancerous effects for humans. However, experiments have been conducted on animals but there
is no current evidence that the DBPs can have the same effects on humans. All the information
collected was obtained from the programs website and other sources that are available. Many
data and statistics were available through these programs. The method was good at comparing
the different methodology used to approach the issue and learn about the existing studies that
have been done. However, it was poor due to the limited information that can be obtained. The
available data are from past years from 1993, 1996, 2005, and so forth. In fact, there may be no
information on newly emerging pathogens or vector borne diseases.
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Interviews were also conducted to get a perspective on the practices to keep the water
clean and regulations from a professional who works within each of the programs. This was
beneficial because it gives us an insight of the water systems techniques from a professional who
had been working in the program for a certain period of time and would know the different
changes and strategies that had taken place. This is also beneficial to the research because the
interviewee can give us an idea of what strategy was efficient at maintaining a clean water
systems and what failed over the time period that they had worked in the water system company.
In addition, it was good to learn from the interview the kind of approaches and strategies that the
program carries out to protect the public health from an outbreak. However, the interviews were
limited due to a difference of perspective in people’s opinions. Therefore, the data obtained is
conflicting because one person may believe one technique is better and others may disagree. The
interview data were also limited because many of the interviewee restricted from answering
certain questions regarding their water systems because they fear that these questions or
information may be used against the company by exploiting them to the media. For this reason,
many interviewees from the water systems were hesitant with answering any questions which is
probably the reason why many requests for interviews were neglected.
Findings and Analysis
Due to the extensive amount of regulations that exist we will be only focusing on the
water guidelines and regulations from World Health Organizations (WHO), the Clean Water
Act(CWA) and Title 22 of the California Code of Regulations (CCR), and The Basin Plan.
Most of the data found is recorded in 2009 and some were from previous years such as 1995 but
the regulations being reviewed was established since 1972 by Congress. There are many water
regulations that exist but we are only focusing on the water systems within San Diego County so
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we will only focus on the regulations that are abided by most of these water systems. The
research was conducted within San Diego County and we came to find that most water systems
and storage within the region follow the same regulations such as the CWA and Title 22 of CCR
for water systems and The Basin plan for Water Sheds. All the data collected are limited to these
regulations and organizations due to the large amount of available resources and regulations
regarding water systems. The quantitative data and information on the water treatments and the
disinfectant by product information are found within World Health Organizations, Department of
Public Health and the Environmental Protection Agency. These data gives us a sense of how
often the water storage and systems are being monitored and the use of different levels of
treatment in the water to disinfect contaminants. In addition, what strategies are to be taken if an
outbreak was to occur within the water systems such as how they would treat the problem and
how the water systems would notify the public regarding the water issue. All these regulations
was reviewed and consist of surveillance and monitoring of the water system to check on the
level of contaminants in the water and whether or not the water should be treated to disinfect the
contaminants.
The WHO guidelines on water safety plans consist of three main components such as
system assessment, effective operational monitoring, and management. In other words, a system
assessment is the formation of a team of experts with good understanding of the drinking water
system involved. The operational monitoring consist of surveillance of the drinking water
systems, technology used, and management all requires a comprehensive understanding of the
system and the range and magnitude of hazards that may be presented and the ability of existing
processes and infrastructure to manage actual or potential risks. This also includes the upgrade of
an existing system that was being planned and Water Safety Plans (WSPs) is collecting and
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evaluating all available relevant information available for consideration of what risks may arise
during delivery of water to the consumer.
Drinking water surveillance are mostly done by authorities responsible for drinking water
supply surveillance which may be the public health ministry or other agency and their main roles
include the public health oversight of organized drinking water supplies; public health oversight
and information support to populations without access to organized drinking water supplies
which include communities and households. The surveillance authorities also consolidate
information from diverse sources to enable understanding of overall drinking water supply
situation for a county or region as a whole as an input to the development of coherent public
health-centered policies and practices.
Lastly, the surveillance authorities also participate in the investigation, reporting and
compiling all information of outbreaks of any waterborne diseases. Most drinking water supply
surveillance program normally include processes of approval of Water Safety Plans. There are
two types of approaches to surveillances. (See Figure 1 in the Appendix)
Many water suppliers company uses the audit approach because it places the
responsibility on the drinking water supplier to provide the surveillance agency with information
regarding their system performance. Furthermore, it is believed to ensure consumers that the data
submitted are reliable because a program of announced and unannounced visits by auditors is
implemented to review documentation and records of operational practices. The unannounced
check ups provide an important means of reassuring consumers that there is true independent
verification of the activities of the water suppliers.
Through periodical surveillance, if there is a concern about the quality of drinking water
then the common approach to disinfect the water contaminants that can be easily done in
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household level is bringing water to a boil and adding sodium or hypochlorite solution to bucket
of water and allowing it to stand for 30 minutes prior too consumption. These are the standard
emergency protocols at the household level for handling infected waters. If there is
contamination in the water systems and the community can treat the water as they use it by the
emergency standard protocol at the house hold level. The water system will make a public
announcement either through the media or papers to inform the public about how to handle the
infected water until they can decontaminate the whole water system.
The most common disinfectant product used by many water system suppliers is chlorine. The
process used is chlorination of the contaminated water. Look at Figure 2 in the appendix for
more information on the specificity of the use of chlorine. Figure 2 demonstrates the handling of
contaminated water through the use of chlorine in the household level. Notice the small amount
needed to decontaminate the water. Chlorine is proven to be very effective at eliminating most
bacteria or water borne pathogens found in water. This is illustrated in Figure 3 in the appendix.
This table (Figure 3) gives a list of bacteria that can be found in water supplies and the bacteria’s
level of resistance to chlorine. Chlorine is an effective disinfectant because it is highly efficient
in removing most water born bacteria. For this reason, chlorination is the most commonly used
chemical treatment by water system to decontaminate their water. However, extreme amount of
chlorine in water can create another health issue known as disinfectant by products (DBPs). The
percentage of potential cancer results from DBPs is quite small but WHO has set guidelines for
level of chlorine in water as shown in Figure 4. Based on these findings, the four compounds are
trihalomethanes(THMs) that can result as a disinfectant by products which can result in potential
cancer is intake is excessive. From the table, Dibromochloromethane is not cancerous at all while
Bromodichloromethane has the highest risk factor. Even with small amounts of these THMs can
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lead to health illness as the amount builds up and potential result in cancer. There are no
concurrent regulations on the level of chlorine allowed to be used in the water systems because
there is no current evidence on humans that these DBPs can lead to cancerous results. Only
animals have been tested for these quantitative analysis. WHO specifically and repeatedly states
in the Guidelines(1993) that: “Where local circumstances require that a choice must be made
between meeting either microbiological guidelines or guidelines for DBPs, the microbiological
quality always take precedence, and where necessary, a chemical guideline value can be adopted
corresponding to a higher level of risk”. In fact, waterborne pathogens pose a real and immediate
threat to health when the DBP are lesser of these two evils so the USEPA have not regulate these
THMs. For this reason, the DBP are of lesser threat found in water compared to waterborne
pathogens and therefore no regulations have been made regarding this issue but these chemical
by products lead to DBPs which can lead to potential result in cancer. Therefore, excessive
amount of chemical treatment in water destroys the water pathogens but the DBPs from the
treatment can still increase the human vulnerability to disease from the water system and storage.
World Health Organization set up the primary stepping stone of water safety guidelines for other
water safety plans to take form and brought this issue to the public attention.
Fig. 4: USEPA CANCER POTENCY FACTORS
Compound
Cancer Potency Factor
Chloroform
0.0060 mg/kg/day
Bromodichloromethane
0.062 mg/kg/day
Dibromochloromethane
Not Cancerous
Bromoform
0.0079 mg/kg/day
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Figure 4: USEPA Cancer Potency Factors
Source: World Health Organization
Guidelines
In addition, San Diego County water systems follow The Clean Water Acts and Title 22
of the California Code of Regulations (CCR) proposed by the Department of Public Health and
the Environmental Protection Agency. The Clean Water Acts (CWA) establishes the basic
structure for regulating discharges of pollutants into the waters of the United States and
regulating the quality standards for surface waters. Under the CWA, Environmental Protection
Agency (EPA) has implemented pollution control programs such as setting wastewater standards
for industry. The EPA has also set water quality standards for all contaminants in surface waters.
Another similar law is the Safe Drinking Water Act (SDWA). The SDWA is the main federal
law that ensures the quality of American’s drinking water. Under the SDWA, the EPA sets
standards for drinking water quality and oversees the states, localities, and water suppliers who
implement those standards. County of San Diego Small Drinking Water system enforces the
SDWA for the rural public water systems in the San Diego County.
The Small Drinking Water system focuses on enforcing the SDWA on the ground water
system from lakes and wells to the small community. In fact, an interview was conducted with
Peter Neubauer, an Environmental Health and Safety Technician who looks over the results sent
from laboratories on the water quality in the Small Drinking Water system. The program carries
out an Audit surveillance where a third party or surveillance agency comes in to take a sample of
the water in the water systems and sends it to a state certified laboratory to get the results of the
water quality. Mr. Neubauer then looks over the results to make sure that they fit the criteria of
the SDWA and Title 22 of the CCR. If there is a contamination in the water, the laboratory will
treat the water through the process of chlorination and send Mr. Neubauer the water result before
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and after the treatment. The surveillances are carried out on a quarterly basis at the minimum but
the Small Drinking Water system carries out monthly surveillances. Peter Neubauer informed us
that the surveillances are done based on the types of service connections in the area. The
different service connections and type of water system classifications are illustrated in Figure 5
in the Appendix. Community water system surveillances are done on a monthly basis in addition
to Non-Transient Non Community water system whereas the last two on the table which is the
Transient Non-Community and State Small water system are done on a quarterly basis.
According the Peter, the surveillances run from a quarterly to monthly surveillances depending
on the types of connectors but most surveillance are done on a monthly basis.
Mr. Neubauer also notified us that rural water systems do not use fluoridation but state
wide, big service connections uses fluoridation. In fact, fluoridation is highly recommended in
water systems because fluoride promotes a better oral health and prevents tooth decay. For this
reason, the cost of fluoridation is high and many smaller rural water systems do not have
fluoridation. Nevertheless, in June of 2008, the San Diego City Council accepted an offer of
funding from the First 5 Commission of San Diego County for the purpose of fluoridating the
City’s public water supply. The California Department of Public Health Drinking Water program
has a set of guidelines for the optimal fluoride level to promote oral health.(Refer to Fig. 7 in
Appendix)
Fluoridation is commonly used statewide because of the health benefits it provides. In
San Diego County, the City of Escondido water systems and Helix Water District have
fluoridation in their water systems and the optimal fluoride concentration is about 0.8 mg/L.
(Refer to Fig. 6 in Appendix) Fluoride is one of the most common elements available on earth
and occurs naturally in water supplies throughout the state of California. Fluoride is present in
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drinking water at optimal levels has been shown to promote oral health by preventing tooth
decay. Water systems are considered fluoridated when the natural level of fluoride is greater then
0.7 parts per million (ppm). The guideline for optimal fluoride level is illustrated in figure 7.
Fig. 7: Optimal Fluoride Levels
Optimal Fluoride Level, Control Range (mg/L)
Fahrenheit
Celsius
mg/L
Low
High
50.0-53.7
10-12
1.2
1.1
1.7
53.8-58.3
12.1-14.6
1.1
1.0
1.6
58.4-63.8
14.7-17.7
1.0
0.9
1.5
63.9-70.6
17.8-21.4
0.9
0.8
1.4
70.7-79.2
21.5-26.2
0.8
0.7
1.3
79.3-90.5
26.3-32.5
0.7
0.6
1.2
Figure7: Optimal Fluoride Levels
Source: CA Dept of Public Health Drinking Water Programs
Today, about 67% of the U.S. population on public water supply has access to fluoridated water.
What strategy of approach do water systems carry out if an outbreak were to occur?
Before the data were collected we believed that there are different strategies to approach an
outbreak if one was to occur but according from the data results most of the water safety
guidelines by the World Health Organizations provide the standard method of approach to an
outbreak which most of the San Diego water system use if an outbreak was to occur. (Refer to
Fig.2 in Appendix) Most of the strategies in the WHO guidelines are compiled based on
information and effective approaches from water systems for many years. In fact, Peter from
Small Drinking Water Systems informed us that if an outbreak or contamination was to occur
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then the certified laboratories running the water quality tests will chlorinate the contaminated
water and if the outbreak is a big issue where chlorination does not work then the Small Drinking
Water System will do a press release to notify the community to boil the water before
consumption or using it and all the public water systems in the area and the consumers will be
notified. Many drinking water systems follow the same guidelines for regulations and approach.
San Diego water sheds follow another set of guidelines known as the Basin Plan. The
Basin Plan is a living document and is always subject to modification based on changing needs
and circumstances with respect to applicable laws, policies, technologies, water quality
conditions, and priorities in the San Diego Region. The surveillance and monitoring program
requires flexibility and must be able to respond to needs specified in the Basin Plan as it is
implemented and revised. Statewide water quality assessments are performed every two years to
provide timely cycle to evaluate the program’s effectiveness and make appropriate changes. The
surveillance and monitoring program provides collection and analysis of samples with the
reporting of water quality data. This includes laboratory support and quality assurance plus
storage of data for fast and systematic retrieval for future references. In addition to this, all the
data includes interpretations and evaluations which lead to recommendations for actions. An
interview was conducted with an engineering intern, Erik Flores who worked with the California
San Diego Regional Water Quality Control Board. Erik explained to us that there are 9 regions in
the CA Water Quality Control Board and his group pertained to region 9 which is from part of
San Diego down to the Mexico border up to Temecula. Surveillance is done on a monthly basis
for the locations in question. Mr. Flores notified us that construction permits were required for
any construction companies planning to work when ground broke to start construction and
regulate the water quality. These permits required the owners of these various construction sites
Sa 19
to keep the site in accordance to the permit (BMP’s, water-run off watch, water samples) all
throughout the construction. When the construction is about 95% completed then the owner
would file a notice of termination to terminate the permit. Permit would either be approved or
rejected on the lines if site maintained its Storm Water Pollution Prevention Plan included in the
permit. Mr. Flores informed us that the engineers from the California Water Quality Control
Board would visit the sites once to do their surveillance once a construction site submits their
Notice of Termination to end their permit. This is when the engineers would look for the water
quality and other things that follow under the code of the basin plans. He informed us in the
interview that permits that were open for more then a 12 month period would require the owner
of construction sites to attain and provide water samples to the engineer for further water quality
analysis.
The San Diego Regional Water Quality Control Board has up to date site monitoring by
engineers who had to follow code on permit word by word making sure once the permit was
terminated or approved, there would be no gray area that a contamination would take place on
the site. Mr. Flores informed us that the San Diego Regional Water Quality Control Board has
strict policies and workers who enforce these policies are very adamant about following the
California code.
The water guidelines of regulations from these organizations on water quality are strictly
enforced by water systems to maintain safe and clean water sites to eliminate all potential
contaminants in the water that may lead to an outbreak that can lead to serious public health
issues. The guidelines and regulations such as The Basin Plan are just regulations that are always
modified when new regulations or information comes up on technologies in surveillances or
techniques and water quality.
Sa 20
This research project was set out to determine if there is a sufficient way to keep water
storage and systems clean to prevent any public health issue that can arise from water born
pathogens in the waters or any water related issues that can contribute to a public health issue.
Although the guidelines are all subject to change with new regulations or information regarding
water quality, the potential outbreak of new water borne pathogen that we have no information
about is still a huge threat to many water systems and contributes to the human vulnerability to
diseases from water storage and systems. Furthermore, from all the data collected it is clear that
the most efficient way to prevent water borne pathogen from spreading in water systems to the
public community is through surveillance. Most water storage and systems follow the same
guidelines and the important thing is consistence surveillance of the water quality. Although
surveillance is a huge part in maintaining safe and clean water, chemical treatments such as
chlorination to clean the water systems and fluoridation to promote oral health also contributes to
safer and cleaner water for the general public.
Nonetheless, based on the data that was obtained, a major issue with maintaining water
quality is the rise of potential diseases and disinfectant by products that can result in cancer from
the significant amount of chemical treatment used such as chlorine in water systems. There are
pros and cons to chlorine because chlorine helps eliminate many viruses and bacteria that can
contaminate water but a significant amount over a period of time may lead to potential disease
and cancer later on in life. This is not a major threat to the public health in water systems but
over a period of time it will become a potential problem for the public health. There is no
regulation for the level of chemical treatment used in water systems because compared to
microbiological water borne pathogens, DBPs is a smaller threat to the public health.
Sa 21
In fact, the research is limited due to the lack of information on potentially new viruses
that we do not have enough information about and the issue of disinfection by products (DBPs).
Some water borne pathogens have become resistant to chlorine but limited information has been
found regarding this issue on how to resolve this problem. The information on DBPs is also
limited and many of the potential problems have shown to cause cancer and other toxic effects in
experimental animals but have not shown in humans yet. The scientific evidence of these DBPs
on humans is inconclusive and therefore, the USEPA have not made it a priority to make
regulations on levels of chemical treatment used in water systems. Moreover, many water
systems carry out audit surveillance which means that the water samples are sent to a certified
state laboratory to test the water quality so we have no more information on the type of
techniques that can better evaluate the water quality because many of these laboratories are not
allowed to pass out these information due to media exposure and etc.
However, as far as this research is carried out the most efficient method to keep water
storage and systems clean and safe for the general public is through consistent surveillance to
track down the water borne pathogens before it spreads and become a bigger issue. The best way
for water systems to decrease the human vulnerability to diseases is through prevention of water
borne pathogens and other water related diseases which from the data obtained is through strict
regulations, consistent surveillance, and chemical treatments. In spite of this, there is a potential
gap in the efficiency of regulations and level of chemical treatments that can be used in water
systems. Excessive amount of chemical treatments in water systems create chemical by products
which result in disinfectant by products which leads to toxic effects and potential cancer. No
regulations are made on the level of chemical treatment used and many people are unaware of
the health issues that may arise from large amount of intake of chlorinated water over a period of
Sa 22
time. More research and studies need to be conducted to find the maximum amount of chemical
that can be put into the service connections in the water systems before it can cause a chemical
by product that may lead to cancer but for the purpose of this research, we can conclude that
water storage and systems have a major effect on the human vulnerability to disease. Access to
cleaner and safer water promotes health and decreases the human vulnerability to disease.
This research project demonstrates the efficiency of regulations and guidelines to
promote clean and safe water systems for the general public health but also the lack of awareness
of potential by products resulting from chemical treatments used that can lead to other health
issues for the general public. All the water guidelines discussed are used by water systems
throughout San Diego County because the guidelines are proven to be efficient in maintaining
clean and safe water due to modifications as new regulations and information on water quality
arises over the years. The only thing to track down any problem is to look out for them before
they can spread onto the public. In other words, for water storage and systems the best strategy to
maintain clean and safe water is through prevention of an outbreak through surveillance and
process of chlorination. Therefore, all the regulations are strategies to form an efficient team with
a good understanding of the water quality and potential problems in water that may cause a threat
to the general public health if not detected. We can also conclude that water storage and system
have a major effect on the human vulnerability to disease but the regulations to keep consistent
surveillance on water system prevents an outbreak of water borne pathogens but more research
needs to be conducted for new regulations to prevent health issues that can result from DBPs that
arise from excessive amount of chemical treatments used in the water to destroy water
pathogens.
Sa 23
Appendix
Fig. 1: Types of Approaches of Surveillances
Audit Approach
Surveillance,
Direct Assessment
assessment activities,
including
Verification testing is
undertaken largely by
the supplier, with the
third party auditing
to verify compliance.
Commonly used by:
Most Drinking water
supplier
Commonly used by:
Independent testing
of water supplies.
Agency has access to
analytical facilities of
its own, with staff
trained to carry out
sampling, analysis
and sanitary
inspection.
Surveillance agency
has capacity to assess
findings and to report
to and advise
suppliers and
communities.
Community managed
drinking water
supplies where
development of inhouse verification or
third party
arrangements is
limited.
Figure 1: Types of Surveillances
Source: World Health Organization Guidelines for Water Quality
Sa 24
Figure 2: Drinking Water Disinfection by Chlorination
Method
Chlorine Compounds:
1) Unscented household
bleach (Sodium
hypochlorite
2) Sodium dischloroisocyanurate table
3) Calcium hypochlorite
What it does



Recommendations
Kills all pathogens
Effective for killing most
bacterias and viruses
Longer contact time
required to kill Giardia
cysts, especially when water
is cold

For typical room temperature
room temperature of 25°C,
minimum contact time
should be 30 min; increase
contact time for colder water

Prepare according to
instructions

Should be added to clear
water or after settling or
clarification to be most
effective

Type and typical dosage
1. Household Bleach(5%) –
4 drops per litre
2. Sodium Dichloroisocyanurate – 1 tablet(per
package)
3. Calcium Hypochlorite
(1% stock solution)- 4
drops per litre
Fig.2: Drinking water disinfection by WHO
Source; World Health Organization Guidelines for Water Safety
Figure 3: Water Borne Pathogens and Significance in Water Supplies
Pathogen
Burkholderia
pseudomallei
Campylobacter
jejuni, C. Coli
Escherichia Coli
(E. Coli)
Legionella spp.
Non-tuberculous
mycobacteria
Salmonella typhi
Health
Significance
High
Persistence in
water supplies
May multiply
Resistance to
Chlorine
Low
Relative
Infectivity
Low
High
Moderate
Low
Moderate
High
Moderate
Low
Low
High
May multiply
Low
Moderate
Low
May Multiply
High
Low
High
Moderate
Low
Low
Sa 25
Other
salmonellae
Shigella spp.
Vibrio Cholerae
High
May multiply
Low
Low
High
High
Short
Short to Long
Low
Low
Low
Low
Fig.3: Waterborne pathogens and their significance in water supplies
Source: Guidelines for Drinking Water Quality
Figure 4: USEPA CANCER POTENCY FACTORS
Cancer Potency Factor
Compound
Chloroform
0.0060 mg/kg/day
Bromodichloromethane
0.062 mg/kg/day
Dibromochloromethane
Not Cancerous
Bromoform
0.0079 mg/kg/day
Figure 4: USEPA Cancer Potency Factors
Source: World Health Organization Guidelines
Figure 5: Water Systems Classification
Water System Classifications Description
15-199 Service
Community Water System
connections used by
year long residents.
Have 200 or more
service connections
used by year long
residents are regulated
by State of CA Dept of
Public Health
Not a community water
Non-Transient Non
system and regularly
Community Water System
serves at least the same
25 persons during 6
months per year.
Example
Community with residential
homes served by a single
water system
School or Workplace
Sa 26
Transient Non-Community
Water System
State Small Water System
Non-community public
water system that does
not provide water to the
same 25 persons during
6 months per year.
5-14 service
connections and does
not regularly serve
potable water to more
than 25 individuals for
more than 60 days out
of the year.
Campground or park
Small residential community
with 10 homes served by a
single water supply
Figure 5: Water Systems Classifications
Source: County of San Diego Small Water Programs
Figure 6: California Statewide Fluoridation Table: SAN DIEGO
POPULATION
OPTIMAL
FLOURIDE
CONC.
122,000
City of
Escondido
261,000
SAN
DIEGO
WATER
SYSTEM
NAME
Helix Water
Distric
JAN FEB MAR APR MAY JUNE JULY
2010 2010 2010 2010 2010 2010 2010
AUG
2010
SEPT OCT
2010 2010
0.8 mg/L
0.84 0.85
0.84
0.82 0.80
0.82
0.84
0.86
0.86
0.34
0.8 mg/L
1.00 1.00
1.00
0.90 0.90
0.90
0.90
0..90
0.90
0.90
Figure 6: California Statewide Fluoridation Table: San Diego
Source: California Department of Public Health
Sa 27
Figure 7: Optimal Fluoride Levels
Optimal Fluoride Level, Control Range (mg/L)
Fahrenheit
Celsius
mg/L
Low
High
50.0-53.7
10-12
1.2
1.1
1.7
53.8-58.3
12.1-14.6
1.1
1.0
1.6
58.4-63.8
14.7-17.7
1.0
0.9
1.5
63.9-70.6
17.8-21.4
0.9
0.8
1.4
70.7-79.2
21.5-26.2
0.8
0.7
1.3
79.3-90.5
26.3-32.5
0.7
0.6
1.2
Figure7: Optimal Fluoride Levels
Source: CA Dept of Public Health Drinking Water Programs
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Sa 29