Graduation Year


Document Type




Degree Name

Doctor of Public Health (Dr.PH.)

Degree Granting Department

Global Health

Major Professor

Ricardo Izurieta, M.D., Dr.P.H.

Committee Member

Azliyati Azizan, Ph.D.

Committee Member

Jaime Corvin, Ph.D

Committee Member

Thomas Crisman, Ph.D.


coliforms, drinking water, indicators, recreational water, septic tank, water quality


Understanding the relationships between human health, water, sanitation, and environmental health is a requirement to understanding the challenges that face researchers when it comes to addressing global health relating to water and sanitation. Access to improved water and sanitation is not only a precondition to health, but to all aspects of daily living. Target 7.C of the Millennium Development Goals (MDGs) addresses worldwide disparities in access to improved water and sanitation by calling for the reduction in "half of the proportion of people without sustainable access to safe drinking water and sanitation by 2015". Over 90% of the population of Costa Rica has access to improved water and sanitation, thus exceeding the water and sanitation targets for the Millennium Development Goals (MDGs). Despite having access to water and sanitation, little is known whether communities are only interested in access or if quality and quantity of water and sanitation systems are as equally as important. Target 7.c of the MDGs does not include water quality in the definition of safe water. Furthermore, the use of the words "safe" and "improved" in the target are often interchanged and can be misleading, especially when considering the impact of water quality on population health. In Costa Rica, households in the Nandamojo watershed have access to improved water and sanitation; it is unclear whether the drinking water is potable with respect to Costa Rican and the World Health Organization (WHO) water quality standards. The impact of leaking septic systems on human and environmental health is also unknown.

Illnesses associated with recreational water are an increasing public health problem, causing a great burden of disease in bathers every year. The global health impact of infectious diseases associated with recreational water exposure has been estimated at around three million disability-adjusted life years (DALYs) per year, resulting in an estimated economic loss of around twelve billion dollars per year. Fecal and chemical contamination of recreational water is a concern, especially in areas of non-point source pollution. Health-based water monitoring is often conducted in recreational waters as a tool for assessing risk. In Costa Rica, recreational water sampling is conducted at coastal beach areas only, neglecting other surface waters used by residents and tourists. Community perspectives regarding recreational water use and the associated risks are limited. Understanding these perspectives will enable public health professionals to better target community needs, such as education and to address the concerns of participating communities.

This dissertation was divided into three chapters. The first chapter explored community perceptions on improved water and sanitation, the second chapter assessed community water systems and the risk of acute diarrheal disease, and the third chapter captured community perceptions on recreational water use and the risk of waterborne illness. Methodologies for water sampling and analyses were used to assess water quality, while household interviews and focus groups were conducted to capture qualitative data.

Results from the first chapter showed participants had positive perceptions towards their improved water and sanitation systems. Household interviews revealed almost half of the

respondents had concerns with water quality, while less than 25% did not think their septic tanks leaked or overflowed during rain events. Focus group discussions revealed common themes. Participants identified water quality, health, pipes, water scarcity, odors, insects, and overflow/infiltration of water and sanitation to be important issues. Participants revealed convenience, improved health and safety and the lack of odors to be themes directly related to customer satisfaction of improved water and sanitation.

Results from the second study revealed 57% of household samples had total coliform bacteria above the Costa Rican standard for safe drinking water exceeding the single standard limit of zero, while 61% failed the World Health Organization standard for fecal coliforms exceeding the single standard limit of zero. AGII was identified in 41 of the 378 household residents (11%). The odds ratio for AGII among household residents with a water sample positive for total coliforms was 1.88 (0.81-3.17). Fecal coliforms were statistically significant for those with AGII (OR = 3.19, 1.43-7.12). Regression modeling analyses revealed individuals with AGII and household drinking water positive for fecal coliforms to be statistically significant (OR = 3.01, 1.33 - 6.84), while other covariates (total coliforms, gender, treated water, and families) also had odds ratios greater than one, but were not significant.

Results from the third chapter indicated most respondents felt recreational water sources, such as streams and rivers were contaminated with human, animal, and chemical wastes. Focus group participants also stated they did not use inland waters for recreational purposes for these reasons. However, many did admit using marine water for recreational bathing and felt these areas were not contaminated. These beliefs did coincide with the water quality results from freshwater sources, but not marine sources. Fecal coliform contamination was widespread throughout the watershed in freshwater sources. Marine water samples failed the World Health Organization (WHO) and Costa Rican recreational water standards for fecal coliform and enterococci in 36% and 6% of the samples, respectively.

The overall results of this dissertation suggest that the definitions of improved water and sanitation have to include, at a minimum, water quality, water quantity, proper construction and containment of storage tanks, and oversight and maintenance of these systems. Given the challenges facing communities in the Nandamojo watershed regarding water and sanitation, it is essential for scientists, researchers, policy makers, water committees, health providers, and community members to design and implement strategies in water resource management and proper waste management. Communities and water committees would also be best served if they worked with government agencies to conduct concurrent testing of both recreational water and drinking water, especially since both them target many of the same parameters.