Graduation Year

2013

Document Type

Thesis

Degree

M.S.E.V.

Degree Granting Department

Civil and Environmental Engineering

Major Professor

James R. Mihelcic

Keywords

Ct Method, Developed Learning Materials, Disinfection, Rural Gravity Fed Water Systems, Sustainable Development

Abstract

Access to safe drinking water has a direct effect on improving human health and their quality of life. One country still struggling with providing access to safe drinking water to all of its population is Panama. Panama's largest indigenous group, the Ngöbe people, is disproportionately affected by lack of access to safe drinking water. One way Panama's Ministry of Health (MINSA) is attempting to increase access to safe drinking water to the Ngöbe people is by disinfecting the water already captured by rural gravity fed water systems constructed within in the Ngöbe-Bugle reservation. This is accomplished using an in-line chlorinator specifically designed to accommodate locally manufactured calcium hypochlorite tablets as a source of chlorine. However, in this study it was hypothesized that the current way MINSA is implementing the in-line chlorinator was ineffective both at educating communities on knowledge of chlorination and in chlorinating water in their water distribution systems.

This study investigated MINSA's implementation method and then compared it to a new method of implementation that was based on a newly developed disinfection field guide created by the author of this thesis. The motivation of this study was to improve this process of implementation which could lead to more effective chlorination thereby decreasing illness caused by waterborne pathogens. Each implementation method investigated attempted to disseminate knowledge of chlorination to community members through a seminar. The MINSA seminar was presented by a MINSA health practitioner and a newly developed seminar was presented by this thesis's author. A survey was developed to assess the knowledge of chlorination of community members after they attended a seminar. Results showed that community members who attended the new seminar on average answered 20 of the 22 questions of the administered survey more correctly than community members attending the MINSA seminar. Additionally, based on the average correct response of community members to survey questions, participants in the new seminar answered more questions correctly compared to participants in the MINSA seminar in all sections of the survey, 32% greater in the "General Knowledge" section; 43% greater in the "MINSA Specific" section; and 36% greater over the total survey. This higher score by new seminar participants suggests that the new seminar is better at educating community members on knowledge of chlorination.

An assessment of each implementation method to effectively chlorinate the studied community's water distribution systems was also completed. This was done by measuring the free chlorine residual of water leaving the studied community's storage tank and entering the distribution system over one week. These concentration values were multiplied by a calculated chlorine contact time of the studied system's distribution system to determine Ct values. Measured Ct values were compared to literature guidelines that provide information on what Ct values will kill commonly found waterborne pathogens in the region. Calculated Ct values above a critical literature value of 40.0 min-mg/L Cl2 were determined to be effectively chlorinating a system's water. Results showed that when using the MINSA implementation method the required Ct level of 40.0 min-mg/L Cl2 was never met at any time during the week. However when using the new implementation method, the required Ct level of 40.0 min-mg/L Cl2 was met at all points during the week except one when tested on the last day where the Ct value was found to be 35.9 min-mg/L Cl2. These results suggest the new implementation method is more effective at chlorinating rural gravity fed water systems in the region compared to the previous implementation method.

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