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Partnerships for enhanced engagement in research (PEER) SCIENCE
Cycle 1 (2011 Deadline)

The fate of enteric pathogens in fluids, fields, and food products: on-farm solutions for the safe reclimation of water and nutrients from sewage   

PI: Maria de la Mercedes Iriarte Puña, Center for Water and Environmental Sanitation, Universidad Mayor de San Simon (UMSS)
US Partner: James Mihelcic, University of South Florida (USF)
Project Dates: May 2012 - May 2014

Project Overview

Domestic sewage constitutes an important source of water and nutrients for agriculture, especially for water-scarce regions such as Cochabamba, Bolivia, where it is used to irrigate more than 2,000 hectares of crop fields. However, this wastewater contains high concentrations of enteric pathogens, which present serious public health risks to farmers, their families, and consumers of crops. In order to protect public health, effective measures must be taken to reduce exposure to these pathogens. Current policy regulates the quality of wastewater as it leaves the municipal treatment plant. However, the reduction of pathogens can also occur after the treatment plant and on the farm, with engineered social and ecological buffers and health protection measures such as on-farm water storage, indigenous farming techniques, strategic irrigation, and crop-washing. The incorporation of these additional measures extends the limits of conventional wastewater treatment to include stakeholders such as farmers and consumers, effectively making sanitation a more community-managed process.

   Bolivia Partnership Picture 1
Taking crop and water samples along the Rocha River, where some farmers irrigate indirectly with
untreated wastewater
   Bolivia Partnership Picture 1A
Microscopic observation of parasites from the effluence from the Rocha River samples
This project looks to measure concentrations of human pathogens in water, soil, and crop samples from six community farms where wastewater is used for irrigation. It will also quantify the differences in pathogen concentrations in the presence and absence of on-farm health protection measures. Specifically, these researchers will measure the specific human pathogens that are responsible for emerging and endemic infectious diseases such as cryptosporidiosis, giardiasis, and helminthiasis. The sampling plan has been designed to measure the effects of different on-farm storage methods, irrigation techniques, and crop washing practices on the survival of pathogens. They will also measure the correlation of the presence of pathogens with traditional water quality indicators such as Escherichia coli. The Center for Water and Environmental Sanitation has developed expertise in laboratory methodologies to detect the above-mentioned pathogens in environmental samples. Their role in this project will be to lead the laboratory analysis component and to provide graduate students who will assist in data collection and field sampling. The U.S. collaborating partner at USF will assist with the design of data collection and sampling techniques in the field. USF graduate students will also collaborate academically with their Bolivian counterparts to collectively publish material and disseminate the results of this study to a broader global audience.
Summary of Recent Activities
During the last quarter of 2013, the research team conducted their final sampling at the wastewater treatment plants in Punata and Arani. The samples were obtained from the anaerobic lagoon inlet and from the outlet of the treatment plant; physicochemical and microbiological parameter analysis was performed at the laboratory. During November 20 - 22, 2013, the team presented two papers at the 15th Bolivarian Congress of Sanitary and Environmental Engineering, and the papers were published in the conference proceedings. After the conference, the research team conducted several workshops to disseminate their research results to local community stakeholders. The Punata workshop, which was held December 4, 2013, was attended not only by students, faculty, research staff, but also by representatives of the mayor’s office, municipal water company (AMAPAS), and farmers who were using the irrigation system with treated wastewater from the system in Punata. The discussion with the community members focused on improvements that could be made to the Punata treatment plant. The AMAPAS representatives noted that the company envisions improvements but needs technical support. A concern was expressed by a representative of the supervisory board about possible risks of cysticercosis spreading to cattle, after finding infected rabbits bred in this area. Water sampling and analysis suggested that the contamination may be spreading through wastewater coming from the treatment plant, which could potentially hurt the livestock industry in the region. AMAPAS finally affirmed its commitment to improving the treatment plant, with technical support from the university. Another workshop was held in Arani, where the team presented the results collected from the local wastewater treatment plant. The meeting took place at a school located next to the plant. The workshop was attended by farmers and irrigators who used the treated wastewater, as well as representatives from the mayor’s office. At the end of the presentation, community members indicated that they generally perform maintenance activities without any technical guidance and that the research team’s support and guidance was very helpful. The representatives from the mayor’s office noted that aside from the planned improvements to the treatment plan, their office has approved the construction of a new treatment plant in a lower area of the municipality, which would mean that in the future no residual wastewater would be discharged to the current wastewater treatment plant being studied by the research team. During the upcoming three months, the research team will conduct evaluation of lettuce irrigated, treated, and washed with wastewater. A workshop to disseminate the results of the project will be held with the Rocha River communities, and work on writing papers for publication will also continue. The project is anticipated to be concluded by the end of May 2014, at which time the final data will have been processed and the final project report will be prepared.

  Bolivia Partnership Picture 2 Sampling point at the entrance of the Arani Wastewater Treatment Plant,
photo courtesy of Dr. Iriarte.

  Bolivia Partnership Picture 3   Sampling point, effluent of the Punata Wastewater Treatment Plant,
photo courtesy of Dr. Iriarte.

1-358 Workshop in Punata
Presentation at the church in Punata,  photo courtesy of Dr. Iriarte.

1-358 workshop in Arani
Workshop at a school in Arani, photo courtesy of Dr. Iriarte.

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