Grantee Research Project Results

Drivers of Fecal Contamination in the Environment of Urban and Rural Areas of Tanzania and the Associated Impact on Ecological Health

EPA Grant Number: F13F31255
Title: Drivers of Fecal Contamination in the Environment of Urban and Rural Areas of Tanzania and the Associated Impact on Ecological Health
Investigators: Harris, Michael
Institution: Stanford University
EPA Project Officer: Lee, Sonja
Project Period: September 22, 2014 through September 22, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Fellowship - Environmental Science , Academic Fellowships

Objective:

Human services (such as sanitation infrastructure) and ecosystem services (such as a soil’s ability to absorb and process nutrients and pathogens) are integral to society’s welfare. When the human services are
not adequate, the development and population growth of a region will degrade the natural ecosystem services. The processes involved in this cycle of degradation are complex and involve many pathways within the natural and built environments. This research will attempt to understand drivers of microbial contamination of the environment in rural and urban areas of a rapidly developing region and how various sanitation infrastructure systems affect relevant ecosystem services.

Approach:

Water quality indicators associated with sanitation systems, specifically fecal indicator bacteria, will be measured in both soil and water reservoirs for a prolonged sampling period across a region with various stages of development and population density. Sampling will occur at multiple frequencies and during both the wet and dry seasons to determine the natural variability due to weather and climate. Drivers of environmental change will be investigated with regard to the various reservoirs of sanitation-related contaminants by recording (1) observational characteristics of the sampling environment, such as animal and human presence, visible wetness and sun exposure, and (2) larger area characteristics, such as sanitation service type and coverage, impermeable surface coverage and population density.

Expected Results:

The relationship between soil contamination, water pollution and development is still unclear, yet the correlations are expected to be positive. Climate and weather have unclear influences, as fecal contamination of drinking water sources is correlated with increased rainfall in some regions and with the dry season in other places. Increased soil moisture should result in increased survival of pathogens and bacteria, while increased rainfall should result in increased runoff and associated washout of contaminants from the soil surface. Increased human activity, such as found in an urban area or rural market area, is expected to correlate with increased contamination and more frequent reloading of contaminants. The quality of sanitation infrastructure should have a direct influence on the concentrations of fecal-related contaminants, such that inadequate sanitation infrastructure and open defecation result in an increase in environmental contamination leading to potential degradation of ecosystem services and a decrease in human well-being.

Supplemental Keywords:

ecosystem services, fecal indicator bacteria, sanitation

Progress and Final Reports:

2015

Final