Graduation Year

2011

Document Type

Dissertation

Degree

Ph.D.

Degree Granting Department

Civil and Environmental Engineering

Major Professor

Maya A. Trotz

Keywords

Bolivia, Guyana, household survey, potable water, public health, Trinidad

Abstract

Water quality and availability are important issues in many developing countries where portions of populations still lack access to potable water. Throughout the English-speaking Caribbean and parts of Latin America, households and businesses invest in water supply systems even when they are connected to and pay for water services from a private or state owned provider. Inconsistent supplies of water from the water companies have led many people to invest in storage tanks which, if operated correctly, can provide water throughout the day even when the supply from the main is low or zero. While these individual systems help to guarantee a more constant supply of water, they may impact water quality when it does reach the household tap. The tanks could become breeding grounds for vectors of human disease and may also affect the concentrations of bacteria, heavy metals and organics in the water.

The goal of this research was to understand how households use water storage tanks and determine the effect of these tanks and the individual practices on water quality. Target plots were used to visualize linkages between water quality parameters and household surveys of localized water practices and perception on water quality.

The study focused on three field sites: Siparia, Trinidad and Tobago, Region 4 Subset in Guyana, and Villa Litoral, Bolivia. Convenience sampling was used to administer surveys to households in the rural areas of Siparia (39), Region 4 Subset (40), and Villa Litoral (57). The Region 4 Subset is comprised of two rural areas, Mon Repos and Mocha, and Georgetown, the country's capital.

Black, high-density polyethylene (HDPE) tanks and water storage drums are predominantly used in the field sites within Siparia and Region 4 Subset, while cement tanks, drums, and jerry cans are used in Villa Litoral. The average age of household water storage devices was 4-10 years in Siparia and Region 4 Subset, and 0- 3 years in Villa Litoral. These devices were found on various elevations to accommodate piped connection, indoor pumping, and rainwater catchment. Cleaning frequency of tanks in Siparia was every few months, while in Region 4 Subset it varied from weekly to every few months. In Villa Litoral 26.3% of the population surveyed cleaned weekly and 38.6% cleaned annually. Disinfection of water sources was practiced by 30% of residents in Siparia and 60% of residents in the Region 4 Subset. While disinfection was practiced, issues with frequency and correct dosage led to inadequate disinfection. Eighty-four percent of households in Siparia and 50% of households in Region 4 Subset disinfected on a monthly or quarterly basis. Of the households that did disinfect, the bleach and/or disinfectant used was allowed to mix for at least 30 minutes in 50% of households in Siparia and 91.6% of households in the Region 4 Subset. Disinfection was not practiced by the majority of households in Villa Litoral. With regards to health, 15% of households in Region 4 Subset and 40.4% in Villa Litoral reported recent waterborne illnesses among house members.

Water samples were taken from households in Siparia (24), Region 4 Subset (40), and Villa Litoral (26). The majority of households in all three communities relied on piped water from their respective main pump. Those who were not connected to piped water relied on rain water. In the Region 4 Subset, 18% of samples tested positive for fecal coliform and 45% for total coliform. In Villa Litoral, 85% of samples tested positive for fecal coliform and 100% for total coliform. The majority of samples from all three communities exceeded the WHO guideline values for lead (0.01 mg/L) and iron (0.3 mg/L). This was most likely due to the material used in the household plumbing and distribution pipe infrastructure as these could leach.

Five indicators (chemical and biological water quality, reach of risk, storage device, female involvement, and household belief) were conveniently projected on target plots to link the results from water quality assessments with reported household practices and beliefs. The greatest risk factors seen were poor water quality and household beliefs like the security of water storage containers and safety of stored water, perceived water description and pressure, and access to water safety media.

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