Polluted domestic water in Costa Rica

The aim of this project was to investigate pollution of a water resource from fertilizer used in coffee plantations and to investigate the inhabitants' willingness to pay to maintain a good quality of the drinking water. Concentrations of nitrite and nitrate in water taken from a coffee plantation were compared with water from an area not as fertilizer intense. During seven weeks groundwater was taken weekly from the coffee farm La Pequena, San Isidro. Surface water was taken weekly from the national park Los Chorros, Tacares de Grecia. Both areas are situated in the Central Valley, Costa Rica and they provide drinking water for the cities Atenas, Orotina and Alajuela. The water samples taken from La Pequena had concentrations of about 14mg/l NO3-and the samples from Los Chorros had concentrations of about 3.5 mg/l NO3-. Concentrations of nitrate in water from the coffee plantations were therefore high just as suspected. Concentration of NO2- varied as NO2- is an unstable chemical form of nitrogen, N. The mean willingness to pay, WTP, for the people interviewed was ¢1,400 per month. The WTP was examined through interviews with people living in these areas. The mean WTP increased with a higher total household income and level of education. Many of the respondents were content with the water quality but were still willing to pay more for their drinking water. Even if the opinions of the current water cost differed the mean WTP were the same. The group with confidence for the distributor had a higher mean WTP. A continuation of the project could be to take water samples at least during a year to study the seasonal variations of concentrations of nitrate and nitrite. A cost benefit analysis could also be of interest to make.