ASSESSING WATER QUALITY IN DOMINICAL, COSTA RICA: PRESENT QUALITY AND APPLICATIONS FOR DETERMINING FUTURE IMPACTS DUE TO TOURISM DEVELOPMENT

Water quality was analyzed in Dominical, Costa Rica, a small rapidly developing town on the Pacific coast. Historically, there are no baseline data against which to evaluate current water quality. Thus, a primary goal of this study was to assess current water quality in Dominical and provide a data set against which the impacts of further tourism development can be compared. Logistical concerns placed limits on the analytical methods which could be employed at the field site. A modified National Sanitation Foundation (NSF) water quality index (WQI), consisting of 9 parameters, was used to quantify water quality in the municipal and surface water resources in Dominical and the surrounding areas. WQI results ranged from 46-67, indicating bad to medium water quality. The municipal water supply is currently not affected by development due to the up-gradient location of the source spring. Nonetheless, the low WQI score of the municipal water supply indicates that other watershed factors have degraded the municipal supply. Presence/absence testing indicates that fecal coliform is ubiquitous in all water sources, thereby placing uncertainty in the microbiological safety of the water for consumption and recreational contact. Although other indicators of water quality including, nitrates and dissolved oxygen, were within acceptable standards for drinking water, they often approached the advisable limits. Thus, the low WQI scores reflect an overall degradation of water quality including widespread fecal coliform contamination. Our data suggest that water resources closest to the development have been impacted the greatest. Continued monitoring will be critical as tourism development intensifies.