Water Quality in Arequipa

Water quality in Arequipa is largely unknown. Many rivers have unwanted contamination both from natural and manmade sources. Dr. Edwin Bocardo and Ing. Jose Pinto are using several metrics to study water quality in Arequipa. While heavy metals is a large water quality concern in the area, their studies mainly focus on detecting contamination of water from organic sources, like wastewater and agricultural runoff.

Benthic Macroinvertebrate Sampling

Dr. Bocardo has led a team of students to take benthic macroinvertebrate samples in both the Chili and Colca Rivers in Arequipa. Utilizing the Andean Biotic Index (ABI), these macroinvertebrates can be used as indicators of water quality of these rivers. These macroinvertebrates are most sensitive to organic changes in water quality, thus they indicate presence of organic contaminants, like wastewater effluents from communities along the rivers. More about macroinvertebrates and how they indicate water quality can be found in a fact sheet.

Simplified Water Quality Index

Water quality data can be difficult to interpret, especially because there are so many potential contaminants to consider, each of which has different ranges that are acceptable. Scientists have developed water quality indexes, which use an equation to summarize several different water quality characteristics into a single value between 0 and 100, where 100 is Excellent water quality. Many different indexes exist, and each includes different contaminants and has a unique euqation for calculating the index value. The SWM team is analyzing several indexes to determine which is most suitable for Arequipa and potentially developing one that is adapted to be regionally-specific.