Another day od pesticide sampling. Every 15 days we return here to sample the river using Chemcatcher passive sampling devices and replace the old Chemcatcher with new ones. The sampling strategy consist of 5 Chemcatcher per catchment which were divided as follows, three of them go into the water, one is field blank and the last one is fabrication blank. The three that are placed in the water are designed to catch 18 acid herbicides, while a field blank is exposed to the sampling location during the deployment at the field site for the purpose of accounting for any contaminants that accumulate in the Chemcatcher samplers. The last one is a fabrication black, never opened to show how the Chemcatcher is when comes from the laboratory, used for reference.