Assess pesticides and fertiliser residuals in the wetland ecosystem

The quality of wetland water is important to sustain life. Overpopulation and land encroachment is degrading the water quality. In this scenario, it is vital to measure the water quality to assess the residuals of fertilizer and pesticides for its long term conservation. If anybody has some expertise in this area, please help with your experience and learning.We are doing a project on this line of assessing the pesticides and fertiliser residuals in the wetland ecosystem. .