Looknorth Canada funded Arctus and Hatfield to develop a Chlorophyll a retrieval algorithm over an Artic lakes, Lac de Gras (NWT), using high resolution remote sensing data (Sentinel 2 and Landsat 8). The objective of this project was to evaluate the feasibility of retrieving Chl-a concentrations in ultra-oligotrophic lakes in northern Canada, which are highly sensitive to increased nutrient loading and climate change. To address the objective, Lac de Gras, Northwest Territories, Canada, was selected as a large ultra-oligotrophic lake. The concentrations of Chl-a in this lake are spatially variable as a result of nutrient-rich effluent discharged by the diamond mine operated by Diavik Diamond Mines (2012) Inc. (Diavik). To fulfill regulatory requirements and manage water quality impacts, Lac de Gras is subject to annual monitoring based on in situ measurements. Based on an extensive in situ data set, this project assessed the feasibility of monitoring Chl-a concentration in Lac De Gras using Sentinel 2, Landsat 8, and Landsat 7 remote sensing data. Despite some limitation in radiometric validation, we demonstrate the benefit of using satellite optical remote sensing for the water monitoring in the Arctic. Validation effort such as radiometric in situ measurement needs to be done in order to understand signal variability measured by satellites in Arctic.