From 2018 to 2023, ministry staff collected water quality samples year-round from seven rivers that flow into Lake Ontario in the Greater Toronto Area. They did this to understand the amount of pollutants and other materials that these rivers carry into the lake. Parameters measured The dataset contains information on the water quality of these rivers, including: - Nutrients - Major ions - Suspended solids - Heavy metals - Microbial indicators Sample types The dataset has two types of water samples: 1. Discrete samples collected at a specific time 2. Composite samples collected over periods of time