I am looking for any water dataset for pollutant or contaminant in water (like mercury, arsenic, etc) and I need the dataset include data of ph, do, ec, orp, and temperature as well. Where I can find those things? I haven't found a relevant dataset.
You can obtain some data about water quality and contaminant from USGS Water Quality databases:
It contains many water quality characteristics for the US territory - these are large and diverse data sets. If you're not familiar with the formats & databases, consider paying someone to do the data wra