Nitrate

The nitrate levels for all the sites are relatively constant and lie within the acceptable range of below 50mg/L (following WHO's guidelines).

Nitrate concentration is low as the source, water that flows into the grease trap, contains a low concentration of nitrate as well. This is probably because the detergents or soaps used had a low concentration of nitrate in them.

There were prevalent nitrate content in the next 4 sites. However, having Tank b4 Pond as a control, we know that the concentrations are normal and probably a natural-occurring concentration in the environment.