MANTECH received an update from a New England Utility this morning about a 2x spike in COD on their source water. They draw surface water from a river which is a tributary to the Connecticut River. The utility runs online PeCOD alongside traditional technologies TOC and UV254, which also detected the spike in organics but to a lesser degree than was detected by PeCOD. The values of the spike are shown below:
- PeCOD: ~9 mg/L pre-storm, ~19 mg/L post-storm
- TOC: ~4.5 mg/L pre-storm, ~6.0 mg/L post-storm
- UV254: ~0.2 pre-storm, ~0.35 post storm
The local and upstream areas are currently experiencing scattered thunderstorms, which are known to contribute extra organics to river systems through surface runoff. This spike on influent COD is valuable information to the WTP operators, as they can now adjust and optimize their coagulation based on the concentration of organics that need to be removed.
See the picture below for a screenshot of the spike, detected and displayed in real-time: