Bacteria modeling


I am attempting to set up a fecal coliform bacteria model in EE 7.1 and am having some issues. In setting up the model, I zero’d out all bacteria concentrations in cwqsr21.inp and set the initial condition to be zero. However, after the first time step, I get bacteria in my domain.

I also tried using the Lake Water Quality Example. I turned on fcoli and with zero inputs and initial conditions I get bacteria in the domain after the first time step with this example also.

I am wondering if I need to use the wqpsl files instead of the cwqsr21 file, but I suspect there may be something else I am missing. Is there an example available where fcoli is turned on?

Thanks very much for any help you can provide.

Hello Jacob,

There are few questions I would like to ask you first. Are you interested in just bacteria modeling or you are using full water quality model with bacteria turned on ? If you are just interested in bacteria modeling, then you could use dye concentration with decay rate which will give good representation of bacteria in the system.

I would recommend doing operation on different time series inside Efdc Explorer. If you change concentration in cwqsr*.inp and then save the data from EE, then EE would overwrite what’s stored in cwqsr*.inp. So, it is important to understand how this process works.

If you are using water quality model, then you need to first understand what type of loading you are using in the model. Original EFDC model only allowed to users to have the mass loading, however, the DSI EFDC model allows the users to have either mass loading or concentration loading. So, regarding the water quality files, first understand the model input is essential.

If you are using mass loading in the EFDC model, then the concentrations would be stored in wqpslc.inp.

Hope it helps.

Janesh Devkota