Toxic module in EFDC 8.4

Hello, I’m Soobin Kim.I’ve had a problem with using toxic module in EFDC 8.4ver.First, I don’t know the exact meaning of parameters.Could you give us some materials regarding toxic parameter and equation?Second, in the multiple toxic caseWhen I typed value of toxic_2’s initial condition, value of toxic_1 was changed.Could you check this and how can I deal with this problem?Sincerely,SB.

Thanks for your question, Soobin. We have materials that covers toxics from a training conducted in October 2017. This is available on Youtube, here: Contaminated Sediment Transport and Partioning Theory (Part 1) - YouTube can learn more about the toxics theory from our knowledge base: Regarding multiple toxics, we haven’t seen any issue such as you describe and I have been unable to reproduce your issue. Please provide more information including a link to a video clip of the issue if possible. There are also several models on our website that you can download and look at to understand the module better:

Thank you for your reply.The video and the materials are very useful!@ By the way, there’s no ‘unit’ of parameter of basic equations in the material that you given. Could you let me know unit of basic equations?Regarding Multiple toxic case, I attach video clip of my computer’s EFDC error.video_1) I change initial condition by assigning the value.video_2) I change initial condition by the step: toxic option>modify initial condition.@ Firstly, I assigned toxic_1 and toxic_2 as 100 and 200 each in both video_1&2, but the problem is that toxic_1 became 200 and toxic_2 became 0 as you can see in the video clip.I checked this problem with another computer(EFDC 8.2) and it worked out(video_1 case) but video_2 case didn’t work.My computer(EFDC 8.4) still have this kind of problem(video_1&2 case).Best regards,SB

Units for all parameters are provided in the Appendix A here: for sending the video. I understand the issue now, we will have a look at this and correct it in the next update.