BOD COD and septic

[mtnspirits]

Hi all,

I've searched and searched and can't find anyone who has posted their BOD and COD numbers of their stillage/wastewater. I know it will be specific to the exact recipe used, but to get people like myself who are starting the permitting process and need to have estimates for septic system load, etc for conversations with local government and engineers, it would be insanely helpful!

So that said, could someone who is making a rum and another making whiskey, who has to dispose of the wastewater into a septic system, please share their numbers?

Thanks!

[Silk City Distillers]

Went through a similar process with our local sewerage authorities. We gave them a number of papers from academic journals that provided estimates of the BOD/COD/TSS, and then made our case based on those numbers. The wildcard is the stillage to overall wastewater ratio, and not the BOD/COD from the individual processes. Problem is, you end up with a BOD range so incredibly wide that your engineer will probably need to design for worst case. If you are holding all wastewater and stillage in holding tanks, the combined BOD would probably be in the ballpark of 500 - 5,000ppm.

To give you an idea of how much the BOD will differ by type of waste, and how much of an impact that process will make. I've seen estimates of the BOD of yeast slurry off the bottom of a fermenter at 135,000ppm. If you are using conicals and settling/pulling off yeast prior to distillation, and you can dispose of it elsewhere, you'll make a material impact on overall BOD.

Here is a good resource I found that covers the BOD by process and type, check tables 11.4 and 11.5.

http://www.biologydiscussion.com/biotechnology/waste-and-waste-water-treatment-with-diagram/8201

You'll quickly see that anything you can dispose of as solids, or even just as slop, will significantly drop your overall BOD. You'll also find that once you start to try to reduce overall water consumption, your BOD will go up.

Our sewerage wanted us to hold all wastewater, CIP, rinse water, and stillage in a holding tank, adjust for temp and pH, allow for settling, and then discharge. Which makes sense, since if we are using 10 gallons of wash/rinse water for every gallon of stillage, we drop the BOD to 1/10th of the point reading.

Check the brewery literature as well, I recall seeing some journal papers specifically on brewery septic design.

[FernandoP]

James, thank you for the post and the link.

However i am still having a heck of a time. i am trying to figure out what my TSS and BoD is, we later our beer prior to distillation, we harvest our yeast and when we dump it, we will provide to our local pig farmer along with the spent grains mixed with backset, he said he is fine with that soup/mix. that being said is there a template to help me figure out and convince our sewage department? any help here will be more than welcome

[Scrounge]

The way you wrote your post it sounds as if you are doing some distilling already? Can you not take a sample and test it to get the numbers you need? If I misunderstand you, than perhaps you could approach another distiller for a sample.

[FernandoP]

Thank you. Not distilling at all, i just presented a process for the question. Is there not a template or a standard for TSS and BOD?

[Scrounge]

There is a very in depth article about this in relation to breweries, that I found on the web somewhere when I was dealing with these issues. I know that's not much help, but ill see if I can find it again. I found it with some hours of googleness before.

[Scrounge]

Just googled "brewery wastewater treatment" and a lot of good stuff came up. A PDF from the "brewers association" had a bunch of case studies full of good info. There are engineers out there that you could consult with I'm sure. I found many around me that had designed systems for wineries and had a great deal of understanding of my situation. Hope you find what you need!

[FernandoP]

Thanks Man, I am sure i will find what I need. I have read all those documents on google, there is great information no doubt about that, but my good friends at the swage department will not consider anything other that a comparison to small distillery that makes whiskey. I do appreciate your help

[Scrounge]

Damn. Any distilleries near you that will give you a sample, to have tested. Your own case study, if you will?

[FernandoP]

looking into that right now. once i get the figures i will post them for everyone. what a pain

[Falling Rock]

You can create a sample without distilling...mash your recipe, extended cook it if deemed necessary and produce the sample, just never ferment or distill it.

[FernandoP]

Falling Rock,

Thank you for your suggestion, I thought about it, but the numbers will be off, you will be testing a solution with a cavity of say 1.07 rather than 1.01, with no left over yeast, high is sugars, etc, etc. I am dealing with a rough dude that wants to know where the sample came from. In that case testing none-alcoholic beer will be more acurate test. at the end of the day I was able to obtain some backset from a distillery, I will have that tested. I also received some numbers from another distillery who is willing to allow us to use them as reference. I will start with the numbers that the distillery provided us and see how that goes, i will keep the certified lab results if needed. again thank you for your suggestion.