.jpg)
Make It Clear: Why You Can't Just Flush and Forget
Make It Clear: Why You Can't Just Flush and Forget
Talking About Blackwater and Greywater
In this conversation, Angela and Shawn discuss the differences between blackwater and greywater. They explain that blackwater comes from toilets, sinks with garbage disposals, and dishwashers, while greywater comes from sinks, showers, and washing machines. They talk about the various ways to treat and reuse greywater, including filtration, sedimentation, biological treatment, and disinfection. They also highlight the environmental impacts of separating blackwater and greywater, such as water conservation, reduction of sewage load, and soil health. Finally, they emphasize the importance of disposing of blackwater appropriately to prevent water pollution and eutrophication.
If you have comments or questions about our podcast, you can reach us through this link. To discuss a project or talk to one of our engineers, call 800-348-9843.
Angela
Hello. Thanks for joining us today. Today it's just going to be Shawn and I. Hi, Shawn.
Shawn
Hey there, good to be back.
Angela
Yeah. And today Shawn and I are going to talk about black water and grey water. Well, first we're to talk about all types of water, what that means, what the definitions are. And then we're going to talk about black and grey. So let's just kick it off. So there are three types of water in case you didn't know, potable water, grey water,
and black water. So for the purposes of what we do, we're really going to focus on black water and grey water. So what exactly is grey water or what exactly is black water first? Black water comes from a variety of sources in your house. It comes from your toilets.
Black water would also come from a sink that has a garbage disposal. So if you have a garbage disposal that you use and you ground up food, that's considered black water. And then your dishwasher, because your dishwasher would also expel food particles. So that would be considered black water. Can you think of anything else, Shawn?
Shawn
I think that covers most of the for black water. We actually have more sources for grey water, which is surprising.
Angela
Yeah.
Angela
Right. Yes. So grey water coming from your home or your… or your business. So grey water is going to be most of the water that comes from your sinks, your shower, your dishwasher.
Shawn
Your washing machine.
Angela
You're, you're, I'm sorry, not dishwasher. I said dishwasher. I meant washing machine. In my head, I saw washing machine.
Shawn
It's alright. Well, in all honesty, dishwater actually is grey water for the most part. It depends on what it is you're washing, I guess, if you really want to get down to it. for the most part, I think they consider your dishwasher to be grey water.
Angela
Yeah.
Angela
So it depends, right? So my dishwater coming out of my dishwasher is going to be grey water because I don't believe that there's anybody in my dishwasher that comes out and scrubs my plates. So I treat my dishwasher like it is for disinfection only. So the dishes that go in the dishwasher need to be cleaned.
Shawn
Yep.
Shawn
Nope, unfortunately.
Shawn
Exactly.
Angela
And then the dishwasher disinfects them. I'm sure my dishwasher is grey water for sure. Not everybody's like that. Some people throw entire spaghetti pans. I'll never forget that commercial where they throw, you know, which one I'm talking about where they throw the spaghetti pan in there and it's, and then a miracle happens. I'm like,
Shawn
I know which one you're talking about.
Then a miracle happens.
Angela
How did that happen? That's not how that works.
Anyways.
Angela
M e and my crazy musings. So bathroom sinks, toilets, kitchen sinks, et cetera.
Angela
All right, so let's talk a little bit about grey water treatment and where you can reuse grey water.
Shawn
Just as a side note, we actually do have a webinar that we do that focuses on grey water reuse. So if you'd like additional information that might be worth listening to, and you can find that on our website. But we would love to talk about how to treat and reuse grey water here.
Angela
Mm -hmm.
Angela
Yeah. And that website is www.orenco.com. So yeah, so let's talk about the different ways to treat, treat grey water. So there's the filtration side. So in the off chance that large particles or impurities got into the grey water, you're going to want to filter those out, right? So you need some,
some sort of filtration to filter out large particles. You also need the sedimentation to allow the settling out of particles.
You can also treat it using biological treatment, so microbes to decompose the organic matter. And then there's always disinfection, so whether that be chemical or UV disinfection to kill off harmful pathogens.
Shawn
Mm -hmm. And what's interesting is that the filtration is usually a mechanical function. So you've got a physical filter that filters out those particles or the hair fibers, that kind of thing. Whereas the other two, the sedimentation and biological treatment are basically a matter of holding time in a tank where the solids will settle out. And then you have naturally occurring bacteria that will
Angela
Yeah.
Angela
Mm
Shawn
eat up any of the other organics that are in there that are maybe not meant to be in there. Not as hazardous as black water, but you know, certainly it does require a little bit of settling time and some biological activity in there. Disinfection though is another mechanical function and that usually requires either UV or chlorination or some mechanical means to disinfect the grey water.
Angela
Right. And then you can use your grey water in a variety of places, depending on the regulations of your state. So some people use it for garden irrigation, flushing toilets in your home. I've seen a number of designs that run the treated grey water back into the house and use it to flush toilets. Anything that could reduce the demand on potable water.
Shawn
Mm
Shawn
I've seen applications too of using it to wash vehicles, like in large commercial truck washes and things like that.
Angela
Mm
Facility. Yeah. Yeah, they'll treat that water and then Reuse it which is great because that uses a ton of water
Shawn
Mm
Angela
All right, so let's talk a little bit about black water. So I think that most of us are familiar with the treatment of black water. what goes into your septic tank is usually considered black water. So it is a combination of grey water and black water, and therefore it is black water. So we've talked a ton. I mean,
Shawn
Mm
Shawn
Mm -hmm. Exactly.
Angela
We have entire podcasts and webinars dedicated to how to treat black water, how to treat your wastewater on multiple levels, depending on what you...
Shawn
Yes.
Angela
what you're required to do and what you need to do. So we…
Shawn
Yeah, I think the important thing you emphasize there is that you need to check your local regulations.
Angela
Yes, yes, for treatment of black water.
Shawn
Mm
Angela
or go find our webinars and podcasts and check those out. Those will help you significantly in the treatment and disposal of black water.
Angela
So let's talk a little bit about environmental impacts. So why separate black water and grey water? Why should that even be a consideration, right? Like you can just plumb them out of your house together, treat all of it in a septic system and call it good. But there's some...
environmental things that you should take into consideration when deciding which direction you want to go. Water conservation being the first. we've talked a little bit about water scarcity and the demand on fresh water. So it is a way to reduce the demand on fresh water resources.
Right? If you don't have to use fresh water to water your garden or flush your toilets, you could use grey water to do that. And then you're saving gallons upon gallons of water, of fresh water. every time. Yeah.
Shawn
I know we're starting to see this a lot in states like California or other places that have arid climates or are prone to droughts. We're starting to see regulations showing up about reusing grey water.
Angela
Mm -hmm.
Angela
Yep. If you're on a gravity sewer, so if you're not on...
If you're not on a pressure sewer, if you're on a gravity sewer, can separating out your grey water for reuse can actually reduce the sewage load. So it can reduce the number of, if enough people were using grey water systems in some of the larger areas where overflows happen, then it would reduce the number of overflows and there would be energy savings at the treatment plants. Yeah. Yeah.
Shawn
One other thing that people don't often talk about, I know this was kind of an aha moment for me when I was reading through some of the material today, was soil health.
Angela
Right! That's a really interesting one.
Shawn
Yeah, there's nutrients in grey water that are beneficial to soil. And so reusing it for gardening or irrigation can actually help rebuild the soil structure.
Angela
Mm
Angela
So it's also really important, as we've talked about many, many times in the podcast and the webinars, to dispose of black water appropriately. And just really quick, the reason that we encourage you to dispose of black water appropriately
is water pollution. always, I...
Having grown up in this industry, it's one of those things in my head that's just like, of course, like the whole reason, and I'm sure I've said it on the podcast before, but I'm gonna say it again. The whole reason that we exist is to protect the water. We exist to protect groundwater specifically and waterways.
Shawn
Mm -hmm.
Shawn
Yes.
Angela
Although technically we discharge directly into waterways on a much less frequent basis than we discharge into the drain field that then goes into the groundwater. But it's the whole reason we do this, right? So we're protecting the drain field and we're protecting the groundwater to keep it free of pollution.
To protect the soil. So I know that we've talked about this. I think we've talked about this before, but it bears repeating that, you, your soil can only take so much. Some states require you to have a backup drain field. Some don't.
So the more that you can protect that soil and not put contaminants into that soil,
at a higher rate, the more longevity you're going to get out of it and the longer it's going to last.
Angela
And then there's eutrophication.
Angela
So the excess nutrients that can lead to algae blooms, which I know that we've also talked about in previous podcasts, the algae blooms that have happened, especially down in off the coast of Florida. Yeah. So.
Shawn
That might be one of those effects that maybe people don't always connect to black water and contamination.
Angela
Is there anything else you can think of Shawn that we want to cover?
Shawn
No, I think that that's actually a pretty good rundown of the differences between black water and grey water and what people need to know.
Angela
Yeah.
Yeah, the important things to take into consideration, what it actually means. It can get kind of confusing.
Shawn
Right.
Shawn
It can, which is actually why we would encourage you, if you have questions about this kind of thing, you can call us. Our 800 number is 1-800-348-9843. And that gets you through to our customer service line. And the folks who answer that line are really knowledgeable about what goes on. And if whoever answers the phone doesn't have an answer to the question you've got, we've got all kinds of folks that have all kinds of information about water and wastewater. And somebody is going to be able to answer your question.
Please call us with questions. We are more than happy to answer questions. We would love to talk to you about your specific situation dealing with black water, grey water, or whatever.
Angela
Yep, absolutely. All right, well, thank you, Shawn, for talking about this with me. thanks to all of you for listening.
Shawn
You bet.
