PODCASTEnvironmentally Speaking EP 8: Gray Water

October 22, 20210

Transcript: Gray Water

CLARICE: It’s never not going to be funny.MARISA: Hi, everybody. This is Environmentally Speaking. I am Marisa Desautel an attorney with a few decades of experience.

CLARICE: Hello. I’m Clarice. I’m bringing your questions and topics to the table to discuss. And today we have another listener request..

MARISA: Listener request.

CLARICE: Woo woo. We are at two. That is a record. It’s a small record but I’m taking it. We have a request to talk about gray water which is great for me because immediately after we got that in I said, what’s gray water, and brought that to you. So in light of recent depressing episodes, I am determined to make this one cheery. But without knowing what gray water is, all of you might be laughing at me.

MARISA: Well, it’s a little gauche in terms of –

CLARICE: Gauche?

MARISA: — cheeriness, I guess. Gray water is a term that refers to water that comes from your bathroom sink, shower, washing machines. It’s used water, but it doesn’t contain any sort of human excrement bacteria, does never come into contact with feces, in other words.

CLARICE: What water is coming into contact with feces? When was this a concern? I have a newfound paranoia. This is not going well for positivity. Okay. [inaudible].

MARISA: Okay. So gray water is what I just said and then black water is what you’re talking about. Anything that comes into contact with human waste is considered black water. So they’re regulated differently as you might imagine.

CLARICE: I hope.

MARISA: Yeah. In fact, interestingly enough there’s a lot of activity going on related to gray water reuse. It can contain traces of dirt and food and certain household cleaning products and it can look, quote, unquote, dirty, but it’s safe and you can reuse it as a source of irrigation for your own yard. Some people are putting in irrigation infrastructure instead of sending the gray water into the municipal wastewater treatment system or into their own private septic system and they’re using it for irrigation. In that sense all of the nutrients and material, so to speak, that’s in the gray water can become nutrients for your lawn or your garden.

[0:03:05] CLARICE: Okay. That feels like a positive reuse.

MARISA: It is. And it’s also keeping the water out of the local sewer or your septic system which reduces the chance of localized pollution, so it’s a great idea, I think. I’ve not done it, but I know that there’s a whole industry related to gray water reuse. Would you do it? Would you reroute your gray water?

CLARICE: If I knew how. If I knew how I think I’d entertain it, but I think what it would come down to is what does that look like in my home because right now I’m picturing a giant pipe going from my washing machine to my tomato plant and I don’t think that’s what it’s going to look like.

MARISA: I’m no plumber, but my guess is it would have to be an end of pipe collection system so that it starts at the edge of your house. It wouldn’t start from your appliance, I don’t think. And that would get buried underground and filtrate that way.

CLARICE: Okay. Hope for positivity is being restored.


CLARICE: What’s the difference between gray water and drinking water? Why are they called different things?

MARISA: Gray water is not meant for immediate public consumption. If gray water is not captured and reused for irrigation, let’s say, it is sent either to your septic system or to the local municipal wastewater treatment collection system where it’s then transported to a wastewater treatment plant and then it’s treated. You’ve got three – generally three, sometimes four levels of treatment at the wastewater treatment plant before the water can be reused or discharged for any reason. So you wouldn’t – you’re not going to drink your washing machine discharge, I mean, unless there was 100 bucks at stake and then maybe.

CLARICE: That’s it? All right. I’ve got higher stakes than 100 bucks.

MARISA: It’s a low bar.

CLARICE: Yeah. That’s a low bar for drinking out of my washing machine.

MARISA: We’re getting off topic.

CLARICE: So there’s a chance that – all right. So gray water, if we’re looking at a scale – what do you call – do we just call it drinking water?

MARISA: Water.

CLARICE: Just water. Okay.


CLARICE: So we’ve got water which feels most vague, but it’s the best. It’s drinkable.

MARISA: Well, that’s not true. Let me back up. Potable water – potable water, excuse me. P-o-t-a-b-l-e, that means water that’s ready and available for human consumption.

CLARICE: Okay. Does potable water come out of anywhere in our home because you’ve told me it’s not in the shower? It’s not from my appliances. Is that what’s coming out of my kitchen sink?

MARISA: Yes. And your refrigerator water conveyance.

CLARICE: Oh, okay. All right.

[0:05:57] MARISA: Yeah. That’s all hooked up to your drinking water supply. So if you are connected to municipal drinking water or if you’ve got a private well on your property it’s all – the connections to the house, you know, result in the same type of drinking water quality.

CLARICE: I’m really happy I asked that. I got very nervous about my kitchen sink. So we’ve got your potable water, we have your gray water, and then we have your black water which hopefully we never actually have. We just flush and avoid at all costs.

MARISA: Yes. And it gets treated.

CLARICE: And gray water being gray can move up to potable but can also deteriorate down to black?

MARISA: If it’s commingled with black water, yes. But generally they’re not – I guess it also depends on what type of wastewater treatment system we’re talking about. Septic systems collect both black water and gray water. Municipal wastewater treatment systems should have a separated storm water and black water system infrastructure. So, yes, they can get commingled depending on what type of system we’re talking about.

CLARICE: And going back to the idea of recycling and reusing gray water. Is this something that you would need a special municipal permit? Is this something that towns are encouraging, or is this all a little new and exciting?

MARISA: The question about permitting, I don’t know. That’s something that you’d want to check with your local zoning permitting office in whatever town or city you live in. Depending on what they say, digging up your yard, I don’t know. There might be a square footage element there that I’m not familiar with. But it’s not like you need to get D.E.M. involved. They don’t oversee irrigation unless there’s some type of drawdown for a local body of water that is considered a state body of water. So you could in theory – let’s say that there is a municipal permitting requirement. If you got permission from the city or town that you’re in, you could in a weekend go out and put in your own gray water reuse irrigation system.

CLARICE: Oh, that feels like a quick turnaround time.

MARISA: Yeah. Yeah.

CLARICE: An easy way to recycle and, you know, give a second life to gray water. Such a bummer name.

MARISA: Well, yeah. I mean, gray water versus black water, now you know the difference.

CLARICE: I’m hoping we rename it to like second use water.


CLARICE: Do some new PR for it. All right. Any big takeaways or anything you’d want to leave us with about gray water?

[0:09:05] MARISA: You know, the only other topic that I get a lot of questions about and it’s an important question, but it’s also been sort of awkward to try to figure out how to fill in people about this information. But D.E.M. the Rhode Island Department of Environmental Management has a very user-friendly website. And on that website they have an entire section devoted to their office of water resources. And there is a ton of information on here including information available to the public in a database that you can search.

And why is this important. Well, let’s say you’re buying a house or you’re selling your house or you just are curious about the age of a septic system on someone else’s property. You can go into this database, put in whatever information that you have and see or take a look at the documents and materials that D.E.M. is providing on the database. So just kind of a random factoid there. Some people know about it. Some people don’t. In terms of gray water, black water, onsite wastewater treatment systems would be the program that you’d look up to try to get to that database.

CLARICE: All right. So before you go out there and dig up your yard and start connecting all sorts of Dr. Seuss pipes to your house, check the D.E.M. website and check your municipality for any sort of zoning codes.

MARISA: Yeah. Good advice.

CLARICE: All right. So on that we will see you guys next week. If you have any questions or topics you’d want to submit, please e-mail at Help@DesautelESQ.com. See ya.

MARISA: Thank you. Bye.

Leave a Reply