Inside the Tank

In this episode, we dig into one of our favorite (and most important) topics: septic tanks. We’re joined by Jessy Tucker, Senior System Engineer at Orenco, to break down why septic tanks matter, how they work, and what really happens inside them. From watertight design and biology to everyday habits that help—or hurt—system performance, we keep the science practical and the conversation easy to follow.

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.

Transcript

00:08

Hello and welcome to Make It Clear, a conversational podcast about all things related to water and wastewater.  I'm your host, Angela Bounds, and I'm joined by my co-host, Shawn Rapp.  In each episode, we'll tackle a relevant topic with facts and expert opinions and make things clear.  

Angela: Hello and thank you for joining us again. Today, we're going to talk about one of our favorite topics.  Septic tanks.

00:37

I know it probably feels like we talk about septic tanks a lot and that's because we do because septic tanks are the foundation of the system. Yes. And it's a really important topic to continue to talk about. There was a period of time where we didn't like as an organization, we had the impression that maybe most of the population that we speak to knew about septic tanks. And what you learn really quickly is that when you stop talking about something, the questions still come up.

01:06

Yes. So we will talk about septic tanks until the cows come home. All right. So today, joining us, of course, Shawn is here. 

Shawn: Yes, I'm here. 

Angela: As always. And we're joined today by Jessy Tucker. Hi, Jessy. 

Jessy: Hello. Thanks for having me. 

Angela: Yeah. Do you want to tell our listeners what you do here at Orenco? 

Jessy: Absolutely. I'm on the systems engineering team. I'm a senior system engineer. I’ve been here about eight and a half years.

01:34

So I help provide support to designers and make sure they're designing with our equipment to criteria. 

Angela: Yeah. So she's here today and she's going to talk with us about septic tanks. So let's jump in. Why do you need a septic tank and why is it important? 

Jessy: That's a great question. Well, in my mind, I think it's a matter of public health and protecting the world's water. I mean, after all, that's what a Orenco is for. 

Angela: That's why we're here. 

Jessy: And you know, it may not always be something people think about. Like, where does the waste go?

02:04

It's not this glamorous topic where you meet a stranger in an airplane and you're like, Hey, this is talking about septic tanks. And where does the poo go? But the truth is not everyone has access to a city sewer. So those of us out, you know, in the boonies or outside of town, you know, what are we doing with that waste? So it's important we educate about why we need a septic tank, why it's important, why they exist. And I'll say like, I grew up out of town, so I was on a septic tank.

02:32

Did I know that as a kid? No, I had no idea. (Angela: Right.) You know, we just had like these set of rules that I had to follow and until I got older I had no idea why. Like don't put that down the drain. 

Angela: Don't put that down. 

Jessy: Be careful. Like don't do your laundry all day back-to-back, you know?  And so I may not have understood it immediately, but as I got older I understood, oh, it's to protect our septic system. (Angela: Yeah.) And we have it to protect our water.

02:56

You know, it's also going to protect your downstream components too, which is something I didn't really think about until probably post college. Like what's its real role.  But you know, why is it important? It is because it's protecting all that stuff downstream. It's protecting your groundwater, but it's also that protection for your drain field or whatever your infrastructure is following it. And without that septic tank, your solids would be heading down there. So your septic tank is containing those solids effectively. 

Angela: Keep it all enclosed. 

Jessy: Exactly. 

Angela: Right.

03:26

Make sure that everything is safe.  It's funny because we all know that I grew up here and grew up with those rules even though we lived in town.  So my children have grown up not using the garbage disposal no matter if we lived in town or out of town. 

Shawn: Right? 

Jessy: I know that. 

Angela: Right? You just don't use the garbage disposal. Well, why? Well, throw the- 

Jessy: Put it in trash. 

Angela: food away. Put in it the trash can.

03:54

Do you really want to get into how things decompose in the dump and how the food will help that? You need biologics? Like we can get into that. 

Jessy: Absolutely. Yeah. My current house does not have a garbage disposal. I grew up with one also, but we never used it. I don't even know what it was for, honestly. 

Angela: I was actually, I just moved out of town and my house has a sand filter on it. And I was floored

04:24

when I saw the garbage disposal. And I was like, what? How dare they? Why would they put a garbage disposal in it? So indignant. My kids are like, you're not going to use it anyways. They pumped your tank. You're not going to use the garbage disposal. It's fine. Don't worry. All right. So what do you think makes a good septic tank? 

Jessy: Well, I think a good septic tank isn't just a tank.

04:53

it's the design that goes into that tank. And in my mind, it's carefully designed. So whether that's done by a designer or a regulator or whoever figured out the recommendations for your location, the application, a lot of thought was put into that particular tank on site. And there's a lot of different components that come into play. And the first one that comes to mind is one that hits home, like it's brought up a lot at Orenco. You want a watertight tank. Like most important, watertight, right?

05:22

And Orenco has been great about educating designers and users about that.  But you know, why would that be important? Right? (Angela: Yeah). So you can either have water coming into your tank or you can have waste leaving your tank.  Both are not good. 

Angela: Both are bad. 

Jessy: Both are very bad. For different reasons, of course. So when it comes in, infiltration, right? So that's when your groundwater or your rainwater is coming in, that's diluting your waste. It's sending more to your drain field or your treatment, whatever's next.

05:51

Or worse, or just as bad, if your tank is leaking, it's coming out, that is getting into your groundwater that's going into the area surrounding your tank. 

Angela: Untreated wastewater. 

Jessy: Exactly.  So not good. So watertight construction, definitely my number one pick for what makes a good septic tank.  And then another element in my mind would be adequate volume because the volume in that tank is, it's essential to letting the biology do its job and work, right?

06:20

And everywhere has different recommendations. We have our own. There's plenty developed. So you can just use your local guidance to figure out what that volume looks like. But, what's important is you have that residence time for your solids to settle and for the biology to occur. So that's really what you need.  So watertight, adequate volume. Those are my top two. Now we didn't really get into like, your septic tank gravity? Is it pumped? Whether it's gravity or not.

06:47

Maybe let's talk about that. So if it's gravity, your outlet really should have a filter. If it doesn't, it really should, right? So the filter's gonna help protect your drain field. But if it has a pump, mean that pump should also have a filter preceding before the effluent reaches that anyways.  And I think that's something to consider. But another point I wanted to bring up was your tank should have adequate access for your operator.  And there should also be safety considerations. 

Angela: Yeah. 

Shawn: Sure. 

07:14

Jessy: So, you should have your access over critical locations, whether it be your inlet, your outlet. If you have a baffle, the crossover tee, there should be an access there. And any access that's open, it should have some sort of secondary safety barrier.  Whether that's an Orenco Tank Shield or an Infiltrator Guardian, you need some sort of safety device. 

Angela: Absolutely. Every, every tank should have a secondary safety device.  Period. End of discussion. 

Jessy: Absolutely. 

Angela: Put it on there.

07:44

If it did not come with one, find one. 

Jessy: And you can always add it after the fact. 

Angela: Call us and you can retrofit your tank...  

Jessy: Absolutely. 

Angela: With a secondary safety device, like the Tank Shield or the Guardian.  Either one, don't care. 

Shawn: You know, it's really interesting when you think about septic tanks, you don't think about how much thought and engineering actually went into that box. (Angela:Yeah.) It's just a concrete box, right? But it's so much more than just a concrete box.

08:12

Angela: Well, even as we're talking about this and  you know, a lot of people will say well if the water comes in (Shawn: mm-hmm) like big deal just like you're just gonna send it to a different place, right and there's a lot of science that goes into it has gone into building this,  you know, wastewater treatment  system. (Shawn: Mm-hmm.) And like if you send all the water out to the drain field that drain field

08:42

becomes hydraulically overloaded because it was designed to handle a certain amount of liquid put on it. 

Shawn: There's a lot of scientific rationale as to why. 

Angela: There's a lot of scientific rationale. It's not… your bugs have to work in certain environments and they eat this and don't eat that. And there's just a lot of science that goes into it. (Jessy: Absolutely.) All right. So why don't you describe for us

09:10

what happens to the wastewater when it enters the septic tank? 

Jessy: Well, when your wastewater enters the tank, your flow is going to slow down dramatically, right?  Your tank is much larger than in that pipe. So your velocity is going to drop, your flows are going to spread out.  And at this point, your solids are going to separate by density and your layering is going to start to occur. So your heavier solids are going to sink towards the bottom, forming that sludge layer.

09:36

Whereas your lighter materials like your fats, your oils, your grease, those are gonna start to float to the top forming your scum layer. And then in time we get that nice middle layer forming. So everything's coming in the tank, your biology's starting to kick off, your primary treatment is occurring through that physical separation and this biological activity.  And these naturally occurring anaerobic bacteria are gonna break down the organic material, they're gonna reduce your BOD.

10:03

and that solids volume. So that's where that real magic is happening.  And so after your liquid level rises, that effluent either is going to flow out your tank by gravity or maybe be pumped out. 

Angela: Interesting. So what biological processes happen inside the tank? I guess I kind of alluded to the bugs just a minute ago, didn't I?  

Jessy: Yeah.  So inside the tank, there's that naturally occurring bacteria, those bugs we keep talking about.

10:27

And I call them bugs quite a bit because that's just the simple way to put it. Well…

Angela: It’s what people understand.  

Jessy: It's just… it's a fun way to put it. They’re bugs. They’re microorganisms. So these microorganisms, they essentially just eat that biological waste and they turn it into that sludge, which is what's settling down to the bottom.  And as these bugs digest and break down that material, they're going to release gas like your methane, your carbon dioxide, hydrogen sulfide, et cetera. And that's that byproduct. So,

10:54

while your septic tank isn't fully treating the wastewater, it's getting it to a point where the BOD is getting reduced by that 50 % and with the effluent filter, your total suspended solids by about 90%, which in turn is gonna improve the treatment downstream, whether that's in your drain field or a secondary treatment process. It's gonna increase its longevity. 

Angela: Yeah. So what kind of microorganisms live in a septic tank? 

Jessy: So we've been alluding to bugs, right? So there's different kinds of bugs in this microbial community.

11:24

There's three main ones I'll highlight on.  There's your anaerobic bacteria, which I lightly brought up. They're the guys breaking down that organic matter into your acids, your gasses, your simpler compounds.  But then there's these two other guys that come into the picture. There's the methanogens and the fermentative bacteria, and they need each other to both operate smoothly and work together. So the methanogenic bacteria, they convert byproducts into methane, as you may have guessed by their name, and carbon dioxide.  And in turn,

11:52

they're stabilizing those solids and they're finishing up that digestion process. So they're what making it able to settle to the bottom.  And when they do their job right, your pH is gonna get closer to neutral, your gas production is gonna be a little bit slower and steadier instead of like a violent bubbling.  And your solids are gonna lose that volatile organic content. And that's how that sludge is really becoming denser and less prone to floating.

12:19

So this is where these fermentative guys come into the picture. They're converting the complex organics into smaller molecules that other microbes in the tank can use. So they're equally important and they're critical to get these processes started, but they need the methanogens also. So what's important is the tank just gives enough time for the biology to work together. And cause I mean, it's all connected.  They all work together to like digest those solids.

12:46

they're gonna reduce the volume of that and they maintain the separation between the layers in the tank as well. 

Angela: Yeah, it's a symbiotic relationship. 

Jessy: Absolutely. 

Angela: It's really important that you keep that balance. 

Jessy: Yes, and they need each other to do their job for sure. 

Angela: As we all do. 

Shawn: Right? 

Jessy: Yeah, so as long as their environment stays stable, they'll stay healthy. 

Angela: So what happens when the biology is off balance or these processes go off balance?

13:15

Jessy: Well, you'll see your treatment diminish, right? So common activities that can disrupt it. Great example would be like laundry day, right? So you do laundry back-to-back all day. You're still in your house. Maybe you're running your dishwasher. Maybe you decide to wash your dog on the same day. An event like this would be an upset to the biology because you're sending so much extra flow and it's the diluted flow. It's not necessarily just waste. It's like gray water, right?

13:44

So you're overloading your tank. So in an instance like that, it would be much better to try and spread some of that out throughout the week, give your bugs a break, right? (Angela: Yes.) Because you want to feed them, but that's like pulling out a fire hose and throwing it at them. 

Angela: And we're saying we suggest that happens and fully understand that life also happens. (Jessy: Right.) But if you can spread it out. 

Jessy: And yeah, exactly. Just spread it out. Another big one would be harsh chemicals.  Right. So we're talking about biology, but it's microorganisms.

14:14

Anything that's toxic is a no-go, right? You're just going to wipe out that biology. So like bleach, your solvents, disinfectants. A great example we have in the do's and don'ts is floor cleaners. So when you get done cleaning your floor, might be tempted to dump that down your toilet or the drain, but you really shouldn't. Another big one on the same line of toxic things would be like pharmaceuticals.  Unused medications should not be flushed down your toilet, right?

14:43

The bugs, the biology, they don't need your medications. So good rule of thumb, if anything's toxic or flammable, that shouldn't go down your drain. That's going to harm the biology.  And if you have any question in it, maybe just don't. 

Angela: Maybe just don't. 

Jessy: Yeah, maybe just don't. If you're unsure, maybe just play it safe. 

Angela: There's a document that we have created called Wastewater Do's and Don'ts.  we've talked about it before on the podcast. It's on our website. You can find it

15:11

if you just search for Orenco Wastewater Do's and Don'ts, it'll, it'll be your top hit, hopefully. And in that document, it talks a lot about what to put down, what not to put down. And all of those recommendations are in an effort to keep things balanced.  

Jessy: Absolutely. 

Shawn: It does talk about some alternatives as well. 

Angela: Yes. Because you can use cleaner cleaners. 

Jessy: Right.

15:37

Angela: Right, less toxic. 

Jessy: Non-toxic cleaners. 

Angela: Non-toxic, there are non-toxic cleaners out there that you can use safely.  So, when things get imbalanced, I think one of the most important things that you can do is return to normal. 

Jessy: Absolutely. 

Angela: Just return to normal use. 

Jessy: Yeah, and actually, that brings up a great point. know, your septic failure, doesn't happen overnight. (Angela: No.) It doesn't happen because

16:06

I had a house cleaner that dumped cleaner down my toilet or, oh I did all my laundry this Saturday. Like it's continual system abuse or a change of habits over time in that lack of maintenance. 

Angela: Yes. If you watch it and pay attention, it'll come, they're very resilient. (Jessy: Yes.) They're very, very resilient and life happens. Like living out in the country now we're on a rural water system and

16:36

I got a phone call because we had increased use and they thought that we had a leaky fixture. And I had to say, no, actually my brother and his whole family stayed at my house for the last week of December. And that's why there was increased use because the water company is just saying, right, increased use. But I'm certain that that week with five extra people in the house did a number

17:04

on the tank. The tank's not used to that.  It's not accustomed to that many people being in the house right now, but it's coming back.  It's going to come back. It's not alarming. 

Shawn: No, they're very resilient. 

Angela: It'll be fine. The biology will be fine. I may have needed to alter some things. If there were five more people living in the house on a consistent basis, then you would need to talk about it. But for the most part, the systems are resilient, but it's like you said, you can't…

17:34

It's not a single event that usually occurs. can be. It can be. We've seen systems fail, like painters. Painters will come in, paint an entire house and clean the brushes and everything in the sinks. And I've seen a system that was severely affected by that.

18:00

Those are anomalous.  

Jessy: Yeah, that's not something that happens every day. 

Angela: That's not something that happens every day. For the most part. (Jessy: Right.) They're resilient and they just bounce back.  All right, anything else you think that we need to know, Jessy?  

Jessy: I don't know. I think you guys had some great questions for us. (Angela: Good.) I'm glad you guys talk about septic tanks a lot. I know it's not something that's glamorous.  If you're out of this industry, you probably don't put a second thought to it, but...

18:27

the simplicity of it, you know, it's pretty incredible really. 

Angela: Yeah. Us septic nerds do a lot of things, I will… I am that person that if I am out in public, unfortunately, and see a septic system, I will go over and stand on the lid.  I will go over and inspect whatever's over there.  

Shawn: See which control panel they're using. 

Angela: Yeah. I'll see what control panel they're using. I'll look at what system they have installed. I'll,

18:57

you know, step on the lid, see how that's doing.  I won't open it necessarily.  If someone leaves their bolts off, there's a good… yeah. If someone leaves, if I see a system out in the wild with no bolts on it, just to plug this, I will absolutely go inside of an establishment and be like, excuse me.  Whoever serviced your septic system didn't put the bolts on. You need to get bolts

19:26

and you need to put them on. It is a safety hazard.  And there is a possibility I will lift that lid and just see what's going on in there. 

Shawn: Yeah. 

Angela: Yeah, that's right. 

Jessy: I've definitely been on vacation and be like, Oh, that's an Orenco lid. Oh, look, there's an Orenco panel. 

Shawn: I think we're also guilty of that.  

Angela: Yeah.  Oh, driving up and down the I-5 corridor, like you can literally stop to use the restroom and in any city,

19:56

There's potentially an Orenco system right there. It's an interesting thing. All right. Well, thank you so much, Jessy, for coming in and talking to us and helping us keep this topic alive. 

Jessy: Absolutely. Thank you so much for having me. 

Angela: Yeah. And thank you all for listening.  

We want to thank you again for joining us today.  Before you go, don't forget to subscribe where you listen to podcasts so you're notified when new episodes are posted. Also, you can leave your comments or suggestions through the contact link on our website www.orenco.com.  Until next time, have a great day!