Anaerobic Vs Aerobic Septic Systems: What’s the Difference?

Welcome to the wonderful world of septic systems! Today, we’re diving into the thrilling, sometimes smelly, science behind how these essential systems work.

It’s a tale of two methods: anaerobic and aerobic. Anaerobic is your no-frills, old reliable, while aerobic is the tech-savvy cousin that’s all about speed and efficiency.

They both get the job done, but in very different ways. So grab your metaphorical shovel, and let’s unearth the gritty details of these waste-busting wonders.

And who knows? By the end, you might just be a septic system aficionado yourself.

Unraveling the Anaerobic Septic System

Anaerobic septic systems are pretty popular. They’re straightforward, cost-effective, and rely on bacteria to break down waste. It’s a natural process!

The Breakdown Process

Here’s how it works: wastewater from your home enters the septic tank, which separates the waste into three layers. Picture a wastewater sandwich.

The top layer, or “scum,” is fats, oils, and grease. The middle is liquid effluent. At the bottom, you’ve got “sludge,” the heavy stuff.

Here come the bacteria! They feast on the scum and sludge, breaking solids into gases, liquids, and simpler solids. That’s your wastewater partly treated, with much less solid waste.

Two-Step Tango: Separation and Digestion

It’s a two-stage dance with anaerobic systems. First up, the “separation” stage. Solids go to the bottom, oils, and grease float up.

The middle layer? That’s what heads out to the drain field.

Stage two, “digestion.” Bacteria chomp away at the solid waste, turning it into simpler stuff. But they can’t eat it all, so some undigested sludge stays put.

This is a video diagram of an anaerobic septic tank.

Weighing Up Anaerobic Systems: The Good, the Bad

Anaerobic Systems: The Upside

Anaerobic systems are simple, sturdy creatures. Fewer parts mean fewer things can go wrong. Plus, they’re generally cheaper to install than their aerobic counterparts.

They don’t need constant power, either, because they use natural processes.

But What About the Downsides?

These systems aren’t as thorough as aerobic ones, so they need a bigger drain field. You’ll need to pump the septic tank now and then to get rid of undigested sludge.

Plus, go easy on strong cleaners—they can harm the helpful bacteria.

Anaerobic Systems: The Perfect Fit?

Are you a suburban or rural homeowner without access to public sewage? An anaerobic system might be right up your alley.

They also work well in places where power can be unreliable.

Anaerobic Systems: The Long Game

To keep your anaerobic system humming for years (we’re talking 20 to 40!), regular maintenance is key.

That means regular check-ups and pumping out that stubborn sludge.

Be careful what you flush, too. Too many harsh chemicals or non-decomposable items can put a wrench in the works, leading to a system upset—or worse, a breakdown.

Diving into How Aerobic Septic Systems Work

Aerobic septic systems are like the advanced cousin of the septic world. They use air (aerobic means ‘requiring air’) to supercharge the waste breakdown process.

The Wastewater Treatment in an Aerobic System

Like anaerobic systems, wastewater in an aerobic system starts in a pre-treatment tank. This is where solids settle, and the first breakdown begins.

The party really starts in the aeration chamber, though. Here, air is pumped in, which wakes up the aerobic bacteria to chomp away on the waste.

Three Stages of Magic: Pre-Treatment, Aeration, Clarification

In the pre-treatment stage, wastewater does its layered thing. Solids sink, and fats float.

Next up is the aeration stage. This is the aerobic system’s showstopper. Air meets wastewater, kick-starting a bacteria boom and super-fast waste breakdown.

Finally, in the clarification stage, clear water parts ways from the remaining solids. Those solids head back to the aeration chamber for another go-round.

The water, meanwhile, usually gets a disinfection treatment before being let out.

This is a video diagram of the typical aerobic system.

Aerobic Systems: What’s Great and What’s Not

Cheers for Aerobic Systems

Aerobic systems are like the overachievers of septic systems. They treat waste more thoroughly and do it faster.

They’re also adaptable, suiting various soil conditions where anaerobic systems might falter.

Jeers for Aerobic Systems

But all that glitters isn’t gold. Aerobic systems can be heavy on the wallet, both in installation and upkeep. They also need constant power to keep the air flowing.

Plus, because they have more mechanical parts, they need professional check-ups more often.

Aerobic Systems: When Do They Shine?

Aerobic systems come to the rescue when anaerobic ones won’t cut it. Maybe the soil isn’t right, or the property’s too small, or there’s a nearby water body.

High-occupancy places or businesses with high wastewater output? Aerobic systems are your hero.

The Long Haul with Aerobic Systems

Want your aerobic system to last? Regular professional check-ups are non-negotiable.

That means making sure the aeration and disinfection systems are in top shape and giving the mechanical parts a good clean.

Aerobic septic systems also require periodic pumping, although the frequency might be less than that of anaerobic systems.

If you treat them right, aerobic systems can keep ticking for 15 to 25 years. But don’t forget: what you put in matters.

Avoid flooding the system with harsh chemicals or non-biodegradable items. That can lead to all sorts of biological and mechanical headaches.

Aerobic vs Anaerobic: The Showdown

Compare and Contrast: How They Work

Sure, both aerobic and anaerobic septic systems have the same end goal: treating wastewater. But they go about it in very different ways.

Anaerobic systems rely on good old Mother Nature, using natural bacteria in a one-step, slow-and-steady process.

On the flip side, aerobic systems bring a bit of human ingenuity, using a multi-stage process with a breath of fresh air to get those bacteria breaking down waste in record time.

Speed and Efficiency: Who Wins?

If it’s a race, aerobic systems take the gold. They’re faster and provide a higher level of treatment, thanks to all that oxygen helping the bacteria work their magic.

Dollars and Sense: Weighing the Costs

On the money front, anaerobic systems are the budget-friendly choice. Their simple design and lack of mechanical parts make them cheaper to install.

Plus, they don’t need electricity, so running costs are low.

Aerobic systems, on the other hand, are the pricier option. They have a higher upfront cost because of the more complex mechanics and need for electricity.

And to keep those mechanics in tip-top shape, you’ll need regular professional check-ups.

Planet Earth: The Environmental Impact

When it comes to being green, both systems have their pros and cons. Anaerobic systems win on the energy front—they have a smaller carbon footprint.

But they require larger drain fields, and the water they let out isn’t as clean.

Aerobic systems use more energy, but the trade-off is cleaner water, making them a good choice in environmentally sensitive spots.

But remember, they need electricity to run, upping their carbon footprint.

So, when choosing between aerobic and anaerobic, it’s all about striking the right balance. You’ll need to weigh up environmental factors, system efficiency, and cost.

Septic System Choice Checklist: Aerobic vs Anaerobic

Deciding between an aerobic and anaerobic septic system? It’s more than just a coin toss. You need to think about your property, budget, and local rules.

So let’s break it down.

It’s All About Location: Soil Type and Property Size

First, consider what you’re working with—your soil and space. Sandy or clayey soil? Anaerobic might not cut it.

Less space or high water table? Aerobic could be your best bet.

All Rules Apply: Local Regulations and Permits

Local regulations aren’t just there for fun—they matter. Some places might give anaerobic systems a thumbs-down due to environmental issues or soil conditions.

Always check local rules before deciding.

Counting Costs: Money and Maintenance

Let’s talk money. Anaerobic systems are the budget-friendly option, but they need regular pumping.

Aerobic systems are pricier but offer thorough waste treatment, which might be worth the investment for you.

The Power of Pro Advice

Septic system installation can be a bit tricky, and there’s a lot to think about. That’s why it’s a smart move to bring in the pros.

They can check out your property, do soil tests, and guide you through local rules. Plus, they’ll give you the lowdown on maintaining your system so it lasts longer and works better.

Remember, choosing between an aerobic or anaerobic system isn’t just a personal choice—it impacts the environment and the future value of your property.

So take your time, weigh up the pros and cons, and make a choice you’re confident about.


And there you have it! We’ve dug into the dirty details of aerobic and anaerobic septic systems.

From the natural process of the anaerobic to the supercharged efficiency of the aerobic, both systems have their own charms and challenges.

Remember, choosing the right one isn’t just about budget or speed—it’s about your land, local rules, and what works best for you and the environment.

So take your time, weigh your options, and don’t forget to ask the pros for advice. Happy waste managing, everyone! Until next time, keep it clean, green, and serene.

Leave a Comment

Share to...