Septic Tank Vs Sewer: Which Is Better

You pull the chain, push the button or depress the lever and it all swirls away. So long as everything is working fine, who really thinks about where the waste goes? Well, if you’re building a new home, you should. There are two options to weigh out for your sewage systems but which is best? Septic Tank Vs Sewer: let’s get into it.

Septic Tanks and Sewers

For most of us, the question of septic tank vs sewer never comes up: if you live in the sticks, you’re probably using a septic system, if you’re in a city your home is almost certainly connected to the public sewer network.

Sometimes, however, you do get the chance to choose. If you’re building your home and have enough space, a septic tank may be the right option for you.

What Is A Septic Tank?

A septic tank is exactly what it sounds like: a large tank, usually buried underground (though above ground versions do exist) in which sewage is collected and, through bacterial action, decomposes before draining away as water.

While this may sound unpleasant, with proper maintenance, it’s actually very sanitary, environmentally friendly and efficient.

Advantages Of A Septic Tank

Septic systems come with a few major advantages over a connection to a public sewer system that make them worth considering for anyone who has the option.

  • Initial Costs: Thanks to being self-contained, septic tanks are relatively cheap to install. Most municipalities will charge you for a connection on top of your planning, materials and labor costs. This fee doesn’t apply if there’s no connection to make.
  • Independence From Municipal Sewer Systems: While there’s certainly something to be said for the convenience of a public sewer system, there are costs involved that can be saved with a septic tank. Monthly or quarterly fees and taxes are required to connect.
  • Environmental Considerations: While you may not think it at first glance, septic tanks are actually very gentle on the environment. Not only is the discharge absolutely fine for the local water-table, thanks to the natural filtration process, there’s far less risk of untreated sewage discharging into local bodies of water than with public systems.

Disadvantages of a Septic Tank

Of course, as with everything involved in planning a house-build, there are trade-offs to be made when opting for a septic tank system over a connection to the public sewers.

  • Regular Maintenance: While you may avoid regular taxes, there are costs associated with running a septic tank. Not only will you probably require the system to be pumped out every 4-5 years, it’s a good idea to dose your tank with bacterial boosters regularly.
  • Potential For System Failure: While septic tanks are a very old technology and are usually highly effective, there is always the risk of failure, leaks and damage. Without municipal involvement, this will be down to you to rectify and it may wipe out any savings you’ve made.
  • Space Considerations: When you consider how much time is spent lining up for the bathroom in the average family, you can see why septic tanks require a reasonably spacious property. It’s always best to go for a system that is slightly larger than you expect to need.

What Is A Public Sewer?

At it’s most basic, a public sewer system is a network of pipes and tunnels which conducts human waste from homes and businesses to a treatment facility.

There are a plethora of good reasons why they’ve been in use for almost as long as we’ve lived in cities. That being said, they also have their downsides.

Advantages of Public Sewers

  • Convenience: When it comes to flush and forget, the public system certainly has the edge. With the local authorities taking charge of your sewage needs, once the connection is made you basically never have to think about it again.
  • Minimal Maintenance: With only a tiny section of the network being on your property, and that being a relatively short run of pipe, there’s not a lot that can go wrong on your end. Save for the occasional blocked line, the municipal authorities handle most of the required maintenance.
  • Capacity: As they’re built to cover wide areas with large populations, it’s unlikely whatever waste you flush will stress the system too much.

Disadvantages of Public Sewers

  • Ongoing costs: Connecting to the public sewer system will bring with it a monthly or quarterly fee to cover your contributions to maintenance, repairs and expansion.
  • Reliance On Municipal Infrastructure: Of course, just because you’re paying your fees for your connection is no guarantee that they’re being used for the upkeep. Older systems, such as those in established neighborhoods can often show their age.
  • Potential For Failure: Thankfully it’s rare but sometimes failures do happen. When this occurs in a public sewer system it can impact swathes of a city all at the same time.

Septic Tank Vs Sewer: Cost Comparison

When considering which system suits your needs best, cost is always going to be a factor. When debating the issue of septic tank vs sewer there’s both the initial outlay and the on-going costs to think about.

Initial Costs

These will vary considerably for both types of sewage systems depending on the particulars of your home. A larger septic tank will cost more than a smaller one and a longer run of sewage pipe will be more expensive than a short one.

Both require excavations and engineers to install but as a general rule of thumb there are some savings to be made by not having to pay a connection fee for the public sewer if you opt for a septic tank.

Environmental Impacts

Naturally, cost is far from the only thing to consider if you’re presented with a choice. The impact on the environment is every bit as important.

In terms of impact on your surroundings and the natural world, septic tanks (assuming they’re properly maintained in good working order) actually have the edge here.

The bacterial decomposition of the waste in a septic system produces relatively clean water, which while we wouldn’t suggest drinking it, can help to replenish the local water-table.

Public waste treatment plants are usually fairly efficient too but the chemicals which are used can present problems. There is also the threat of untreated sewage entering bodies of water via run-off during heavy rain.

Suitability and Other Considerations

Of course, while we’d all like to save a few dollars and be as eco-friendly as possible, there are other serious considerations when choosing the sewer system for homes.

Location and Land Requirements

For the vast majority of homes, the choice is no choice at all. Location plays probably the biggest role in determining whether a home has a septic tank or a connection to the municipal system.

The general rule here is: rural homes will have a tank and those in cities and towns will be linked into the municipal system. Exceptions may be found in smaller towns or if you’ve got a particularly large property.

Septic tanks can be quite large and you need the space to ensure they’re fully buried. This requires a decent sized property to even enter into consideration in most circumstances.

While you could potentially squeeze a smaller system into the average suburban yard, the questions around capacity make it rarely worth consideration.

Regulations and Restrictions

Saving the biggest consideration for last: do your local planning and health departments allow septic tanks to be put in place at all?

Many urban locations will force the issue via building codes and public health regulations. While septic tanks, when properly looked after, are clean and efficient, there is simply no way to effectively enforce the caveat of “properly looked after” on a city-sized population.

If you consider the potential public health impacts of dozens of failed, broken or leaking septic tanks in an area the size of a city block, you can see why the codes were put in place.


Ultimately, which sewer system suits your home best will depend on your own circumstances but don’t write off either option without some serious thought.