Residential Plumbing Differences: City Sewer vs Septic Tanks

Everybody uses the bathroom, yet nobody wants to talk about sewage when it comes to residential plumbing issues. In this article, we’re tackling the taboo by breaking down the differences between septic tanks and city sewage lines.

How Does a Septic Tank Work?

A septic tank is a large container that is usually made of plastic, concrete, fiberglass or PVC. It is used as a primary treatment for wastewater that comes from toilets, showers and sinks.

Recently installed septic tanks are now often divided into two chambers, separated by a wall with small openings about halfway between the top and bottom of the tank. This allows solids and liquids to separate. When wastewater enters the tank, solids are trapped in the first chamber, while liquids can move into the second chamber unhindered. In the first tank, solids are broken down by anaerobic bacteria in a process that does not require oxygen, in order to decrease the volume of the chamber. Once solids have been broken down, the liquid is able to move into the second chamber, where it is cleaned further.

Once wastewater has gone through the two chambers of a septic tank, it is deposited into a septic drain field or leech field. Here, any leftover impurities are trapped by the soil, while water is allowed to drain into the ground.

How Do You Maintain a Septic Tank?

Unfortunately, anaerobic bacteria are not able to break down all of the solids found in domestic wastewater, and thus solid materials start to build up in septic tanks over time. Depending on load, the average septic tank should be drained about once every five or so years. In order to do so, a plumber has to pump fecal sludge out of the tank using a specialized vacuum truck.

Other maintenance issues often arise from improper disposal of non-biodegradable waste. When things like condoms, feminine hygiene products or nappies are flushed down a toilet, they can cause septic tanks to fill rapidly and clog up, as anaerobic bacteria are unable to break down inorganic materials. When this happens, a specialized plumber will have to open the tank and ascertain how bad the problem is. More often than not, the plumber will have to call a vacuum truck to remove the inorganic material. If you only notice a blockage after the tank starts to overflow, call a plumber immediately.

The Differences Between a Septic Tank and City Sewage: Should I Hire a Specialist?

For residents who do not have a septic tank, the most common alternative is a connection to city sewage pipes. In these instances, residential sewage is flushed into communal sewage lines that drain into large sewage facilities that are able to treat the waste. These lines should, technically, never block up.

When a blockage occurs in a home that is connected to city sewage lines, a plumber can usually flush the drains with a high-pressure water jet in order to break up the blockage. If this is not possible, a qualified plumber will have to remove whatever is blocking the pipes.

However, if a blockage occurs in a home that uses a septic tank, it is best to call a plumber that specializes in tank-related issues. Because septic tanks operate differently to city sewage lines, plumbers have to have intimate knowledge of the workings of a septic tank before trying to fix any plumbing issues. For example, it is important that a healthy level of anaerobic bacteria is kept alive during any maintenance or repair jobs, otherwise the functioning of the tank will be compromised and it will start to clog up again. Moreover, a tank specialist will know that fixing a septic tank involves more than just fixing the tank itself – tank-related issues can also effect the leech field, or can be caused by the field itself.

Consequently, due to the delicate nature of septic tanks and their ecosystems, it is best to call one of Art Plumbing, Air Conditioning & Electric’s tank specialists to assist you with tank-related plumbing issues you may be experiencing.