SEWER BACKFLOW PREVENTER
One of the biggest developments in sanitation over the last two hundred years has been the emergence of the modern sewer system. Whereas previously each home was responsible for its own sewage disposal, vast structures are now in place that connect each home to a communal sewer system. Wastewater and sewage leave each individual home and are taken away and treated by the local authority. While this system is extremely efficient – working so well most of us don’t often give it much thought – there are times when it can go wrong.
In some areas, particularly those that are prone to flooding, water can very quickly enter the sewage system. If this water gets too much, it overwhelms the pipes, causing water to back up long each of the individual input pipes. Where this gets particularly bad is when it leads to the pipes flooding back into individual homes. This leads to sewage entering homes, causing the sewage system to work in exactly the reverse way than it was designed.
THIS HAS TWO MAIN PROBLEMS:
it can be extremely difficult to repair a flood caused by sewage water; most of what the water touches will need to be disposed of, and repair costs can very quickly rise to the tens of thousands of dollars.
the biohazard nature of sewage is such that flooding can cause health hazards. On top of this, sewage waste is extremely unpleasant to deal with. All in all, sewage backflow is something to avoid at all costs.
Luckily, the development of sewer backflow preventers can provide some level of protection for a home. This guide will explore exactly what is meant by a sewer backflow preventer, the different options available, and the steps you can take to minimize the risk of sewage entering your home.
WHAT IS A SEWER BACKFLOW PREVENTER?
A sewer backflow preventer – as the name suggests – is a device that will keep sewage from back along the sewer system into your home. They are surprisingly simple devices, which function as a valve. After being installed in your sewer pipes, they are hinged at one end.
As water and sewage leave your home, the valve will lie flat, allowing for the liquid to pass over it. However, if and when there is backflow, the valve will rise up, sealing off the pipe and, effectively, causing a blockage. This will force the pressure to be relieved elsewhere, rather than allowing sewage to flow up into your home.
In some parts of the country, a sewer backflow preventer is known as a ‘backwater valve’ – these two terms are used totally interchangeably and refer to precisely the same piece of equipment.
These devices are not new inventions, and it’s worth checking to see if there is one already installed in your home. If so, you may need to maintain or replace it, since they do have limited shelf-lives (see the section below on maintenance); however, it’s likely that a little bit of care and attention is all that an older model needs.
WHY DO I NEED A SEWER BACKFLOW PREVENTER?
Why you need a sewer backflow preventer should, by this stage of the guide (if not before), be fairly obvious. A device that prevents raw sewage from entering your home should not be a difficult sell. However, in some instances, you may actually not need a backflow preventer.
if you are not connected to the mains utilities, it’s unlikely that you’ll need to have one installed. If you live in an area a long way away from the local sewers, it’s very unlikely that you will experience backflow. Similarly, unless you live in an area particularly prone to flooding, the chances of you needing a sewer backflow preventer are lower than in a more flood-prone area.
However, as with many types of failsafe devices, they are extremely straightforward and cheap to install, and, if the worst happens and you do need one, you will absolutely not regret it. Think of it as an insurance policy. Regardless of your sewer system, installing one effectively guarantees you won’t experience a backflow – and that has to be worth it.
WHAT ARE THE DIFFERENT TYPES OF BACKFLOW DEVICES?
There are three main types of backflow devices. Which type you choose is ultimately a matter of personal preference, budget, and the specific design of your sewage pipe. The three different options are as follows:
SEWER CHECK VALVE
This device is the simplest of the three. It’s built like a basic valve with a swinging flap. When the water pressure in the ‘wrong’ direction builds, the valve rises and prevents liquid from rising up through the pipes into your home.
MANUAL SEWER GATE VALVE
This is a slightly more advanced type of device. Although functioning in basically the same way as the sewer check valve, the key difference is that this device is switched on manually, once you notice the pipes beginning to back up (or suspect that it may happen). Once you’ve done this, the device remains in place until you switch it down again.
AUTOMATIC FLOOD GATE VALVE
In most instances, this is the best option of the three, as it combines the other two. It can raise itself automatically as the backup continues. However, you can also override it and switch it on manually. This means you don’t have to wait for the pressure to build up before sealing off your home. It also gives you a fall-back if there is a backflow when you are not at home.
CHOOSE THE RIGHT DEVICE
If you are deciding to install a backflow preventer, there is a series of questions that you need to ask yourself. These questions will need to be undertaken in conjunction with a professional (usually a plumber), and there may be local restrictions on which devices are available to you.
THE KEY QUESTIONS YOU NEED TO ASK ARE:
What is the anticipated flow rate of the system?
In gallons per minute
What are the pressures involved?
In static and pumping conditions
What is the diameter of my pipe?
What type of fluids travel through my pipe?
Potable water, slurry, sewage, or wastewater
What type of discharge pipe do I have?
Open or closed
How far is the feed of the discharge pipe?
Naturally, the answers to these questions will vary greatly depending on your specific circumstances. Making sure you have exactly the right fit is vital in the device being effective.
HOW DO I MAINTAIN A BACKFLOW PREVENTER?
As mentioned previously, it’s vitally important that you maintain the backflow preventer or it is unlikely to operate at full capacity – thereby rendering it totally useless. In general, you should expect a backflow preventer to work for about 5 to 10 years at its best; after that, it is most likely time to make a change.
The following are all signs that you need a new backflow preventer. If you experience water in your home that matches any of the following:
If you notice any of these, you should immediately call a plumber, as these are signs that something is seriously wrong with your sewer and water systems. The plumber will be able to advise on whether it’s time for a full replacement.
In general, most backflow valves are easily accessible. During times when it’s not in use, you can open the access door, ensure that it is able to move freely, and is free from sediment. Using a rap, give it a wipe (on all sides), and that’s all you need to do. Check once every 3-6 months, or after you suspect it has been used, and you will ensure that it will be there when you need it.
IF IN DOUBT,
call in a plumber, and if you’re unsure, replace the valve. Like a lapsed insurance policy, a poorly maintained backflow valve is far more galling than not having one at all. Ultimately, installing a sewer backflow preventer is an extremely straightforward equation. Getting one installed will ensure (or at least reduces the chances) of raw sewage entering your home. It’s a simple process to install one, although you will need the help of a professional.
Depending on the makeup of your pipes and your home, you may have a choice of different backflow preventers to choose from; otherwise, you will have a simple valve installed. Aside from some gentle maintenance, there’s very little input required from you the homeowner.
However, when it is really needed, you will soon find that you appreciate having had one installed.