If you thought that solid waste is the only waste considered to come from a household, then you thought wrong. A septic tank is one of the most common ways in which homes in Uganda can dispose of wastewater without contaminating our environment. Ideally, many homes and factories possess a septic tank or bio-digester to help dispose of liquid waste. In Uganda, a septic tank is of vital importance to any household. It is an underwater sedimentation tank used for wastewater treatment through the process of biological decomposition and drainage. A septic tank is installed underground and treats wastewater with natural processes from household plumbing produced by bathrooms, kitchen drains, and laundry.
HOW IT WORKS.
A septic tank digests organic matter and separates floatable matter (e.g., oils and grease) and solids from the wastewater. It is connected by two pipes, the first is an inlet and the second is an outlet. The inlet pipe is used to transport the water waste from the house and collect it in the septic tank. It is kept here long enough so that the solid and liquid waste is separated from each other.
The second pipe is the outlet pipe. It can also call the drain field. This pipe moves out the pre-processed wastewater from the septic tank and spreads it evenly in the soil and watercourses. When wastewater has been collected after a while it will begin to, separate into 3 layers.
The top layer is oils and grease and floats above all the waste. This is commonly referred to as “scum”. The middle layer contains wastewater along with waste particles. The third and bottom layer consists of particles that are heavier than water and form a layer of sludge.
Bacteria inside the tank do their best to break down the solid waste, which then allows liquids to separate and drain away easily. What is left at the bottom of the tank needs to be periodically removed as part of general maintenance.
EMPTYING A SEPTIC TANK
When septic tanks reach their maximum capacity, the waste within must be emptied for normal waste removal to occur. A waste removal vehicle with a large pressurised vacuum attached to a hose sucks up the sewage into the vehicle’s waste tank. The hose is then submerged in the septic tank and the pump is activated to increase pressure forcing the waste to rise and fill the waste tank. Once a septic tank is emptied, the sewage is transported to an approved storage and treatment facility.
The frequency of how frequently a septic tank is emptied depends on its size. Ideally smaller tanks can be emptied annually and larger ones can last some years without the need to be emptied.
SIGNS YOUR SEPTIC TANK ID FULL
Below are a few signs that your septic tank may need to be emptied as soon as possible.
i) Slow drainage
On those special occasions when your drains take longer than usual to drain our wastewater without evidence of clogging, then your tank may be full.
ii) Smells
Walking down the streets of Kampala, you must have taken a whiff of a strong sewage stench once or twice. You know this smell well. And if you ever smell this stench in the safety of your four-walled house, it should be no secret that this is evidence of a full tank. The gas from within the tank is being forced back up the pipes causing a foul smell.
iii) Water pooling
Puddles of sewage water tend to make an appearance around the septic tank drainage area. When you see this, your tank may be full.
“The grass is always greener over the septic tank.”
-Erma Bombeck