2.2.1 Aqua-privy (septic tank latrine)
Aqua Privies are essentially small septic tanks located directly underneath a squatting plate. These have a drop-pipe which extends below the liquid level in the tank to form a simple water seal. To prevent odour, fly and mosquito nuisance, the water seal has to be adjusted with each use by adding water to the tank via the drop-pipe to replace any losses. Waste is deposited directly into the tank where it decomposes anaerobically (i.e. without oxygen) in the same way it would in a septic tank. The tank requires dislodging. Most Aqua Privies in Cape Coast sub metropolis were installed over 40 years ago, and they are now operating as holding tanks due to inadequate upkeep of the soak-away systems. Table 1 below provides a comparison of the advantages and disadvantages of an aqua-privy system.
Table 1 Advantages and disadvantages of aqua privy
Advantages Disadvantages
Does not need piped water on site Water must be available nearby
Less expensive than a septic tank More expensive than VIP or pour-flush latrine Flies, mosquitoes and smell nuisance if seal is lost because insufficient water is added

2.2.2 Water closet (WC) with Septic tank
A septic tank is an underground watertight settling chamber into which raw sewage is delivered through a pipe from plumbing fixtures inside a house or other building. The sewage is partially treated in the tank by separation of solids to form sludge and scum. Effluent from the tank infiltrates into the