Cassette toilets are favoured by many as the answer to the cost of pumping out an in built holding tank. There are at present three basic types of cassette toilet, the simple plastic type which has a self contained watVacuum Casette Toileter supply and the bowl and tank are clipped together until the tank is full and requires carrying off to be emptied and cleaned. A back to basics approach to sanitation situations.
A more sophisticated system consists of a plastic floor mounted toilet with an integral tank which requires a trap door behind the toilet to enable the full cassette to be removed and emptied.