be placed within the bowl by the distribution device during or immediately after the flushing has occurred in which case a pre determined small amount of additive will enter the toilet bowl after the flap or trap is closed following flushing and the additive will remain within the bowl that limited amount of additive will provide a liquid covering of the trap within the bowl because of a blue or other coloring the chemical odor will mask sewerage odors from the tank as well as any unsightly appearances of the bowl to the user the particular chemical additive used may be selected by those skilled in the art from available toilet chemicals by way of example a fluid ounce of a commercial additive chemical may be mixed with a much larger amount of water such as an ounce of chemical to 64 fluid ounces of water in the container that volume may be sufficient for example to treat 30 gallons of sewerage generated from 20 gallons of water from the fresh water reservoir that is used to flush the bowl hence a limited relatively small and exact amount of chemical additives may be consistently used that helps to control the costs of operating the restroom by using a limited amount of additives the bowl can have a fresh smell or odor each time the bowl is flushed and the effects of the additive will last a longer time because of the regular small amounts of additive injected into the system that is the effects of the chemicals will not dissipate or dilute in the waste tank during interims between servicing the portable restroom different types of additive injector valves or measuring or metering valves are commercially available thus the selection of the valves depends upon obtaining a commercially.