In order to balance the varied objectives of wastewater charges, different tariff systems have been developed. A tariff is a system of procedures and elements which determines the customer’s total water/ wastewater bill. Any part of that bill can be called a charge, measured in

• money per time (e.g. per month) or

• money per volume or

• money per unit pollution load.

Most tariffs are a combination of elements dependent on consumption or other factors. Usually a connection charge is further put on a customer who joins the public water supply and/ or sanitation systems.

Since water use is easier to observe or meter than is wastewater discharge and the volume of wastewater produced is related to the amount of water supplied, the cost of wastewater treatment is often included in water supply rates or tariffs.

There are different types of tariff systems that can mainly be divided into fixed charges, volumetric charges, and combinations of the both.