PUCRS 2006

What is a prepaid water meter?

There are several types of prepaid water meters but the idea behind them is the same. 2If you cannot pay upfront, you are unable to access water. 3Water from prepaid water meters typically costs more than water billed from the utility. As a result, those in most need are denied access to water.
In the United States, the typical prepaid water meter is used in areas without access to water infrastructure. 4The users are poor, often immigrant workers, who travel long distances to collect water from the meters. 5To get water you drop quarters into the slot and place your 1bucket at the faucet.
A similar type of meter has been used in South Africa where prepaid water meters replaced previous free communal standpipes in rural townships. The meter worked by inserting a plastic card with a chip that could be bought for R60 (US$9). In order to get more water, money can be added to the card at a store.
Other types of prepaid water meters are used in individual homes - this system was used in the United Kingdom some time ago.

Source: http://www.citizen.org/cmep/Water/humanright/meter/index.cfm

 The alternative which contains the prepositions that best complete the sentences below is: Prepaid meters have been launched with the aim _________ improving water service; however, they might be a problem _________ those who cannot afford paying _________ water services.

Escolha uma das alternativas.