**Table  2.3 Urban sanitation and wastewater treatment characteristics by level of economic development**

|**Characteristics**<br>**by level of**<br>**economic**<br>**development**|**Low-income**<br>**countries**<br>**(43 countries)**<br>**<$975**<br>**GNI/cap**|**Lower-middle-**<br>**income countries**<br>**(55 countries)**<br>**$976-3,855**<br>**GNI/cap**|**Upper-middle-**<br>**income countries**<br>**(46 countries)**<br>**$3,586-11,905**<br>**GNI/cap**|**High-**<br>**income countries**<br>**(66 countries, 27 OECD)**<br>**>$11,906**<br>**GNI/cap**|
|---|---|---|---|---|
|Access to basic<br>sanitation<br>services|Low coverage,<br>especially for<br>urban poor;<br>Mainly non-<br>sewered options|Increasing<br>coverage but low<br>access for urban<br>poor;<br>Increasing use of<br>sewerage|Generally<br>acceptable<br>coverage;<br>Higher sewerage<br>levels|Good coverage;<br>Mainly sewered|
|Wastewater<br>treatment|Virtually no<br>treatment or very<br>few treatment<br>facilities;<br>Severe operational<br>deficiencies;<br>Affordability<br>issues dominate|<br>Some treatment<br>facilities;<br>Often poorly<br>operated and/or<br>design capacity<br>exceeded;<br>Affordability<br>issues persist|Increasing<br>treatment<br>capacity;<br>Continued<br>operational<br>deficiencies;<br>Difficulties in<br>mobilizing needed<br>investments|Generally high treatment<br>levels;<br>Increasing investments over<br>past 20 years in non-OECD<br>countries;<br>Major investments over past<br>40-50 years in OECD<br>countries|
|Water pollution<br>issues|Health problems<br>from inadequate<br>sanitation and raw<br>domestic sewage<br>“in the streets”|Severe health<br>problems from<br>untreated<br>municipal<br>discharges|Severe pollution<br>problems from<br>poorly treated<br>municipal and<br>mixed industrial<br>discharges|Primarily concerned with<br>amenity values and toxic<br>substances|

_Sources:_ Adapted from Bartone, 1997; income data from World Bank, 2010.

_Wastewater treatment in low-income countries._ In low-income countries, wastewater treatment plants, if they exist, are minimal or function poorly, and basic sanitation is the primary focus. In Ghana, for example, about 70 mostly decentralized wastewater and fecal sludge treatment plants collect less than 10 percent of the generated wastewater. Of the 70 plants, about 10 function more or less as designed, and most of these belong to larger hotels (Murray and Drechsel 2010). Under these circumstances, the key pollution concern is to protect public health by isolating households from fecal sludge and raw domestic sewage in the streets.

In these countries, policymakers and consumers face financial, institutional, and technical challenges when considering improvements in sanitation and wastewater management. Affordability is a critical issue. Only non-conventional, low-cost sewerage and treatment options are likely to be feasible alternatives to on-site sanitation options except in the city centers and richer neighborhoods of the larger cities.

Two key constraints affecting many wastewater collection and treatment systems in low-income countries are the high frequency of power-cuts and the low volumes of water supply per capita. Frequent power outages can affect pumps as well as treatment plants. Where sewers exist, many fall into disrepair due to temporal or general lack of sufficient water quantities to flush them.

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