Issues in Wastewater Reuse and Recycling, and the Future of Water Reuse

Despite a long history of wastewater reuse in many parts of the world, the question of safety of wastewater reuse still remains contentious mainly because of the quality of reuse water.

There always have been controversies among the researchers and proponents of extensive wastewater reuse, on the quality the wastewater is to meet.

In general, public health concern is the major issue in any type of reuse of wastewater, be it for irrigation or non-irrigation utilization, especially long term impact of reuse practices. It is difficult to delineate acceptable health risks and is a matter that is still hotly debated.

Issues other than quality of reuse water include socioeconomic considerations, and hydro-geologic conditions. The socio- economic considerations include community perceptions, and the costs of reuse systems.

Wide community level surveys in various States of Australia during early 1990s indicated that in general, public is not reluctant to the concept of wastewater recycling within the community. In one of such surveys, however, less than 15% readily agreed for potable reuse.

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Wastewater reuse has not been implicated as the cause of any infectious disease outbreaks. A more specific study of the city of St. Petersburg, Florida to estimate the potential risk to the exposed population concluded that:

There is no evidence of increased enteric diseases in urban regions housing areas irrigated with treated reclaimed wastewater, and.

There is no evidence of significant risks of viral or microbial diseases as a result of exposure to effluent aerosols from spray irrigation with reclaimed water.

However, the study recommended that adequate treatment schemes must always be designed to eliminate, or at least minimize the potential risks of disease transmission.

The economic considerations are necessary because, when “first- hand” water is available at a cheaper price, it may not be worthwhile to reuse wastewater, unless there are other special conditions.

Consideration of hydro-geologic conditions helps to compare the reuse water quality and the quality of alternative sources intended for the same kind of use.

Irrigation, for example is the highest water consuming activity in any country, and hence is the first option considered in any reuse planning. For example, 90 percent of available water supply in the Indian subcontinent, and a staggering 98 percent in Egypt, is used in irrigation.

The Future of Water Reuse

As of now, major emphasis of wastewater reuse has been for non- potable applications. In spite of developing sound technological approaches to producing water of any desired quality from reclaimed wastewater, it has generally been too expensive to be taken seriously as a potable supply option.

There are several other key issues that include evaluation of health risks associated with trace organic and inorganic contaminants in reclaimed water, application of membrane treatment processes in production of high quality reclaimed water, optimization of treatment trains for wastewater reclamation projects to be cost-effective, that require additional research and demonstration for progress in reclaimed water reuse applications.

Read Also : What is Wastewater and Sources of Wastewaters

There also is a psychological threshold that is keeping us at bay for reuse in portable applications, even when there are no other viable long-term options.

If water reuse projects are to succeed, efforts to generate greater community awareness to judge water by its quality and not by its history and seeking their increased participation in such schemes will also be needed.