A number of persons have been publicly complaining that they do not agree with the siting of the new sewage treatment plants (STPs) built by the Water Services Corporation. They insist that, since a by-product of these plants could be used for irrigation, they should have been placed in the middle of agricultural areas as this would remove the need to transport water from the plants to the fields where it is to be used. There are several reasons why this argument is fallacious.
The first thing to remember is that we have numerous areas – I could mention at least 15 – where land is fertile and agriculture particularly important. Only three STPs have been built and I have not heard anyone suggest exactly in which particular agricultural area they should have been sited. Mrieħel was once mooted but that area is urban and industrial rather than agricultural. Selecting any three localities would still leave us with the problem of transporting water from that STP site to the rest of the country.
Perhaps to overcome this difficulty it has been suggested that, instead of building only three STPs, we should have built several but, again, no precise number is ever mentioned. Apart from the significant take-up of land (each plant would also require access roads and services), such a solution would greatly increase both costs and risks. One considerable expense, for example, would be the rerouting of part or the entire sewage network. A much higher staff complement would also be needed to run and maintain the system.
Sewage treatment plants are not exactly picturesque structures and their negative visual impact on the landscape must not be underestimated. I would say that their physical presence is not compatible with agri-tourism and the use of the countryside as a socio-cultural amenity.
The main objection to the siting of STPs in farming areas is, however, agro-environmental. There is a tendency to think of these plants as “water factories” but they are, in fact, facilities where sewage is treated. True, water does comes out of one end, but sewage has to enter from the other.
This means that raw sewage would have to be transported through agricultural fields to wherever the plants are built, with all the risks this implies. The truth is that nobody has bothered to ask farmers whether they would be happy to have sewage plants on their land or close by. I hold no brief for the Ministry for Resources and Rural Affairs but can understand their concerns regarding safety issues of food production and the multi-functional role of agriculture, including its contribution to the tourist sector.
Has anyone thought about the consequences of raw sewage accidentally flooding hectares of greenhouses and high-value horticultural crops? The recent incident at the northern STP is a vivid illustration of the dangers. Should we opt to pump sewage to every agriculturally-sensitive corner of the island so as to avoid transporting water? Up to a point, a certain risk already exists because some sewage pipes run through agricultural land but we should strive to reduce this risk, not increase it in a vain attempt to cut costs.
The irony is that such a risk would be useless because there is another aspect that is overlooked by those who would place STPs on farmland. While these plants produce more or less the same amount of water throughout the year, irrigation requirements vary greatly from one season to another. There would inevitably be times when the immediate region around the STP would be unable to absorb all the treated sewage effluent. What should be done with this water is another issue but it would definitely have to be moved away and a pipeline would have to be constructed anyway to carry water, not towards agricultural areas but away from them.
For all these reasons, I believe that the present siting of the sewage treatment plants represents the most reasonable choice that could be made in the circumstances. They make use of the existing sewage system and are relatively far enough from agricultural areas so that any inconvenience and danger of contamination are reduced as much as possible.