When we think of sewage, resource is perhaps not the first thing that comes to mind. Sewage is mostly considered a nuisance: a source of pollution and disease and, at best, a hassle to dispose of.

As the world’s clean freshwater supplies dwindle, however, more and more countries are looking to sewage as a precious water and nutrient source, making treated sewage reuse part of the overall water strategy. This is to be expected when one considers that domestic sewage is 99.9 per cent (pure) water.

Water scarcity is increasingly being recognised as a real and fast-growing human and geopolitical issue having widespread consequences.

The degree of reuse varies by country. Large parts of Australia and the US make extensive use of treated wastewater for agriculture and industry while Singapore’s (rather unfortunately nicknamed) toilet-to-tap strategy aims to provide half of the nation’s water needs through purified wastewater by 2060. In Singapore, wastewater is treated to drinking quality, mixed with other water sources and distributed to consumers as part of the potable water supply.

Additionally, Singapore factors national security into the equation and makes use of treated sewage as a means of providing a local, secure water source rather than depending heavily on water imports from neighbouring Malaysia as it did in the past.

Malta very much stands among the water-poor nations. Rainfall is scarce, unevenly distributed and generally not well harvested so that most of it just runs straight to the sea, while causing flooding. The aquifer, on the other hand, is severely over-extracted and, with ever-increasing levels of nitrates, it has become very much a limited and dwindling resource.

With no other sources of freshwater, Malta looks to the sea to provide potable water and reverse osmosis plants provide over half of the municipal water supply, a proportion that will continue to increase unless major changes are made in the way we manage water.

Reverse osmosis comes at a cost: monetary, environmental and, possibly, a threat for our national security. A fuel crisis or an oil spill, for example, could completely disrupt our ability to purify seawater, leaving us without an adequate drinking supply.

The Maldives, the tiny island nation in the Indian Ocean, suffered just this crisis in December when the only seawater desalination plant was damaged in a fire. With no freshwater supplies over or underground, bottled water had to be shipped in from nearby countries to provide for its 130,000 residents. This situation could also happen in Malta, especially as we move towards reverse osmosis being the only source of potable water.

In the recent past, treated sewage has been looked at and experimented with as a potential resource for agriculture. Malta’s first sewage plant, built in 1982 in Marsascala, was appropriately sited to provide water for agriculture, feeding nearby fields that mostly did not have access to water.

By time, however, the water quality deteriorated and rife, unregulated drilling of boreholes gave farmers a free, better quality alternative right at their doorstep.

An integrated national water plan that adequately manages all water resources as one system is a must

The illegal dumping of animal slurries into the sewerage system together with saltwater infiltration into sewers meant treated effluent was of lower quality, leading farmers to essentially sideline this resource altogether.

Fast forward quite a few years to the present where we now have sewage treatment plants in Ras il-Ħobż, in Gozo, Iċ-Ċumnija, limits of Mellieħa, and Ta’ Barkat, near Xgħajra, limits of Żabbar, which process raw sewage and dump the treated effluent into the sea.

While this situation is very welcome for the quality and health of our seas, ensuring that we comply with EU environmental laws, the system does not provide for reuse.

Unfortunately, reuse was not a determining factor in the siting of the new sewage treatment plants built at a cost of more than €110 million and costing a few million euros to run every year.

The plants now are located in areas where there is little to no nearby agricultural demand for water. An extensive distribution system is required if this water is to be recovered and used.

Moreover, in their current configuration, the treatment plants are not capable of providing water for reuse because the quality of the water is such that, while it is acceptable for disposal into the sea, it cannot be used for irrigation or for any other use.

On its website, the Water Services Corporation quotes plans to polish sewage water to even better quality and then have it “piped to a number of strategic locations where hydrants will be accessible for use”. No mention is made, however, about the pricing of the water and who the intended end users will be.

Will it be possible for this water to compete with completely free, onsite borehole water? Unless that source is controlled, there is little hope for real re-use by either agriculture or industry.

The €22 million polishing plant project risks being a white elephant if a comprehensive plan for the take-up of this water is not in place.

The WSC also mention plans for aquifer recharge with this polished water during the winter months when demand for the polished water would be low to non-existent. Of course, the success of this scheme depends heavily on the quality of the water which, in part, depends on the level of control over what goes into the sewers in the first place.

This scheme would also need to be accompanied by regular transparent water quality tests, together with educational campaigns to inform the public about the process water would go through to put minds at rest about health issues.

One hopes that the €22 million plus investment involved in these polishing plants is planned diligently.

It is heartening to note that some pioneering work in direct potable reuse was carried out locally by Marco Cremona who developed a process that recovers useable water from sewage for hotels which are heavy water users and for whom a cost-effective and sustainable source of water makes a lot of sense.

Named HOTER, the process treats the hotel sewage to produce second class water for use in toilet flushing and for landscaping purposes. Surplus second class water is then polished to first class potable water for use in showers and wash hand basins.

The water recovery rate can be as high as 90 per cent and the energy consumed is less than what is used by a seawater RO plant and a conventional sewage treatment plant combined.

This commercial plant installed at a local hotel is still awaiting the necessary permits from the public health authorities. It is understood that this is the first system of its kind worldwide.

Perhaps such small, on-site treatment plants could provide an efficient solution on a national level, thus removing distribution headaches from the equation.

As things stand, the WSC is embarking on a multi-million euro polishing plant project to be in a position to treat sewage to a level that can be used for irrigation and industry but there seem to be no plans available for the take up of this water.

While making the water available for reuse is a step in the right direction, the move will not be fruitful unless it is part of an integrated national water plan that adequately manages all local water resources as one system.

Difficult decisions about aquifer extraction, water pricing, agricultural practices, storm water management and rainwater harvesting must be made urgently if we wish to safeguard our national water resources.

Although both the Labour and Nationalist parties committed to a water plan in their electoral manifesto, actual action has been scant.

Following stakeholder engagement during the course of last year, news on the development of the plan has been non-existent since then. The 2015 Budget mentioned the ongoing development of a national water management plan with an aim of this being ready and adopted by next year.

One strongly hopes this matter is being given the grave importance it is due.

Greta Muscat Azzopardi is a member of the Malta Water Association.