Reduction of the applied fertilizers for the crops, controlling the compounds in the water in every step of its treatment and supply.
It consists of controlling the chemical composition of the water from the WWTP, the resulting mix after being blended with other water sources (especially the groundwater) and to consider the contained of Nitrates, Phosphates when the fertilization of the crops is carried out. The problems addressed with this practice are:
1. To reduce the pollution by Nitrates, Phosphates, and others in the soil.
2. To reduce the intensity of treatment of denitrification and removing the Phosphates and other compounds, and then, they are applied through fertilizers.
3. To add to the water resources the groundwater with high salinity due to the resulting mix with the reclaimed water is considerably less salty.
4. Offset the deficit between the need for water and the real resources.
The control implemented at each step allows to streamline all the factors in the process of reusing, especially reducing the polluting by an excess of fertilization.
Apart from this, one of the worst problems in this region is the overexploitation of the aquifers, which in turn, has caused a decreasing of its quality and increasing of its salinity. With this measure, it is possible to make the most of this groundwater, and reduce the exploitation.
Another point is that the Irrigator Community of Miraflores has a real needs of 7.765.000 m3/year and its concession for groundwater of the Watershed Authority of the River Segura barely reaches 4 million of m3 per year, being reduced this deficit.
24 analyses of water (1 per fortnight) and the labour of one technician at half time.
It is also required an usual consumer of the water treated, so as to be adapt the tertiary treatment to requirements of the user.
Evidence of success
Addition of 1.5 million m3 per year (from the WWTP) to the Irrigator Community of Miraflores and addition of groundwater of high salinity. Reduction of the cost of the tertiary treatment in the WWTP.
In this practice has been essential the collaboration of the Research Centre "CEBAS CSIC" of Murcia, that is controlling the nutrients levels of the water, as well as ESAMUR, adapting the tertiary treatment to the user needs.
Potential for learning or transfer
The pollution of the water bodies by nitrates or phosphates due to the intensive agricultural activity is a common problem in many territories of Europe.
Apart from that, the cost of the tertiary treatment is usually very high and with this practice, it is possible to mark down its cost, reducing the removal of the compounds considered like a fertilizer.
As far as the kind of organization can develop this good practice, I should add that in the case of Spain, considering that the water is a public good, the users have to associate in users communities so its exploitation (in this case, as the water use is an agricultural application, the association in charge of the practice is an irrigators community), but however the only essential requirement to undertake this practice is an usual consumer of the water treated.
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