Italian national policy governing agricultural use of oil mill waste water (Alento)

Editor's note 6Jun14: Sources D142-4

Regional and national legislation regarding the agricultural use of oil-mill waste water (OMW) falls under the mandate of much wider national and international water protection frameworks. Use of OMW is regulated by national legislation, while regions have several responsibilities for regulating the agricultural use of OMW including mandatory conditions of preventive announcements of OMW and mandatory monitoring programs.

The disposal of by-products and residues created during the process of olive oil extraction continues to pose significant problems to Mediterranean countries. While solid and semi-solid olive residues are commonly used in olive by-products, residue water from olive oil extraction, must be first treated. Treatment of OMW is expensive and requires special plants. Given that most olive mills are small, often family owned affairs which are scattered across olive growing regions, it is impractical if not impossible for each mill to have water treatment facilities. OMW is also produced in great quantities in very short periods of time (during the olive harvest season) making treatment processes even more problematic.

Italian law (574/96) on OMW disposal allowed spreading of waste waters on agricultural land under strict guidelines to prevent polluting effects of the high organic content of olive mill waste water on soils and water. In addition, all Italian regions with more than fifty olive mills have to carry out monitoring programs on soil and eventual water sources affected by OMW spreading. The Campania region has also produced its own “Technical Guidelines”.

The Italian Ministry of Agriculture is the formal implementer of regional policies regulating the agricultural use of OMW. However, individual regional resolutions regulating the agricultural use of OMW delegate implementation to local town councils.

Implementation, impacts, effectiveness of Agricultural Use of Oil Mill Waste Water (Alento)

The Campania region hosts almost 10% of Italy’s olive oil mills. The most environmentally and economically sound method of disposing of OWM and residues is the process of “spreading” or “fertigation”, whereby waste products are applied to soils. The large proportion of organic matter and wide range of nutrients found in olive processing waste products can improve soil fertility; however, its high phenol, lipid and organic acid concentrations can also turn it into a potential phototoxic material and pose a threat to the quality of soil, surface and sub-surface water. Under regional resolution OMW is used exclusively for agronomic use after consideration of pedo-geomorphic, hydro-geological and agro-environmental characteristics of proposed sites, in line with the safeguarding surface and groundwater. Restrictions are in place with regard to types of soils, OMW products that may be used for fertigation, the quantity of OWM per soil surface area.

All farmers intending to dispose of OWM through agronomic use must follow a thorough application process which includes: signed declarations of intent from olive mills’ legal representatives as well as land owners; technical assessment reports from experts; proof of adequate and secure storage facilities and form of transportation for OWM and proposed timetables for the spreading of OMW. All applications are made to the local town council

The Campania Regional Environmental Agency (ARPAC) is responsible for monitoring the positive and/or negative environmental impacts of the agricultural use of OWM on affected soil and, subsequently, on water quality through its three times a year monitoring program. Close monitoring is carried out on a selected sample of sites where OWM is spread on agricultural land and includes annual readings of principal chemical, physical and bio-chemical parameters of soil and water samples. Water quality in the Alento study site has been classified as good by ARPAC (ARPAC, 2001-2002).

The introduction of policy regulating the spreading of OMW on agricultural land in 1996 helped olive farmers in the study area to some degree by reducing the need for and costs associated with sending all OMW to treatment facilities. However, restrictions with regard to types of land eligible for spreading, maximum storage periods and the bureaucracy of the application process have rendered the agricultural use of OMW an impossibility for many olive farmers. Interviews with local stakeholdersindicate that the 2005 prohibition of application of OMW to land with slopes values above 10% has been very problematic: olive farming in Alento is practiced predominately in inland hilly areas with 82% of the study site has slope gradients over 15%. Similar dysfunctions are noted with regard to the banned category of “land with water tables situated less than 10m from zero level”, the impracticality of carrying out spreading a maximum of thirty days after pressing.

If agricultural use of OMW is not an option and OMW treatment facilities are not readily available at reasonable costs, there is a higher risk of unregulated, illegal, dumping of OMW in the study site with subsequent negative impacts on soil and water quality.

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