New soil production in Sangone Park

Area characterisation:

Sangone park is located along the banks of the Sangone river in the district of Mirafiori South, a peripheral area of Turin. The association obtained the concession of 2.000 m2 in Sangone Park. This part of the city is famous because here FIAT was born and all the area was design and developed to host its workers. Today the area suffer from post-industrial heritage such as high seniority of population, great unemployment, loss of relational fabric.

Objective:

Given competition of land uses in urban areas, the scarcity of the resource soil endangers urban environments. Contamination, poor chemical, physical and biological fertility and high heterogeneity are common traits of urban soils. Previous and ongoing projects have typified soils, fertility and environmental quality.

Therefore, the NbS aims at:

testing and providing soil of good agronomical and environmental quality for new urban green areas and restoration of derelict industrial areas.
pursuing minimum maintenance of new soil composition.
investigating the new soil concept at its very base, considering a wide variability of materials that may compose mixtures used as cultivation substrate.
establishing a sampling strategy, and laboratory and field tests to prepare a methodology for generating new soil, centering on chemical, physical and agronomic quality of materials and mixtures,
producing guidelines providing best strategy for preparing and utilising new growing medium of
starting mineral and organic materials, quality of the site to be restored, type of plants to use.

Actions:

Planning and preparatory activities (administrative and technical procedures)

Planning started in 2016 with the proGIreg research project proposal. The City of Turin (green
department) faced the problem of finding soil to build new parks without taking soil from agricultural
land. The company Dual srl needed to reuse soil from deep excavation in Turin.
First experiments of mixing soil with compost in urban construction sites proved unsatisfactory.
Envipark proposed to use ACEA compost and the biotic compound produced by CCS Aosta, and adding zeolites for water retention capacity and lower material weight (as superficial layer on ground application and roof substrate mixes).
Arpa and Città Metropolitana sought to overcome administrative limitations in the use of soil from deep excavation.

Co-design and engagement activities

Co-design activities involved representatives from companies, research centres and authorization
bodies depending on the topics covered. Social involvement of the local population is key to increase awareness about the experimental site developments and aims, thus requiring:

Meetings with neighborhood committees and the owners of the urban gardens located in Mirafiori
Brief training on new soil organized by actively involved project partners (POLITO, UNITO, City of
Turin, Arpa Piemonte (TLP of City of Turin), Città Metropolitana di Torino (TLP of City of Turin).

Creating a technical table for design and implementation processes of NEW SOIL to decide how on formulate the new soil recipe, analyse regulations for formulating the request to authorization bodies and carry out chemical analyses to support decision making.

Potential impacts/benefits:

The New Soil experimentation allows evaluating market potential of natural solutions that fully meet public authorities’ demands for soil used in urban green areas. Therefore, including new soil as a product in regional price lists and public procurement specifications.

Definining the final material mixture used as ‘New Soil’ required a number of chemical characterizations in order to comply with legislation standards for land application.
Setting up a discussion and coordination board with the authorities in order to promote new soil through legislative support to recognize the background values of pollutants in the destined locations of regenerated soil.
Extensive monitoring of soil samples on both the testing area and the control area by the University of Turin for chemical analyses and PM10 and temperature.
Obtaining useful indications for the public administration to regulate standards and update bureaucratic processes for including new soil in the urban environment.
Monthly wetting with 2500 liters of water during very dry weather conditions
Turin is leading the way to convince road construction authorities to modify price lists, tender specifications and authorization procedures.
A team at the municipality identifying urban land quality in different areas as a reference for new soil materials quality. In 2021, a resolution by the Piedmont Region approved basic values.

The NbS tested a new type of soil already used in other NbS in the Living Lab, thus underlining the
experimental purpose and potential uses. Being in a public park, the new soil area presents proGIreg
activity to a wide target group.

NbS benefits