Guest Speakers and Visit to Waste Management Facility

The guest lecturer on Tuesday spoke on the regional Municipal Solid Waste (MSW) plan for Cagliari. The plan is based on the EU Environmental Action Programme and observes the waste hierarchy mandatory for EU member states. The intention is to foster for Sardinia a circular economy as opposed to a linear economy: an economy that capitalizes on waste as a resource. The trend in developmental economics is for an increase in economic prosperity to correlate with more waste production. However, the policies Sardinia has implemented to promote separate collection together with lowered consumption from the 2008 economic crisis has led to an increasing trend in recycling and a reduction in waste disposal. The speaker compared Sardinia’s progress to the rest of Italy and Europe as a whole. Within Italy, Sardinia has performed seventh best, behind the more prosperous, industrialized Northern regions with more capacity for resource recovery. Comparatively, rich countries in Northern Europe produce less waste, have high emphasis on recycling, have banned waste to landfill and have implemented policy/infrastructure for resource recovery.  It was interesting to learn the role that Germany plays in determining the waste management goals for the other European states. Member states can face fines should they not make their annual goals or demonstrable progress towards said goals. I also took note of how newer, lesser-developed EU member states from Eastern Europe are given greater leniencies in meeting targets. The speaker outlined specific actions that can be taken to reduce waste production, such as door-to-door collection, Green Public Procurement (GPP), tipping fees, transparent bags and reduction of collection frequency. 90% of municipalities in Sardinia provide door-to-door collection, apart from the three major cities of Alghero, Sassari and Cagliari.

The guest lecturer on Wednesday, engineer Stefano Milia from CNR – National research center, spoke regarding the remediation of contaminated sites and associated calculations. He presented fundamental concepts, such as the site-specific approach and choosing the most appropriate technology for remedial action.

                                                                                                                          

Back in the US, my family has been contemplating acquiring the properties surrounding our business. However, these properties are adjacent to a brownfield site currently undergoing remediation and a former dry cleaner; furthermore, our business property is a remediated former gas station and adjacent to the municipal water tower. As such, we are considering whether or not to conduct a Phase II Environmental Site Assessment (ESA) to assess current soil and groundwater environmental conditions. This service would determine whether these sites have incurred any sort of impairment as a result of the surrounding properties. Given our circumstance, the topic of Wednesday’s lecture was of particular interest to me. Through Freedom Of Information, I acquired and read the brownfield site characterization, which detailed the site layout and contaminant concentrations. The contaminant of interest was trichlorobenzene, which Stefino informed us is a Dense Non-Aqueous Phase Liquid (DNAPL). Prior to this lecture, I was not aware of the factors that contribute to choosing the most appropriate remediation technology: soil properties, characteristic of contaminants, tendency of contaminants to migrate, and spatial distribution of contaminant in different phases and fractions. It was also useful to learn how an engineer may design to prevent the migration of contamination. Now that I better understand the remediation process from the perspective of an environmental engineer, I intend to share my insights with my family to better inform our decision.

On Thursday, the group went on a site visit to a regional waste management facility. In 2004, before the implementation of separate collection, the facility received 80,000 tons of trash annually; the facility now receives 20,000 tons, resulting in a separation efficiency of 70-75%. Waste is sorted into three sections: metals, organics and paper/plastic. Bulky items go into the mixed waste section, which is sent to a shredder, after which magnet separators recover metals. The majority of metals, however, are recovered prior to this stage through separation: the shredded items are mixed with other materials, which complicates recovery. Crushed metal bales are then sold at market value: aluminum, for example, sells for 500 Euro/ton. 

With respect to organic waste, Sardinia does not produce a significant amount of yard waste; as such, the facility aggregates yard with agricultural and food waste. From organic waste, the facility produces compost for sale to local farmers. Currently, they are looking to expand operations to create a commercialized product to sell to supermarkets. We only toured the plastic operations, as they didn’t require us to wear protective clothing. Initially, the plastics are debagged and loaded onto a conveyor, where, amongst other factors, they are sorted through optical separation by color and PET from not PET. This process involves infrared sensors, an HD camera, and workers performing quality control. 

After the plastics and papers have been siloed, they are bound with plastic and sold to WTE plants for resource recovery. 

There is a landfill on site to store the bales temporarily when the WTE plant is at capacity or undergoing maintenance.

 The facility employs 35 workers and 3 engineers, which is anticipated to increase as the facility expands operations. The facility operates eight hours a day on weekdays and food waste is collected on Saturday mornings.