City update: Parma
The pilot work of AMIIGA in the city of Parma is assessing natural attenuation as a remediation option of groundwater contamination. We talked with Marco Ghirardi, project manager of AMIIGA in Parma.
The work of AMIIGA in the city of Parma is assessing natural attenuation as a remediation option of groundwater contamination.
Marco Ghirardi works in the office Quarrying and Water Quality of the City of Parma and he is the project manager of AMIIGA in the City.
Marco, what is Natural Attenuation?
The Environmental Protection Agency defines Natural Attenuation as "A variety of physical, chemical, or biological processes that, under favourable conditions, act without human intervention to reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater. These in situ processes include biodegradation, dispersion, dilution, sorption, volatilization, radioactive decay and chemical or biological stabilization, transformation, or destruction of contaminants" [EPA, 1999].
The use of monitored natural attenuation as a remediation strategy involves filing a formal regulatory application to allow natural biological, chemical and physical processes to treat groundwater contaminants, and conducting ongoing monitoring to verify the effectiveness of these processes.
The Italian law indicates that PCE concentrations in groundwater should not exceed 1.1 µg/l. If this limit is exceeded, is a Municipality obliged to reduce the PCE values to the limits set by the law?
According to the Italian laws, we are not obliged to reduce the thresholds below 1.1 µg/l; in fact, we have three main possibilities:
- with an approved program by the national environmental Agency, to evaluate if a level of pollution is dangerous for the environment and the human targets or not;
- to isolate the source of the pollution and limit its spread, by isolating the contaminants by a waterproof barrier;
- to remediate, that is to reduce the thresholds below 1.1 µg/l.
Which progress have you made since the beginning of AMIIGA project in Parma?
We have drilled 6 new wells in the pilot area to monitor the groundwater: now we have a better knowledge of the stratigraphy of the working area and the depth of the groundwater level.
We have also planned 7 monitoring campaigns of the groundwater quality: the latest analysis have showed that the pollution by chlorinated hydrocarbon is extended out of the pilot site of Santa Croce square: this is a very important data to elaborate our management plan.
We have also worked hard to upload the data to implement a new WEB-Gis: a real progress for our FUA.
Finally, we are elaborating the numerical model of the shallow groundwater: when the model will be ready, all local, environmental Authorities will be able to use the data for the remediation procedures.
What are the next step for the 2018?
We will continue to develop the numerical model of the shallow groundwater. We will collect new samples in our pilot site and will start to evaluate the natural attenuation. And above all, we will prepare the first complete draft of the management plan for our groundwater. It seems it will be a very busy 2018!