Project Type: SVE (soil vapor extraction) decontamination and pump and treat.
Conceptual Framework:
- Activity: Dedicated to the activities of forging, stamping, and deep drawing of metals and plastics, the activity began in the 1950s until 2008. Currently, the site is completely dismantled with historical contamination in the groundwater level from organochlorines in the center of the plot.
- Type of medium: Highly productive water level within the upper aquifer of the Llobregat Delta.
- Remediation objectives: Set with the client to reduce organochlorine concentrations to below 500 µg/l.
- Decontamination via SVE: With 4 differentiated lines, aiming to extract possible vapors accumulated in the unsaturated and interface zone. Between November 2022 and October 2023, 1,793,129 m³ of vapors were extracted from the subsurface and treated with a feces separator and a 0.5 m³ activated carbon filter.
- Decontamination via pump and treat: Installation of 3 high-flow pumps, one at the focus and two downstream of the contamination plume. Between November 2022 and January 2024, 21,815 m³ were treated, and the resulting water was treated with a feces separator, a hydrocarbon separator, and a 2 m³ activated carbon filter.
- Decontamination via infiltration: With the aim to act where MPE has no influence, between November 2022 and April 2023, an infiltration operation of sodium persulfate was carried out on 4 devices downstream of the plume. A total of 16,500 L of oxidizing solution were infiltrated.
Evolution: Rapid reduction of concentrations:
- Vapors: Rapid improvement, in less than a year the concentrations decreased from 1000 to 0 ppmv.
- Groundwater: The evolution was slower, reaching the objectives up to a year and a half after the start of operations.
