Contaminated groundwater is extracted through horizontal or vertical drains which are connected to a vacuum pump and then treated or discharged aboveground. Treated water can be re-infiltrated. A substrate can be added to infiltrated water to stimulate the biological degradation of the contaminant. Substances that increase the availability of the contamination (including co-solvent flushing and surfactant flushing) can be added as well.
Pump & treat
Pump and treat can be used for mobile, water-soluble compounds such as (light) mineral oil, volatile aromatics (benzene and TEX), chlorinated solvents (CVOC and mono-and dichlorobenzene), naphthalene, pesticides, vinyl chloride, dichloromethane and a number of heavy metals such as cadmium, nickel and zinc. Pump and treat can be applied to the saturated soil zone. Part of the soil contamination will be desorbed when flushed and pure product will (partly) dissolve in the groundwater and can be extracted from the water phase. The permeability of the soil should be moderately to well. This technique is applicable for both the source and the plume. Pump and treat is often combined with soil vapor extraction and air injection.
The duration of the remediation ranges from several years to decades, depending on the type and extent of the contamination. The site disturbance is low. The required space aboveground depends on the chosen technique, but can be limited to a container and possibly a cleaning installation. Depending on the implementation method pump and treat can cause subsidence and drought.
Related cases and HIP-pilots
Related cases: Amsterdam (Asterweg): CVOC, BTEX and mineral oil***, Amsterdam: mineral oil, BTEX **, Anaerobic bioremediation of CVOC (The Hague)***, Apeldoorn (Deventerstraat 323a): CVOC ***, Bergen op Zoom (busstation): Mineral oil, BTEX en PAH’s***, Boekelo (Texoprint): CVOC ***, Den Bosch (de Kruithoorn): CVOC*, Den Haag (Boreelstraat e.o.): CVOC ***, Den Haag (W. Royaardsplein): CVOC ***, ISCO Defensie-eiland Woerden, remediation CVOC, mineral oil and BTEX***, Kampen (IJsseldijk): Mineral oil, BTEX, naphthalene**, Nijverdal (Smidsweg 100a):BTEX, PAH’s, naphthalene and mineral oil**, Petrol station: combined techniques for BTEXN and oil (Putten)***, Putten (Garage Koster): Mineral oil, BTEX, Naphthalene***, Rotterdam Europoort: mineral oil and BTEX, Veenhuizen (Norgerhaven): CVOC ***, Veere (Neeltje Jans): Mineral oil***, Wassenaar (Langstraat): CVOC**, Zedelgem (Belgium): CVOC, Zwolle Russenweg: Mineral oil, turpentine **