Converse of object

• contaminate: The virus can survive in landfill sites and could contaminate groundwater.

• pollute: By burying human waste, there is also an increased risk of polluting the groundwater.

• pump: It proposes to use pumped groundwater to provide the required flow during dry periods.

• protect: On first reading it appears to be a laudable attempt to establish good water quality standards and protect groundwater.

• rise: Flooding can also be caused in other ways eg from sewers, run off or rising groundwater.

• use: However, the experiment was carried out using groundwater instead of rainwater due to a lack of rainfall during the period of the experiment.

Preposition: through

• aquifer: Hydraulic gradient - the prevailing inclination of the water table or piezometric surface which provides the driving force to transmit groundwater through an aquifer.

Adjective modifier

• polluted: Once polluted, groundwater is extremely difficult to clean up.

• contaminated: The curtain will also stop the flow of contaminated groundwater into the highly fractured surrounding rock.

• shallow: CASE STUDY 2 BACKGROUND A former inner city heavy industrial site had soil and shallow groundwater heavily contaminated by previous use.

• local: Four years later, the corpses were still there, and they were beginning to pollute the local groundwater.

• deep: Consequently, tubewells that would bring up deep groundwater through handpumps appeared to be an efficient solution for hundreds of villages.

• natural: This allows tree roots and natural groundwater to travel unhindered across the site.

Modifies a noun

• recharge: River flows picked up smartly in late November and significant groundwater recharge has begun in some areas.

• aquifer: A major groundwater aquifer, two fifths of Kuwait's entire freshwater reserve, remains contaminated to this day.

• replenishment: The drainage of the airfield must be designed to prevent local flooding, and to ensure groundwater replenishment.

• hydrograph: The impact of the two recent exceptional episodes is evident in the groundwater level hydrographs.

• remediation: He also has extensive experience of various groundwater remediation techniques.

Preposition: in

• aquifer: The groundwater in the aquifer feeds chalk streams like the Ver.