Groundwater discharge conditions include evaporation, exploitation, runoff,
springs and etc.
(3) Groundwater flow field characteristics
The groundwater depth of wells (holes) in landfills and surrounding areas within a
certain range is clarified, and a groundwater contour map is drawn to analyze the
groundwater flow direction and hydraulic gradient.
(4) Hydrogeological parameters
Where existing hydrogeological parameters lag behind requirements, hydrogeological tests (pumping tests, dispersion tests, and etc.) can be carried out based on
existing wells and hydrogeological monitoring wells (boreholes), which are combined with integrated ground geophysical methods and hydrogeological exploration
wells to identify the hydrogeological parameters of the study area.
When the hydrogeological data are unavailable, borehole drilling is needed to
analyze the stratigraphic feature of sites, especially of non-standard MSWLFs and
non-standard oil depot contaminated sites. Boreholes drilled for hydrogeological
survey should serve multiple purposes: contributing to exploration in prospective
sites of monitoring wells and later functioning as pollution monitoring wells.
The large-scale groundwater flow direction in an area can be found through
consultation with local relevant units, such as departments responsible for water
resources and environmental protection or geological survey agencies. Further, the
groundwater flow direction specific to investigation objects can be clarified through
geological exploration. Appropriate and effective techniques should be selected for
hydrogeological survey according to actual site conditions and existing working
conditions.
2.2.4 Monitoring Well Deployment
(1) Principles
For groundwater contamination sites, groundwater monitoring wells are deployed
according to the following principles:
• Deploying at least six wells for MSWLFs, including one for groundwater
background monitoring and five for the spread of contamination monitoring;
deploying at least five wells for HWLFs, and at least five for comprehensive
waste disposal sites which should meet the requirements of the Pollution
Control Standards for Hazardous Waste Landfills (GB18598–2001); for gas
station (oil depot) contaminated sites, deploying two to three wells for pore
water monitoring, at least two wells for karst water monitoring and five to six
wells for fissure water monitoring, with focus on the upper bed of light
non-aqueous phase liquid (LNAPL)-contaminated aquifer and on the lower bed
of dense non-aqueous phase liquid (DNAPL)-contaminated aquifer.
2.2 Content of Investigation
17
springs and etc.
(3) Groundwater flow field characteristics
The groundwater depth of wells (holes) in landfills and surrounding areas within a
certain range is clarified, and a groundwater contour map is drawn to analyze the
groundwater flow direction and hydraulic gradient.
(4) Hydrogeological parameters
Where existing hydrogeological parameters lag behind requirements, hydrogeological tests (pumping tests, dispersion tests, and etc.) can be carried out based on
existing wells and hydrogeological monitoring wells (boreholes), which are combined with integrated ground geophysical methods and hydrogeological exploration
wells to identify the hydrogeological parameters of the study area.
When the hydrogeological data are unavailable, borehole drilling is needed to
analyze the stratigraphic feature of sites, especially of non-standard MSWLFs and
non-standard oil depot contaminated sites. Boreholes drilled for hydrogeological
survey should serve multiple purposes: contributing to exploration in prospective
sites of monitoring wells and later functioning as pollution monitoring wells.
The large-scale groundwater flow direction in an area can be found through
consultation with local relevant units, such as departments responsible for water
resources and environmental protection or geological survey agencies. Further, the
groundwater flow direction specific to investigation objects can be clarified through
geological exploration. Appropriate and effective techniques should be selected for
hydrogeological survey according to actual site conditions and existing working
conditions.
2.2.4 Monitoring Well Deployment
(1) Principles
For groundwater contamination sites, groundwater monitoring wells are deployed
according to the following principles:
• Deploying at least six wells for MSWLFs, including one for groundwater
background monitoring and five for the spread of contamination monitoring;
deploying at least five wells for HWLFs, and at least five for comprehensive
waste disposal sites which should meet the requirements of the Pollution
Control Standards for Hazardous Waste Landfills (GB18598–2001); for gas
station (oil depot) contaminated sites, deploying two to three wells for pore
water monitoring, at least two wells for karst water monitoring and five to six
wells for fissure water monitoring, with focus on the upper bed of light
non-aqueous phase liquid (LNAPL)-contaminated aquifer and on the lower bed
of dense non-aqueous phase liquid (DNAPL)-contaminated aquifer.
2.2 Content of Investigation
17