Download - Groundwater
Confined and Unconfined
Confined Aquifer: groundwater between impermeable layers of rock
with less movement of water and replenished by rain or stream water
some distance away from the aquifer
(www.tas.gov)
Confined and Unconfined
Unconfined Aquifer: direct contact with the atmosphere through the porous soil or rock layer and replenished directly
by rain or stream water from the porous layer.
(www.tas.gov)
Porosity
Percentage of the openings or pores in a given volume of the rock which
contain water
(www.who.int)
Specific Yield
The ratio of the volume of water that can be extracted to the total saturated volume
(www.who.int)
Chemical Composition
Inorganic constituents: bicarbonate, calcium, chloride, magnesium, silicon, sodium, sulphate and carbonic acid
(www.eolss.net)
Chemical Composition
Trace Constituents: boron, carbonate, fluoride, iron, nitrate, potassium and
strontium
(www.eolss.net)
Groundwater chemistry and quality affected by:
evapotranspiration, dissolution, and precipitation of soluble minerals, acid
base reactions, ion-exchange and sorption and oxidation reduction
reactions(www.dec.na.gov)
Chemical behaviour of groundwater affected by:
temperature, ionic strength, pH and Eh
(www.dec.na.gov)
Mineralogy of the rock types forming catchments or aquifers, overlying land uses, proximity to the coast, source of recharge water, soil type and aquifer
structure affects groundwater chemistry.
Land use activities such as soil cultivation, fertilizer application, animal
grazing and wastewater disposal has important role in the availability of
nutrients such as nitrogen and phosphorous in groundwater.
Microbes
free of microbial contamination because of long vertical transport for
microbes to reach aquifers
Microbial Contamination
leakage from sanitation systems, disposal systems, underground storage
tanks and accidental waste water discharge
(www.acatech.de)
Common pathogens
Bacteria : Escherichia coli, Salmonella species, Shigella species, Vibrio Cholerae and Legionella species
(www.acatech.de)
Common pathogens
Viruses :Piconaviridae, Caliciviridae, Reoviridae, Adenoviridae and Coronaviridae
(www.acatech.de)
Common pathogens
Protozoans: Crptospiridium pavum, Giardia lambia, Taxoplasma gondii and Entamoeba histolytica
(www.acatech.de)