Table 1.

Inorganic pollutants presented in groundwater.

Contaminant	Source for the Groundwater	Problems	MCL (mg/L) (USEPA, 2018)	Reference
Aluminium	Groundwater passes through some kind of rocks. Mines discharge.	If present in drinking water, it could cause turbidity increment besides water discolouring.	0.05–0.2	[23]
Antimony	Municipal waste disposal. Industrial production and flame retardants such as glass manufacturing, ceramics and lead industry. Fireworks or explosives.	Cause a change in cholesterol and glucose concentrations in blood in laboratory animals exposed to risky levels of antimony during their existence. Decreases longevity. Has a biochemical changes in laboratory animals and toxic effect on neurobehavioral.	0.006	[23,24]
Arsenic	Industrial activities such as smelting of metals (zinc, lead, copper ore) Using pesticides. Naturally found in aquifers.	Liver, kidney and skin damage. Decrease blood haemoglobin. Chronic and acute toxicity. Can cause various forms of cancers. Hindrance of children’s development.	0.010	[25,26,27]
Barium	Naturally takes place in some kind of soils such as limestones and sandstones. Landfill leachate. Fertilizers and pesticides.	Cardiovascular and kidney diseases. Mental disorders. Metabolic syndrome.	2	[28,29]
Cadmium	Industrial and mining waste. Phosphate fertilizers. Landfill leachate.	High blood pressure. Replace zinc biochemically in the human body. Liver damage Destroy testicular tissues and blood cells (red).	0.005	[30]
Chloride	Industrial and domestic waste. Saltwater intrusion.	Changes in drinking water taste. At high levels, it can deteriorate water heaters, municipal pipes, pumps and works equipment.	250	[23,31]
Dissolved solids	Naturally found. Human activities such as landfill leachate, feedlots.	When presented, the water became unacceptable and objectionable to many. Affect the performance and life of water heaters.	500	[32]
Iron	Mining corroded metal, industrial waste. Naturally found in sediments and rocks.	Changing water taste. Affect plumbing fixtures and clothes colours in laundries.	0.3	[26]
Lead	Industry, mining, gasoline and plumbing.	Affect babies’ mental growth and can change red blood cells chemistry. Increase blood pressure. Probable carcinogen.	0.015	[28]
Zinc	Industrial waste, metal plating, is the major ion in sludge. Naturally, it is found in mining areas.	Cause a change to the drinking water taste. Toxic to plants if exposed to high levels.	5	[27]