Thursday, 22 September 2016

GROUNDWATER POLLUTION (vis-à-vis Groundwater Quality) AND CAUSES


Groundwater in it’s natural state is made up of dissolved substances including gases. These contribute greatly to it’s quality. The surrounding environment (Formations), anthropological and bacterial activities influence it’s quality as well.


Below is a rundown of factors that determine the quality of any groundwater:


They can be categorised into:

1.   Physical factors;

2.   Bacterial factors;

3.   Chemical factors;

4.   Anthropological factors.


Physical factors can be easily seen with the eyes without first being analysed in the laboratory. They are apparent to the physical senses of sight, smell, taste and in some cases, touch. It can be known physically if a groundwater is polluted or not by Colour changes, Odour, presence of suspended materials. The presence of suspended materials make the water appear cloudy. Commonsensically, no sane person will like to consume anything, let alone, water that is not appealing to the eyes.


Chemical pollutants are determined by the mineral composition of the underlying and surrounding Formations. It varies in concentrations and proportions. Some are localized, while some are regional. For instance, regions where limestone is predominant tend to  have hard water which is of no economic use due to the high percentage of Calcium and Magnesium ions prevalent in the groundwater. Likewise, places rich in Coal deposits, Hydrocarbon deposits such as Crude oil, Tarsands have Sulphur and other harmful compounds prevalent in their groundwater. Chemical pollutants are determining factors on the pH of the groundwater. These pollutants include, but not limited to, Calcium, Magnesium, Chlorine, Lead, Iron, Copper, Phenols, Zinc and Sulphur.


Bacterial factors: Bacteria thrive well mostly in places where oxygen is available. So the amount of Dissolved Oxygen Concentration (DOC) in the groundwater may determine whether bacteria will be in it and the amount or not. Deeper boreholes usually have no bacterial activities in them because no bacteria can thrive at such depth. Temperature increases with depth while Dissolved Oxygen Concentration reduces with depth. Unsanitary sewage disposal methods, defecation in open water bodies and water channels and dump sites  are main sources of bacterial contaminations to groundwater. The predominant bacterial pollutant in groundwater is Escherichia coli, commonly known as E. coli .
Anthropological factors: Industrialization and urbanization has posed great danger to the ecosystem. While trying to better lives by industrialization, mankind has ended up releasing toxic wastes into the surroundings. Some of these wastes like Brine, Metals, Ammonia, Sulphates, Plastics and Rubber by-products cannot be safely disposed off, hence, hole is bored into the ground and is discharged directly into the ground thereby polluting the nearby aquifer. Wastes discharged through this means cannot be effectively controlled as at seeps across the underlying and surrounding Formations. Brewing companies and Oil companies release most of their wastes directly into the ground. Mining activities, tank and pipeline leakages also pollute the groundwater.

However, the baby cannot be throw away with the bath water merely because it soiled the bath water. Polluted groundwater can still be remedied depending on the degree of contamination and the nature of the pollutant. 

The treatment includes:
          Disinfection: This involves using Chlorine, Ozone, and Flourine in a calculated proportion.

          Coagulation: this involves adding of alum to make the dirts to form larger clumps and facilitate sedimentation.
          Sedimentation: Here, heavier particles are allowed to settle under gravitational effect and then decantation takes effect.

          Aeration: In this case, the water is exposed to air so that encourage precipitation. This  is for water polluted with Iron and Manganese. Once precipitation is over, it can be decanted easily.


          Filtration: This helps to remove bacteria and other pollutants like organic matter. This is the most common of all techniques.


HAVE YOUR SAY!!!

Wednesday, 7 September 2016

CAUSES OF WATER BOREHOLE FAILURES IN NIGERIA


Water is one of the most (if not the most) essential requirements for life existence on earth. It is a well known fact that the human body is made up of about 75% water. Apart from water for drinking, it is relied on for industrial and domestic chores. It is available in the surface and sub-surface. But the surface water is usually not enough and in most cases not available all year round due to seasonal variations namely: Rainy and Dry Seasons. During the Rainy Season, the Surface water becomes readily available (though may or may not be enough depending on the need) but the contrast is the case during Dry Season. Hence the resort to Boreholes.

Let’s start by defining a Borehole. In the simplest term, as the name implies: Bore Hole.  It means to ‘bore a hole’; or simply put: ‘to drill a hole’, ‘to sink a hole’, ‘to punch a hole’ on the ground to create a cavity inside the ground where water can accumulate, be stored and harvested when needed. The hole can be shallow (as in wells), or deep. The depth to drill, the Geologic factors of the area and the financial capacity of the client determine the technology to deploy in the drilling. While some deploy hand-operated (manual) rigs for drilling, others deploy motorised rigs.
However, the type of rig to be deployed is determined by the underlying Formations.

AND NOW THE BIG QUESTION...

                WHY THE FAILURES OF BOREHOLE?

A borehole is said to have failed when the yield has grossly reduced when compared to the yield produced immediately after drilling and could not be reconciled with the pumping test data. These can result in borehole failures:

  • Failure to do a proper Geophysical survey to delineate the underlying Formation(s) and it’s extensiveness. Most clients do not know the fact that a survey MUST be done to ascertain the availability of water in their chosen locality before the actual drilling. This is called water prospecting. Incompetent drillers harvest on their ignorance to swindle them their hard earned monies.
  • Failure to use the appropriate rig. Different rigs are designed to be used for different terrains. Some drillers (especially quacks) are fond of this.
  • Incompetent drillers. Quacks abound in all professions despite all regulatory actions of government agencies to checkmate them. Borehole drilling is not an exception.
  • Poor / lack of supervision during the drilling. To ensure that the specifications recommended for the borehole is strictly adhered to, there is need for supervision during drilling.
  • Formation characteristics. Not all geological materials produce water. Moreover, deep static water level, Ferric water and Saline water are major hindrances in areas they are prevalent.
  • Usage. Over usage resulting from over pumping by the owner can result to failure of the borehole especially in areas where recharge rate is less than discharge rate.
  • Poor / improper installation. During installation, standard pumps, PVCs (screens and blinds), gravels and grouting should be put in place.

Considering the amount of money required in borehole drilling, care should be taken in the choice of a driller. Moreover, an advice from a Geologist / Geophysicists should be solicited for.

HAVE YOUR SAY!!!

Monday, 29 August 2016

HOW SAFE IS THE WATER YOU DRINK?

HOW SAFE IS THE WATER YOU DRINK?
It is a natural occurring compound that is ubiquitous in nature. Nothing is as refreshing as taking a bottle of chilled water after a hectic day. You may be to conversant with water thereby neglecting it’s components. As big as it may appear, it can be isolated into molecules. Each molecule is simply made of two elements: Hydrogen and Oxygen in the ratio of 1:2 respectively. By weight, it consists of 11.1888% Hydrogen and 88.812% Oxygen, if and only if it is pure.
WHY THE CRUSADE FOR PURE WATER?
Human life has been under threat since the existence of man on earth. Majority of the threat comes from what we consume. Majority of what we consume is water or water-related either in carbonated drinks, caffeinated drinks, or any drink at all.
To this effect, a lot of organisations like WHO, UNICEF, Governmental and Non Governmental Agencies have come up with some standards to ensure that the water we take in is fit for the body.
You may say “I get my water from the public supply system hence I’m covered”. Yes are covered but not totally covered. Why? Although the water from the public supply is usually treated with Chlorine or other disinfectants (Fluorine in rare cases), yet as it travels along the distribution channels (systems), it corrodes the pipe (if it is made of Iron or Lead) in which it flows through. At some points, the pipes may burst or have some leakages hence carrying along some contaminants that usually dissolve in it. But still it may still appear colourless. It will be disastrous consuming such water as Lead and Iron tend to accumulate with time in the body causing Lead poisoning or Iron poisoning as the case may be. This will in turn lead to heart failures and other health challenges which if not treated medically will lead to untimely death. However nowadays, PVC pipes are fast replacing the easily corrodible Iron and Lead pipes and it is a cheaper technology than the former.
Water by nature, apart from being ubiquitous, is a universal solvent. This makes it possible for it to dissolve as many water-soluble salts, ions or molecules that comes its way as possible. That is why in same places, the water is hard (does not easily form lather with soap), while in others it is soft. Water becomes hard when it dissolves some Calcium or Magnesium compounds especially in limestone regions. The degree of the concentration of these compounds determines the hardness of this water which in turn determines it’s economic value. Water that is too hard cannot be used for any useful household purpose because it is ‘sticky’ when felt in-between fingers. It wastes lather. It has no economic value.
Naturally, it is available on the surface and sub-surface. It follows a cycle called ‘THE WATER CYCLE which is mainly controlled and co-ordinated by the forces of Precipitation and Evaporation.  However, the surface water is usually  not in sufficient quantity for domestic use, let alone industrial unless in places where we have perennial water bodies like streams, lakes, rivers and oceans. Then they can be readily harnessed. But they pose a great danger unless treated adequately.
It is the quest for ample water that made man to begin probing the earth in search of it and it dates back as far the primitive era. But the methods of earth probing and borehole drilling has been greatly modernised.
The problem is that the technology and the processes appears simple (yet it is not), the quacks have gained access into the market with the attendant borehole failures scattered all over the place especially in Nigeria. The government seems to be doing little to curb this menace. The earlier professionals are allowed to take their rightful place, the better – so as to prevent unnecessary but avoidable investment loss.
Geologist, Geophysicists and Geoscientists have the right knowledge of the terrains and they are in a better place to provide the necessary framework for probing the earth, exploration and exploitation of the vast mineral resources.

WHAT DO YOU THINK?