Logarithm and exponential made easy

https://www.mathsisfun.com/algebra/logarithms.html

https://www.mathsisfun.com/algebra/exponents-roots-logarithms.html

PETROL CARS WILL VANISH IN 8 YEARS SAYS US REPORT

Where will we run to when..

Petrol cars will vanish in 8 years, says US report from Stanford economist

May 15 2017 at 11:08 AM

" A Tesla Model S, which has 18 moving parts, one hundred times fewer than a combustion engine car. "Maintenance is essentially zero," says Stanford University economist Tony Seba. "That is why Tesla is offering infinite-mile warranties. You can drive it to the moon and back and they will still warranty it."

No more petrol or diesel cars, buses, or trucks will be sold anywhere in the world within eight years. The entire market for land transport will switch to electrification, leading to a collapse of oil prices and the demise of the petroleum industry as we have known it for a century.

This is the futuristic forecast by Stanford University economist Tony Seba. The professor's report, with the deceptively bland title Rethinking Transportation 2020-2030, has gone viral in green circles and is causing spasms of anxiety in the established industries.

Mr Seba's premise is that people will stop driving altogether. They will switch en masse to self-drive electric vehicles (EVs) that are 10 times cheaper to run than fossil-based cars, with a near-zero marginal cost of fuel and an expected lifespan of 1 million miles (1.6 million kilometres).

Only nostalgics will cling to the old habit of car ownership. The rest will adapt to vehicles on demand. It will become harder to find a petrol station, spares, or anybody to fix the 2000 moving parts that bedevil the internal combustion engine. Dealers will disappear by 2024.

Cities will ban human drivers once the data confirms how dangerous they can be behind a wheel. This will spread to suburbs, and then beyond. There will be a "mass stranding of existing vehicles". The value of second-hard cars will plunge. You will have to pay to dispose of your old vehicle.

It is a twin "death spiral" for big oil and big autos, with ugly implications for some big companies on the London Stock Exchange unless they adapt in time.

The long-term price of crude will fall to $US25 a barrel. Most forms of shale and deep-water drilling will no longer be viable. Assets will be stranded. Scotland will forfeit any North Sea bonanza. Russia, Saudi Arabia, Nigeria, and Venezuela will be in trouble.

It is an existential threat to Ford, General Motors, and the German car industry. They will face a choice between manufacturing EVs in a brutal low-profit market, or reinventing themselves a self-drive service companies, variants of Uber and Lyft.

They are in the wrong business. The next generation of cars will be "computers on wheels". Google, Apple, and Foxconn have the disruptive edge, and are going in for the kill. Silicon Valley is where the auto action is, not Detroit, Wolfsburg, or Toyota City.

The shift, according to Mr Seba, is driven by technology, not climate policies. Market forces are bringing it about with a speed and ferocity that governments could never hope to achieve.

"We are on the cusp of one of the fastest, deepest, most consequential disruptions of transportation in history," Mr Seba said. "Internal combustion engine vehicles will enter a vicious cycle of increasing costs."

The "tipping point" will arrive over the next two to three years as EV battery ranges surpass 200 miles and electric car prices in the US drop to $US30,000 ($40,600). By 2022, the low-end models will be down to $US20,000. After that, the avalanche will sweep all before it.

"What the cost curve says is that by 2025 all new vehicles will be electric, all new buses, all new cars, all new tractors, all new vans, anything that moves on wheels will be electric, globally," Mr Seba said.

"Global oil demand will peak at 100 million barrels per day by 2020, dropping to 70 million by 2030." There will be oil demand for use in the chemical industries, and for aviation, though Nasa and Boeing are working on hybrid-electric aircraft for short-haul passenger flights.

Mr Seba said the residual stock of fossil-based vehicles will take time to clear, but 95 per cent of the miles driven by 2030 in the US will be in autonomous EVs for reasons of costs, convenience, and efficiency. Oil use for road transport will crash from 8 million barrels a day to 1 million.

Insurance costs to fall by 90 per cent

The cost per mile for EVs will be 6.8 cents, rendering petrol cars obsolete. Insurance costs will fall by 90 per cent. The average American household will save $US5600 per year by making the switch. The US government will lose $50 billion a year in fuel taxes. Britain's exchequer will be hit at the same rate.

"Our research and modelling indicate that the $10 trillion annual revenues in the existing vehicle and oil supply chains will shrink dramatically," Mr Seba said.

"Certain high-cost countries, companies, and fields will see their oil production entirely wiped out. Exxon-Mobil, Shell and BP could see 40 per cent to 50 per cent of their assets become stranded," the report said.

These are all large claims, though familiar those on the cutting edge of energy technology. While the professor's timing may be off by a few years, there is little doubt about the general direction.

India is drawing up plans to phase out all petrol and diesel cars by 2032, leap-frogging China in an electrification race across Asia. The brains trust of Prime Minister Narendra Modi has called for a mix of subsidies, car-pooling, and caps on fossil-based cars. The goal is to cut pollution and break reliance on imported oil, but markets will pick up the baton quickly once the process starts.

China is moving in parallel, pushing for 7 million electric vehicles by 2025, enforced by a minimum quota for "new energy" vehicles that shifts the burden for the switch onto manufacturers. "The trend is irreversible," said Wang Chuanfu, head of the Chinese electric car producer BYD, backed by Warren Buffett's Berkshire Hathaway.

At the same time, global shipping rules are clamping down on dirty high-sulphur oil used in the cargo trade, a move that may lead to widespread use of liquefied natural gas for ship fuel.

This is all happening much faster than Saudi Arabia and Opec had assumed. The cartel's World Oil Outlook last year dismissed electric vehicles as a fringe curiosity that would make little difference to ever-rising global demand for oil.

It predicted a jump in crude consumption by a further 16.4 million barrels a day to 109 million by 2040, with India increasingly taking over from China as growing market. The cartel said fossils will still make up 77 per cent of global energy use, much like today. It implicitly treated the Paris agreement on climate targets as empty rhetoric.

Whether Opec believes its own claims is doubtful. Saudi Arabia's actions suggest otherwise. The kingdom is hedging its bets by selling off chunks of the state oil giant Saudi Aramco to fund diversification away from oil.

Opec, Russia, and the oil-exporting states are now caught in a squeeze and will probably be forced to extend output caps into 2018 to stop prices falling. Shale fracking in the US is now so efficient, and rebounding so fast, that it may cap oil prices in a range of $US45 to $US55 until the end of the decade. By then the historic window will be closing.

Experts will argue over Mr Seba's claims. His broad point is that multiple technological trends are combining in a perfect storm. The simplicity of the EV model is breath-taking. The Tesla S has 18 moving parts, one hundred times fewer than a combustion engine car. "Maintenance is essentially zero. That is why Tesla is offering infinite-mile warranties. You can drive it to the moon and back and they will still warranty it," Mr Seba said.

Self-drive "vehicles on demand" will be running at much higher levels of daily use than today's cars and will last for 500,000 to 1 million miles each.

It has long been known that EVs are four times more efficient than petrol or diesel cars, which lose 80 per cent of their power in heat. What changes the equation is the advent of EV models with the acceleration and performance of a Lamborghini costing five or 10 times less to buy, and at least 10 times less to run.

"The electric drive-train is so much more powerful. The gasoline and diesel cars cannot possibly compete," Mr Seba said. The parallel is what happened to film cameras - and to Kodak - once digital rivals hit the market. It was swift and brutal. "You can't compete with zero marginal costs," he said.

The effect is not confined to cars. Trucks will switch in tandem. Over 70 per cent of US haulage routes are already within battery range, and batteries are getting better each year.

EVs will increase US electricity demand by 18 per cent, but that does not imply the need for more capacity. They will draw power at times of peak supply and release it during peak demand. They are themselves a storage reservoir, helping to smooth the effects of intermittent solar and wind, and to absorb excess base-load from power plants.

Mark Carney, the Governor of the Bank England and chairman of Basel's Financial Stability Board, has repeatedly warned that fossil energy companies are booking assets that can never be burnt under the Paris agreement.

He pointed out last year that it took only a small shift in global demand for coal to bankrupt three of the four largest coal-mining companies in short order. Other seemingly entrenched sectors could be just as vulnerable. He warned of a "Minsky moment", if we do not prepare in time, where the energy revolution moves so fast that it precipitates a global financial crisis.

The crunch may be coming even sooner than he thought. The Basel Board may have to add the car industry to the mix. There will be losers. Whole countries will spin into crisis. The world's geopolitical order will be reshaped almost overnight. But humanity as a whole should enjoy an enormous welfare gain.

Drilling of crude Oil well

https://m.youtube.com/watch?v=7opX3uLKDqU&itct=CA8QpDAYACITCOHuw8rb7NMCFYOzVQodlv4BbjIHcmVsYXRlZEj-kIe3jL_Hn3Y%3D&client=mv-google&hl=en&gl=NG

Drilling of Crude Oil Well and Casing

https://youtu.be/7opX3uLKDqU

Nigerian HND is Equivalent to First Degree in US

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Farooq A. Kperogi via Google+
8 months ago +10
Ibrahim Waziri: From HND in Nigeria to PhD in America
What you will read
below is the inspirational story of a 29-year-old Nigerian from Bauchi who
Read more
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I read his account on your blog. Gives one hope, even if only a fraction of those who try will ever get in.
Muhammad Sani Aliyu 8 months ago
so this show and give people like us more hope about career development 
US IBRAHIM 8 months ago
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Farooq A. Kperogi via Google+
8 months ago +5
My column in today's Daily Trust on Saturday
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Wonderful. we are proud of youth like him. may almighty Allah bless him and bless our daily struggle in order to fashion our future. 
Babangida Muazu 8 months ago
Salam bro,, my name is Bashir monsur from lagos nigeria, I am one of several million yearning to have my masters done abroad with HND in Nigeria but don't
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Monsur Bashir 8 months ago
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MisG Ifezue
8 months ago +3
This is very inspiring, am inspired! Thank you for sharing and God bless you
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Lawan Abdulhamid
1 month ago
Mash Allah
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Umar Aliyu
8 months ago
This is amazing. Our Bsc counterparts in Nigeria see us as sinners or some kind of empty headed persons. This is actually inspiring.
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Monsur Bashir
8 months ago
Salam bro,, my name is Bashir monsur from lagos nigeria, I am one of several million yearning to have my masters done abroad with HND in Nigeria but don't sincerely know how. I have distinction in electrical electronics engineering in 2009 and since
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Adeyemi Laolu
8 months ago
His testimonies are so inspiring. His determination worked for him in a bigger way. What stops Nigeria from emulating this Southern University
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Nafi'u Mohammed
7 months ago
I don't know of a word to express my appreciation to you prof. What you are doing is what defines you as a good hearted and patriotic citizen. May Allah continue to guide your way and reward you in abundance. 
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Gambo Adamu
8 months ago
I am really proud of you aboki Allah yayiwa karatun albarka amen.
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I Badjie
8 months ago
Boiler Up!!!
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sani ashurah
8 months ago
Quite interesting. We wish more success in your endeavour. Congratulations to Ibrahim, his Mentor nd the entire Nigerians.
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OLUWASEUN DAVID
8 months ago
Okay, does that indicates that all US universities accept HND from Nigeria institutions. 
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abdulfatah suleiman
8 months ago
Masha Allah. Inspiring indeed
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Daniel Ugwa
8 months ago
Congratulations. Very proud of you
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Yusuf Alkali
8 months ago +1
Very inspiring story. Unfortuatley Nigerian Universities do not recognise quality. I am sure there a lot of HND graduates who cannot secure admission into Masters prgramme not to talk about PhD in Nigeria. My collegue was able to secure masters admission into a Nigerian university and graduated as the best student. He apply for PhD was rejected because he had HND. The candidate was sound and intelligent but he was denied admission because of the quantity not quality in him.
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RAYYAN BAWA
8 months ago
What an inspiring and great story. My sincere Regards to prof kperoogi.. You are one of my role model prof and I enyoy your weekly column on weekly trust "notes from atlanta". Rayyan Muh'd bawa from Bauchi State 
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Muneer Musdapha
8 months ago
Mr.Kperogi, you did a very good job. May Allah reward you abundantly. 
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Abdulwasiu Ibrahim
8 months ago
May Almighty Allah make it more easier for you and grants long live to enjoy what you suffered for, Amiin
@Farooq A. Kperogi, Jazak Allahu khair. May Almighty Allah stand for you anywhere anyway . Amiin 
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shuarau abdulhakeem
8 months ago
I thank Allah on your behalf.
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Saturday, September 3, 2016
Farooq A. Kperogi at 1:32 AM
Ibrahim Waziri: From HND in Nigeria to PhD in America
By Farooq A. Kperogi, Ph.D.
Twitter: @farooqkperogi
What you will read below is the inspirational story of a 29-year-old Nigerian from Bauchi who graduated with an HND in Electronics Engineering from the Federal Polytechnic, Bauchi, in 2009 and wound up getting a PhD in Information Security from Purdue University last month.
His journey started when he sent me an email in late 2009. He wanted to know if his HND would qualify him to study for a master’s degree in the US. I told him yes, and sent him links to two articles I wrote about studying in the US. I also guided him on how to take the GRE and TOEFL, how to apply to US universities, and how to get funding for his studies.
I didn’t think what I did would amount to anything. I have rendered countless such mentorships to several people. But two years later, I got an email from Ibrahim (now Dr. Waziri) that he was enrolled in a master’s program at a university here in Georgia thanks entirely to my guidance, which I frankly didn’t even remember until I searched my email archive. He even visited me in my home.
A few years later, he was accepted to the prestigious Purdue University to study for a Ph.D. He graduated a month ago with high honors and has accepted a well-paying job in Washington DC. To say I am delighted and proud of this energetic, passionate young man’s success is to understate the incredibly overwhelming joy I feel.
I requested Dr. Waziri to write a short piece detailing his journey to serve as an inspiration to many young people with HNDs who think their educational journeys have ended. Enjoy it:
Getting a Ph.D. from an American university has always been dream. But like many HND graduates, I always wondered if I would be able to continue with my studies in the US with a Nigerian HND. Would the HND be recognized as the equivalent of a bachelor’s degree? I had no clue until I came across Prof. Farooq Kperogi’s Weekly Trust column and blog.
In November 2009, I read Prof. Kperogi’s article titled “Studying in America: What you need to know.” After reading the article, and understanding how the process of getting accepted into an American University was, I emailed him to inquire whether my HND was equivalent to an American bachelor’s degree. He answered my questions, provided in-depth guidance, and later published another article titled “HND and American Universities, ” which provided a step-by-step guide on how an HND graduate can continue studying in the US.
Following guidance from Prof. Kperogi’s article, I submitted my OND and HND transcripts to the Word Education Services (WES) for evaluation. (WES is the largest international credential evaluation service in America and Canada). The evaluation results said my HND was equivalent to an American bachelor’s degree.
At the time my transcripts were under evaluation, I prepared for and took my Graduate Records Exams (GRE) and benefitted from the resources Prof. Kperogi generously shared with me. I got impressive scores. I applied for the master’s program at Georgia Tech, Southern Poly State University, and Georgia Southern University. I got accepted into Georgia Southern.
In August 2012, I started my Masters of Science degree in Applied Engineering (with a focus in Information Technology) at Georgia Southern University. It is at Georgia Southern that I met my mentor and amazing professor by the name of Prof. Jordan Shropshire, who is now a Professor of Computer Science at the University of South Alabama. I worked in Prof. Shropshire’s lab as a Research and Teaching assistant were I learned how to conduct research and mentor students. For my work, I got a tuition waiver and a monthly stipend.
I worked on different projects relating to Network Security and Cloud Computing, which resulted in my first academic publication. My performance during my master’s program was really impressive to the point that I got inducted into the Phi Kappa Phi Honor Society, the oldest and most selective honor society in the US. This is what my mentor, Prof. Shropshire, said about me:
“Ibrahim was my best graduate assistant at Georgia Southern University. He is intelligent, professional, and responsive. He completes complicated projects on time and under budget. A patient man, he excels at explaining complex subjects to non-technical persons. Even under the most stressful conditions I don't think I've ever seen him lose his cool. For these reasons (and many others) I wouldn't hesitate to hire him again. ”
– Source: Ibrahim Waziri’s LinkedIn profile.
In May 2014, I graduated with my master’s degree. Immediately after, in August 2014, I started my Ph.D. in Information Security at Purdue University, one of the best universities in the world. I worked extremely hard, taking more classes than required per semester. Because of the rigor of the research training I got from my master’s degree program, I was able to work on my dissertation while doing my course work. This enabled me to complete my 90 hours coursework and dissertation in 2 years. This is unusual. Ph.D. education in US universities typically lasts a minimum of 4 years.
I graduated with my Ph.D. in August 2016. My research areas are Network Security, Cloud Computing, and Virtualization Security. I have published and presented papers relating to Firewalls, Phishing Attacks, Cyber Forensics, etc.
While at Purdue University, I worked as a Cyber Anti-Fraud Analyst for RSA, the Security Division of EMC. And I also interned as a Cyber Security Analyst for the US Federal Government, working with USITC in Washington DC. This is what Prof. Sam Liles, one of my professors during my Ph.D. program, said about me:
“Ibrahim showed exceptional understanding of how to analyze malware and problem solve in a class he took with me. His work with volatile malware samples and structured laboratory problems shows a lot of promise. If you are looking for a savvy thinker and capable individual, he is the right person. I enjoyed watching his thinking processes and following along as he solved several complex problems. Almost always forgotten when recommending somebody, but very important is that Ibrahim is simply a nice guy and easy to get along with. ”
– Source: Ibrahim’s LinkedIn profile.
I currently work as a Security Research Engineer in Washington, DC. I still consider myself a student and want to gain more in-depth hands-on experience in the ever-changing Cyber Security field. But, ultimately, I want to come back home (Nigeria) to help tackle the Cyber Security issues Nigeria faces. You can look me up on LinkedIn or on my personal page at

The Role Of Polytechnic Education In Nigeria’s Quest For Economic Diversification Under Buhari

INTRODUCTION
The development of Polytechnic education is fundamental, if Nigeria must succeed in its quest for economic diversification. The essence of Polytechnic Education is to train students in technical areas where they can graduate and be self-employed, and also create employment for others. Polytechnic education can be a means to an end out of the present economic recession in Nigeria. It can be a tool for securing employment and emancipation of people through the provision and acquiring of necessary knowledge and skills. The role and importance of Polytechnic education in Nigeria cannot be overemphasized and can serve as a panacea to some economic problems. The administration of President Muhammadu Buhari aims at reducing unemployment through entrepreneurial development and the Polytechnic education issine qua non in meeting that target. This paper shall examine the role
ESTABLISHMENT OF POLYTECHNICS
The principal aim for the establishment of Polytechnics in Nigeria is to turnout the middle-level manpower needed for industrial and technological development of the country.
The Polytechnic is established in various parts of the country by an Act of the National Assembly to provide full-time courses in technology, applied science management and other fields of studies, and to make provisions for the general administration of such polytechnics.
Section 1 of Federal Polytechnics Act 2004 (hereinafter referred to as “the Act”) provides for the establishment of Federal Polytechnics in Nigeria. It states:
“There are hereby established the Federal Polytechnics specified in the First Schedule to this Act (in this Act severally referred to as “the polytechnic”) which shall have such powers and exercise such functions as are specified in this Act.”
FUNCTIONS AND OBJECTIVES OF POLYTECHNIC
Polytechnic education places emphasis on practice-based learning and skills acquisition.
Section 2 of the Act provides for functions of polytechnics, thus:
“(1) The functions of each polytechnic shall be-
(a) to provide full-time or part-time courses of instruction and training-
(i) in technology, applied science, commerce and management; and
(ii) in such other fields of applied learning relevant to the needs of the development of Nigeria in the area of industrial and agricultural production and distribution and for research in the development and adaptation of techniques as the Council may from time to time determine;
(b)to arrange conferences, seminars and study groups relative to the fields of learning specified in paragraph (a) of this subsection (1);
(c)to perform such other functions as in the opinionq of the Council may serve to promote the objectives of the polytechnic.
(2) Nothing in this section shall preclude the government of a State or any of its agencies from setting up a polytechnic similar to any polytechnic established under this Act.”
The main objective of polytechnic education is the promotion of technical and vocational education and training, technology transfer and skills development to enhance the socio- economic development of the country.
Polytechnic education plays a vital role in human resource development by creating skilled manpower, enhancing industrial productivity and improving the quality of life. It targets the students’ training in courses and programs such as engineering, estate management, architecture, carpentry, woodwork, farm, farming, town planning technology, management, applied arts and crafts, hotel management and catering technology. It equips the student. With small capital and support from corporative, a graduate can setup himself and train people. This became necessary in order to train people who will be good in technical work while others will be in administration, education, teaching etc.
Polytechnic trained graduates are expected by virtue of their training to be more practical in skills unlike their colleagues trained in the universities who are often more theoretical. Industrial Training (IT) exposure gives the academics a chance to seek inputs and feedback from practicing professionals who can provide valuable insight into the skills and abilities students would need in their career. This is why in Polytechnic curriculum, it is compulsory to have industrial attachment or internship for one year after the first two years before returning to complete for the next two years.
Polytechnic education offers an opportunity for students to personally practice the theoretical models in the classroom to enhance their chances of securing employment after graduation. They are to serve the middle-level manpower management needs of the country in the drive towards industrialization and economic diversification.
CHALLENGES
The polytechnics are not first choice institutions for many students because, opportunities for academic progression are limited and public recognition of the Higher National Diploma (HND) was low, but the Buhari administration has harmonized this such that progression of university graduates are the same as Polytechnics.
Even though polytechnics have been producing graduates ever since their establishment, there seems to be no distinctive practical traits exhibited by the polytechnic graduates that distinguish them from the university trained graduates.
President Buhari’s administration is scrutinizing the system in order to identify the gaps created and proffers ways to achieve their mandate of producing practically-oriented graduates to aid the country’s industrialization and economic diversification process or agenda.
A situation where Polytechnics graduates are looked down upon, because of the discrepancies existing between BSc and HNDcertificate has contributed greatly to the undermining of this all-important educational sector of the country. In most establishments, whether private or public, the discrimination exists at the point of entry and during promotion, with no recourse to individual talents and efficiencies. The move by the President Muhammadu Buhari’s administration to remove the disparity between BSc and HND certificates is a positive step to address the challenge.
It is interesting to note that the developed countries of Europe and America, including developing ones as China and India owe their technological dexterity to products of their polytechnic/technical institutions.
The Federal and state government is working hard to implement policies that would give the polytechnics their pride of place. Allowing a further disintegration in polytechnic education would consequently, do a great disservice to the country’s development. This government will do its best to bring Nigeria’s polytechnics at par with their peers in other countries.
WAY FORWARD
Since the Polytechnics are expected to give more practical approach to the training of its students, there is therefore the need to come up with more forward-looking and resourceful ways of ensuring that its graduates acquire distinct practical expertise that would distinguish them from their colleagues trained in other similar tertiary institutions such as the universities.
President Muhammadu Buhari’s administration is bringing solution to these challenges by encouraging Polytechnic education by harmonizing the HND and BSc. They are even contemplating making polytechnics to award Bachelor of Technology instead of Higher National Diploma (HND) in Technology.
CONCLUSION
Polytechnic education must therefore not be seen in terms of screw drivers and spanners but must be seen as encompassing all fields of applied learning relevant to the needs and development of Nigeria in the areas of knowledge needed in ensuring that resources of all types are efficiently translated into desired products and services.
Some offer education courses in petroleum engineering, petroleum technology which includes how to refine petroleum products. This is the kind of situation that Nigeria will now see need since it is now too expensive to import petroleum products. Government will now be training these people. This is one of the reasons I have been advocating that government should not destroy local refineries which I prefer to call modular refineries (i.e. what they call illegal refineries) but should integrate them into our refining system and allocate crude to them formally instead of sending Navy or Army to destroy them. Buy the crude they produce, test it through the Standard Organization of Nigeria. If it is approved, you buy it and put it into circulation. You do not allow them to produce it and sell straight. When it is integrated in our refining system, those who were trained in petroleum engineering and petroleum technology in the polytechnic and universities will be the heads in those areas.
Those who have been very rich men in the world have been those who were not administrators. They have been those who have had their skills like Henry Ford who established Ford Motors. He had the skills and knowledge and was able to impart it. It is said that it is not the actual doing of the work that he earns from but the knowledge which he imparts in the doing of the work.
In conclusion, I pray that the Government, as a policy, in addition to the co-location policy of mini refineries with mega refineries and to maximally reap the benefits of Polytechnic training, encourage and integrate local or modular refineries into the petroleum refining system of Nigeria.
I had recently submitted as part of the solution to the Niger-Delta crisis as follows on local refineries:
a) Integrated modular refineries now privately owned and operated by locals without license, otherwise called illegal refineries into formal refining system.
b) Accordingly, Government do cease the destruction of illegal refineries and rather engaged in dialogue with the representatives of this group as the actual operators may not come out for the dialogue for fear of set up and arrest.
c) That Government may formally agree to provide Technical assessments and quality appraisal of the products of these refineries and if found of quality, formally purchase same and distribute in her formal distribution channels.
d) Government will officially allocate crude oil to the persons payable in Naira and they will purchase and refine and sell for domestic consumption.
e) If Government does not allocate crude to them, they will take by their means and government will lose the fund from crude and refined products.
f) The concerns for the environment can be addressed by formally allocating land to the refiners, considering and professionally approving the designs of the refining sites and machines which will address environmental concerns of the different products and product lines.
Thank you.
Being a Keynote Matriculation Lecture at the first Matriculation/Inauguration Ceremony of Sure Foundation Polytechnic on 27th January, 2017.
Presented By: Senator (Dr.) Ita Enang, SSA to the President on National Assembly Matters – Senate
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Editor January 28, 2017 POLITICS,
SPECIAL REPORT
Tags » BUHARI, ITA ENANG, SURE FOUNDATION POLYTECHNIC
Skills Training Courses
Masters in Education

Portable Water Treatment With UV Light

04, 2011
EFFECTIVE AGAINST: Efficient at inactivating vegetative and sporous forms of bacteria, Giardia lamblia, Cryptosporidium cysts, and other pathogenic microorganisms.
INEFFECTIVE AGAINST: Not recommended if the untreated water contains high levels of coliform, substantial color, or suspended solids. (Where total coliform bacteria exceed 1,000 colonies per 100 mL or fecal coliform bacteria exceed 100 colonies per 100 mL.)
Contents
1 Uses
2 How ultraviolet radiation works
3 Capacity
4 Maintenance
5 Special considerations
6 Questions to ask before you buy
Uses
Ultraviolet (UV) light has been used to disinfect water supplies for more than 75 years, but only recently have home UV systems become available. Municipalities sometimes use UV instead of chlorination for disinfection to avoid the byproducts that chlorination may produce in the treated water supply. The primary advantage to UV treatment is that it disinfects water without the use of chemicals. Its primary disadvantage is the lack of residual disinfection.
UV devices may either be point-of-use or point-of-entry. UV light kills bacteria, viruses, and some cysts. It does not kill Giardia lamblia cysts or Cryptosporidium parvum oocysts, which must be removed by filtration or distillation. UV is not recommended if the untreated water has a coliform content exceeding 1,000 total coliforms or 100 fecal coliforms per 100 milliliters.
It is important to note that, although UV is an effective disinfectant, disinfection only occurs inside the unit. No disinfection occurs beyond the treatment unit to kill bacteria that survived or were introduced after UV treatment. If residual disinfection is necessary, chlorination may be necessary in addition to or as an alternative to UV.
How ultraviolet radiation works
UV systems expose water to the light from a special lamp. The light is at a specific wavelength, capable of killing common bacteria. The percentage of organisms killed depends on the intensity of the UV light, the contact time that the water has with the light, and the amount of suspended solid particles in the water. The system adds nothing to the water, produces no tastes or odors, and typically requires only a few seconds of exposure to be effective. Treatment of the water occurs as the water passes into the light. The light penetration into water is shallow, usually only 2 to 3 inches.
Suspended solid particles in the water can shield organisms from the light. The untreated water entering the unit must be completely clear and free from any sediment or turbidity to allow all of the bacteria to be contacted by the light. In addition, inorganic constituents such as iron, manganese , and hardness must be below certain specified levels for the UV unit to effectively treat the water. Water with a high hardness (calcium and magnesium) may also coat the sleeve with scale (a whitish deposit of hardness), which may require routine cleaning or addition of a water softener. Therefore, UV devices are often combined with other technologies such as particle filters, carbon filters, ion exchange units , and reverse osmosis systems to remove particles prior to UV disinfection. UV is often the last device in the treatment train (a series of treatment devices), following reverse osmosis, water softening, and filtration. The UV unit can either be a point-of-entry system, treating all the water entering the house, or a point-of-use device, treating water from a single tap as a final disinfection method.
The typical UV treatment device requires electricity and consists of a cylindrical chamber that houses a low-pressure mercury lamp that produces the UV light. A quartz glass sleeve encases the bulb, which prevents the water from contacting the lamp and helps keep the lamp at an ideal operating temperature of 104 F. The lamp produces the UV light. Approximately 95 percent of the radiation passes through this glass sleeve and into the untreated water. The untreated water either flows in a thin film over the sleeve, or it flows through quartz glass tubing that is spiraled around the lamp. The latter design allows for a longer contact time between the UV light and the untreated water. Lamp intensity, contact time, and general water quality determine the effectiveness of the process.
A UV unit should be located as close as possible to the point of use because any part of the plumbing system could be contaminated with bacteria. Before using a UV system for the first time, disinfect the entire plumbing system with chlorine.
Capacity
There is a limit to the numbers of bacteria that can be treated with UV. An upper limit for UV disinfection is 1,000 total coliforms per 100 milliliters or 100 fecal coliforms per 100 milliliters.
UV systems may have a flow rate capacity of 0.5 gallon per minute to several hundred gallons per minute. Household water requirements dictate the level of treated water needed.
Maintenance
Regardless of the quality of the equipment purchased, it will not perform satisfactorily unless maintained in accordance with the manufacturer’s recommendations for maintenance, cleaning, and part replacement. Keep a logbook to record water test results, equipment maintenance, and repairs.
Because UV radiation must reach the bacteria to kill them, the housing for the light source must be kept clean. Commercial products are available for rinsing the unit to remove any film on the light source. An overnight cleaning with a solution of 0.15 percent sodium hydrosulfite or citric acid effectively removes such films. Some units have wipers to aid the cleaning process.
UV systems are designed for continuous operation and should be shut down only if treatment is not needed for several days. The lamp needs a few minutes to warm up before the system is used again following shutdown. In addition, the plumbing system of the house should be thoroughly flushed following a period of no use. Whenever the system is serviced, the entire plumbing system should be disinfected prior to relying on the UV system for disinfection.
UV lights do not burn out but gradually lose effectiveness with use, so the lamp should be cleaned on a regular basis and replaced at least once a year. It is common for a new lamp to lose 20 percent of its intensity within the first 100 hours of operation, although that level is maintained for the next several thousand hours. Units equipped with properly calibrated UV emission detectors alert the owner when the unit needs cleaning or the light source is failing – an important feature to ensure a safe water supply. A detector that emits a sound or shuts off the water flow is preferable to one with a warning light. Detectors should not supplant annual replacement of the light source or regular cleaning of the lamp housing.
The treated water should be tested for coliform bacteria on a monthly basis for at least the first six months of the device’s use. If bacteria are present in the treated water, the lamp intensity should be checked and the entire plumbing system should be shock chlorinated.
Special considerations
Ensure the system you choose is installed and operated according to the manufacturer’s instructions. After installation, retest both the raw water (prior to treatment) and the treated water at a state certified laboratory to ensure it is working properly and removing the contaminants. You should continue to test the quality of both the untreated and treated water annually. This annual test will also help you determine how well your treatment system is working and whether maintenance or replacement of components may be necessary.
The following affect the disinfection efficiency of a UV system:
* Contact times and flow rate
* Depth of water being treated
* Chemical and biological films that develop on the surface of UV lamps
   * Water quality - the presence of other contaminants
   * Clumping or aggregation of microorganisms
   * Turbidity
   * Color
   * Short circuiting in water flowing through the UV contactor
   * Accumulation of solids on the surface of the UV sleeves
Questions to ask before you buy
Before purchasing a water treatment device, have your water tested at a
state certified laboratory to determine the contaminants present. This will help you determine if ultraviolet radiation is an effective treatment method for your situation. See Questions to Ask Before You Buy A Water Treatment System for more information.
Adapted from: Wagenet,L., K. Mancl, and M. Sailus. (1995). Home Water Treatment . Northeast Regional Agricultural Engineering Service, Cooperative Extension. NRAES-48. Ithaca, NY.
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drinking water, drinking water treatment

Solution to water well drilling problems

Solutions to Well Drilling Problems
Plan for the best and be ready to take corrective actions when your plans go wrong! This section of the tutorial is designed to help you solve the problems you will encounter when you drill wells. Don't be discouraged.... use your common sense and learn what you can from the situation you are in! Common problems include:
G-1: Excessive Fluid Loss
G-2: Borehole Caving
G-3: Drill Bit Jamming
G-4: Drilling Fluid Backflow
G-5: Objects Dropped Into Well
G-6: Resistant Beds Encountered
G-7: Contaminated Soil/Water-Bearing Zones
G-8: Flowing Wells
G-9: Marginal Aquifer Encountered
G-10: Casing Jams During Installation
G-11: Well Stops Producing Water
G-12: Footnotes & References
G-1: Excessive Fluid Loss
Large amounts of make-up water is usually required and must be immediately available at all times when drilling in permeable sand and gravel. This is important because drilling fluid sometimes suddenly flows into permeable formations which are being drilled rather than circulating back up the borehole.
If return circulation is suddenly lost, immediately switch the 3-way valve to direct the drilling fluid back to the pit through the by-pass hose (this minimizes the loss of valuable water). Then quickly pull-up the drill pipe 1-2 metres from the bottom of the borehole so that it is less likely to become jammed if the bottom portion of the hole collapses.
If drilling has been proceeding with a thick bentonite mud, the best possible action is then "to wait" (Australian, 1992) . A waiting period may allow the fluid to gel in the formation and provide a seal sufficient to allow circulation to be restored. If drilling has been proceeding with water or natural mud, replace the fluid with a thick bentonite slurry, circulate it down the borehole and let it sit for a while. When ready to circulate back down the hole, hit the drill pipe rapidly with a hammer to jar loose the mud and open the pipe.
If waiting and thickening the drilling mud do not restore circulation, question why the circulation was lost. If the drilling fluid is being lost into a highly permeable saturation formation, it may be possible to construct an excellent well! Therefore, test the well yield before deciding to proceed with the steps outlined below.
If it is necessary to drill further, try adding thickening materials to the drilling mud. This may occur when extremely unstable formations or those containing open fractures are encountered. Almost any granular flake or fibrous material can be used to provide a wad to block a lost circulation zone. Local materials such as bran, husks, chaff, straw, bark, wood chips, cotton, feathers, or even fibre or wool bedding can usually be located readily and used (Australian, 1992) . This material should be pushed down the hole and allowed to block the fractures.
The "gunk squeeze" method of sealing off a zone of lost circulation involves forcing a large amount of clay or cement into the zone of water loss (usually at or near the drill bit) and forcing it into the formation where it swells and fills-up any cracks (Australian, 1992) . The best way is to mix a very high concentration (6 - 7 kg/L) of bentonite. Once mixed, immediately lower it into the borehole in a sealed bag or container which can be ruptured when opposite the lost circulation zone. This material can be forced into the formation by pressurizing the borehole or by pushing it with a block on the end of the drill string.
If the lost circulation zone cannot be blocked, drilling sometimes may proceed without return circulation. The cuttings are carried away into the formation cavities. It may be necessary to occasionally pump a slug of thick mud to clear the bottom of the hole (Australian, 1992) .
Alternatively, casing can be placed to seal-off the problem zone. Ensure that the hole has fully penetrated the problem zone which is to be protected by the casing; Running the casing too soon may not overcome the problems for long. Finally, if none of these options work, it may be necessary to abandon the hole or to continue drilling using a air rotary drilling machine (Australian, 1992) .
G-2: Borehole Caving
The main cause of borehole caving is lack of suitable drilling mud (see
Section 5). This often occurs in sandy soils where drillers are not using good bentonite or polymer. The problem can be seen when fluid is circulating but cuttings are not being carried-out of the hole. If you continue to push ahead and drill, the bit can become jammed, the hole will collapse when you try to insert the casing or a huge portion of the aquifer may wash-out making it very difficult to complete a good well. The solution is to get some bentonite or polymer or, if necessary, assess the suitability of natural clays for use as drill mud (see Appendix H ).
Borehole caving can also occur if the fluid level in the borehole drops significantly (see Footnote #1 ). Therefore, following a loss of circulation or a night time stoppage, slowly re-fill the borehole by circulating drilling fluid through the drill pipe (pouring fluid directly into the borehole may trigger caving). If caving occurs while drilling, check if cuttings are still exiting the well. If they are, stop drilling and circulate drilling fluid for a while.
Sometimes part of the borehole caves while the casing is being installed, preventing it from being inserted to the full depth of the borehole. When this occurs, the casing must be pulled out and the well re-drilled with heavier drilling fluid. When pulling the casing, no more than 12.19 m (40 ft) should be lifted into the air at any time; more than this will cause thin-walled (Schedule 40) PVC to bend and crack.
G-3: Drill Bit Jamming
The drill pipe and bit may become jammed when the drilling fluid is not allowed to thoroughly clean the borehole prior to stopping to add another joint of drilling pipe or the fluid is too thin to lift gravel from the bottom of the borehole. Therefore, if the drill bit starts to catch when drilling, stop further drilling and allow the drilling fluid to circulate and remove accumulated cuttings from the borehole. Then continue to drill at a slower rate. If it continues to catch, thicken the drilling fluid.
If the drill bit and pipe become jammed, stop drilling and circulate drilling fluid until it is freed. If circulation is blocked, try to winch the bit and pipe out of the borehole. Stop the engine and use a pipe wrench to reverse rotation (no more than 1 turn or the rod may unscrew!). Rapidly hit the drill pipe with a hammer to try and jolt the bit free.
If these actions are not successful, use lengths of drill pipe without a bit attached or Wattera tubing to "jet out" the cuttings. Attach the pipe or tubing directly to the discharge hose from the mud pump. Thicken the drilling fluid to ensure that the cuttings holding the bit can be removed. Then place tension of the stuck pipe with the drill rig winch. Once fluid starts to circulate out of the borehole, slowly push the jetting pipe/tubing down the borehole beside the jammed drill pipe until the bit is reached. When fluid starts to circulate out of the stuck pipe and/or it loosens, pull the stuck drill pipe and resume circulation of the thickened drilling fluid back down the drill pipe and bit. Remove the jetting pipe. If water freely circulates out the borehole, slowly lower the drill pipe and bit and resume drilling.
G-4: Drilling Fluid Backflow
Sometimes drilling fluid comes up through the drill pipe when you disconnect the swivel. This is caused by falling soil particles pressurizing drilling fluids at the bottom of the hole. Immediate action is required because this occurs when either the borehole is caving-in or when drill cuttings have not been cleaned well enough from the borehole. If you notice backflow of drilling fluid, immediately re-connect the drill pipe and continue circulation to clean-out the cuttings. If caving is suspected, thicken the drill mud while continuing circulation.
G-5: Objects Dropped Into Well
Unfortunately, sometimes wrenches, rocks etc are inadvertently dropped into the borehole when drilling. In addition, the LS-100 is often operated near its design limits with a high degree of structural stress on the drilling stems and tools; encountering unexpected layers of very soft sand or filter or hard rock can cause cave-ins or tool breakage and all the drill pipe can be lost in the hole.
If objects are dropped into the borehole after the final depth has been reached, it may be possible to leave them there and still complete the well. If this is not the case, it may be possible to make a "fishing" tool to set-up on the lost gear. For example, if a length of well screen falls down the borehole, it may be possible to send other sections down with a pointed tip on the end and "catch" the lost casing by cramming the pointed end hard into it. These types of "fishing" exercises require innovation and resourcefulness suitable to the circumstances - there is no single right way of doing this work. If sediment has caved in on top of the drill bit or other tools, circulation should be resumed in the hole and the fishing tool placed over the lost equipment.
If the lost tools/bit(s)/drill pipe are not critical, do not even try to retrieve them and just move over and start drilling a new hole. Even if the equipment is important, it is still best to start drilling at a new location while others try to retrieve it since considerable time can be spent on retrieval and there is a low likelihood of success.
G-6: Resistant Beds Encountered
Once a resistant bed is encountered and the rate at which the drill bit is penetrating the formation drops dramatically, a decision needs to be made whether to stop drilling or to continue. If the resistant bed is comprised of gravels, the drilling fluid may need to be thickened to lift-out the cuttings. If the resistant bed is hard granite, drilling with the LS-100 should cease. Other drilling methods should be found or drilling should be attempted at another location. Remember, to help as many people as possible and to get the best value for donor dollars, DRILL THE EASY BOREHOLES FIRST!! It is not worth wearing-out the equipment by grinding away for hours and hours to gain a foot or two of borehole depth.
G-7: Contaminated Soil/Water-Bearing Zones
It is sometimes necessary to drill through aquifers which contain contaminated water. In these situations, drill until a confining layer (clay or rock) is encountered. Insert the casing and then seal the annular space with a grout slurry. To avoid damaging the grout seal, let the grout cure for at least 12-24 hours prior to resuming drilling (Driscoll, 1986).
Grout is prepared by mixing 19.7 L (5.2 gal) of water with every 42.6 kg (94 lb) sack of cement (Driscoll, 1986) ; 5 volumes grout slurry can be made by mixing 4 volumes cement powder with 3 volumes fresh water (Australian, 1992) . Alternatively, each sack of cement can be added to a clay-water suspension formed by mixing 1.36 - 2.27 kg (3-5 lbs) of bentonite with 25 L (6.5 gal) of water (Driscoll, 1986). This mixture helps hold cement particles in suspension, reduces cement shrinkage, improves the fluidity of the mixture and prevents excessive penetration of grout into these formations.
Cement grout is normally placed by just pouring it into the annulus. Alternatively, some grout could also be poured into the casing and/or the casing could be raised several feet and then pushed into the grout that accumulates at the bottom of the borehole. Place the grout in one continuous operation to form a good seal (Driscoll, 1986). Since irregularities in the size of the borehole and losses into formation may occur, the driller must be prepared to augment initial estimates of grout volume on short notice.
Where contamination is severe, follow special procedures to ensure that a very good seal around the casing is achieved (see Appendix I). When you finish grouting, ensure that you leave about 0.5 metres of grout in the casing (see Footnote #2).
G-8: Flowing Wells
Sometimes the water in a confined aquifer is under so much pressure that it will flow out the top of a well which is drilled into it. Special precautions and construction techniques must be used to control the water pressure and flow or serious environmental problems can result. The free flow of excess water to waste can result in the depletion of a valuable resource and in unnecessary interference with other well supplies. Free flow from the well casing or a breakout of uncontrolled flow around the well casing can cause serious erosional and flooding problems on the owner's and adjacent properties that may be very difficult and costly to correct.
Sometimes natural flow can be brought under control by extending the well casing 1.5 - 6 m (5 - 20 ft) into the air. This can allow the pressure in the pipe to balance that within the aquifer. A spout with a tap can then be installed in the side of the casing. A hand pump can be installed at a later date if the pressure in the pipe drops over time.
G-9: Marginal Aquifer Encountered
Sometimes a very thin or relatively impermeable aquifer is encountered which must be developed to provide a reliable water supply. Ensure that the borehole penetrates the full thickness of the aquifer, extending as far below it as possible. Install the well screen adjacent to the entire aquifer thickness with solid casing installed above and below it. After developing the well, install the pump cylinder as low as possible in the well.
If a well is being completed in a fine sand/silt aquifer within 15-22 m (50 - 75 ft) of ground surface, a 20 cm (8 in) reamer bit has sometimes been used (e.g. Bolivia). This makes it possible to install a better filter pack and reduces entrance velocities and passage of fine silt, clay and sand particles into the well.
Yield can be maximized by adding a small amount of a polyphosphate to the well after it has been developed using conventional techniques. The polyphosphate helps remove clays that occur naturally in the aquifer and that were introduced in the drilling fluid (see Footnote #3).
Enough time must be allowed between introduction of the polyphosphate and development, usually overnight, so the clay masses become completely desegregated (Driscoll, 1986) . After the polyphosphate solution is surged into the screen (see Footnote #4 ), water should be added to the well to drive the solution farther into the formation.
G-10: Casing Jamming During Installation
Sometimes it is not possible to lower the casing and well screen to the bottom of the hole. This can be due to part of the borehole collapsing, clays in the aquifer swelling and reducing the size of the borehole or the borehole being crooked resulting in the casing digging into the wall of the borehole. These problems are most common where 10 cm (4 in) schedule 40 casing is being inserted into a 15 cm (6 in) borehole. This is because the outside diameter of the casing couplers is 13 cm (5.25 in), leaving an annular space of just over a quarter inch on each side of the casing! It does not take much swelling of clays or slight deviation from vertical to result in the casing jamming.
If the casing does not slide freely into the borehole, it is not advisable to try and force the casing down. Striking it hard in an attempt to drive it may cause the screen to deform; rotating and pushing it down can cause the screen openings to become hopelessly plugged with fine materials.
To avoid these problems, minimize the amount of pull-down pressure when drilling so that the bit can run freely under its own weight. Also, casing there is no problem with casing jambing when 7.6 cm (3 in) schedule 40 casing is used. Keep in mind, however, that a 7.6 cm (3 in) casing is too small to take a 6.4 cm (2.5 in) pump cylinder or most submersible pumps. Usually, however, these issues are not a concern.
If you need to construct a 10 cm (4 in) well and the casing has jammed, the best solution is to pull the casing / screen from the borehole. This involves cutting the casing into 6-12 m (20 - 40 ft) lengths (longer than this will result in the casing bending and cracking). Slowly re-drill the borehole with a 15 cm (6 in) reamer bit or, if available, a 18 or 20 cm (7 or 8 in) bit. Concentrate on the portion of the borehole where the casing jammed. While this can take several hours, it often eliminates blockages and allows the casing to slide to the bottom of the borehole. As soon as the reaming is completed, re-glue and re-insert the casing.
If it still jams, your last resort is to try and "wash" the casing down by installing the drilling rods down inside the casing and circulating drilling fluid through a wash-down valve (see Section 7). Fluid is pumped down through the casing and out the bottom of the screen where it will pick-up and carry soil particles back up to the surface between the casing and the hole walls. The amount of water passing through the screen openings can be minimized by attaching a surge block to the lower end of the drill string. Be sure to secure the pipe with a rope to prevent the casing from dropping if the blockage was localized and is removed with the circulation process. Failure to do so could result in the casing dropping to the bottom of the hole without the casing extending to the surface. When the casing is finally installed to the appropriate depth, stabilize the open bottom end of the casing by pouring in 30-60 cm of coarse gravel into the well. If the casing still jams above the water bearing formation, the only other option is to obtain and install 7.6 cm (3 in) casing and well screen.
G-11: Well Stops Producing Water :
A well can suddenly no longer provide the same amount of water that it did before. If you move the pump handle and it feels OK but little or no water comes out the spout, the well may be dry. Confirm this by measuring the water level in the well and try to determine which of the following causes is responsible:
Natural Lowering of the Water Table: Water levels in shallow dug and bored wells experience large fluctuations due to climatic conditions. The natural seasonal change in water level often will often be several metres. This is likely the cause of the drop in yield if the level of water within the well does not rise up, even several hours after pumping. All that can be done is to construct a new well, ensuring that the well casing is set far enough below the water table (ideally 5 to 10 metres) to assure an adequate water supply during the dry summer periods when the water level declines. Also, check how many people are drawing water from the
Well Water Interference : The construction of water and sewer mains, drainage ditches and highways (road cuts) can occasionally affect ground-water levels and interfere with nearby shallow wells. In addition, the static water level in a well may be affected by large withdrawals of ground water from nearby large capacity wells or de-watering equipment for construction works (see Footnote #5). The potential for well interference depends greatly on the lithology of the producing formation and the magnitude of well usage.
Screen Blockage: Sometimes the problem is that the well screen has plugged-up with fine sand and silt particles, with accumulated iron deposits or with growths of nuisance bacteria (naturally occurring, non-health related bacteria with can produce rotten egg smells, random slugs of iron rich water etc). This is likely the case if the water level in the well is near its original construction level but drops to the bottom of the pump cylinder as soon as the well is pumped. The well should be extensively re-developed to try and restore the efficiency of the screen and gravel pack (see Section 10). Unfortunately, if the problem occurred once, it will probably occur again. Be prepared to repeat the development process as needed to extend the life of the well.
G-12: Footnotes & References
1 The drilling fluid prevents caving of the borehole because it exerts pressure against the wall. As long as the hydrostatic pressure of the fluid exceeds the earth pressures and any confining pressure in the aquifer, the hole will remain open. The pressure at any depth is equal to the weight of the drilling fluid column above that point.
2 Before drilling out the grout plug, the effectiveness of the seal can be checked by measuring water-level change in the casing over time. In wells with a low static water level, the casing can be filled with water or drilling fluid and later checked for any water loss. If the static water level is high, the casing can be nearly emptied and any influx of water into the casing can be measured.
3 Frequently used polyphosphates include sodium tripolyphospate [Na 5P3 O10), sodium pyrophosphate (Na 4P 2O 7), tetra sodium pyrophosphate (NaP 2O 7) and sodium hexametaphosphate (NaPO 3) (Anderson, 1993).
4 About 6.8 kg (15 lb) of a polyphosphate should be used for each 400 L (100 gal) of water in the screen. 0.9 kg (2 lbs) of sodium hypochlorite should also be added to every 100 gal of water in the well to control bacterial growth promoted by the presence of polyphosphates (Driscoll, 1986) . Polyphosphates should be premixed before introduction into the well because they do not mix easily with cold water. Occasionally the mix water is heated to help dissolve the chemical (Driscoll, 1986). Polyphosphates should NOT be used in formations with thinly bedded clays and sands because these chemicals tend to make the clays near the borehole unstable, causing them to mix with the sand (Driscoll, 1986) continually passes into the borehole during pumping (Anderson, 1993).
5 When a well is pumped, the water level in the immediate area of the well is lowered and a cone of depression develops around the well. The size and the shape of the cone will depend on the aquifer characteristics of the water-bearing formation in which the well is completed and the rate of pumping. This is likely the cause if there are two or more wells located within 100 m of each other and if water levels return to normal in both wells once pumping has stopped or within some reasonable time afterwards. Water level recovery depends on the quantity of water withdrawn from the aquifer and the length of time the wells were pumped. All that can be done is manage the rate at which water is taken from the interfering wells.
Australian Drilling Industry Training Committee Ltd (1992) Australian Drilling Manual 3rd edition" , Macquarie Centre: Australian Drilling Industry Training Committee Ltd, ISBN 0-949279-20X.
Driscoll, F. (1986) Groundwater and Wells , St. Paul: Johnson Division
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