industrial training report (tsholo)

8/7/2019 Industrial Training Report (Tsholo)

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BOTSWANA COLLEGE OF ENGINEERIND AND TECHNOLOGY

INDUSTRIAL TRAINING

REPORT

7/23/2010

FRANCISTOWN CITY COUNCIL: Water and wastewater

department

BY TSHOLOFELO BASHE

Student ID: 4049

Date of attachment; may 24 2010 to July 23 2010


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TABLE OF CONTENTSACKNOWLEDGEMENT ........................................................................................................ 3

INTRODUCTION..................................................................................................................... 4-8

WORK DETAILS .................................................................................................................... 9-18

RECOMMENDATIONS and ............................................................................................ 19

CONCLUSIONS

..................................................................................................................................................................


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ACKNOWLEDGEMENTWorkers of Francistown City council under water and wastewater department have been helping me wholeheartedly toacquire knowledge on their organization.They also assisted me

on writing my report. I send the special thanks to those listed

below:

Mr. B.Legwaila

Mrs. Mhlanga

Mr B. koolopileMr A. Mmusi

Mrs L. Lokwalo

Mr Hulela

Mrs I. Gokatweng

Mr. C.N Masole


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INTRODUCTIONI reported on the 24th of May 2010 in Francistown City

Council under Water and Waste Water department(sewerage) for industrial training. I did the industrial

training to aquire skills and knowledge about water and

waste water and also to know their core main duties such as

treating waste water.

The City Francistown has around 300km of sewer lines 19

sewerage pump stations, a 15000m3/day capacity

trickling/bio-filter wastewater treatment plant, a set of 5

waste stabilization ponds, vacuum tankers and other utility

vehicles in the fleet, some tools and equipments for its

sewerage operations. The department is responsible for the

safe collection, conveyance and treatment of wastewater

generated within the city from both onsite and offsite

sanitation facilities in an environmental friendly manner.

The sewerage department comprises of two sections,

namely; Operations and Maintenance and the Wastewater

TreatmentPlant.

OPERATION AND MAINTERNANCE UNIT

inspections, building control, bye-laws and sewerage

charges, maintenance and repair of the sewer reticulation


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system, sewer cleaning and blockage clearing.

THEWASTEWATER TREATMENT PLANT

The Mambo Water Care Works was officially wetcommissioned on the 23rd June 2003. It was designed and

supervised by Stewart Scott International (SSI), financed by

Department of Sanitation and Waste Management (DSWM)

formerly under the Ministry of Local Government. Since its

commissioning, the plant never met the Botswana set

standards for discharge of effluent to the outside. This ismainly caused by industries that discharge of influent of high

chemical oxygen demand (COD), however there are also

some shortcomings in the design of some units of the plant

that have some contribution in the plants poor performance.

This includes dosing of flocculent, incineration of screenings,

and harvesting of methane gas.

Having design capacity of 15000m3/day, the plant only

receives about 6000m3/day o sewerage through the

sewerage network with 19 pump stations and vacuum

tanker services as litters to help sewerage reach its

destination.

THE TREATMENT UNIT

During the treatment process, three products are

formed 1 ) Effluent (treated water) 2)Sludge, which is


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pumped into the digesters for treatment and then flows into

the drying beds for drying. The sludge is then manually

removed and disposed off. 3) Methane Gas which is

supposed to be used to ignite the incinerator.

Basically there are three main sections which make

sure that the treatment process is fully effected namely:

1) Process Section #Control wastewater quality

#Units monitoring

#Operate treatment plant

2) Electro-Mech Maintenance Section 3)Laboratory Section

POLICIES

The policy of Botswana Government is to provide

waterborne sewerage to its citizens in order to protectgroundwater sources and prevent waterborne diseases.

This is in line with the Township, the waste management,

the water and public health acts.

The City of Francistown has a sewerage master plan which it

is following in implementing the sewerage infrastructure

development in the city. Phase 1 has already been

successfully implemented. Phase II is now being

implemented.


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In the mean time measures are being implemented in

order to improve the quality of the final effluent from the

plant e. g the rejuvenation of the old ponds to work together

with the treatment plant.

SERVICES

FREE SERVICES

#Attending sewerage blockages in all council lines

#Cleaning council sewer line

#Inspection of sewer connections and sewer relatedproblems

#Industrial effluent monitoring

#Advising stakeholders on wastewater management

#Promote reuse of treated effluent, sludge and biogas

PAID SERVICES

A new comprehensive schedule of sewerage charges has

been prepared as part of Government Cost Recovery

Programme and is now in effect having been implemented in

July 2005. The charges are with respect to the sewer

connection fees, re-use of treated effluent, wastewater from

other councils, maintenance charges for damages to sewer

pipes and illegal connections.

#Most of the funds for running the sewerage infrastructure

are provided by the government through the Revenue

Support Grant. The funds raised by sewerage charges


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constitute only about 10% of the budget. This is a problem in

that any reduction s in the RSG by the government affect the

operations of Department pro-rate

AREAS OF COOPERATION

A.Hands-on training of staff in the cooperation of staff inthe operation and maintenance of sewerage network

and the wastewater treatment plant.

B. Provision of support to the telemetry system being

put in place for monitoring the operation andmaintenance of sewer network, the plant and the pump

stations.


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WORK DETAILS

BLOCKAGES: Blockages are reported to the Operations

and Maintenance Unit. Blockages that were not from the

council sewer line were paid P30/blockage. When

unblocking a sewer pipe we used iron rods. A rod was

uncoiled until it reached the blockage in the sewer pipe

through the manhole. When it reached the blockage it was

twisted until the blockage is loosen and breaks away. If the

blockage did not break or it is difficult to break due to fats

roots, food grease ,hair and other organic matter, a chemical

called crunch was poured in the drain together with the

boiling water to dissolve it .Crunch was then opening the

sewer and drain and also dissolved the blockage.Precautions taken when handling crunch was avoiding

contacting it with skin clothes and eyes.

VACUUM TANKER SERVICES: Drainages were also reported

in Operations and Maintenance Unit at 50/load. Drainages

that were attended were the septic tanks and the pit-latrines. When using a vacuum tank a hosepipe was inserted

in the septic tank or pit-latrine then the vacuum pump is

switched onto pump the sewer. The gauge showed the

amount of sewer in the tank. When the sewer is finished in


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the pit latrine or septic tank the pump was stopped and the

leaver was lifted them water was poured in the hosepipe to

flush the remaining sewer from it. The collected sewer was

then b disposed to the plant in Mambo Water Care Works for

treatment.

CONSTRUCTION AND REPAIR: In construction and repair,

damaged manholes were repaired and identification of

connection points for the clients. When identifying a

connection point in an area we looked for a nearby manhole.

When the manhole was found then the connection point was

easily identified looking at the depth of the of manhole, thedistance as well as the angles from the building or area that

needed the connection point.

INSPECTION AND BUILDING CONTROL: Under inspection the

clients booked for inspection of plumbing appliances and paid

P50/inspection. During the time of inspection it was made sure that

plumbing appliances are connected correctly. It inspected whether

the taps for cold and hot water were connected on correct sides,

which is for hot water, on the left side, and for cold water, on the

right side. It was also inspected whether there are no leakages on

the taps. The toilets were also inspected to see if they flush well and

no leakages found on their connections. The bathes were inspected

to see if there are safe to use, this was done by knocking on the

baths surface, if it made a lot of noise it was not safe, but if it did not

make noise it was safe. The basins were inspected to see if water

flows easily to the gully and also to see if their


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Overflow control pipes are working. The manholes were also

inspected to see if there were done at the correct depth slopes and

angles. This inspection of plumbing appliances was done to make

sure that blockages are overcome on the sewer line and also

leakages of water. Under building control section there wasassessing files of building control under sewerage works office for

sewerage connection. There was compulsory requirements and

checklist. Those are 1.One copy of detailed floor plan

showing internal plumbing. For multi-storey buildings, schematic

drainage drawings for each storey shall be submitted.

2. Copy of certified ID [O-mang or passport for non-

citizens], certified copy of plot certificate [e.g. title deed], and recent

letter received at mailing address as proof. 3. Sewer

reticulation drawings must show flow direction and final sewer

connect point. Ensure that proposed sewer connection points are

shown accurately as they appear on the ground.

4. Gully traps vent pipes

and any other fixtures must be shown on the plan in correct

positions. 5. Ensure sewer lines are not connected

in acute angle or against flow directions

6. Minimum sewer diameters should be as follows: 110mm inside

plot and 160mm outside plot boundary 7. Manholes should be

provided at every change sewer alignment, every change of gradient

at the head of all sewers, for branches at every junction of two

sewers and lastly at every change in the size of sewer.

8. Minimum manhole size should be 450mm x 600mm

9.Manhole construction and manhole cover types must be specified

10. Manhole deeper than 800mm should be provided with step irons

PLANT PROCESS: Plant is where the waste water is treated to

extent that it can be re-used in construction and watering. Daily grit

(soil) was removed. It was ensured that the classifier and the paddle


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drives are running. After that blowers were started to introduce

high pressure air at the bottom of the chamber. The valve was then

closed for the air outlet to blow up particles. After a minute a valve

was opened for heavier particles to be forced to go through the pipe

leading to classifier, this is where the separation of particles tookplace. The process is called degriting. Grit consists of inorganic and

organic substances, e.g. soil, wood; food scraps EST. Under this

section readings of influent and effluent were recorded daily prom

prosonic level controller at 2 hours interval starting at 8am until

4pm hence calculating the daily flow.

Controlling and operating the humus tank

valves which allow sludge to flow back into the plant wasdone in 2 hours interval starting at 8am until 4pm. Disluging

drying bed was done manually after every week because

drying beds took long to dry due to winter season

degriter tank 1


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LABORATORY PROCESS: Under these section every

day around 10: a m and 3pm samples were collected from

the effluent, trick filter and the influent. These samples are

used for measuring no of settled solids in an hour by the

influence of gravity.


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measuring no of settled solids in inf1


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Particles that settle are those that have greater specific

gravity than water. The no of solids also determine the

nature of population around the city hence how to design

the primary settlement tanks

Samples 1


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The samples were also tested pH and

temperature using pH/temp meter.Meaasuring temperature

is basically important for its effect on the properties e.g.

speeding up chemical reactions in solubility of gases and

amplification of taste and oudours. PH was measured

because in wastewater within a range of favorable to

particular organisms involved such as bacteria. Chemical

process used to coagulate wastewater dewaters sludge or

oxidize certain substances such as cyanide ion require pH to

be controlled within a rather narrow limits.

ph and temp meter 1


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The samples were also used for measuring no

of solids in water. They were poured in the Petri-dish then

placed in an oven for 2 hours at 105oc for drying after that it

was cooled then weighed by the analytical balance. The total

no of solids dissolved and suspended solids were also

measured. The samples were filtered, the liquid that passes

through the filter paper was used to measure the total solids

dissolved while the suspended solids were measured by the

solids that remained in the filter paper after heating them to

dry. This process was done because in portable waters mostof matter is in dissolved form and consists of mainly

inorganic salts, small amounts of organic matter and

dissolved gases. In all other liquid materials the amount of

undissolveds colloidal and suspended matter increase with

the degree of pollution.


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Chlorine test was done in the effluent only. The sample was

tested using photometer. A sample was poured in tube then

placed in the photometer, after that the photometer

calibrated to choose the fraction which is 25 for chlorine, the

photometer then instruct to start the test 1. For test 1 DPD1

Pill was put in the sample, it is the returned to the

photometer again, then the photometer will instruct to start

a second test using DPD3 Pill then the test will be done. The

result will then appear in the display, showing free chlorine

combined chlorine and tot chlorine. This chlorine is done to

check whether the amount of chlorine in water is suitable foruse without any harm.


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RECOMMENDATIONS

It is important that every level of worker in the company be

able to do their job to the full extent. Delays due to

numerous consulting of higher members of the company

reduce the effect of the workforce hired. Errors are made by

unskilled laborers who are hired by the company. This also

produces time delays and costly mistakes which would

require the skills of a higher ranked employee of the

company. This causes a chain of time consuming that ripplesthrough the workforce to a certain extent. Not all safety

regulations are followed by the employees. This leads to risk

of mishaps and serious injuries to employees.

CONCLUSION

The time spent on all the sites increased my knowledge of

the industry in practical sense and thus gives me the

confidence to be certain of the future growth of my skills and

knowledge of the industry.

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