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City
of Harare - Sewerage and Water Part 2
Councillor
Michael Laban
February
16, 2003
Previous
article
Hello
I am still waiting
for some information from officials, but will continue with what
I have, rather than wait any longer. The previous note on sewerage
brought a fair amount of response, some from sewerage and water
engineers. Some very interesting points raised, and I would like
to get in touch with most of them because they undoubtedly know
more than I do.
The second part
of this sewerage and water story is about water. The City Department
of Works has two divisions – the Planning Services Division, and
the Engineering Services Division. Under the engineering Services
Division, there are several branches, one of them being Sewerage
and Farming, and another being Water. In some respects it is important
that they remain separate, because the people and the equipment
used for fixing sewerage pipes are not supposed to be the same people
and equipment used for fixing water pipes, even though it is the
same methods and equipment being used to fix pipes. Unfortunately,
due to a shortage of everything, sewerage and water repair crews
are often transported in the same vehicles.
One bad aspect
of the branch separation is that when you say "water"
they only talk about water. If you want to talk about the whole
concept, and the fact that we are polluting our own water sources,
you have to consciously make the distinction and talk about water
and sewerage. It is a bit frustrating because each branch has their
own problems and wants assistance with those problems.
I first had
a meeting with Engineer Lovemore Mlanda, the Acting Deputy Chief
Engineer. (Principle Engineer, Water Branch), and Bernard Chatukuta,
who in 1997 became the Senior Engineer, and in 1998 was promoted
to principle engineer and head of Water Section. Last week I visited
Morton Jaffray with Mr Chatukuta and the Chief Chemist.
The Water
Branch deals with the extracting, treatment and distribution
of water.
Extraction Water
comes from 4 water sources;
1. Harare
Dam (formerly Henry Hallam)
2. Seke Dam
(formerly Prince Edward) These two are 100 percent council owned.
Water extracted from them is treated at the Prince Edward Works,
which has a capacity of 90 megalitres a day, but only treats 65
megalitres.
3. Lake Chivero
4. Lake Manyame
(formerly Darwendale) The city owns 83 percent of both these lakes.
Water extracted from them is treated at Morton Jaffray, which
has a capacity of 614 megalitres, but only treats 480 to 500 megalitres
a day.
So we have a
capacity to treat 704 megalitres a day, and an ability to treat
between 545 and 565 megalitres a day (at this time).
Apparently,
the projected demand for water, made in the mid to late 90s, was
700 megalitres a day by 2002. It was predicted, and now has happened
- treated supply is below demand. If there are no rains this year,
we will have to make do on less, because of the contamination of
our sources of water. There is a Warning Statement from the SADC
Drought Monitoring Centre from 12 December 2002. It would seem that
both construction of more sewerage treatment capacity and/or another
source of water supply (the second is the only option that the Water
Branch wants to consider) are long-term solutions – i.e. up to five-year
construction programmes.
The above Harare
water sources supply Harare, Norton, Chitungwiza, Ruwa, Epworth,
and Sublime Township. Through the Department of Water, Harare also
supplies some major government establishments such as Nkomo Barracks,
Elfrida Barracks and the ZDI, the Domboshawa Training Centre and
Chikurubi Prison.
There are no
estimates on how much of Harare’s water needs come from boreholes.
None of the City’s supply is borehole water. There is likewise no
information on how much effluent is treated through septic tanks,
just the knowledge of which parts of the City have no sewerage reticulation
system. For example, all Epworth sewerage is dealt with in local
septic tanks, and does not flow into the City’s system.
Treatment
I
will not get into this too deeply – my notes are not the best and
it is quite technical. At Morton Jaffray, the raw water comes in
from Chivero and Manyame to a mixing chamber, where activated charcoal
is added. It then runs to clarifiers, where Aluminium Sulphate and
Ecol 2000 are added (along with other chemicals as needed such as
Sulphuric Acid to alter the PH to 6.3). The clarifiers take water
in from the bottom, allow the algae and other substances to settle
to a "blanket" towards the bottom, and cleaner water flows
off the top. This water flows through filters, which are basically
large sand beds. These are backwashed when they are full and are
equipped with air blowers etc. to do this. The backwash should be
transferred to the Otis Sludge Disposal plant. Water that goes through
the filters has chlorine and lime added and is all mixed again.
It goes to three sumps. From Sump 1, 3 small pumps send it to Lochinvar
through 750 mm pipe. From Sump 2, pumps 4, 5 and 6 send it to Lochinvar
and sometimes to Warren Control through 975 mm pipes. From Sump
3, pumps 7 to 14 send it to Warren Control through 2 x 1300 mm pipes.
There are two
works at Morton Jaffray, the Old Works, opened in 1954, and the
new works, opened in 1976. While the staff is dealing with very
old facilities and a great deal of pressure, I found the attitude
very disturbing. Everything seems to be done on a "minimum
to get by" basis. Aluminium Sulphate comes by tanker truck
daily and is pumped through hoses into tanks in a building. When
I was there we had to climb over the hoses in the doorway, because
they stayed that way all the time, since more was coming the next
day. Various pipes delivering chemicals to the water streams were
secured by twists of wire. To add the activated carbon, which comes
in a large paper bag, a hosepipe is inserted into the bag, turned
on, and the bag lain on the walkway grill. It then flows out of
the bag and runs into the mixing tank below. When asked how long
they had been using carbon, and how long they had been doing it
like this, I was told "always". The officials say they
have been asking for a pump to introduce the activated carbon properly
since they started (1997-8 for some). The original works, however,
did not have provision for this pump, so I can only conclude that
sometime since 1976 the City started adding carbon to the water
and no one has ever found the resources to get the equipment to
do it properly.
Many more technical
things looked wrong too, but I cannot really comment since I know
so little. As a non-technical observer, many other things gave a
bad impression. There were cobwebs everywhere – thick ones. The
windows were dirty – very dirty. The grass was not cut. None perhaps
vital to the efficient working of a water treatment plant, but things
that give the impression that only the minimum has been done to
avoid complete breakdown.
I made a deal
with the officials there. If they could change their attitude and
give a better impression of the works, I would do my bit to make
Council and the people of Harare aware of the problems, and try
to get them what was needed to make it work properly.
The Otis
Sludge Plant (perhaps I have the name wrong) just sits there.
In the Department of Works Report for 2000, it is said to be ready
to be turned on, just waiting for the contractor to return from
overseas. It has never been turned on. There is some dispute over
payment or contracts, which has never been finalised, and so it
sits. The Head of Water did not know any details – just the comment
that "the Jews" had made it! Being very fond of Jews,
but not at all fond of the Israeli government, I am interested to
see what the real case is and who is involved.
Distribution
I
am waiting for a map of the system, so forgive me if my notes are
wrong, but the general impression is still the same.
Warren Control
is obviously the biggest distribution works with 14 new pumps, and
from there and Lochinvar water flows, usually by gravity to about
14 reservoirs around the city (those big concrete things you can
sometimes see). Letombo and Alex Park are our two major reservoirs.
Water from the Prince Edward Works enters the system in Hatfield,
there are three main valves that are used to control flows and pressures,
and several smaller pumping stations to take the water over higher
ground (especially to the North East suburbs).
From what I
understand, bad smelling water is usually a result of algae growth
in the reservoirs, although some of it smelt bad (like fish) just
after the filters at the works, before Chlorine was added. When
there is a bad smell, it is often treated with Chlorine in the reservoir
concerned.
The major problems
outlined to me were the usual – funding. Water asked for $6.1 bn
in the budget and was allocated $848 million for maintenance and
upkeep. I hope they got more for new works, because an 11.4 megalitre
reservoir costs $120 to $150 million to build. This is the same
size as the Hatcliffe Reservoir. Highlands Reservoir is 61.74, and
Greendale Reservoir is 70.79 megalitres. The officials also complain
that there is too much bureaucracy in the procurement system.
I am told that
we use more chemicals in the treatment of our water than any other
municipality, and that Harare water is the cheapest of any municipality.
If you look at water as a manufactured product, with raw water as
the input, and the addition of power, labour, plant and chemicals
to produce potable (drinkable) water as the outcome, then the cost
of water should be based on that. However, there are only two things
that the City charges us for – rates and water. (At least on a regular
basis, dog and bicycle licenses etc are a minor thing). From those
two things the City must also finance the provision (or failure
to provide) of sewerage, clinics, libraries, rubbish collection,
roads, administration, etc. etc. It is a difficult calculation but
I am suspecting that the price of water should be increased up to
ten times. That would make a huge political issue of an already
over politicised utility.
Water Demand
Management
WDM
is a big issue these days. It stands for Water Demand Management,
and has some fascinating aspects. Apparently, Bulawayo has kept
water demand down to the levels they achieved during the 1992 drought.
2003 is the International Year of Fresh Water, and various organisations
(and some individuals like myself) are involved in using it, and
"Water Week" (17 to 22 March) to promote water issues
at all levels. Environment Africa (specifically Thoko Ngwenya) is
the secretariat. Both pollution/sewerage and WDM will be part of
what I will be putting forward for our City, so I guess that is
the next topic in my attempts to communicate with you all. Again,
all comments are appreciated, even if I am not getting back to everyone
and you think you are being ignored.
For more information,
contact Cllr Laban by email at: mlaban@mango.zw
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