Old water plant leaves Maseru vulnerable

Tsitsi Matope

IF the water-sprinklers could talk, they would complain of how they are made to sprinkle the evergreen lawns in some of Maseru’s leafy suburbs, even on rainy days.
The numerous car-washing enterprises mushrooming in the capital would also speak of the wasteful practices that have seen the formation of artificial streams at these outposts, with little concern for the costs involved in ensuring there is running water in the city.

While the majority of Maseru’s residents do not seem to think twice before turning on their water-taps, the truth of the matter is the Water and Sewerage Company (WASCO) not only pays millions of maloti to treat and distribute the precious liquid, its purification processes are also facing serious challenges.
Each day, the treatment plant, situated above the Mohokare River, which also happens to be the source of water for Maseru, creaks and groans to produce the millions of litres of water the city needs to remain functional.

During a visit to the Maseru Water Treatment Plant by the Lesotho Times last week, there was no hiding the glaring fact that urgent intervention was needed to salvage operations at the facility.
Although the plant’s capacity is 45 megalitres a day, it is a battle before an average of 34 megalitres are released into the distribution network.

In an interview during last week’s tour, WASCO Water Production Supervisor, Motlalepula Moahloli, said it was a great concern that the water demands for Maseru continues to increase.
“The city has grown a lot in the last five years, while at the same time, wasteful water-use practices are boosting the demand for water,” Mr Moahloli said.
Indicating the evidence of the strain on the plant, it was obvious there is need to refurbish the facility which, according to Mr Moahloli, was established in 1972.
During last week’s visit, it appeared in every unit of the plant, there was some component no longer functioning smoothly.

While some components are replaceable, other critical ones have silently given up and become permanently disabled, Mr Moahloli said.
“More frequent than not, our maintenance team is on call to attend to various infrastructure-related failures.
“We have to do all we can to ensure we produce quality water, although it is not easy at all,” Mr Moahloli said.
Considering the poor state of affairs at the plant, more water cuts each time a critical component breaks down, should not come as a surprise.
“The plant last underwent major refurbishment in 2005. Since then, we have not had a major maintenance operation. Allowing such major works requires an alternative plant with significant capacity or else residents might go for many days without water,” he said.

Despite the decision not to deny residents water for several days, the company loses about 28percent of its treated water every month due to leakages, while the infrastructure-related problems continue mounting.
Between January 2013 and March this year, six special low-lift pumps worth over M4million broke down.
“We installed this submissive pump (low-lift or slurry pump) you see here in the scrap yard, in January and now it is no longer working after just three months. We installed this other one in November last year and after two months, it also failed.
“The pump malfunction also caused last weekend’s water cuts in the central business district and suburbs around the Central Business District.”

Mr Moahloli said under normal circumstances, the company expected each new pump, worth M700 000, to function the whole year before it starts developing any problems.
“We are investigating the cause of the malfunction to establish whether the problem is with the pumps or it’s our system.”

He also attributed frequent breakdowns to old pumps, some of which are beyond repair.
“Some of the pumps are more than 10 years old and have been repeatedly repaired,” he said.

However, on Monday last week, a maintenance team could be seen at the Intake Pump Station next to the Mohokare River replacing a flexible pipe, which had broken during the installation of the low-lift pump.
A few metres away in the Main Pump and High-Lift Pump stations, lots of water was gushing out. Only a 10 percent water-loss of the maximum produced is acceptable during the treatment process, Mr Moahloli said.
“You see, major leaks like these are going to cost us the allowable range, but there is nothing we can do,” Mr Moahloli added.
“We just have to wait for the maintenance team to complete the intake works before they can attend to this new problem.
“Our major concern at the moment is the Intake Pump Station, where the core of our business starts.
“This is a high-risk area because we pump water from the river using electricity. During heavy rains, this whole area is submerged in water.
“The sand chokes the pumps and it is just unbelievable how we still ensure the city has water under such circumstances.”

Under normal circumstances, slurry pumps (low-lift pumps or submissive plumps), which are designed specifically to operate in a high-silt environment, should be able to sustain such conditions.
However, from the Intake Pump Station, the raw water undergoes the pre-chlorination process, which kills unhealthy organisms (viruses, bacteria, algae and protozoa.)
To enable effective chlorination, the city’s water needs two cylinders of chlorine for both the pre- and after-treatment for a month’s production.
The two chlorine cylinders, Mr Moahloli said, cost M140 000.
He further explained that three chemicals; chlorine, flocculant (SudFloc) and lime are used to treat water.
“During rainy seasons, we use a primary flocculant and, because the water would be very dirty, we use more of this chemical, up to 10 000 litres, which lasts us two weeks.”
A tonne (1000 litres) of the primary flocculant costs M 12 790, meaning for a month’s supply, the water company pays M255 800.
Mr Moahloli further said in dry seasons, a secondary flocculant is used and a 10 000-litre drum can last a month. A tonne costs M 7 822 and a monthly supply costs M78 220.
The effectiveness of the treatment is tested eight times and this includes the extensive tests for heavy metals and microbiological organisms done at the laboratory.
“Tests are important because some of our equipment is no longer functioning properly, so we have to be sure we have the right quality product.”
He cited the failure of the scraper bridges in which water was supposed to settle for two hours before it got into the sand filters (the final stage of treatment).
“The scraper bridges are not working due to an electro-mechanical defect.”
However, once the treated water gets into the sand filters, it seeps through while the floc (residue) is left suspended on top of the sand.
“We have just bought 150 tonnes of the special sand media for M270 000. Why we buy this type of sand in South Africa is because we don’t have it locally.
“We use a certain size of sand granules which we cannot get here.”
The sand, which runs off with each operation, is replaced after every five years.
The water from the sand filters is again dosed with chlorine to ensure it reaches the acceptable quality.
“Our water quality is currently at less than 1 NTU. The acceptable quality range is less than 5 NTU and anything exceeding that is intolerable and unsafe for human consumption,” Mr Moahloli said.
He added both the treatment processes and release into the distribution network demand heavy use of electricity.
Water released is distributed to the company’s eight intermediate pump reservoir stations where it gravitates into the network, he further explained.
“In high elevations, we have booster pump stations which further pump water to those areas and this further increases electricity costs. ‘
This is why it is not advisable to build houses higher than the already existing water reservoirs as water can only go up to the level of the reservoirs.”
Mr Moahloli said WASCO, on average, pays M350 000 per month for its post-paid electricity charges and M50 000 per month for its pre-paid booster pump stations in Maseru.
In the last financial year, WASCO spent an average of M1.4 million per month on electricity charges for all its operating centres countrywide.
With an approved 12 percent electricity tariff increase this year, the company is likely to face serious challenges that might see residents being subjected to endless water-cuts.

 

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