Representational Image. (File Photo)

HYDERABAD:`40 crore a year. That is the amount Greater Hyderabad spends every year to keep many of its roads clean using mechanical road sweeper (MRS) machines huge lorries equipped with brushes and vacuum suction that are expected to leave the city roads squeaky clean.

However, it was found that the average efficiency of the machines was very poor, just around 33 per cent. Though huge sums of money were changing hands every year, but there were no visible changes in the ambient air quality in areas where the machines were being deployed, the Telangana Pollution Control Board (TGPCB) decided to find out why.

The findings by IIT Hyderabad, which was asked to conduct a pilot study on the efficiency of MRS machines– a first of its kind in the country by the PCB, found that in most cases, the operators did not take care of the very basic requirement, that of changing worn-out brushes. According to sources in the PCB, it was also found that in several cases, the operators switched off the vacuum suction to save on fuel, or the suction pressure was not maintained at the required level to suck in the dust and silt from the roads.

“It is not uncommon to see ‘lofting’ of dust when a MRS machine is at work. This shows there is either no suction or not enough suction. There were also several doubts whether the machines were actually working or just being driven around as the contractors are paid using a GPS tagging mechanism,” a PCB source said. “With `40 crore being spent a year on these machines, the presumption is that they work efficiently. The present system is not performance linked.”

The IIT-H study, which was discussed at a workshop on improving efficiency of the mechanical road sweepers to mitigate the road dust and to improve the air quality at the PCB office on Tuesday, revealed that the average silt removal efficiency at 40 study locations suggested by the GHMC was just 32.7 per cent. In 17 of the locations, the average MRS silt removal efficiency was less than 25 per cent, and in 28 of 40 locations, it was less than per cent. In only two of the 40 locations swept by MRS was the silt removal level more than 75 per cent.

The study also revealed that the MRS machines’ upkeep was poor, especially when it came to changing the brushes that can get worn out quickly while spinning in contact with the road surface. The study found that the brush and suction conditions were very poor in almost all of the surveyed MRS machines, with 95 per cent of all such vehicles ending up with the lowest ratings for brush and suction conditions.

Instead of sucking up the dust and silt from the roads, the study also found that six of the 40 MRS machines were actually leaving behind dust patches despite sweeping, indicating that the machines sometimes deposited dust in certain locations. According to the study, the operators revealed that while brushes are replaced in 21 sweeping vehicles once a week, in 13 cases they were changed once every 2 to 4 days, while one vehicle was doing so once in 10 days, with 5 vehicles replacing their brushes only once a month.

Mechanical sweeping myth busted

40 mechanical road sweepers in city roads.

`40 crore paid to contractors every year to operate the machines

Average road silt removal in 40 locations: 32.7%.

17 locations had less than 25% efficiency

28 locations had less than 50% efficiency

2 locations had more than 75% efficiency

MRS machines found depositing dust patches in six locations

Way forward

Training on using mechanical sweepers, suction monitoring.

Changing brushes every two to four days.

Cleaning of filters every two days.

Checking suction systems for leaks.

Payments be linked to performance based on video verified suction pressure, GPS based tracking of coverage.

Efficient machine sweeping can improve city air quality by up to 20%

HYDERABAD: The Telangana Pollution Control Board (TGPCB) has said that if all the mechanical road sweepers in Hyderabad work as they were designed to do, then the city’s ambient air quality could see a significant leap for the better.

Addressing a workshop on efficiency of mechanical road sweepers in the CURE area of Greater Hyderabad at the PCB office in Sanathnagar on Tuesday, the board’s chief environmental engineer B. Raghu said that the study by IIT Hyderabad on MRS machines found that if they were to function properly, then the ambient air quality in Hyderabad is likely to improve by 15 to 20 per cent. This could also help the city reach the goal of meeting the National Ambient Air Quality standards, he said, according to a PCB press release.

The IIT-H study was taken up based on the findings that road dust is contributing about 32 per cent of PM10 particles, and 26 per cent of PM2.5 particles in the city’s air. These findings were the result of a study by PCB and IIT Kanpur a few years ago. The IIT Kanpur study had found that silt deposition on city’s roads ranges from 5 to 15 grams per square metre against the ideal conditions of less than 3 grams per square metre.

Professor Asif Qureshi of IIT Hyderabad made a detailed presentation on the operation of the mechanical road sweepers and suggestions to improve the performance of the machines, the press release added. The workshop was attended among others by officials from the city’s three municipal corporations, TGIIC, HMDA and CDMA.

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