The Water Services Corporation, saying it is still counting the cost of last week’s storms, said it faced serious problems whenever it rained heavily due to storm water run-off from private roofs and yards which are illegally connected to the sewer system.

But it did not say if anything was being done to identify the culprits and what action it would take.

Describing its mission, the WSC said it extracts water from the underground aquifer and produces fresh water from the sea by means of reverse osmosis plants which it distributes from reservoirs to its consumers, as well as being responsible for the collection and treatment of wastewater.

It said that during the downpours sewage pumping stations failed to keep up with the massive increase in flow due to the huge amount of rainwater that entered the sewer system all over the country.

“It is estimated that every house connection that has an illegal storm-water connection to the public sewer system creates a 60-fold increase of its normal sewage flow. In large wastewater catchment areas this resulted in scores of manholes being lifted by the water pressure and carried for quite some distance. One manhole cover was never found. In such cases manholes cannot be replaced until the water flow subsides and repairs are carried out. The pumping stations in these areas experienced an increase of 3.5 times the normal operation levels. However, no damage was noted,” the WSC said.

Added to this, so much more foreign material also entered the sewers, causing blockages further down the system, that, at the sewage treatment plants, even wooden planks had to be removed from the intake screens.

On the water production side, up until Thursday, 28 October, over 3,000 cubic metres per day of underground water were being lost because the boreholes and pumping stations were being “pumped-to-drain” until the turbidity (cloudiness) of the groundwater returned to acceptable levels.

“This turbidity is due to the excessive surface water that seeps into the groundwater at an abnormally high rate without the natural filtration that would normally occur. Further major runoffs from farms or freshly fertilised fields caused shutdowns of groundwater sources due to increases in nitrates.”

The WSC said that at the seawater desalination plants, engineers adjusted the pre-treatment process prior to membrane filtration of the sea water because of increased turbidity at the sea shore wells, thereby avoiding the risk of plant shutdowns.

On the other hand, the buried infrastructure in all flooded areas withstood the storm and there were no signs of infiltration into the network which would otherwise have had to be shut down. The WSC worked around the clock with heavy machinery where necessary in order to rectify matters in the shortest possible time,” it said.

The WSC added it encounters similar problems every time it rains heavily due to the storm water run-off from private roofs and yards that are illegally connected to the sewer system.