The equivalent of at least 4.5 million two-litre bottles of water went to waste after the last heavy storm caused groundwater to become excessively cloudy, needing to be thrown away.
“This turbidity is due to the excessive surface water that seeps through into the groundwater at an abnormally high rate without the natural filtration that would normally occur,” the Water Services Corporation said in a statement yesterday.
This meant that up until Thursday more than 3,000 cubic metres of groundwater were lost per day because boreholes and pumping stations were being “pumped-to-drain” to bring the turbidity back down to acceptable levels, WSC said.
“If there was any way to save the water, we’d do it,” a WSC spokesman said, pointing out that the corporation had to keep the system up and running in the most efficient way possible to provide people with water.
Further major runoffs from farms and freshly fertilised fields caused shutdowns of groundwater sources due to increases in nitrates, WSC said.
According to Marco Cremona, hydrologist and environmental entrepreneur, the “quasi-annual occurrence” of pumping out of groundwater revealed the lack of flood mitigation infrastructure and the vulnerability of water production sources to such incidents.
Furthermore, he said, all animal farms had to abide by regulations relating to the storage and application of manure on fields and yards by 2008, and the fact that WSC shut down its pumping stations year after year because of this shed light on the lack of enforcement and compliance.
During the downpours that showered the island last week, sewage pumping stations also failed to keep up with the massive increase in flow due to the huge amount of rainwater entering the system.
The WSC estimates that every house which has an illegal storm water connection to the public sewer system creates a 60-fold increase in the normal sewage flow. Pumping stations in large wastewater catchment areas experienced an increase of 3.5 times the normal operation levels, the corporation said.
This caused “scores of manholes” to be lifted by water pressure. During the floods, the Civil Protection Department had issued a warning for drivers to look out for these uncovered manholes.
“In such cases manholes cannot be replaced until the flow subsides and repairs carried out,” WSC said.
On top of this, it said, foreign material like wooden planks blocked the sewers and had to be removed from the intake screens in the sewage treatment plants.
Luckily, buried infrastructure withstood the storm and there were no signs of infiltration into the network which otherwise would have had to be shut down, WSC said.
Mr Cremona calculated that the WSC’s statistics revealed that approximately four per cent of local roof drains were connected to the sewage system, which meant this small percentage was responsible for the problems affecting a nation.
Moreover, he pointed to problems derived from sewage overflow, including public health hazards and the stench in creeks where the sewage discharged into the sea.
“And all this because Mepa does not enforce the cistern-in-every-new-building law and fails to carry out inspections,” Mr Cremona said.
Moreover, if storm water reservoirs were set up to save rainwater, the system would be essentially collecting sewage.
“We have anarchy in the water sector – illegal extraction of groundwater, illegal roof drain connections to the sewerage system, blatant non-compliance with the cistern-in-every-building laws, non-compliance with regulations of farmyard manure, theft of mains water, undisclosed leakages in the sewerage system and many others,” he said.
Future generations would suffer the consequences of these problems, he added.