Waste Oils officials were cleared of dumping oils in the drainage system earlier this month because the investigation had failed to satisfy criminal proceedings which could lead to conviction.

The director and plant manager of Waste Oils Co Ltd were, on July 6, acquitted of dumping contaminated liquid waste into the public drainage system.

Carmelo Falzon, 65, of Birkirkara, director, and Oliver Debono, 48, of Sta Venera, plant manager, were charged of dumping the waste in April 2009.

Giving the motivations behind his judgement today, Magistrate Anthony Vella said that the manholes at Spencer Hill and Timber Wharf in Marsa were inspected in March 2009 after residents complained of bad odours.

Two manholes were found to have a considerable quantity of oil which should never have been dumped into the drainage system.

Following a Water Services Corporation, Malta Environment and Planning Authourity and Transport Malta investigation, Waste Oils Co Ltd was suspected as the culprit.

The company's property was inspected on April 2, 2009 and a flexible pipe, the ends of which was covered in oil similar to that found in the drainage system, was found connected to the company's plant on one side and to an unused bathroom drain on the other.

Technical reports were drawn up and recommendations for steps to be taken against those responsible were made.

Two years later, MP Owen Bonnici submitted an official complaint and the director and plant manager were charged in court on April 2, 2011.

Magistrate Anthony Vella said in his judgement that the prosecution did not prove its case.

It was true that drainage close to the company was contaminated by a large quantity of oil but it was not established from where this was coming.

If the authorities had suspected the accused and a pipe in their establishment was identified as being used for the purpose, a sample should have been taken from the pipe and the sump which the company's rain water drained into to establish if the liquid within the pipe and the sump was contaminated by oil.

These samples had been taken but the results in a report which had been presented did not indicate contamination so the court doubted if the oil was really being dumped from that pipe.

Another test which could have been done was to throw coloured water down the pipe to see where that water would come out from.

This was not done even though it was recommended in a report. This report clearly indicated there could have been changes to the drainage system over the years which were not indicated in the official plans.

It was also recommended that special cameras be inserted into the drainpipes but this was also not done.

Flexible pipe photos, the magistrate said, showed a clear liquid rather than black oil. There were also no photos showing where the pipe was connected to to show the source of the alleged contamination.

It had not been proven that the samples taken from the pipe and the sump were contaminated.

So it seemed the authorities jumped to a conclusion too quickly following the April 2, 2009 inspection, he concluded.