A black substance found in a freshwater pool in Kerċem earlier this month was not burnt oil but appeared to be related to animal waste, a preliminary investigation has found.

Popularly known as l-Għadira ta’ San Raflu, the protected site in Gozo was reportedly vandalised on May 5 when it was contaminated with a black substance. The act prompted condemnation across the board as it also endangered species such as ducks, turtles, fish, and frogs, which live in the habitat.   

At the time, there had been claims that the culprits had dumped burnt oil. However, efforts by the Civil Protection Departments to collect the substance using absorbent pads used for oil spillage were unsuccessful. Investigations have so far drawn a blank as nobody has been charged.

The matter was raised in parliament on Monday by Opposition MP Kevin Cutajar in a question to Environment Minister Aaron Farrugia.

Cutajar asked whether there had been any developments in the criminal investigation, the nature of the substance used, the impact on the area’s biodiversity and any measures being taken to clean the site.

Farrugia replied that investigations by the Environment Resources Authority, the Health Directorate and the Water Services Corporation showed that the black substance was not burnt oil as no such chemical was detected.

Microbiological tests have shown the presence of bacteria associated with animal waste, the minister said. Moreover, preliminary indications showed a substantial presence of microscopic organisms in the pool which could have caused this incident.

It was not clear from the reply if this animal waste was generated from within the pool or had been dumped.

The environment minister said that further details would be given in the coming weeks.