It’s believed illegal dumping is responsible for an alarming contamination in a Ferntree Gully creek.

Photos via the Friends of Koolunga Native Reserve show a milky substance filling the waterway where ducks used to reside.

Locals say it’s the second contamination this year, and they’re fed up.

Rowan Jennion, vice-president of the Koolunga Native Reserve, told 3AW Mornings “we don’t know exactly what it (the substance) is”.

“(The EPA) have been very helpful in responding,” he said.

“Unfortunately with the timing of the incident, they haven’t been able to track (the source) as yet.”

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