Citizen suit allowed in environmental cases

Dear PAO,

I have been noticing some neighbors dumping trash in a nearby creek across our subdivision. It is not part of my property, nor am I directly injured or damaged by the acts of the said persons. However, I have been noticing that the once thriving creek seems to be losing its vibrance in terms of plants and animals. There are fewer fishes caught according to local fishermen and the plants that used to flourish are no longer there. Can I file a case even if I am not directly affected?