In the story you link the system discharged sewage into the ocean because it was overwhelmed with a unexpectedly large amount of debris that prevented 6% of the

In the story you link the system discharged sewage into the ocean because it was overwhelmed with a unexpectedly large amount of debris that prevented 6% of the daily flow from being processed. In this case, it seems like the alternative was having the sewage overflow onto the land, which is a bit less desirable.