Environmental permits create legal compliance limits; exceeding permitted effluent levels is a regulatory non-compliance event even if immediate human harm is unlikely. NPPE ethics and law themes emphasize that professionals must hold paramount the public interest, which includes environmental protection, and must comply with applicable laws and permit conditions. Where reporting obligations exist (common in environmental approvals), the appropriate first step is to ensure timely reporting to the proper regulatory authority so the matter is addressed transparently and in accordance with legal requirements. Option B best reflects this duty. Option D (root-cause analysis) is important, but it does not replace immediate compliance actions and required notifications; corrective investigation should follow promptly after reporting/containment steps are initiated. Option A prioritizes reputation management rather than compliance and public interest. Option C is inferior to B because anonymous reporting is generally not appropriate for a responsible manager acting on behalf of the permit holder; regulators typically require formal reporting with complete information and accountability. Even “only fish” impacts engage environmental protection duties and can still be significant. Therefore, the Manager should first ensure the issue is reported to regulators (B).