What is the minimum time frame New Categorical Dischargers must submit a Baseline Monitoring Report before discharge commencement?

The correct answer reflects the requirement for New Categorical Dischargers to submit a Baseline Monitoring Report at least 90 days prior to commencing any discharge. This timeframe is established to ensure that dischargers have sufficient time to collect the necessary information regarding their wastewater discharges and to conduct any required sampling and analyses. The goal is to ensure compliance with environmental regulations and to provide regulatory authorities with adequate notice to review the report and assess environmental impacts prior to discharge activities taking place. This advance notice helps in preventing potential violations and protecting water quality.

The options suggesting shorter timeframes do not align with regulatory standards, which aim for extensive data assessment and thorough preparation before any discharge begins. Thus, the requirement of a 90-day notice ensures preparedness and compliance, ultimately supporting environmental protection.