The National Pollution Discharge Elimination System (NPDES) program is complex and far-reaching, with a variety of permitting requirements. The program controls water pollution by regulating point sources that discharge pollutants into waters of the United States and establishes specific requirements for discharges from industrial sources. NPDES permittees are subject to facility inspections by their regulating authority. Knowing what inspectors are looking for and what violations they most often find, is essential to a successful inspection.

In all but four states, the NPDES permitting program is administrated by state agencies. Both the EPA and these delegated agencies have the authority to conduct inspections to determine compliance, and they may enter permitted facilities at reasonable times to conduct an inspection. Generally, NPDES inspections involve:

• Reviewing discharge monitoring reports
• Interviewing facility personnel knowledgeable of the facility
• Inspecting the processes that generate and treat wastewater
• Inspecting monitoring equipment
• Sampling wastewater discharges to navigable waterways and other points in the generation or treatment process
• Reviewing how samples are collected and analyzed by the laboratory

These inspections can result in violations. The common violations can be grouped into four categories:

Inadequate monitoring and reporting

• Failure to submit monitoring reports or submitting them late
• Inadequate monitoring records kept
• Failure to calibrate pH meters properly

Exceedance of permit effluent limits

• Inadequate operations and maintenance
• Failure to control upstream users/tenants
• Inadequate operator staffing or training
• Inadequate treatment for new pollutants or reduced limits

Noncompliance with specific permit conditions

• Noncompliance with required special studies and monitoring
• Noncompliance with required special plans
• Failure to provide required secondary containment required
• Failure to notify regulatory authority of violations or changes to the facility

BLR’s Checklist for Handling Agency Inspections can assist in preparing for your next NPDES facility inspection.