The National Pollutant Discharge Elimination System (NPDES) program requires permits for the discharge of pollutants from any point source into waters of the United States. Preston prepares applications for NPDES permits that are required for the direct discharge of industrial process wastewater and storm water. Wastewater pretreatment discharge permit applications can be prepared for submission to municipalities that require such permits when industrial wastewater is discharged into city sewers. Additionally, pretreatment systems can be designed to reduce the amount of contamination in industrial wastewater that is discharged into municipal sewers.

Annual storm water sampling is often required by the facility’s NPDES permit. Sampling must be completed on a significant rainfall that is preceded by 72 hours of dry weather. Unless the facility has a storm water basin that can hold a 10-year, 24-hour rainfall event for 24 hours, two types of samples from each discharge must be collected. Preston has extensive experience collecting storm water samples from various types of facilities.

The prevention of storm water contamination requires adequate storm water management controls, proper management of materials, regular facility inspections, and annual storm water sampling. However, not all facilities with NPDES storm water permits are required to perform annual sampling. Storm Water Pollution Prevention plans are required for all facilities that have individual or general NPDES permits for storm water discharge. In accordance with the U.S. EPA’s final NPDES General Permit for storm water discharges associated with industrial activities, Preston can develop a Storm Water Pollution Prevention Plan for a facility using feasible Best Management Practices.

Certain types of facilities – e.g., cement manufacturers and facilities that store coal – are limited in the solid content of their permitted storm water discharge. In order to reduce the amount of solids discharged from a facility, Preston can design and provide construction supervision for a storm water basin that will adequately hold a 10-year, 24-hour rainfall event. In addition, outfall structures for basins can be specified to effectively reduce solid discharge or prevent the discharge of substances (e.g., oil) to navigable waters.

Expansion of residential, commercial, and industrial developments frequently results in the disturbance or destruction of wetland areas. The U.S. Army Corps of Engineers (ACE) has established wetland delineation requirements and guidelines that should be followed prior to developing an area. Preston has a professional who can accurately identify wetlands and is certified to prepare wetland delineation plans according to ACE guidelines.

The U.S. Army Corps of Engineers (ACE) requires submission of a wetland mitigation plan in situations where planned residential, commercial, or industrial development will impact – i.e., disturb or destruct – a wetland or wetland complex. Wetland mitigation can come in the form of avoiding the impact altogether, minimizing or rectifying the impact, reducing or eliminating the impact over time, or compensating for the impact. Preston has a professional who is certified to prepare wetland mitigation plans according to ACE guidelines.

Facilities – having an oil storage capacity greater than or equal to 1320 gallons – that could discharge oil into navigable waters of the United States are required by the federal Water Pollution Control Act to maintain Spill Prevention Control and Countermeasure plans. Preston can develop site-specific Spill Prevention Control and Countermeasure plans for the owners or operators of such facilities.