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Water Quality Models and Tools

DEP maintains several water quality models and tools used by the NPDES permitting program. These models and tools are generally used in NPDES permit development and/or utilized by permittees as a part of permit conditions.

Water Quality Models

PENTOXSD and WQM 7.0 are water quality models used to aid in the development water quality-based effluent limits. Technical Reference Guides and Supplemental Information are available in the Documentation folder of the ZIP files. For download instructions open the ZIP files and review the Read Me file. Please Note - Windows 7 or later and Microsoft Access 2010 required.

  • PENTOXSD v2.0d (ZIP) - PA Single Wasteload Allocation Program for Toxics and Other Substances.
  • WQM 7.0 v1.0b (ZIP) - Wasteload Allocation Program for Dissolved Oxygen and Ammonia-Nitrogen (Updated March 2012).

NPDES Permit Tools

DEP has developed several tools to aid in NPDES program implementation. These tools are Excel based and do not require installation. Instructions for each tool are available on the first tab of the workbook.

For technical issues or questions, contact the Bureau of Clean Water's Division of Planning and Permitting at 717-787-8184.