Information provided for reference purposes only

Note: This information is provided for reference purposes only. Although the information provided here was accurate and current when first created, it is now outdated. All the links in the document have been removed.


NPDES Storm Water MSGP: Compliance Monitoring

The MSGP provides coverage for six types of storm water discharges which are subject to effluent limitation guidelines, provided that the discharges are not already subject to an existing individual NPDES storm water permit. These storm water discharges include:

  • Contaminated  runoff from phosphate fertilizer manufacturing facilities;
  • Runoff from asphalt paving or roofing emulsion production areas;
  • Runoff from coal piles at steam electric generating facilities;
  • Runoff from spray down of lumber and wood products in storage yards (wet decking) used by the timber industry;
  • Coal pile runoff from all facilities covered by the MSGP; and
  • Mine dewatering discharges composed entirely of storm water or ground water seepage from construction sand and gravel, industrial sand, and crushed stone mines located in EPA Regions II, VI, IX, and X. 

Facilities with discharges subject to any other effluent limitation guideline may not seek coverage under the MSGP for those discharges. Those facilities should contact their NPDES Storm Water Permitting Authority for further assistance.

Monitoring is required for discharges subject to numeric storm water effluent limitations (described above) to determine compliance with those limits. Compliance monitoring is required to be performed on an annual basis (except for the mine dewatering discharges which are to be monitored quarterly with results submitted annually no later than November 30th for the previous four quarters). The annual monitoring period extends from October 1 to September 30 while quarterly periods for mine dewatering discharges run Oct-Dec, Jan-Mar, Apr-Jun, and Jul-Sep.  Results from both annual and quarterly compliance monitoring must be reported annually and may be used to meet the quarterly analytical monitoring requirements for the specified pollutants, where compatible. Exhibit 6 lists those discharges that are subject to compliance monitoring and the respective parameters for which monitoring is required.  Consult the for specific effluent limitations values.


Disclaimer: The information contained on these pages is a general statement of policy. It does not establish or affect legal rights or obligations. It does not establish a binding norm and is not finally determinative of the issues addressed. Agency decisions in any particular case will be made by applying the law and regulations to the specific facts of the case. This applies to all pages in the NPDES Storm Water Program web hierarchy (