Thursday, February 26, 2009

Maintenance of Stormwater Controls - BMPs - Regulatory Requirements

Once installed stormwater Best Management Practices (BMPs) or stormwater controls need to be maintained in order to remain effective. The most intuitive example is a stormwater detention basin or pond. If the pond is sized to remove 90% of suspended solids, it will only meet this target removal efficiency if it is maintained at its designed size. Over time, an effective pond will trap sediment; this sediment displaces the water volume in the pond and its removal efficiency begins to drop. Without maintenance (which in this example would be removing accumulated sediment), the pond will eventually approach 0% removal efficiency.

From a regulatory perspective, most State permits require that stormwater BMPs be maintained; in this context, BMPs could be any structural or non-structural control measure that the site uses.

Using the recent US EPA Multisector General Permit (MSGP-2008) as an example, dischargers must "maintain all control measures ... in effective operating condition. Nonstructural control measures must also be diligently maintained (e.g., spill response supplies available, personnel appropriately trained). If you find that your control measures need to be replaced or repaired, you must make the necessary repairs or modifications as expeditiously as practicable."

Maintenance of stormwater controls requires:

  • Scheduled routine inspections, conducted by qualified staff
  • Detailed evaluation under comprehensive site compliance evaluations
  • Detailed documentation
  • Rapid corrective action

Industrial sectors that are required to conduct routine benchmark monitoring will find maintenance to be especially important. In addition to conducting routine visual inspections of their controls, they will also be collecting and analyzing samples of their stormwater discharge in order to demonstrate that their controls remain effective.

Caltha LLP provides expert technical support to clients nationwide in addressing stormwater permitting and SWPPP requirements, including developing effective inspection and preventive maintanence programs, and providing employee training programs.

[Read further information on Stormwater - SWPPP Services]

For further information contact Caltha LLP at
Caltha LLP Website

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