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EPA Finalizes Monitoring Requirements for Dispersant Use

AUGUST 2, 2021 ─ Subpart J of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) directs EPA to prepare a schedule of dispersants, other chemicals, and oil spill mitigating devices and substances that may be used to remove or control oil discharges.   

In 2015, the EPA issued a notice of proposed rulemaking to update Subpart J and address issues and concerns identified during the 2010 Deepwater Horizon spill response where approximately one million gallons of dispersants were deployed over a three-month period.  The proposal also addressed recommendations from the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling Report to the President.  

A 2019 report from the National Academies of Sciences examined dispersants in marine oil spill response and concluded that dispersants can be a useful tool for oil spill response.  Every oil spill presents unique circumstances and challenges, the report noted, and dispersants are one of a variety of options – each with advantages and disadvantages -- available to responders as they work to contain and clean up a marine oil spill.  A 2021 NOAA review found that over the past 40 years and approximately 400,000‐reported spill incidents, there were only 27 incidents in the United States where dispersants were used and none since the 2010 Deepwater Horizon spill.

EPA recently finalized monitoring requirements for dispersant use. The remaining provisions in the 2015 proposed amendments (i.e., authorization of use, testing protocols, and listing) remain under consideration.

The new monitoring requirements are for subsurface use of dispersants and prolonged surface application of dispersants during major spills.  The goal is to have improved environmental field monitoring data to support decision-making when dispersants are used, including data to evaluate the overall effectiveness, including the transport and environmental effects, of the dispersants and the dispersed oil. 

These monitoring requirements apply as follows:

  • Subsurface – Any subsurface use of dispersants,
  • Prolonged Surface – Any surface use of dispersant for more than 96 hours after initial application, and
  • Major Oil Discharges – Any surface use of dispersant in response to oil discharges of more than 100,000 U.S. gallons occurring within a 24-hour period.

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Last updated Wednesday, March 13, 2024 5:31pm PDT