Department of Health Seal

TGM for the Implementation of the Hawai'i State Contingency Plan
Section 19.6
ENVIRONMENTAL HAZARD MANAGEMENT PLAN

19.6 Environmental Hazard Management Plan (EHMP)

If contaminated media is left on site under a restricted use closure, an Environmental Hazard Management Plan (EHMP) also must be prepared to manage environmental hazards identified in the EHE over the long-term. An EHMP presents all necessary information in a single, stand-alone document that identifies the nature and extent of remaining contamination, potential environmental concerns posed by the contamination, and appropriate measures to ensure that these concerns are adequately addressed. The EHMP is typically attached to the closure document, and if applicable, to the environmental covenant restricting site use.

In the EHMP, long-term environmental hazards must be clearly assessed and documented to ensure that in-place management of the remaining impacted media is viable and carried out properly. A discussion of the need for and management of institutional and/or engineering controls must be included. This could include restrictions on future use of the property, installation of vapor mitigation systems under buildings, capping of contaminated soil to prevent exposure or leaching, or long-term monitoring of groundwater, etc.

The EHMP must include the following at a minimum (also see Section 18.5.16):

  • Brief summary of the site background and history of contaminant releases
  • Identification of the Chemicals of Potential Concern
  • Clear depiction of the extent and magnitude of remaining contamination in soil, groundwater and/or soil gas, presented on easily readable, to-scale maps with a north arrow
  • Identification and discussion of all potential environmental hazards
  • Requirements for long-term monitoring of contaminants in soil, groundwater, and/or soil gas
  • Discussion of engineering and/or institutional controls needed to address identified environmental hazards to eliminate exposure pathways
  • Guidance on proper handling, reuse and disposal of contaminated soil and/or groundwater that is encountered during future site activities
  • Specific description of construction worker protections and notifications required
  • Use restrictions to protect occupants, residents, guests, etc.
  • Measures for repair or replacement of engineering controls that are disturbed or breached during future site activities
  • Any other information required to adequately mitigate and manage remaining environmental concerns at the site

A brief Fact Sheet that summarizes key elements of the EHMP in simple, non-technical terms is required for large, complex sites where significant public review is anticipated.