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Regulatory Updates

Worst Case Discharges of Hazardous Substances – Proposed Rule

Wade Narin van Court, Ph.D, PE | May 25, 2022

In compliance with the Clean Water Act (CWA), the U.S. Environmental Protection Agency (EPA) recently proposed a new rule for onshore non-transportation-related facilities requiring specified facilities to plan for worst case discharges (WCDs) of CWA hazardous substances that could cause substantial harm to the environment[1]. Comments on this proposed rule are being accepted until July 26, 2022.

This rule, which will become Title 40 of the Code of Federal Regulations Part 118 (40 CFR 118), will apply to any facility with a total on-site aggregate capacity[2] meeting or exceeding 10,000 times the Reportable Quantity (RQ) of any of the 296 CWA hazardous substances listed in 40 CFR 117.3 and could be reasonably expected to harm the public or the environment.

Who Is Potentially Affected?

This rule would apply to any facility meeting the proposed threshold, so it may affect a wide range of activities, including but not limited to:

  • Agriculture
  • Extraction industries
  • Petrochemical industry
  • Hospitals
  • Academic institutions
  • Retail and wholesale dealers
  • Manufacturers
  • Warehouses
  • Storage facilities

What Would Your Facility Need to Do?

  1. Determine the WCDs for their CWA hazardous substances
  2. Assess potential impact(s) of the WCDs on the environment

If a facility’s WCD “could reasonably be expected to” result in substantial harm[3], the facility would need to prepare a Hazardous Substance Facility Response Plan (HSFRP) and submit it to the EPA. If the Regional Administrator’s review of the HSFRP determines the facility may cause significant and substantial harm to the environment, based on the proposed criteria, the facility’s HSFRP will need the EPA’s approval.

Under this proposed rule, the EPA would require the HSFRP to be consistent with the National and Area Contingency Plans and have the following components:

  • Facility and owner or operator information
  • Hazard evaluation and reportable discharge history
  • Response personnel and equipment
  • Evidence of contracts or other approved means to ensure the availability of response personnel and equipment
  • Notification lists
  • Discharge information
  • Personnel roles and responsibilities
  • Response equipment information
  • Evacuation plans
  • Discharge detection systems
  • Response actions and disposal plans
  • Containment measures
  • Training and exercise procedures
  • Self-inspection procedures
  • Coordination activities

What Can You Do to Prepare?

  • While this rule is still in the proposed stage, a facility can be proactive in determining which of the 296 CWA hazardous substances may trigger this requirement for their facilities
  • Consider joining with your industry group to comment on the rule
  • Determine if you can reduce ongoing inventory of CWA hazardous substances to avoid becoming subject to the rule
  • If you might become newly subject, determine if you have the procedures in place that will support development of an HSFRP
  • Review existing plans and procedures to see what updates may be necessary

If your facility needs assistance in evaluating the applicability of the proposed HSFRP rule, please contact your TRC client lead or Dr. Wade Narin van Court at



[2] The applicability threshold is based on container capacities and not the actual amount of a substance stored at a facility.

[3] The substantial harm criteria will depend on a facility’s potential to injure fish, wildlife, and sensitive environments; adversely impact a public water system; and/or harm the public, and/or the facility’s reportable discharge history.

Wade Narin van Court, Ph.D, PE

Wade Narin van Court has more than 34 years of consulting experience for a variety of government and private sector clients and facilities, with expertise in oil/chemical release prevention and response; homeland security and emergency preparedness; regulatory compliance and permitting; and geotechnical, environmental, and civil engineering. Wade has assisted clients in the transportation, maritime, oil and gas, and industrial/commercial sectors with a wide range of consulting services for all phases of their operations. Wade has a Ph.D and M.S. in Geotechnical Engineering from the University of California at Berkeley and a B.S. in Civil Engineering from the University of Washington. Contact Wade at

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