1. CLEAN WATER ACT HAZARDOUS SUBSTANCE WORST
CASE DISCHARGE PLANNING REGULATIONS
Office of Emergency Management
September 2023 Update
2. STATUTORY AND
Under section 311(j)(5)(A) of the Clean Water
Act (CWA), the President:
“shall issue regulations which require an owner or operator of a . . .
facility . . . to prepare and submit to the President a plan for
responding, to the maximum extent practicable, to a worst case
discharge, and to a substantial threat of such a discharge, of oil or a
Oil requirements promulgated in 1994:
Facility Response Plans (FRP) under Subpart D
of 40 CFR 112.
EPA has never proposed worst-case discharge
planning regulations for CWA hazardous
substances (HS) under 311(j)(5).
3. CONSENT DECREE
Litigation filed by Environmental Justice
Health Alliance for Chemical Policy
Reform, Clean Water Action, and
Natural Resources Defense Council
against EPA for failure to issue WCD
planning regulations for CWA HS
12 Mar. 2020
EPA entered into a settlement
agreement. The agreement requires:
•Proposed action by March 12, 2022 (signature
•Final action by September 2024 (signature date)
March 10, 2022
May 27, 2022
Comment period closed
No later than September
4. CWA 311(J)(5)(C)(IV)
ONSHORE FACILITY DEFINITION
An onshore facility that,
because of its location, could
reasonably be expected to
cause substantial harm to
the environment by
discharging into or on the
navigable waters, adjoining
shorelines, or the exclusive
5. APPLICABILITY CRITERIA: OIL FRP (40 CFR 112.20)
Transfers over water from vessel and
total oil storage capacity greater than
or equal to 42,000 gallons?
Total oil storage capacity greater than
or equal to 1 million gallons?
Submit Response Plan
Appendix C, Attachment C-1
No submittal of Response Plan, except
at RA discretion
Located at distance such that discharge could
cause injury to fish and wildlife and sensitive
Located at distance such that discharge would shut
down a public drinking water intake?
Within each aboveground storage area, does the
facility lack secondary containment sufficiently
large to contain capacity of largest AST plus
sufficient freeboard for precipitation?
Has experienced reportable oil spill in an amount
greater than or equal to 10,000 gallons within
the last five years?
Depends on planning
Plan implementation activities:
• Compliance Dates
• Worst Case Discharge
• Consistency with NCP/ACP
• Qualified Individual
• Response Actions
• Equipment Testing
• Contract or Other Means
for Response Resources
• Drills and Exercises (PREP
6. PROPOSED APPLICABILITY CRITERIA:
Differences in applicability criteria with the Oil FRP program:
▪Adequate secondary containment not a substantial harm criterion.
▪Facility within 0.5 mile of WOTUS part of applicability (rather than
just planning distance).
▪Public receptors as a substantial harm criterion.
Facility meets capacity threshold
quantity applicability of 10,000x RQ
of CWA HS
Facility is within 0.5 miles to
navigable water or conveyance
Submit Response Plan
No submittal of Response Plan, except
at RA discretion
Ability to adversely impact public drinking
Experienced a reportable discharge of
CWA HS that reached water within the last
Depends on planning
Plan implementation activities
• Consistent with NCP/ACPs
• LEPC Coordination
• Designated QI
• CWA HS FRP Components:
• Hazard Evaluation
• Response Planning
Ability to cause injury to fish, wildlife and
Ability to cause injury to public receptors
7. APPLICABILITY: SCREENING CRITERIA
MAXIMUM CAPACITY ONSITE
Proposed – CWA Hazardous Substance Reportable
Quantity (RQ) Multiplier
• EPA designated 296 CWA HS under 40 CFR 116.
• The RQs were established from categories of quantities EPA
deemed harmful based on acute aquatic toxicity, set in 40 CFR
• 10,000x multiplier of the RQ as the threshold amount.
• Proposed using onsite storage capacity rather than quantity on
• Solicited comment on other multipliers (e.g., 100x, 1,000x) and
RQ thresholds in pounds:
All facilities 79,393
RQ x10 52,404
RQ x100 27,165
RQ x1,000 10,599
RQ x10,000 1,659
Estimated facility universe using a 10,000x
multiplier of the RQ within .5m of navigable
8. APPLICABILITY: SCREENING CRITERIA
DISTANCE TO NAVIGABLE WATER
If a facility exceeds the maximum capacity onsite for a CWA HS,
owner/operator must determine proximity to navigable water.
Proposed: Facility owner or operator whose nearest opportunity for
discharge is located within 0.5 mile of navigable water or
conveyance must complete the planning distance calculation
• Consistent with approach in 40 CFR 112 for oil (precedent).
• Industry should be familiar with how to do the calculation.
• Not specific to individual CWA HS and therefore does not
consider physiochemical properties unique to each hazardous
9. PLANNING DISTANCE PARAMETERS
Factors affecting overland transport including:
▪Nearest opportunity for discharge to navigable waters;
▪Ground conditions which may include topography of the surrounding area,
drainage patterns, land use coverage, impervious cover, soil distribution or porosity,
and soil absorption rate or soil saturation during adverse weather conditions
▪Properties of the CWA hazardous substance, which may include evaporation rate
based on wind speed; atmospheric stability, ambient temperature, pressure, and
humidity; reactivity with rainwater and/or other substances; ignitability and
explosive potential; flooding; and pooling.
Factors affecting in-water transport including:
▪Point of entry to navigable water;
▪Flow rate and duration of the discharge;
▪Direction of the discharge at the point of entry;
▪Surface versus underwater entry; and
▪Conditions of the receiving water including the velocity of the navigable water
which may be affected by: slope of the river; hydraulic radius; turbulence and
potential for cross-channel mixing; Manning’s Roughness coefficient; differentiation
of still, tidal or moving waters; currents; wave height; tidal influence; and water
temperature and salinity.
Adverse weather conditions, which shall
be calculated based on adverse winds,
currents, and/or river stages, over a range
of seasons, weather conditions, and river
Properties of the CWA hazardous
substance solubility in water, speciation in
water, density (relative to water), polarity,
vapor pressure, reactivity with water and
common solutes in natural waterbodies,
human toxicity, mammalian toxicity, aquatic
toxicity, and flammability.
10. APPLICABILITY: SUBSTANTIAL HARM CRITERIA
ABILITY TO CAUSE INJURY TO FISH, WILDLIFE AND SENSITIVE
Proposed: Facilities self-determine formulas/methodologies to
use for overland transport and transport in water for planning distance using EPA-
provided parameters and toxicity thresholds – using LC50.
Facility must determine:
1) Location of fish and wildlife and sensitive environments (FWSE) receptors; and
2) Whether WCD of CWA HS would result in exposure of receptors to a concentration meeting or exceeding the
concentration on the list provided by EPA.
• Adult fathead minnow tests used to create the original RQ classification; available for all 296 CWA HS.
• Proposed 10% of the LC50 to extrapolate to lower concentrations than the lethal dose that are more relevant to
discharges of hazardous substances to the environment.
11. APPLICABILITY: SUBSTANTIAL HARM CRITERIA
ABILITY TO ADVERSELY IMPACT PUBLIC WATER SYSTEMS
Proposed: Require coordination with public water systems to determine whether
any of the criteria are met.
Facility owner/operator must work with water facility to determine whether a
worst-case discharge would result in a concentration at downstream public
water intake that results in:
1. Violation of any National Primary Drinking Water Standard or State Drinking Water
2. Compromised ability of the drinking water treatment facility to produce water that
complies with any National Primary Drinking Water Standard or State Drinking Water
3. A risk of adverse health impacts in people exposed.
4. Contaminated public water system infrastructure.
5. Impairment of the taste, odor, or other aesthetic characteristic of the water.
12. APPLICABILITY: SUBSTANTIAL HARM CRITERIA
ABILITY TO CAUSE INJURY TO PUBLIC RECEPTORS
Proposed: A separate substantial harm criterion based on impacts to
public receptors with planning distance parameters using toxic
endpoints – 10% of RQ concentration.
• Public receptor: parks, recreational areas, docks, or other public spaces
inhabited, occupied, or used by the public at any time where members of
the public could be injured as a result of a worst case discharge to
• Same planning distance parameters recommended for FWSE but toxicity
thresholds at 10% of the RQ concentration value for mammalian oral
toxicity for each RQ category.
13. APPLICABILITY: SUBSTANTIAL HARM CRITERIA
REPORTABLE DISCHARGE HISTORY
Proposed: Has had a discharge of a CWA hazardous substances above the
RQ that reached water within the last 5 years.
The NCP does not set quantitative thresholds for major releases. Instead of relying on the
NCP definition of a major release, this approach uses the reportable quantity of each
hazardous substance that reached water to define discharges that would meet the
substantial harm criteria.
• This is a conservative approach given that the RQ quantity is an amount that “may be
harmful” and not a worst case discharge.
• Acknowledges spill history as an indicator of risk for worst case discharge.
• Does not align with major release under NCP, however, does not explicitly contradict
14. PROPOSED RESPONSE PLANNING
▪Reportable discharge history
▪Personnel roles and responsibilities
▪Response equipment information
▪Discharge detection systems
▪Drills and exercises
Consistent with NCP and ACPs
Qualified Individual (QI) Designation and Duties
15. RECAP OF TIMELINE
March 28, 2022: Federal Register publication
May 27, 2022: Comment period closed
Final Rule: by September 2024 (30 months after