# 550.215 What hydrogen sulfide (HS) information must accompany the EP?
The following H<sub>2</sub>S information, as applicable, must accompany your EP:
(a) *Concentration.* The estimated concentration of any H<sub>2</sub>S you might encounter while you conduct your proposed exploration activities.
(b) *Classification.* Under 30 CFR 250.490(c), a request that the BSEE Regional Supervisor classify the area of your proposed exploration activities as either H<sub>2</sub>S absent, H<sub>2</sub>S present, or H<sub>2</sub>S unknown. Provide sufficient information to justify your request.
(c) *H*<sub>2</sub>*S Contingency Plan.* If you ask the Regional Supervisor to classify the area of your proposed exploration activities as either H<sub>2</sub>S present or H<sub>2</sub>S unknown, an H<sub>2</sub>S Contingency Plan prepared under 30 CFR 250.490(f), or a reference to an approved or submitted H<sub>2</sub>S Contingency Plan that covers the proposed exploration activities.
(d) *Modeling report.* If you modeled a potential H<sub>2</sub>S release when developing your EP, modeling report or the modeling results, or a reference to such report or results if you have already submitted it to the Regional Supervisor.
(1) The analysis in the modeling report must be specific to the particular site of your proposed exploration activities, and must consider any nearby human-occupied OCS facilities, shipping lanes, fishery areas, and other points where humans may be subject to potential exposure from an H<sub>2</sub>S release from your proposed exploration activities.
(2) If any H<sub>2</sub>S emissions are projected to affect an onshore location in concentrations greater than 10 parts per million, the modeling analysis must be consistent with the Environmental Protection Agency's (EPA) risk management plan methodologies outlined in 40 CFR part 68.