40 CFR — Protection of Environment
Appendix 8 to Subpart A of Part 435—Reference C
United States · 40 CFR — Protection of Environment · Status: effective
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- 40 CFR — Protection of Environment, Appendix 8 to Subpart A of Part 435—Reference C, United States, version 1 as recorded 2026-07-09, yourstate.us, https://yourstate.us/provision/190075
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Full text
The reference C16-C18 internal olefin drilling fluid used to determine the drilling fluid sediment toxicity ratio and compliance with the BAT sediment toxicity discharge limitation (see § 435.13) and NSPS (see § 435.15) shall be formulated to meet the specifications in Table 1 of this appendix.
Drilling fluid sediment toxicity ratio = 4-day LC5. of C16-C18 internal olefin drilling fluid/4-day LC5. of drilling fluid removed from drill cuttings at the solids control equipment as determined by EPA Method 1644: “Method for Conducting a Sediment Toxicity Test with Leptocheirus plumulosus and Non-Aqueous Drilling Fluids or Synthetic-Based Drilling Muds” after sediment preparation procedures specified in EPA Method 1646, which are published as appendices to Subpart A of this part and in “Analytic Methods for the Oil and Gas Extraction Point Source Category,” EPA-821-R-11-004. See § 435.11(ee) and (uu).
Table 1—Properties for Reference C16-C18 IOs SBF Used in Discharge Sediment Toxicity Testing
Legislative history
This is a federal regulation, adopted through agency rulemaking under the Administrative Procedure Act — not enacted by a recorded vote of Congress.