40 CFR Appendix 8 to Subpart A of Part 435, Reference C16-C18 Internal Olefin Drilling Fluid Formulation
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
|Mud weight of SBF discharged with cuttings (pounds per gallon)||Reference C16-C18 IOs SBF (pounds per gallon)||Reference C16-C18 IOs SBF synthetic to water ratio (%)|
|Plastic Viscosity (PV), centipoise (cP)||12-30|
|Yield Point (YP), pounds/100 sq. ft||10-20|
|10-second gel, pounds/100 sq. ft||8-15|
|10-minute gel, pounds/100 sq. ft||12-30|
|Electrical stability, V||>300|