A vault is allowed above or below grade and must meet NFPA 30 and NFPA 30A requirements.
Okla. Admin. Code § 165:26-2-71
Added at 21 Ok Reg 2079, eff 7-1-04; Amended at 22 Ok Reg 1752, eff 7-1-05; Amended at 25 Ok Reg 2187, eff 7-11-08Amended by Oklahoma Register, Volume 34, Issue 24, September 1, 2017, eff. 9/11/2017