Toxicity-based permit limitations are determined using the chronic screening value of 6 mg/L, a CV of 0.6, a zero background concentration (unless known to be otherwise), the regulatory flows described at OAC 252:606-6-52, and chronic mixing zone equations described at OAC 252:606-6-55 through 6-57. The toxicity-based MAL is based on a monitoring frequency of 3/week.
Okla. Admin. Code § 252:606-6-22