Except as provided in 40 CFR 125.30-125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT):
BAT Effluent Limitations----------------------------------------------------------------------------------------------------------------
Stream Pollutant parameter BAT effluent limitations----------------------------------------------------------------------------------------------------------------Produced Water:
(A) All coastal areas except Cook ..................................... No discharge.
Inlet.
(B) Cook Inlet...................... Oil & Grease......................... The maximum for any one day
shall not exceed 42 mg/l, and
the 30-day average shall not
exceed 29 mg/l.Drilling Fluids, Drill Cuttings, and
Dewatering Effluent: \1\
(A) All coastal areas except Cook ..................................... No discharge.
Inlet.
(B) Cook Inlet:.....................
Water-based drilling fluids, drill SPP Toxicity......................... Minimum 96-hour LC50. of the
cuttings, and dewatering effluent. SPP Toxicity Test \4\ shall be
3% by volume.
Free oil............................. No discharge. \2\
Diesel oil........................... No discharge.
Mercury.............................. 1 mg/kg dry weight maximum in
the stock barite.
Cadmium.............................. 3 mg/kg dry weight maximum in
the stock barite.
Non-aqueous drilling fluids and ..................................... No discharge.
dewatering effluent.
Drill cuttings associated with non- ..................................... No discharge. \5\
aqueous drilling fluids.Well Treatment, Workover and Completion
Fluids:
(A) All coastal areas except Cook ..................................... No discharge.
Inlet.
(B) Cook Inlet...................... Oil & Grease......................... The maximum for any one day
shall not exceed 42 mg/l, and
the 30-day average shall not
exceed 29 mg/l.Produced Sand........................... ..................................... No discharge.Deck Drainage........................... Free Oil \3\......................... No discharge.
Domestic Waste.......................... Foam................................. No discharge.----------------------------------------------------------------------------------------------------------------\1\ BAT limitations for dewatering effluent are applicable prospectively, BAT limitations in this rule are not
applicable to discharges of dewatering effluent from reserve pits which as of the effective date of this rule
no longer receive drilling fluids and drill cuttings. Limitations on such discharges shall be determined by
the NPDES permit issuing authority.\2\ As determined by the static sheen test. See Sec. 435.41(ff).\3\ As determined by the presence of a film or sheen upon or a discoloration of the surface of the receiving
water (visual sheen).\4\ As determined by the suspended particulate phase (SPP) toxicity test. See Sec. 435.41(ee).\5\ When Cook Inlet operators cannot comply with this no discharge requirement due to technical limitations (see
appendix 1 of subpart D of this part), Cook Inlet operators shall meet the same stock limitations (C16-C18
internal olefin) and discharge limitations for drill cuttings associated with non-aqueous drilling fluids for
operators in Offshore waters (see Sec. 435.13) in order to discharge drill cuttings associated with non-
aqueous drilling fluids. [61 FR 66125, Dec. 16, 1996; 62 FR 1681, Jan. 13, 1997, as amended at 66 FR 6917, Jan. 22, 2001; 77 FR 29846, May 18, 2012]