In Reply Refer To: HS 5231 Decenber 3, 1990

Shell Offshore Inc. Attention: Mr. C. D. Megllllgan voAvtce Po.t Office Box 60159 NOTED - KRArtEf New Orleans. Louisiana 70160

Gentleaen:

Reference is aade to the following plan received Noveaber 29, 1990:

Type Plan • I n i t i a l Plan of Exploration Uaaa - OCS-G 7962 Biock • 806 Araa - Mississippi Canyon Activities Proposed - Veils G and H

In accordance with 30 CFR 250.33, this plan is hereby deeaed subaitted and is now being considered for approval.

Your control i.^abor ls N-3929 and should be referenced in your communication and correspondence concerning this plan.

Sincerely,

(Orig. SUH Donald Giroir

D. J . Bourgeois Regional Supervisor Field Operations

Wi 11 iaa: on: cck: 11/30/90: POECOM

Shell Offshore Inc. M a e — W S W O J I C — • » »

One Shsll Square P O Box 80159 New Orleans Louisiana 70160

Oeepwaier Division

NOV 2 9

Regional Supervisor Office e Field Operations Minerals -qement Service 1201 Elmwoou Park Boulevard New Orleans, LA 70123-2394

Dear Sir:

SUBJECT: PLAN OF EXPLORATION SOI OCS-G 7962, MISSISSIPPI CANYON BLOCK 806 OFFSHORE LOUISIANA

Shell Offshore Inc. (SOI) herewith submits for your approval an Initial Plan of Exploration (POE) f r Locations G and H in the captioned lease. Drilling may commence as early December 28, 1990.

LEASE STIPULATIONS

The captioned lease is not part of any Biological Sensitive Area, Shipping Fairway or Military Warning Area. A search for cultural resources prior to drilling Is not required.

SHALLOW HAZARDS

SOI submitted a Shallow Hazards Report on May 16, 1988, for Mississippi Canyon Blocks 763 and 807. The report included the eastern portion of Mississippi Canyon Block 806 where the proposed locations, G and H, are located.

This Plan is submitted In accordance with 30 CFR 250.30, effective May 31, 1988, and consists of a series of attachments describing details of our Intended operations. The attachments we desire to be exempted from disclosure under the Freedom of Information Act are marked "Confidential."

The drilling rig we propose to use, the Drillship DISCOVERER SEVEN SEAS, has previously been approved for use in the Gulf of Mexico.

LY9033102 - 0001.0.0

2

Should you require additional Information, please contact Al Pickett in our New Orleans office at (504) 588-0198 or 588-6312.

Yours very truly, fimulNAL SIGNED BY

fl. D. MFGJLUGAN

G. 0. Megllligan

Division Production Administration Manager

ARP/rvk

Attachments

LY9033102 - 0002.0.0

INDEX OF ATTACHMENTS PLAN OF EXPLORATION

SOI OCS-G 7962. MISSISSIPPI CANTON BLOCK 806

orrsHOKrLOUisiATff ATTACHMENT NO. OF NO. DESCRIPTION COPIES

1 Index of Attachments 9

2 Plat, Lease Vicinity, and Transportation Routes 9

3 Description of Activities and Hydrogen Sulfide 5* Comments

4 Plat, Surface Location of Wells 9

5 Plat, Proposed Bottom-Hole Locations and Depths 5*

6 Geologic Structure Map 5*

7 Cross Section WNW-ESE 5*

8 General Information (Schedule of Activities, Safety 9 Features, Hydrogen Sulfide Precautions, Pollution-Prevention Features, Drilling Operations, Well Abandonment)

9 Comments, Spill Prevention, Control and 9 Countermeasure Plan

10-A Comments, Air Emissions Data 9

10- B Diagram, Air Emissions Source and Elevation 9

11- A List, Drilling Mud Components and Additives 9

11-B Table, Mud and Cuttings Discharge Volumes 9

12 Description of Onshore Support Facility and 9 Support Vessels' Description and Travel Frequency

13 Certificate of Consistency, Louisiana 9

14 Public Notice 9

15 Chemosynthetic Organisms Comments 9

16 S1te-Spec1f1c - Shallow Hazards Data 5*

17 Environmental Report 9

•Confidential Attachment 1

LY9033102 - 0005.0.0

Y-10.248.490.00

BLOCK 762 SOI

OCS-G 7957

BLOCK 806 'SOI

OCS-G 7962

BLOCK 807

\soi OCS-G 7963

* Y-10.216.800.00

SURFACE LOCATION

• 2478' FEL fc 4439' FNL OF BLK.

M M i l ' FEL I 9991* FBL OF BLK.

ATTACHMENT 4 •HELL OFFSHORE IIC.

PROPOSED SURFACE LOCATIONS fc BATHYMETRY FLAN OF EXPLORATION

901 OCS-S T99t I U . 009 MISSISSIPPI CANYON

BLOCX 909

mmm uwsu» 0 4000*

GENERAL INFORMATION PLAN Or EPLoffATTflN

SOI OCS-G 7962, MISSISSIPPI CANYON BLOCK 806 OPPSriORg LOUISIANA

SCHEDULE OF ACTIVITIES

Drilling each location Is expected to require about 110 days, thus i f all wells are drilled, the entire program would require about 220 days.

SAFETY FEATURES

The Drillship Discoverer Seven Seas complies with all of the regulations of the American Bureau of Shipping (ABS), International Maritime Organization (IMO) and the United States Coast Guard (USCG).

HYDROGEN SULFIDE PRECAUTIONS

The geological formations that will be encountered in the plan wells are not expected to contain hydrogen sulfide (H^S). (See Attachment 2.)

POLLUTION-PREVENTION FEATURES

All waste is collected and transported to shore for disposal. Sewage is treated prior to being dumped overboard.

DRILLING OPERATIONS

All drilling operations will be conducted under the provisions of 30 CFR, Part 250, Subpart D, and other applicable regulations and notices, including those regarding the avoidance of potential drilling hazards and safety and pollution prevention control.

WELL ABANDONMENT

The well(s) will be drilled, evaluated, and either temporarily or permanently abandoned 1n accordance with 30 CFR, Part 250, Subpart G. If further exploration, development, or production activities are to be undertaken thereafter, appropriate plans will be submitted.

Attachment 8

LY9033102 - 0006.0.0

OIL SPILL CONTINGENCY PLAN PLAN OP EXPLORATION

SOI OCS-G 7962. MISSISSIPPI CANVON BLOCK 806 OFFSHORE LOUISIANA

SOI's "011 Spill Contingency Plan" was approved by the MMS on November 4, 1987. The latest revisions to the "011 Spill Contingency Plan" were submitted to the MMS for approval on July 27, 19SC. The drilling plans proposed herewith will rely primarily on the spill equipment stored at the Clean Gulf Associates base in Venice, Louisiana. Section I I I of the approved plan lists available equipment at this base plus other bases from which additional equipment can be drawn. Section I I lists the preventive measures to be taken to r ilmize oil spills and the reporting procedures to be followed 1n the event that one occurs. Section VI provides a detailed discussion of the clean-up procedures to be Initiated, Including a listing of the personnel who make up the clean-up organization.

OIL SPILL RESPONSE TIME

Activity Time Required

—THWsl— Make calls (e.g., agencies, CGA, response team, 1 vessel, etc.]

Muster response team at Venice (2)*

Move equipment (2)*

Boat run (14 nautical miles) from West Delta 30 3 to Venice (M/V "Masco 8" with 12-knot maximum speed)

Load out of equipment 2

Channel run to open water (SW Pass) 3

Run time to spill location at 12-knot maximum 6 speed for 71 nautical miles (Including deployment)

RESPONSE TIME (Hours) 15

( )* denotes not in critical path and not Included in Response Time.

Attachment 9

LY9033102 - 0008.0.0 Attachment 9

5

A review of the MMS Spill Trajectory Analysis for the subject lease blocks (launch site C-58) shows the following probabilities of a major spill striking the listed land segments within 10 days of the spill:

SOI would utilize the full resources of Clean Gulf Associates, as well as the other resources identified in the SOI M01l Spill Contingency Plan", to respond should this type of spill occur. This Includes seeking approval for Corexit 9527 dispersant application i f the resources threatened justify such a request. The dispersant use decision will be guided by the MIRG model.

The strategies and response modes to prctect resources in the event of a spill threat are stated in Volume I I of the Clean Gulf Associates Operations Manual.

Reference: (A) Draft EIS for Sales 123 and 125 published August 1989, pages IV-36 through 39 and (B) Clean Gulf Associates Operations Manual, Volume I I , Maps 6 and 7.

Land Segment Probability (%)

17. Lafourche, Louisiana 18. Jefferson, Louisiana 19. Plaquemines, Louisiana

2 1

16

Attachment 9 (Cont'd.)

LY9033102 - 0009.0.0 Attachment 9 (Cont'd)

PROJECTED AIR EMISSIONS PLAN DT EXPLORATION

SOI OCS-G 7962T77! " "T^ HjjggMj BLOCK 806

—m^L J SMtFcM

DRILLING PHASE

A dynamically positioned drillship will be used for this exploratory drilling. The sources of air emissions for a typical drillship are the main diesel set (17,000 hp), an auxiliary diesel set of about 700 hp, and an emergency diesel set of about 120 hp. The main diesel set is assumed to have a 50 percent load factor, and the auxiliary and emergency sets are assumed to have a 1 percent load factor. This totals a daily horsepower usage of 204,000 hp-hr. or a 30-day monthly total horsepower usage of 6,120,000 hp-hr. Based on the emission rates for oil-fired reciprocating engines (Table 4.4 of EPA's Report 450/3-77-026 entitled "Atmospheric Emissions from Offshore Oil and Gas Development and Production"), the following gaseous emissions would be generated for each well during the 110 days/well drilling operation:

DISCHARGE (METRIC TONS) PER Will ANNUAL RATE

NO, 318.81 1057.9

°2 21.50 71.3

.C 10.63 35.3

CO 46.71 155.0

Particulates Unknown Unkr'A n

WATER TRANSPORTATION

The horsepower usage of the two vessels to be used in connection with this operation is as follows:

190 Ft. Cargo Vessel

2400 hp x .80 (load factor) x J j j - x — j g j j f f i x 3.7 months - 1,193,472 hp-hr.

80-100 Ft. Standby Vessel

165 hp x .80 (load factor) x x ilO days - 333,960 hp-hr.

1000 hp x .80 (load factor) x l j F m x 110 days «= 88,000 hp-hr.

TOTAL = 1,615,432 hp-hr.

LY9033102 - 0010.0.0 Attachment 10-A

7

Based on Table 4-*, the s*aecus emi'.ions generated by water transportation are J-? follows:

DISC'iARGE (METRIC TONS) PEP. WELL ANNUAL RATE

23.20 77.0

so2 1.56 5.2

HC 0.77 2.6

CO 3.40 11.3

Particulates 'inknown Unknown

TOTAL ANNUAL iO SCHARGE (METRIC TONS)

CO 166.3

rsp, so2, HT;X, voc 1,249.2

cmission F. -.. otionr

Th:- r*ru^ J t 'oc-Uicn Is 33 statue it Hes fron the nearest shoreline. Therefore, the nisftlr.ii • xwnption {t) for the various pollutants is as follows:

CO E - 3400 (53) 2 / 3 * 47,973 Tons/ .'.

ISP

so2

N0X E » 3?.3 (53) - 1,765 Tons/Yr.

The to ta l annual rfivjharge does not exceed the exemption totels above; consequently, no further a i r qual i ty review is required for the enissions from the operations In connection with th is plan.

EMISr.I0.<S' L0- AT10,V A.«? ELEVATION

The diesel exhaust stacks are located fore of the helideck. iht elevation at the out le t 1s 80 feet above the keel (5b.25 feet above the water level when the ship i s f u l l y loaded).

LY?J33102 - 0011.0.0 Attachment !0-A (Cont'd)

ATTACHMENT 10 B

DRI.XING MUD -yf> ggg Alw ,ODITIVES

PU>: •* 'ATL>»KATirH SOI OCS-C 7962. HCSS.SSIPPt CAiTTON BLOCK 806

OFFSHORE LOUISIANA

I . ITEMS USED OH A ROUTINE BASIS

IDF BAF/OD M-I MILPATK DESCRIPTION

TI* BAK BAR'.Tl, BA'tlOD H - I BAR BARITE/MILBAR BARITE (BARIUM SULFATE)

VOF WYOMING BENTONITE AQUAGEL M - I GEL M.LUEL DF LI SMITE CARBONOX TANNATHIN LGCO LIGNITE

IDF CLS Q-BROX.N R D - l l l UNi CAI b'-ENT ; 0 ' /^SVLFOKATK

CAUSTIC SODA CAUSTIC SODA CAUSTIC SODA CAU STU SODA SODIUM iiV&tfBIX. ALUMINUM STEARATE ALUMI'RJM STEA OTE ALUMINUM STEARATE JLlBTftUM STEARATE ALUMIN1 K RATS

LDC LTP2 LIHE I . . ' " * CALCIIJM »P r,v ODE IDF CAUSTICIZED CC-H CAUSTILIG LIGCON BLENDED LI•NTJK/CAUSTI

SODA ASH SODA ASH SODA ASH SODA ASH SODIUM CARlttttTB SODIUM BICARBONATE BICAf B BICARB BICARB BICARBWLUE OF SODA IDF HI-TEMP BARAKEX RESINEX I I CFEMTROL-X/FILIREX SELECTED POL/MBR UEND

IDF DRILLI". i J.KCEMT COB BIT. DD H.O DETERGENT IDF DEFCfcfc BAKA-rCFOAM I DEFOAM-X W. . DEFOAM/LD-8 DEFOAMER (USUALLY ALCOHOL BAMR)

IDF HYHU- AKZAFLtS DMS - NO'UOnlC MUD S»TU'ACIUC IDF CMC CMC OR "EUEX CMP c SODIUM CATBO T METHY* CELLULOSE

SALT SALT SALT SODIUM CHTXJRIDB

IDF 3TARCH IMPERMEX MY-LO-JEL » .'. TARCH PREGELAIINIZED STARCH

IDF AF-21 CYPAN, WL-100, POLYPAC SF-101 c rPAN or. WL-IOC SODIUM POLYAC. VLATE

DRfl DEXTRID POLY SAL I 'SM-LOS i ORGANIC POLVMER DRISPAC/TDF-FLR DRISPAC OR PAC POv /-PAC POLYANIONIC IXLLLXHSF GYPSUM CYP a»7 GYP GVPSUM (.rusif* OF »:v.s)

POLYi.. u SULFONATED 'MALE* NEW-VIS POLYSACCHARIDE roi.YMER

DDB HME/SUPERDPILL £2"'SUPERDRIL W/SLTtADRIL GILSONITE ("<BAI£1>; - H> ItRAL HYDROCARBON IDFXSB BLACK MAGIC SUPERMIX (SFT) MPV-'-AT. W BLACK MACIC SUPERMIX (SFT) MC 1 coNO'uikASs . •* o n a t t r u n ID LUBE ENVIRO-TORO. LUM 10*. LUBE-151 LUBRISAL OR. >N4r LOVUC tr: Hia MICA TEX MCA (0 OR F) MIL-MICA MICA-FLAKES IDF WALNUT BULLS HALL-NUT NUT PLUO (C, K, OR •) MTL PLUC CROUND WALNUT ' « CURR NUT BULLS

LT90U102 - 0012.0.0

2

IDF BARIOD - I MILPARK nPSCRIPTION

SOO I ! * CnONATE IRONITE SPONGE "NC OXBONATE IDFLOC

SAPP

roH r a MP-l BEN-EX SOLTEX

SOOIUH CHROMATE IRONITS NO-SULF E-Z MUD SAPP

KOH KCL MF-i, BORUFLOC BEN-EX SOLTEX

I I . OIL BASE MUD ADDITIV7S

IN7LRDRIX EMUL INTERI T.I U FL INTER' kIL DEFLoC INTF.'dJRII - ESX INTERDRILL VISTONE IDF quiac MME tflSTA ODC

INVE.TMUL E-Z MTL DRILT.tPAT DUR .IONE (Z.L TONE LIME VISTA ODC

SODIUM CHROMATE IRONITE

C"LP-X PtLV PLUS SAIP

KOH KCL MF-1 GELEV

SOU >

VERSArR! .

VFRSATHIN VEKS.. .:. VERSACLL LIME/QUICKLIV*' VISTA ODC

SODIUM CHROMATE P T N T U

MIL CART. SEPARA!'

JA.-P

SHAU TROL KOK KCL I V - l BMN-EX SO -TEX

CARBO-TEC L 'V.RBO-MUL

CARBO-GEL '.IMF VISTA ODC

SODIUM CHROMATE Atcachnent 11-A

H f SCAVENGER (ZINC CARBONAT:) PO! Y CV1AMIDE POLYMER SODTJM A«:I J PYROPHOSPHATE ORGANC/ALUMINUM COMPOUND POTASSIUM IP DROXTDE POTASSIUM CHLORIDE (POTASSIUM) SELECTIVE fLOCULANT CLAY EXTF.'JDER WATPR rCuUBLE SULFONATED ASPHALT

PRUw'v EMU LIFTER SECONDARY DU'LSTFIKR DISPERSANT HIGH TtMP. STABILIZER, FILTRATE CCNIROL VERCOSIFItR WEILHT SUSPENDING AGENT CALCIUM H'.ZROXIDS LOW TOXICITY MINFRAL OIL (DIESEI.

SUBSTITUTE)

I I I . NONROUTINE ADmilVES

TRADE NAMF SUPPLIER DESCRIPTION

HF-100 A-25 BIOSPOT XC POLYMER ACETIC ACID

HYD'A FLCIDS CL"CO D.EMICAL HiLFARK KELCO MILPARK

POLYALCOHOL/WATER BLEND - LUBRICANT SURFACTANT/WATER BLEND FOR STUCK PIPE SURFACTANT/WATER BLEND FOR STUCK PIPE XANTHAM CUM (POLYSACCHARIDE) GLACIAL ACETIC ACID SOLUTION

IV. METHOD OF DISPOSAL-A l l water base mud and aud additives w i l l te disposed of overboard .into the " a l f o f Mexl-o provided the material t-> be discharged meets the t o x i c i t y l l s i l t specified In the USEPA NPDES General Permit No. CMC28XXXX. Any ' l u i d conti i .Ing f r*e o i l w i l l be t ranc r orted to a 29 B a l t * f o r disposal . Diesel w i l l not be used ln muds to be discharged, except f o r spot t ing To f r e* w x k pipe ln accord with Part I . / . 1 ( c ) of the permit. A l l d r i l l c - i t t ings , sand, and other we l l sol ids from d r i l l i n g wi th water based mudi- w i l l be discharged ove t to i ru . butt ings 'roa d r i l l i n g wi th j l l based mud and diesel p i l l s and buf fe r s w i l l be hauled to i t : s i t e for disposal .

Revise »/9/00 JML

Atr chment 11-A (Co-cd)

LY9033102 - 0013.0.0

"JO AND CUTTIN6S DISCHARGE VOLUMES ^ A N Or ExPLORATTM

SOI UC.-G 7962. MISSISSIPPlTATJYON BLOCK 806 OFFbHORE LOUISIANA

AH mud and cuttings w i l l be discharged 1n compliance with the NPDES General Permit GMG 280000 for Discharge of Ef f luents. No f lu ids containing free o i l w i l l be discharged. Daily discharge rates wH l vary over the H f e of the w e l l . Assi.me that the discharge rate is uniform over the H f e of the we l l .

Assume th?t the cut t ings ' volume discharged 1s calculated hole volume times 4.

Assume that the nud volune discharged Is calculated hole volume times 11 (accounts for d i lu t ion to me in-vain rheological propert ies) . These values are Uken from Walk, Haydel and Associates Inc. (1988).

MEAS Dr TH CASING HOLE INTERVAL INTERVAL DEPTH JL SI2E SIZE LENGTH VOLUME (FT.) (IW.) (IN.) (FT.) (BBL.)

4,350 0 ML 4,550 200 30.000 30.000 200 175 6,000 1,650 20.000 26.000 1,450 951 7,500 3.150 15.000 18.500 1,500 498 9,000 4,650 13.375 17.500 1,500 446 11,000 6,650 11.750 14.750 2,000 422 13,000 8,650 $.625 12.250 2,000 291 21,000 J6,r:0 TD 8.500 4,000 280

6auc* Hole Tota l : 3,064

Total Cuttings: 12,256

Total Mud: 33,/04

Attachment 11-B

LY9033102 - 0014.0.0

PLAN OF EXPLORATION SOI OCS-G 7962, MISSISSIPPI CANYON BLOCK 806

ONSHORE Louisrara

ONSHORE SUPPORT FACILITY

The onshore support base for this ac t i v i t y w i l l be SOI's exist ing Venice Terminal. This f a c i l i t y Is located on the Mississippi River near Venice, Louisiana, approximately 35 miles uprlver from the Gulf of Mexico. The physical plant covers 14 acres and Includes 1,000 l inear feet of waterfront, 3,000 square feet of o f f i ce space, 3,200 square feet of personnel quartering space and 7,200 square feet of covered warehouse area. One 45-ton crane and two fork trucks are used for material handling operations. No expansion of the Venice Terminal w i l l be required for this a c t i v i t y . In addit ion to the above, tubular goods w i l l usually be shipped by land to Venice from one of the contract warehouses located in Morgan City, Louisiana, which w i l l also require no expansion. Also, while personnel transported by hel icopter w i l l be picked up and returned to SOI's Venice Terminal, both A1r Logist ics and PHI operate bases a t Venice for refuel ing and maintenance.

SUPPORT VESSELS

TRIPS ITEM SUE OR MODEL USE PER WEEK

Boat 1 9 0 C a r g o 3 or 4

Boat 190'+ Standby N.A.

Helicopter Bell 206B, 212, 214 or Crew Change and M1sc. 18 to 22 412

Attachment 12

LY9033102 -0015.0.0

COASTAL ZONE MANAGEMENT CONSISTENCY CERTIFICATION

PLAN OF EXPLORATION Type of Plan

MISSISSIPPI CANYON BLOCK 806 Areas and Block

SOI OCS-G 7962 Lease Number

The proposed activities described In detail In this Plan comply with Louisiana's approved Coastal Resources Program ar.d will be conducted In a manner consistent with such programs.

Such findings are summarized on the final page of the attached Environmental Report (ER).

A request 1s being made to the official state journal, the State Times, published in Baton Rouge, for publication on November 30, 1990 of our notice of exploration plans. Additionally, arrangements have been made with the Placquemines Gazette in Placquemlnes Parish, Louisiana, for publication on November 30, 1990 of our notice of exploration plans.

SHELL OFFSHORE INC. (SOI) Operator

Division Health, Safety, and Environment Manager

Attachment 13

LY9033102 - 0016.0.0

PLAN OF EXPLORATION PLAN OF EXPLORATTSH

SOI OCS-G 7963. MISSISSIPPI CANVON BLOCK 806 OFFSHORE LOUISIANA

PUBLIC NOTICE

Public Notice of Federal Consistency review of a Proposed Exploration Plan by the Coastal Manageinent Section/Louisiana Department of Natural Resources for the Plan's consistency with the Louisiana Coastal Resources Program.

Applicant: Shell Offshore Inc. Deepwater Production Division Production Administration P. 0. Box 60159 New Orleans, LA 70160-0159

Location: Mississippi Canyon Block 806 OCS-G 7962

Lease Offering Date: May 22, 1985

Description: Proposed exploration plans for the above area provide for the exploration for oil and gas. Exploration activities will Include drilling from a drillship and transport of drilling crews and equipment by helicopter and/or cargo vessel from an onshore base located at Venice, Louisiana. No ecologically sensitive species or habitats are expected to be located near or aff.cted by these activities.

A copy of the plan described above 1s available for Inspection at the Coastal Management Section Office located on the 10th Floor of the State Lands and Natural Resources Building, 625 North 4th Street, Baton Rouge, Louisiana. Office hours: 8:00 a.m. to 5:00 p.m. Monday through Friday. The public Is requested to submit comments to the Coastal Management Section, Attention OCS Plans, P. 0. Box 44487, Baton Rouge, Louisiana 70804-4487. Conments must be received within 15 days of the date of this notice or 15 days after the Coastal Management Division obtains a copy of the plan and It Is available for public inspection. This public notice Is provided to meet the requirements of the NOAA Regulations on Federal Consistency with approved Coastal Management Programs.

Attachment 14

LY9033102 - 0017.0.0

CflEMPSYNTHETIC OPgAN SMS COMMENTS £21 QCS-G 7962. MISSISSIPPI CANVQN 8Q6

OFFSHORE. LOUISIANA

SOI originally f i l l <d a report on 5/16/88. This report included Mississippi Canyon Blocks 763, 807 and the eastern portion of Block 806. These locations are in this eastern portion of Block 806.

Location G: x - 916242 4439' FNL y - 10228201 2478 * PEL

Location H: x - 915909 5551' FSL y - 10222351 2811" FEL

SOI examined deep-tow, high-resolution, geophysical data and found no evidence of shallow faults or slumping on the seafloor within the vicinity of Locations G and H. No conclusive evidence was observed in the data supporting the presence of active hydrocarbon seepage zones occurring within the vicinity of the locations.

The Dri l l Ship "Discoverer Seven Seas" is a dynamically positioned vessel that requires no anchoring and is scheduled to be used in the Mississippi Canyon Area.

SOI believes that the planned exploratory drilling activity within the captioned Mississippi Canyon Area will not disturb any chemosynthetic organisms.

fy 0) &4l~SL <t&m fty* M. W. Loveland A. C. Nunez v Division Geological Engineer Shallow Hazards Interpreter

ATTACHMENT 15

1 . TITUS PAG.":

CoruWnlai <Sfuei| Associates, 1 759 Parkway Street J u p i t e r , F l o r i d a 33477-4567

ENVIRONMENTAL REPORT (PLAN OF EXPLORATION)

GULF OF MEXICO: OFFSHORE LOUISIANA MISSISSIPPI CANYON AREA BLOCK 806 (OCS-G 7962)

21 November 1990

Mr. Richard Heyer S h e l l Offahore Inc. One S h e l l Square

701 Poydrae S t r e e t Room 2678

New Orieana, Louiaiana 70139 Telephones (504) 588-6391

"Applied Science and Technology"

i i

TABLE OP CONTENTS

?nqo

1. TITLE PAGC i

LIST OP FIGURES i r

2. DESCRIPTION OP THE PROPOSED ACTION 1

2.a DESCRIPTION OF PROPOSED TRAVEL MODES AND ROUTES AND FREQUENCY FOR MOVING SUPPLIES AND PERSONNEL TO AND FROM TKE OFFSHORE ACTIVITY SITE AND THE ONSHORE BASES . 1

2.D IDENTIFICATION OF SUPPORT BASES AND NUMBER AND TYPES OP NEW WORKERS ASSOCIATED WITH THE PROPOSED ACTIVITIES . . 1

2.c IDENTIFICATION OF THE NUMBER, LOCATION, AND SIZE OF ANY NEW SUPPORT FACILITIES THAT WILL NEED TO BE PROVIDED FOR THE PROPOSED ACTIVITIES 1

2.d DESCRIPTION OF ANY NEW TECHNIQUES OR UNUSUAL TECHNOLOGY THAT MAY AFFECT COASTAL WATERS 1

2.e MAPS SHOWING LOCATION OP THE PROPOSED ACTIVITIES IN RELATION TO EACH OP THE AFFECTED STATES' COASTAL ZONES . 1

2. f FOR DEVELOPMENT OPERATIONS COORDINATION DOCUMENTS, THE MEANS PROPOSED '.X> TRANSPORT OIL AND GAS TO SHORE FROM THE LEASE AREA, THE ROUTES TO BE FOLLOWED, AND THE ESTIMATED QUANTITIES OP OIL AND GAS TO BE MOVED ALONG SUCH ROUTES 1

3 . DESCRIPTION OP THE AFFECTED ENVIRONMENT AND IMPACTS 3

—

3. a PHYSICAL AND ENVIRONMENTAL 3

|jj (1) Commercial Fiahing 3

mm (2) Shipping 5

(3) Small Craft Pleaaure Boating, Sport Piahing, and

_ Recreation 5

(4) Cultural Reaourcea 6

(5) Ecologically Senaitive Featuraa 6

(6) Exiating Pipellnea and Cablea 7

(7) Other Hineral Uaoa 8

I 1

i i i

TABL2 OP CONTENTS (Continuad)

Page

(8) Ocean Dumping A c t i v i t i a a 8

(9) Endangered or Threatened Speciea 8

3. b SOCIOECONOMIC 8

4. UNAVOIDABLE ADVERSE IMPACTS 9

4. a SUMMARY OP THE UNAVOIDABLE ADVERSE IMPACTS 9

4.b STATEMENT CONCERNING THE UNAVOIDABLE ADVERSE IMPACTS . . 9

5. REFERENC— 10

6. PINAL STATLMENT 12

i v

L I S T OP FIGURES

riayxt aticgirtlgn £iai 1 Location of Mississippi Canyon Ar JS Block 806 relative

to the Louisiana coastal zona (Adapted front xcnor. MMS, 1984) 2

1

2. DESCRIPTIOM OP T U PROPOSED ACTION

BJSSCPIPTIPN QF PRQPQSEP TRAVEL HOPES • I RQtfTH ANP FREQUENCY FOR MOVING SUPPLIES AND PERSONNEL TO FRQM. THE OrT3HQl« ACTIVITY SITE AND THE ONSHORE BA.;E3

Shall Offshcre Inc. plans to conduct axploratory a c t l v l t i e a in MJisisalppi Canyon Area Block 806. Helicopters and boata w i l l move supplies and peraonnei to and from the offahore and onahore locationa. Kelicopters w i l l make 18 to 22 round t r i p a per week and boata w i l l make 14 round t r i p a per month. I f aervicing only the propoaed leaae area, helicoptera and boata w i l l normally take the moat direct route, weather snd t r a f f i c conditiona permitting (aee Figure 1).

?.b IDENTIFICATION OF SUPPORT BASES AND NUHBER AND TYPES OF NEW WORKERS ASSOCIATED WITH THE PROPOSED ACTIVITIES

The support baae w i l l be located ln Venice, Louiaiana. Tha base ia capable of providing the aervicea neceaaary for the propoaed A c t i v i t i e s . No new f a e i l i t i e a or workera w i l l be raeded for the propojed a c t i v i t i a a . Tha i n i t i a l CCS Socioeconomic Data Base Report w i l l be developed after the MMS and the Statea of Alabama, Louiaiana, and Hiaaiaaippl have identified the apecific paramatera to be addreaaed in theae aeriannual reports.

2.c IDENTIFICATION. QF THE NUMBERi LOCATION, AM? SHE 9T ANY NEW aa?PQRT FACILITIES THAT WILL NEEP TO BE PRQYIPIP PPR THI PROPOSED ACTIVITIES

No new support f a e i l i t i e a w i l l be needed for the propoaed a c t i v i t i e s .

2.d DESCR TION OF ANY NEW TECHNIQUES OR UNUSUAL TECHNOLOGY THAT MAY AFFECT COASTAL WATERS

No new techniques or unusual technology w i l l be uaed during the propoaed a c t i v i t i e s .

2.e MAPS SHOWING LOCATION OP THE PROPOSED ACTIVITIES IN RELA"'ON TO EACH OF THE AFFECTED STATES' COASTAL ZONES

Figure 1 ahowa the location of the propoaed a c t i v i t l e a in relation to each of the affected Statea' coaatal sonea. The propoaed a c t i v i t i a a w i l l take place in watera adjacent to the State of Louiaiana.

2.f fQR PEYItoPHIWT OPERATIONS COORDINATION PQCVMENTSi THE HfAlfi PROPOSED TO TRANSPORT OIL AND GAS TO SHORE PROM THK LEASE AREA. THE ROUTES TO BE FOLLOWED AND THK ESTIMATED QUANTITIES OF OIL AND GAS TO BE MOVED ALONG SUCH ROUTES

This Plan i s exploratory. No o i l or gas w i l l be produced for sale from these proposed a c t i v i t i e s at t h i s time.

AW1XU' ( Y \ \ APPROXIMATELY ' S *8 *. • 53 STATUTE MILES

. 1 i « i S 4A NAIITtr.Al iM ci

(BY AR) I c S 4« NAUTICAL MUES

806

TTIFl L0UI8IANA AND MI88I88IPPI i l l) COASTAL ZONES

K A U IN MILKS 0 10

DC Aif IM MLOMBTKM

Figure 1. Looation of Mississippi Canyon Aroa Btock 806 relative to tho Louisiana coastal zone * (Adapted from: USDOI, MMC. 1964).

3

3. DESCRIPTION OP THE AFFECTED ENVIRONMENT AMD IMPACTS

3.S PHYSICAL AND ENVIRONMENTAL

Th* propoaad activitlea ar* located eouth of some of the moat productive fishing grounda in the Gulf of Mexico. National Marine Fisheries Service Zone 13, which ie located approximately 35 km (19 nmi) north of the leaae area, accounted for approximately 8.5% of the commercial fiaheriee harvest from the western and central Gulf of Hexico (USDOI, BLM, 1981, Visual No. 5; USDOI, MMS, 1984, Visual No. 4-1). Gulf watera account for approximately 30% of the total annual U.S. fiaheriee harvest (USDC, 1982).

The Gulf fiahery ia dominated by the shellfish fiaheriee. Shrimps, crabs, and oyatera (with smaller amounta of clams and scallops) are the moat valuable fiaheriee and are usually worth three or four times mor* than th* graatar voluae of finfish catch (USDOI, BLM, 1979). The USDC (1982) l i s t a the annual commercial fiaheriee landinga atatiatice for tha northern Gulf coaat area onahore from the leaae area.

Tha shrimp fishery in the Gulf of Mexico includee the brown (PtnstVff MfaEBIfJf white (£. eetlferual. and pink (£. duoraruml shrimps. 7h*e* species are taken almopt inclusively by trawla *.n dept ."is ranging from approximarely 2 to 73 m (6 to 240 f t ) . Theae shrimps arw estuavine-dependent apeclea which spawn in the open ocean, go through a aeriea of larval phaaea in tho plankton, migrate during the post-larval phaae tc the eatuarine nuraary areaa, and then return to the open Gulf aa adulta. The USDOI, BLM (1977, Viaual No. 5) indicatee the aeaaonal variation in the habits of each of theae speciee. The leaae area is located outside the major shrimp spawning groum J and migration routes in the northern Gulf (USDOI, MMS, 1984, viaual No. 4-1). Planktonic agga and larval atagea of a l l tsnercially iaportant shrimp apeclea may occur periodically in th* lease area.

Th* blu* crab (CilUnectes fjpldufi) makes np 98% of the crab harvest in th* Gulf of Mexico (Riley, 1970). Its l i f * cycle i s eimilar to th* shrimps' in that i t has planktonic, estuarine, and open ocean phases. Adulta spend most of thair lives in the estuaries; thus, th* blue crab harvest i s takan primarily inshore of the leas* area. Gravid females migrate to th* opan Gulf to release their egga during apring and summer. Consequently, gravid females and planktonic larvae may occur seasonally in the leaae area.

Th* propoaad activitiaa are located outalde comm*. - \y important finfish fishing grounds (USDOI, MMS, 1984, Viaual No. 4-1). Thr** species of menhaden known from th* Oulf make up th* major finfish tonnace taken. These ar* Brevoortia patronus. fi. gunteri. and fi. jmlthl. Brevoortia oatronua comprises most of th* Oulf catch. Pure* saining i s th* major capture methoa used i i this fishery (Lindall et al., 1972).

Rad anappar (Lut1anua campechanus> and var .oue species of grouper ( i . e . , th* red grouper IplntPXlllUs Bfi£ifi AU1 9«9 Mvctarooerca

4

mlcroleolsl compose the commercial hook-and-line fiahery of the northern Gulf of Mexico. Theae fiahea may be taken over irregular bottom areaa in depths of 2 to 305 m (5 to 1,000 ft) (Terlco Corooration, 1976).

Tha atriped mullet (Muall cephalus> la generally found in nearahore areaa euch aa harbors, eatuariee, baya, and along beachea. Zt ia a schooling fiah and ls generally taken with aaines and trawlt.

The Atlantic croaker (rUcrppogonljf undulltm) i« »n abundant fiah in eatuarine watera. Perret et a l . (1971) reported croaker to be the most abundant juvenile commercial fiah taken in eatuariea. Croaker ia harvested and marketed both aa a food fiah and aa an industrial bottom fiah (Lindall et a l . , 1972).

The Florida pompano (Trachlnotua carolinust ia prima-Ily an Inahore fish that is taken mostly in the surf or at paaaee. Xt ia seasonally abundant (January to April) in ehrimping areaa.

Tho Spanish mackerel <Scomberomorua maculatusl mlgratea seasonally along the Gulf coast.. I t ia generally taken in nearahore areas.

The red drum (Sclaenopa ocellatuai ia taken predominantly in nearahore habitats, aa are the sheepshead tArchosargus probatocephaluai. flounders, and the black drum (Pooonlaa cromial.

seatrouts, including the spotted fCvnoscion nebulosus>, the silver (£. QO$bJlfl), and the aand (£. aranarlual. are important to the bottom fiah fisheries in the northern Gulf (Lindall et a l . , 1972). They are usually taken in offahore areas with bottom ttawla.

TerEco Corporation (1976) describes eome additional fi-h jpeciee ot the northern Gulf which are important to coauiercial and/or sport fishermen and their predominant method of capture. Moat of the northern Gulf fiahee are temperate, with soma incursions from Caribbean fauna. They exhibit aaaaonal distribution and abundance fluctuations related to oceanographic conditions (U8DOZ, MMS, 1984, p. 106). Many of the coastal speci*a (e.g., the croaker, Mlcrouogoniaa undulatus) are estuarlne-deptmdent. because eetuarlaa or coaatal marshes are a cr i t i c a l habitat during come phase of their l i f e cyclee. Rogers (197?) postulated a net inshore-offshore iovement for many demersal shelf fish specias. Thus, i t is probable that many of theae apeclea may recur u> the leasa area at some phase of thair l i f e cycles.

Eggs and larvae (ichthyoplankton j of vtu* lovs r'.»K arc J KI ly important fish species are probably also presen. - the Intv^e a.ea on occasion. Sixty-nine fish species hava been id~nt .f.V. fxum zooplankton samples taken along the northern Gulf coaat. Dor.'.ant .-.Asa -ere the families Sparidae, Lutjanidae, Triglidae, SOT rer iditU, >r.« Synodo -if. tiae. atinPtCfflua cgprlnvfl, Pristtpomoldaa acruilonp. L» . gr.-jAunt* •» aarslatus. gfrrtnui ItrgPftnChUl* and Svnodua foetenr. ware tne sVWi U.o.-.nt specias (Chittenden snd Moore, 1976). Since t t t ;a/jorJ.ty of ichthyoplankters are at the mercy of water movemo- ta. tho'. r distributions vary considerably with space soU v.; sa. rtw* pr«A :y

factors influencing ichthyoplankton in tha northern Gulf ara tha Loop Currant, tha Mississippi River, and local runoff. Dua to "patchiness" in diatributiona, praaanca and abundance of ichthyoplankton at any given inatanca cannot ba predictad.

The propoaad activitiee probably wi l l temporarily degrade the water quality in the immediate vicinity of the d r i l l s i t e due to discharges of drilling fluida and cuttings. This may cauae certain fiah speciee to avoid the area, commercial flahlng may be effected temporarily. The situation ahould revert to normal aa eoon aa drilling ia completed. Cumulative effecta of increasing o i l and gae activitiee off the northern Gulf coaat on annual catches ara as yet unknown. However, there ara no data to indicate that o i l and gaa activitiee are responsible for any decline in annual catenae (USDOI, BLM, 1979, p. 181).

Any o i l apill that would impact the aeafloor could conceivably k i l l benthic organisms auch aa shrir-ps or cauae a variety of sublethal effecte. The potential long-term effects of a s p i l l on the benthos are unclear because reaults of hydrocarbon analyses are inconclusive (U8DOZ, BLM, 1979, p. 160).

An o i l s p i l l would temporarily degrade water quality and introduce toxins into the water. Ichthyoplankton, i f preeent, may be killed or functionally impaired. However, moat adult fiahea encountering a apill and associated toxic water would probably exhibit avoidance behavior. Thia effect would oe t«r.porary and fishe should return to the araa after dispereal of the e p i l l . No aignificant or persistent direct effects from an o i l apill on fiah populations would be expected. Recruitment from surrounding areaa ahould quickly replenish any affect*' ichthyoplankton populations once the ep i l l haa disperroa. Any s p i l l would be handled according tu an o i l apill contingency plsn approved by the MMS.

3.a(2) Shipping

The propoeed activities ara located approximately 47 km (25 nmi) south of a fairway (USDOI, MMS, 1984, Viaual No. 11). Th* proposed activitiaa are rated aa having minimum potential impact on ahlpping ae they are greater than 5 km (2.6 nmi) from a fairway (USDOI, BLM, 1979, p. 145). The offshore atructure wi l l be equipped with a l l aafety equipment required by th* U.S. Coast Ouard and th* MMS to alert ships of i t s presence in a l l weather conditions.

3.a(3) email Craft Pleasure Boating. Snort Plehlno. and Recreation

Ditton and Graefe (1978) determined that o i l and gaa atructures ar* th* most popular offshore recreation destination areaa, attracting 87% of th* boats that fished offshore in their study area. Certain pleasure boata (i.e., sailboats, pleasure yachte, and/or open ocean racing power boats) may be slightly inconvenienced by having to maneuver around the offshore structure and i t s support vessels. This inconvenience i s considered extremely minor as offshore structures ean be avoided and empl* maneuvering room i s available.

Any sport fishing which might occur in ths lease s r s s could bs temporarily affected by degradation of wstsr quality during d r i l l i n g . Such s change in wstsr quality could cause some desirable species to avoid the immediate leaae area. However, any auch effecta are expected to be temporary and loca l i s e d and ahould not affect any fiahery potential in tha area aa a whole. Populations should rsturn to normal ones d r i l l i n g i s completed.

3.a(4) Cultural Resources

C o s s t s l Environments, Inc. (1977) has identified two types of cultural resources which may be found in the northern Gulf of Hexico areat (1) h l a t o r i c c u l t u r a l reeourcee or shipwrecks; and (2) prehletoric cultural reeourcee or tracee of previouely undeserved human c i v i l i z a t i o n a (USDOI, MHS, 1983, pp. 228-240). Approximately 82% of the known ahipwrecke are located within 10 km (5 nmi) of ahore, with only a email percentage occurring on the OCS (USDOI, BLM, 1979, p. 91). Known submarine archeological s i t e s sre extremely r s r s , with none being identified to dsts in Federal offahore leasing areaa (USDOI, BLM, 1979, p. 91).

The propoeed a c t i v i t i e e are located outaide the Hlatoric and Prehistoric Cultural Resources High Probability Lines (USDOI, MMS, 1984, Visual Mo. 11) snd therefore sre i n s large offshore s r s s where h i s t o r i c snd p r s h i s t o r i c reeourcee s r s considered unlikely to be found. An Archeological Survey was not required for t h i e lesse s r s s .

3.8(8) Ecologically Sensitive FMturai

Several areaa of environmental concern are located o-ohore of the leeae area. The Louisiana Coaatal Zone Management Prograa. has been developed by the rtate to regulate the aignificant land and watar a c t i v i t i e e between the oute* limlc of thb c o s s t s l watere and land up to the Intracoaatal Waterway and/or the 10-ft contour. Land uses whicn are regulated are thoae that have a d i r e c t and significant impact on tha coastal area requiring a State permit, and thoee wh . .-h are required by Federal law to be conaiatent with the management program (USDC and LDNR, 1980). The program provides for the protection of beaches, dunes, wetlands, submerged grsss beds, ba r r i e r islands, oyater reefa, c u l t u r a l resources, wster quality, a i r quality, biological resources, and w i l d l i f e habitat. Unique ecological features include zoological, botanical, and geological formationa characterlatic of coaatal processes (Burk and Associates, Inc., 1975; USDC snd LDNR, 1980). Biologically sens i t i v e areas of the north-central Oulf area include estuarine and coastal ocosystems comprised of s a l t marshes, oyster beds, grass beds, barrier beaches, snd dunes (Coastal Knvironments, Inc., 1980). These c o s s t s l ecosystems contsin nursery areaa for many species of economic importance as well ss habitat, rookeries, aajor overwintering s i t e s , and nesting areas for many endangered and threatened species, such aa the southern bald eagle, brown pelican, golden eagle, osprey, red cockaded woodpecker, American peregrine falcon, and various aarine t u r t l e s (USDOI, BLM, 1979, Visual Ho. 3; Coastal Environments, Inc., 1980; USDC snd LDNR, 1980).

7

There are two existing "Special Managetnent Areas" designated by th* Louiaiana Coaatal Management Prograni (USDC and LDNR, 1980, pp. 104-108). These areas ara th* "Louiaiana Offshore Oil Port'' (LOOP or Suparport) and th* "Marah laland Wildlife Refuge and Oam* Preserve." Th* lease area ia located 283 km (153 nmi) southeast of Marah laland Wildlife Refuge and Game Preserve and 101 km (55 nmi) southeast of the LOOP. None of the propoaed activitiee in thia leaae area should have any effect upon the Special Management Areaa.

conspicuous areaa of environmental concern for Louiaiana are depicted by the USDOI, BLM (1979, Viaual Noa. 1 and 4) and the USDC and LDNR (1980, Figure No. D-l).

The coaatal zona area ia alao of recreational importance to reaidents and touriata. Most recreational activitiee focus on the area'a water reeourcee which include beachea, boating areaa, and flahlng areas. The propoaed activitiee ahould have no effect on protected areas of biological significance, remnant coaatal banka, or oyster grounds.

While o i l apilla during drilling operationa are rare (Danenberger, 1976), the possibility of a apill does exiet. Oil fouling in any coaatal area could directly or indirectly affact « variety of speciee, including threatened or endangered species or sptciea important to commercial and sport fiaheriee. Direct effecta on biota would include fouling (particularly birds), suffocation (particularly fishes and turtles), and toxicity from contact or from the ingeation of o i l or contaminated food. Any of theae effecte could be lethal, cauae weakening, or cauae a greater susceptibility to predation. Significant ecological or economic impacts could alao reeult from the fouling of oyster beds and habitata. Indirect effecta would include the destruction of c r i t i c a l habitats, especially breeding and nursery areas. Any effecta on endangered or threatened epeciee would be significant.

Oil fouling of the coaatal trea could alao have adverse socioeconomic effects. Tourism i s an important part of Gulf coast economies. Removal of beach or other coastal areaa f-o- recreetional use by o i l fouling would aignificantly decreaee tourism Lu the _ff*ct<jd area and cause loes of income and a variety of ripple effects in local economiee.

Any s p i l l would be handled according to an o i l apill contingency plan approvad by the MMS. I f a s p i l l did occur during operations, i t i s unlikely that i t would affact any nearshore or onehore areaa or resources.

3.a(6) Baiting pipeline* snd CabUi

Thar* are no exlating pipellnea or cables in th* lease area (USDOI, MMS, 1986; P. Torres, MMS, 1990, personal communication).

3.1(7) Other Minersi Usee

Other then potential o i l end gee reeervee, there ere no known mineral reeourcee in the leaae area.

3.a(8) Ocean Dumping A c t l v l t i e a

The propoeed -^tivitiee are not located in an area designated for ocean dumping activities.

3.a(9) Endangered or Threatened Speciaa

The USDOI, BLH (1979, p. 45) considers poeeible impacts of lease activitlea on endangered apeclea in thia area of the Oulf to be temporary, localised, and chance occurrences. Zt haa judged the potential impacts on endangered species to be remote possibilities without major potential for direct effects on sny single species. Zn addition, i t has been determined that lease activitiee w i l l not result in the destruction or modification of designated c r i t i c a l habitats or potential c r i t i c a l habitats. Onahore f a c i l i t i e s are locsted in a previously developed area and pose no new or additional threat to endangered or threatened apeciee.

Six endangered apeciee of cetacears occur in the Qulf of Hexico. They are the blue whale tBalaanoptara musculus>, fin whale (Bfllaenopteri phVSSlyS), humpback whale (Megaptera novaeanollael. right whale (Eubalaena glagjaU*). Ml whsle (Balaenoptera boreal 1st, and sperm whale (Physeter catodon>. Generally, most of these larger cetaceans occur in continental shelf, slope, or deep oceanic waters (USDOI, BLM, 1981). The etetus and migration patterna of theae species in the Oulf of Mexico sre unknown (Lehmsn, 1982).

several endangered or threatened apeciee of aea turtles, including the Kemp's ridley (Leoldochelva kempii\. hawksbill (CretmoffhtlYB imblrciti)/ leatherback (Dermochelys coriacea \. loggerhead (CarettB caretta), and green (Chelonia mvdasi, may occasionally v i s i t tha leasa araa. Tha primary danger to marine turtles would be possible collisions with boats; however, no adverse effects of vessel traffic have baan reported or documented in the araa, and the probability of an impact i s estimated to be low (USDOZ, MMS, 1988). No c r i t i c a l habitat for any of thaaa species i s known to exist in tha laasa araa (USDOI, BLM, 1979, pp. 73-74).

3.b SreiQECONCfHC

The i n i t i a l OCS Socioeconomic Data Baae Report wi l l ba developed aftar the MMS and the States of Alabama, Louisiana, and Mississippi have identified the specific parameters to ba addreased in these semiannual reporte. No new personnel w i l l ba naadad for the proposad activitlas.

9

4. UNAVOIDABLE ADVERSE IMPACTS

4.S SUMMARY OP THE UNAVOIDABLE ADVERSE IMPACTS

Offshors structures wi l l result in minimal navigational interference to ships using established fairways. However, during times of reduced v i s i b i l i t y , vessels have the greatest potential to deviate from eatabliahed fairways and impact offahore structures <USDOI, BLM, 1979, p. 230). Discharge of drilling muda and cuttings and air emissions during drilling operations wil l adversely affect marine organisms, water and air guality, and commercial flahlng aa described by the USDOI, BLM (1979, pp. 229-231). These impacts are temporary, however, and will ba limited to an extremely small area. They are juatified by the national intereet in discovering and developing badly needed reeervee of o i l and gas. During tha exploratory operationa, a l l discharges w i l l comply with a l l applicable MMS and BPA requirements. No significant adverse impacts are expected. The propoeed activitiee covered by thie Plan ehould not reeult in unavoidable impacts on wetlands, cultural reeourcee, recreational activitiee, ahoreline aesthetics, or other lar>*t uses.

4.b STATEMENT CONCERNING THE UNAVOIDABLE ADVERSE IMPACTS

None of the environmental consequences expected during normal operations should produce significant or cumulative adveraa environmental effecta. The effecte of a poaaible o i l apill ahould have no overall cumulative or long-term effect on the environment, except in the poaaible event of contamination of endangered marine apeciee. A apill would be handled according to an o i l apill contingency plan approved by the MMS. Thus, i t ie unlikely that a apill would occur during operationa and affect any nearahore or onehore areaa or reeourcee. The propoeed activitiee ehould have no aignificant impact on endangered epeciee or c r i t i c a l habitat. The information presented in thie Environmental Report indicatee no clear or preeent reaaon not to proceed with the proposed activitiee. withdrawal of the Plan would raault in the loss of potential hydrocarbon production from this area.

10

S. REFERENCES

Burk and Associates, Inc. 1975. Louisiana Coastal Resources Inventory. Vol. I , Geographic areas of p a r t i c u l a r concern. New Orleans, LA.

Chittenden, M. E., J r . , and 0. Moore. 1976. Composition of tha ichthyofauna inhabiting ths 110-m bathymetric contour of tha Gulf of Maxico, Miaaiaaippi River to tha Rio Grande. Dapartmant of Marina Resources Information Cantar for Marina Rasasrch, Tsxss ASM University. 15 pp.

Cosstsl Environments, Inc. 1977. Cultural resources evaluation of tha northern Gulf of Maxico. National Park Sarvica, Washington, D.C.

Coaatal Environments, Inc. 1980. CPA-2, Offahora MiaBissippt-Alabams-Plorida, biologically aenaitiva areaa. Baton Rouge, LA.

Danenberger, K. P. 1976. O i l a p i l l a , 1971-1975. Gulf of Mexico outer continental shelf. USGS C i r c . No. 741.

Ditton, R. B. and A. R. Graefe. 1978. Recreational Fiahery Uae of A r t i f i c i a l Reefa on the Texea Coaet. Department of Recreational Parks, Texaa ASM Univereity. 155 pp.

Lehman, J . 1982 (paraonal communication). U.S. Department of the I n t e r i o r , Minerele Manageaent Service Oulf of Mexico OCS Office, Metairie, LA.

L i n d a l l , w. M., J r . , J . R. H a l l , J . B. Sykaa, and B. L. Arnold, J r . 1972. Louiaiana Coaatal Sonet Analyses of Reeourcee and Resource Development Needs in Connection with Estuarine Ecology. Sections 10 and 13, Fiahery Resources end t h e i r Needs. A report for the U.S. Army Corps of Engineers, New Orieana, LA. Contribution No. 14-17-002-430. 323 pp.

Perret, w. s., B. B. Barrett, H. R. Latapie, J . P. P i l l a r d , N. R. Mock, C. B. Adkins, N. j . Oaidry, and C. J . white. 1971. Cooperative Oulf of Mexico Estuarine Irventory and Study, Louisisna. Phase I , Area Description nnd Phase IV, Biology. Louieiana w i l d l i f e and F i s h e r i e s Commission.

Riley, P. 1970. Fisheries of tha Unitad Stetes, 1969. U.S. Departaent the I n t e r i o r , Bureau of Commercial Fi s h e r i e s . C.P.S. No. 5300. 87 pp.

Rogers, R. rt., J r . 1977. Trophic interrelationships of selected fishes on tha continental shelf of the northern Oulf of Maxico. Ph.D. dissertation, Texaa ASM Univereity. 229 pp.

TerEco Corporation. 1976. Ecological Aspects of tha Upper Continental Slope of tha Gulf of Maxico. A raport for tha U.S. Departaent of tha I n t e r i o r , Buraau of Land Managamant Qu±f of Mexico ocs o f f i c e , Naw Orleans, LA. Contract Mo. 08S50-CT4-12.

11

U.S. Department of Commerce. 1982. Current Fi s h e r i e s S t a t i s t i c s No. 8200. F i s h s r i s s of ths United States, 1981. U.S. Department of Commerce, National Oceanic %nd Atmospheric Administration.

U.S. Department of Commerce and Lou' ina Department of Natural Resources. 1980. Louis! ma . a l Resources Program Final Environmental Impact Stat .nt. :.-misiana Department of Natural Reaourcea, Baton Rouge, LA.

U.S. Department of the Inter i o r , Bureau of Land Management. 1977. Pinal Environmental Impact States* *•. Propoeed 1977 Outer Continental Shelf O i l and Gaa Leute Sale 47, Gulf of Mexico.

U.S. Department of the Inter i o r , Bureau of Land Management. 1979. F i n a l Environmental Impact Statement. Propoaed 1979 Outer Continental Shelf O i l and Gaa Leaae Sale SSA, western and Central Gulf of Mexico. 181 pp.

U.S. Department of the Inter i o r , Bureau of Land Management. 1981. Pinal Environmental Impact Statement. Propoeed 1981 Out r Continental Shelf O i l and Gaa Leaae Salea 67 and 69, Gulf of Mexico. 300 pp.

U.S. Depertment of the Inter i o r , Minerala Management Service. 1983. F i n a l Regional Environmental Impact Statement. Gulf of Mexico. 1,004 pp.

U.S. Department of the In t e r i o r , Minerala Management Service. 1984. Pinal Environmental Impact Statement. Propoaed O i l and Gaa Leaa" Salee 94, 98, and 102. Gulf of Mexico. 752 pp.

U.S. Depertment of the In t e r i o r , Minerala Management Service. 1986. (Pipeline Maps). Gulf of Mexico OCS Office, Metairie, LA.

U.S. Depertment of the In t e r i o r , Minerala Management Service. 1988. Draft Environmental Impact statement. Gulf -f. Mexico Sales 118 snd 122t central and Western Planning Areas. OCS EI8/IA MMS 88-0003.

12

». FINAL STATEMENT

To ths best of our knowledge, the set of findings included l r the Environmental Report snd Plsn indlcstee thst esch of ths proposed a c t i v i t i e s , t h e i r sssoclsted f s c i l i t i s s , and effects s r s s l l consistent with snd comply with the provisions and guidelines of the Louisiana-approved Co s s t s l Zone Management Prograra The propoeed a c t i v i t i e s w i l l be conducted i n s manner consistent with the Cosstsl Zone Management Prcgrsm ss outlinsd in MDWC and USDC (1980) snd USDC snd LDNR (1980).

The propoeed a c t i v i t i e s w i l l be carried out snd completed with the guarantee of the following itemsi

1) The beet available ind aafeet technologies w i l l be u t i l i z e d throughout the project. Thia -acludea meeting a l l applicable requirements for equipment types, general project layout, aafety systems, and equipment and monitoring systems.

?) A l l operstions w i l l be covered by an o i l a p i l l contingency plan approved by the MMS.

3) A l l applicable Federal, State, end lo c a l requirements regarding a i r emissions, water quality, and discharge for the propoeed a c t i v i t i e e , ae well aa any other permit conditions, w i l l be complied with.