Skip to Content

Notice

Draft Modification of the National Pollutant Discharge Elimination System (NPDES) General Permit for the Eastern Portion of the Outer Continental Shelf (OCS) of the Gulf of Mexico (GMG280000)

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of draft modification of NPDES general permit for the Eastern Portion of the Outer Continental Shelf (OCS) of the Gulf of Mexico (GMG2800000).

SUMMARY:

The Regional Administrator (RA) of EPA, Region 4 (“Region 4”), is today proposing to modify, in part, the National Pollutant Discharge Elimination System (NPDES) general permit for the OCS of the Gulf of Mexico (General Permit No. GMG280000) for discharges in the Offshore Subcategory of the Oil and Gas Extraction Point Source Category (40 CFR part 435, subpart A) as authorized by section 402 of the Clean Water Act (“CWA” or the “Act”), 33 U.S.C. 1342. The existing general permit, issued by Region 4, and published at 63 FR 55718, October 16, 1998, authorizes discharges from exploration, development, and production facilities located in and discharging to all Federal waters of the Eastern Gulf of Mexico seaward of the outer boundary of the territorial seas. Today EPA is proposing to modify the general permit numbering system to make it specific to the Region 4 area of responsibility. Additional modifications are being made to add tables for produced water discharge critical dilution concentrations and for chemically treated seawater used to pressure test piping and pipelines. These modification are being incorporated into part I.B.10 of the permit along with associated effluent limitations and monitoring.

This permit modification is in accordance with a settlement entered into by EPA with various parties which filed a petition for review of the October 16, 1998, general permit in the Fifth Circuit Court of Appeals under the caption Marathon Oil Company et al. v. Browner, Civ. 99-60090. After the permit was issued, and aside from other provisions within the permit which specify that any operator authorized by the permit may request to be excluded from coverage and receive an individual permit pursuant to 40 CFR 122.28(a)(4)(iii), EPA determined that the method for calculating effluent limitations and monitoring requirements for produced water discharges that appear as part I.B.3 in the permit are not appropriate for coverage under a general permit in the manner set forth in the October 16, 1998, general permit. The intent of this proposed modification is to establish a table of critical dilution concentrations for use in determining toxicity limitations. Those permittees that have produced water discharges that would fall outside of the proposed table would need to apply for and receive individual NPDES permits.

In brief, EPA today proposes to modify the general permit as follows: changing the general permit numerical designation; requiring permittees to indicate what type of effluents the facility is expected to discharge within Start Printed Page 48504the written notification of intent; allowing approval of a shorter notice to drill (NTD) notification period in certain circumstances; the addition of a section 403(c) reopener clause; inclusion of a new table to be used by those permittees discharging produced water to calculate the critical dilution concentration; and the addition of limitations and monitoring requirements for those permittees discharging chemically treated freshwater or seawater used for the hydrostatic testing of new pipes and pipelines and condensation. Any operator seeking coverage under the general permit may be subject to some or all of the proposed modifications.

Finally, EPA also is providing today some additional clarifications and minor corrections of existing general permit language based upon questions and comments received by the Agency subsequent to the original permit issuance. This information is provided for clarification purposes only and is not part of the permit modifications being noticed for comment today.

DATES:

Comments on this proposed action must be received by October 10, 2000.

ADDRESSES:

Persons wishing to comment upon or object to any of the proposed permit modifications in Section III or wishing to request a public hearing, are invited to submit same in writing within sixty (60) days of this notice to the NPDES and Biosolids Permits Section; United States Environmental Protection Agency, Region 4; Atlanta Federal Center; 61 Forsyth St. S.W.; Atlanta, GA 30303-3104, Attention: Ms. Ann Brown.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Mr. William Truman, Environmental Scientist, telephone number (404) 562-9457, or at the following address: United States Environmental Protection Agency, Region 4, Water Management Division, NPDES and Biosolids Permits Section, Atlanta Federal Center, 61 Forsyth Street S.W., Atlanta, GA 30303.

Table of Contents

I. Introduction

II. Coverage of General Permit

III. Proposed General Permit Modifications

IV. Clarifications and Minor Corrections

V. Cost Estimate

VI. Unfunded Mandates Reform Act

VII. Paperwork Reduction Act

VIII. Regulatory Flexibility Act (RFA), as Amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 601 et seq.

I. Introduction

In 1972, section 301(a) of the Federal Water Pollution Control Act (also referred to as the Clean Water Act) was amended to provide that the discharge of any pollutants to waters of the United States (U.S.) from any point source is unlawful, except if the discharge is in compliance with an NPDES permit.

On October 16, 1998, Region 4, issued a general permit for discharges of pollutants from exploration, development, and production facilities located in all Federal waters of the Eastern Gulf of Mexico seaward of the outer boundary of the territorial seas. The previous permit (July 9, 1986, reissued by Region 4 in 1991) was issued jointly by Region 4 and Region 6. Region 6 subsequently, reissued a permit in 1992 and 1999 for the Western Portion of the Outer Continental Shelf (“Western Planning Area”).

For consistency, Region 4, developed a permit similar to those issued by Region 6, taking into account any site-specific considerations. Both Regions adopted the same method of determining produced water toxicity limitations using the Cornell Mixing Zone Expert System (CORMIX) to calculate critical dilutions. However, information from the vast number of operating facilities in the Western Planning Area as compared to the relatively few operating facilities in the Eastern Planning Area, enabled Region 6 to develop model input parameters based upon information from a large number of operating facilities. Region 6 also was able to develop a series of critical dilution tables based upon this information, and critical dilution tables for a large segment of potential permittees were developed and included within the Region 6 general permit.

In this modification, EPA is publishing critical dilution tables as part of the general permit, such as those used in Region 6's general permit. Due to the fact that fewer than 30 produced water dischargers exist in Region 4's permit coverage area, Region 4 elected to model the toxicity limitations using the range of data gathered from the operators within this area. Region 4 believes this approach will include all the expected permittees, and will avoid the significant resource demands that would have been required to support a critical dilution table for the ranges used by Region 6. The derivation of critical dilution tables on the scale of those developed by Region 6 would have required over 200 runs of the CORMIX model just to generate ranges that take into account the variations in discharge flow rate, discharge pipe diameter, and distance from the pipe to the sea floor. Currently, EPA is unaware of any facilities in Region 4's area which fall outside of the critical dilution tables in today's proposed draft. The small number of potential permittees did not justify the expenditure of available resources to produce numerous tables.

EPA, Region 4, proposes to modify this general permit by including a critical dilution table comparable to those utilized by the Region 6 general permit. In accordance with 40 CFR 122.28(3)(i) and (c)(1), any owner or operator with a facility with produced water effluent will be required meet the critical dilution values within the limits of the table, or to apply for and obtain an individual permit in order to discharge into U.S. waters. Existing discharges of produced water shall continue to be authorized under the 1991 general permit as reissued by Region 4, if a timely Notice of Intent (NOI) was submitted to obtain coverage under the general permit issued on October 16, 1998.

Additionally, EPA has received numerous requests regulated community regarding the need of a NPDES permit for the discharge of fluids used in the hydrostatic testing of pipelines. These fluids primarily consist of seawater, biocides, corrosion inhibiting solvents (CIS), and other treatment chemicals. The Region 6 general permit addresses this activity under miscellaneous discharges, with prescribed limits on chemical concentration and toxicity. For consistency, Region 4, proposes to modify the general permit to include effluent limitations and monitoring requirements for chemically treated seawater.

EPA, Region 4, also proposes to include an additional requirement for submitting an NOI. Under paragraph (4), part I.4., Notification Requirements (Existing Sources and New Sources), the permittee shall provide information on the types of discharges expected along with data regarding outfall locations.

In addition, to further distinguish permits issued under this general permit from those previously issued by Regions 4 and 6, Region 4 proposes to modify the general permit number to include an alpha character in the 6th position. Permit coverage will be assigned as GMG28A001—A999, GMG28B001—B999, GMG28C001—C999, etc.

II. Coverage of General Permit

Section 301(a) of the CWA provides that the discharge of pollutants is unlawful except in accordance with the terms of an NPDES permit. The EPA has determined that oil and gas facilities seaward of the 200 meter water depth in certain parts of the Eastern Portion of the Gulf of Mexico as described in the NPDES general permit are more Start Printed Page 48505appropriately controlled by a separate general permit, individual permits, or both, 40 CFR 122.28(c). This determination covers both existing sources and new sources. This decision is based on the Federal regulations at 40 CFR 122.28, 40 CFR part 125 (Subpart M—Ocean Discharge Criteria); the Environmental Impact Statement; and the Agency's previous decisions in other areas of the Gulf of Mexico's OCS. As in the case of individual permits, noncompliance with any condition of a general permit constitutes an enforceable violation of the Act under section 309 of the Act.

With this proposed permit modification, all lease blocks with operating facilities discharging produced water will be required to meet the critical dilution limitations in the table, or to apply for and obtain individual permits in order to discharge into waters of the U.S. This notice to modify the general permit will also clarify and correct certain aspects of the general permit issued on October 16, 1998.

III. Proposed General Permit Modifications

Today, EPA is proposing the following permit modifications. These provisions represent the only revisions in this notice that are subject to the federal public notice and comment requirements.

1. General Permit Number (63 FR 55718, October 16, 1999)

The original general permit, issued jointly by Regions 4 and 6 on July 9, 1986, carried the permit number of GMG280000. On November 19, 1992, Region 6 issued a final permit for the Western Gulf of Mexico under GMG290000. In order to distinguish the current permit coverage numbers from those facilities covered by the permits previously issued by Regions 4 and 6, EPA is proposing to designate those facilities covered by the Region 4 permit as General Permit Number GMG28AXXX, where the 6th significant figure will carry an alphabetic designation. The new numbering convention will be, e.g., GMG28A001—A999, GMG28B001—B999, GMG28C001—C999, etc. All notices of general permit coverage provided since the effective date of the November 16, 1998 permit, will be changed to as indicated above. The last three digits of the assigned permit number will remain the same.

2. Notice of Intent (NOI) Requirements (Part I.B.4, 63 FR 55747)

Part I., section A. 4.(4) requires information identifying the receiving waters and the location of the discharge outfalls. EPA believes that more information is required pertaining to the nature of the permitted discharges. To aid in compliance tracking, EPA proposes that the permittee identify the types of discharges expected for the operation applied for under the general permit. Expected discharges would be identified by the nomenclature used in part I., section B.1-10. Additional information may be required regarding miscellaneous discharges (63 FR 55750).

3. Notice To Drill (Part I.A.4, 63 FR 55747)

In recognition that there are situations where a permittee may be unable to meet the minimum 60 day notice period due to unforeseen circumstances, EPA today proposes to modify the 60 day requirement by adding “or lesser notice as approved by the Director” to allow for case-by-case requests for a shortened notice period.

In emergency situations where “Severe Property Damage” may result (see definition 47, 63 FR 55756), or loss of life, or personal injury, bypass provisions at part II.B.3. (63 FR 55752) may be utilized. Upset provisions may also be available as specified at part II.B.4. (Id.).

4. Section 403(c) Reopener Clause

As a result of the President's Executive Order 13158 on Marine Protected Areas dated May 26, 2000, the EPA has been directed to reduce pollution of beaches, coasts, and ocean waters by developing CWA regulations that strengthen water quality protections for coastal and ocean waters. These new standards will guide the agency when it reviews proposals for onshore and offshore activities that result in discharges to ocean or coastal waters. In developing these regulations, EPA may set higher levels of protection in especially valued or vulnerable areas. As a result of this development the following reopener clause will be added as new paragraph 7, part I., section A. Permit Applicability and Coverage Conditions as follows:

7. 403(c) Reopener Clause.

In addition to any other grounds specified herein, this permit may be modified or revoked at any time if, on the basis of any new data or requirements, EPA determines that continued or increased discharges may cause unreasonable degradation of the marine environment or if EPA determines that additional conditions are necessary to protect the marine environment or special aquatic sites. Also, coverage under this permit may be denied or revoked and an individual NPDES permit application required such that any concerns, as stated, may be included in an individual NPDES permit.

5. Produced Water Discharges (Part I.B.3, 63 FR 55749)

The nature of produced water discharges could be toxic to marine organisms in the immediate vicinity of these discharges. Rapid and dispersed mixing are important to reducing and eliminating toxic effects. The measure of any toxic effects vary with discharge volume, density, depth, flow rate, discharge pipe opening diameter and orientation, and current speed. EPA proposes to replace Appendix A for the calculation of permit limitation for produced water toxicity. Rather, these variables will be considered within a table of produced water critical dilutions developed using CORMIX model (Version 3.2). The Limiting Permissible Concentration (LPC), the critical dilution, at the edge of the 100-meter mixing zone is defined as the arithmetic formula of 0.1 × LC50, or LC50=10 × critical dilution. This corrects the 0.01 multiplier originally used in the general permit. Finally, for purposes of this general permit, the small quantities of water generated during production as a result of condensation are exempt as “produced water” and subject to the “miscellaneous discharge” limitations and monitoring requirements of the permit (see infra).

The table is only for produced water effluent discharged below the surface using a vertical port orientation:

Table 4.—Produced Water Critical Dilutions (Percent Effluent) for Water Depths of Less Than 200 Meters

Discharge rate (bbl/day)Pipe diameter
>0″ to 5″>5″ to 7″>7″ to 9″
>0 to 5000.110.110.11
501 to 10000.220.220.22
Start Printed Page 48506
1001 to 20000.370.370.37
2001 to 30000.480.480.48
3001 to 40000.560.560.56
4001 to 50000.650.660.66
5001 to 60000.730.780.78
6001 to 70000.770.780.78
7001 to 80000.840.860.86

Table 4-A.—Produced Water Critical Dilutions (Percent Effluent) for Water Depths of Greater Than 200 Meters

Discharge rate (bbl/day)Pipe diameter
>0″ to 5″>5″ to 7″>7″ to 9″
>0 to 5000.080.080.08
501 to 10000.120.120.12
1001 to 20000.180.180.18
2001 to 30000.220.220.22
3001 to 40000.240.250.25
4001 to 50000.280.280.28
5001 to 60000.300.300.31
6001 to 70000.320.320.32
7001 to 80000.350.350.35

The tables were formulated using the following CORMIX (Version 3.2) input parameters:

Surface density: 1023.0 kg/m3

Discharge density: 1070.2 kg/m3

Density gradient: 0.163 kg/m3/m (linear)

Discharge concentration: 100%

Legal mixing zone: 100 meters

Darcy-Wiesbach friction constant: 0.02

Current speed: 5 cm/sec (< 200 meters), 15 cm/sec (>200 meters)

Vertical discharge angle (Theta) 90° is directed toward the surface, −90° is directed toward the seafloor

Wind speed: 4 m/sec

6. Miscellaneous Discharges (Part I.B.10, 63 FR 55750; Table 2, 63 FR 55759 and Table 3, 63 FR 55761)

EPA is proposing to modify the existing list of miscellaneous discharges to add additional wastewater sources: (1) chemically treated freshwater and seawater which has been used to hydrostatically test new piping and pipelines, and (2) water produced as a result of condensation during the production process. These discharges will be limited for free oil, concentration of treatment chemicals, and toxicity. Effluent limitations and monitoring requirements will be the same as authorized by the Region 6 general permit (part I.B.11, 64 FR 19162 and 19163).

Proposed Permit Limitations

Treatment Chemicals. The concentration of treatment chemicals in discharged chemically treated freshwater and seawater which has been used to hydrostatically test new piping and pipelines shall not exceed the most stringent of the following three constraints:

(1) The maximum concentrations and any other conditions specified in the EPA product registration labeling if the chemical is an EPA registered product, or

(2) The maximum manufacturer's recommended concentration, or

(3) 500 mg/l.

Free Oil. No free oil shall be discharged. Discharge is limited to those times that a visible sheen observation is possible unless the operator uses the static sheen method. Monitoring shall be performed using the visual sheen method on the surface of the receiving water once per week when discharging, or by use of the static sheen method at the operator's option. The number of days a sheen is observed must be recorded.

Toxicity. The 48-hour minimum and monthly average minimum No Observable Effect Concentration (NOEC), or if specified the 7-day average minimum and monthly average minimum NOEC, must be equal to or greater than the critical dilution concentration specified in this permit in Table 4-A for seawater discharges and 4-B for freshwater discharges. Critical dilution shall be determined using Table 4 of this permit and is based on the discharge rate, discharge pipe diameter, and water depth between the discharge pipe and the bottom. The monthly average minimum NOEC value is defined as the arithmetic average of all 48-hour average NOEC (or 7-day average minimum NOEC) values determined during the month.

Proposed Monitoring Requirements

Flow. Once per month, an estimate of the flow (MGD) must be recorded.

Toxicity. The required frequency of testing for continuous discharges shall be determined as follows:

Discharge rateToxicity testing frequency
0-499 bbl/dayOnce per year.
500-4,599 bbl/dayOnce per quarter.
Start Printed Page 48507
4,600 bbl/day and aboveOnce per month.

Intermittent or batch discharges shall be monitored once per discharge but are required to be monitored no more frequently than the corresponding frequencies shown above for continuous discharges.

Samples shall be collected after addition of any added substances, including seawater that is added prior to discharge, and before the flow is split for multiple discharge ports. Samples also shall be representative of the discharge. Methods to increase dilution also apply to seawater and freshwater discharges which have been chemically treated.

If the permittee has been compliant with this toxicity limit for one full year (12 consecutive months) for a continuous discharge of chemically treated seawater or freshwater, the required testing frequency shall be reduced to once per year for that discharge.

Table 5-A.—Critical Dilutions (Percent Effluent) for Toxicity Limitations for Seawater to Which Treatment Chemicals Have Been Added

Depth difference (meters)Discharge rate (bbl/day)Pipe diameter
>0″ to 2″>2″ to 4″>4″ to 6″>6″
All0 to 1,0001224.724.524.6
>1,000 to 10,00011.212.412.214
>10,0009.6242320

Table 5-B.—Critical Dilutions (Percent Effluent) for Toxicity Limitations for Freshwater to Which Treatment Chemicals Have Been Added

Depth difference (meters)Discharge rate (bbl/day)Pipe diameter
>0″ to 2″>2″ to 4″>4″ to 6″>6″
All0 to 1,0001.11.22.92.9
>1,000 to 10,00019392824
>10,00013634174

IV. Clarifications and Minor Corrections

EPA also is providing the information in this section to help further explain or clarify existing requirements of the general permit based on questions and comments received following the original issuance of the permit.

1. Permit Transfers (Part I.A.4, 63 FR 55747)

The Agency has received several comments regarding the transfer of discharge authority where a facility is sold during the period of general permit's coverage. Part of the confusion over transfers resulted in the requirement for an NOI with required information be submitted to the EPA for each discharging facility in order to secure permit coverage. If a facility is purchased or sold to another operator, permittees have raised the concern that the new operator will be required to resubmit the same data from the original operator's NOI to maintain permit coverage. This would result in a redundant review by EPA of this information and untimely delays. EPA is clarifying that where the operator notifies EPA within 30 days prior to the transfer, no additional NOI documentation need be submitted.

The Agency is not deviating from standard procedures for transfer of NPDES permits as set forth in 40 CFR 122.63. EPA does not believe this requirement to be burdensome to industry. It is not EPA's intent to conduct another NOI review. Presumably, all of the NOI requirements would have been previously submitted to EPA for review, and subsequently approved by EPA. If the facility remains operational, then the NOI by the new operator, should simply reference the previously submitted NOI, EPA's authorization to proceed, and the assigned permit number. It is not EPA's intent to encumber the industry's transactions, but rather to keep the Agency informed as to ownership and entitlement of the permitting responsibilities.

There is also some confusion by industry over the steps required to submit an NOI for non-operational or newly acquired leases. For these leases, the general permit states that an exploration or development production plan must be prepared and submitted to EPA before an NOI can be accepted. These plans are normally the responsibility of the Mineral Management Service (MMS), and not part of the EPA permit process. This requirement is corrected to read: “No NOI will be accepted for either a non-operational or newly acquired lease until such time as an exploration or development production plan has been prepared.”

2. Notice To Drill (“NTD”) (Part I.A.4, 63 FR 55747)

The general permit states that an NTD shall contain the assigned NPDES general permit number “assigned to the lease block.” EPA has realized that this language has caused some confusion as general permit coverage is given on an individual facility basis within a given lease block, rather than to the lease block itself. Therefore, EPA is clarifying that it is the facility's assigned permit coverage number that must be included in the NTD.

3. Notice of Intent—Latitude and Longitude Requirements (Part I.B.4, 63 FR 55747)

Under the general permit, as part of the facility's submission, the NOI Start Printed Page 48508requires inclusion of the latitude and longitude of proposed outfall location(s). Concerns have been raised that, in addition to the environmental conditions experienced at the time of siting, due to inherent errors in the positioning equipment the exact outfall location can vary from the originally proposed site. Additionally, while a well surface location may be fixed, the location of the discharge will be in part dictated by the size, layout and actual orientation of the facility in the lease block. This uncertainty can be in the range of several hundred meters. EPA recognizes the practical realities of this type of operation and, therefore, is clarifying that EPA will allow flexibility in the actual placement of a facility after review of the photodocumentation survey. Consistent with MMS protocol, EPA will allow flexibility in placement of a surface location. However, the final siting shall be placed no further than 500 m from the proposed surface location covered by a photodocumentation survey.

4. Notice of Intent—Update of Technical References and Notification Address (Part I.A.4, 63 FR 55747)

Part I.A.4.(10) and (11) refer to the bottom conditions within 1000 meters of the proposed discharge site. For clarification purposes, EPA is taking this opportunity to update its technical references as follows:

“(10) Technical information on the characteristics of the sea bottom in accordance with MMS Notice To Lessees 98-20, Shallow Hazard Requirements, or the most current MMS guidelines for shallow hazard investigation and analysis.”

“(11) MMS live bottom survey in accordance with MMS Notice To Lessees 99-G16 Live-Bottom Surveys and Reports, or the most current MMS guidelines for live-bottom surveys and reports,” for facilities * * *.

EPA also is updating the Agency address for submission of all notices required under the general permit. All NOIs, NTDs, Notices of Commencement of Operations (NCOs), Notices of Termination of Operations (NTOs), and other subsequent reports shall be sent by certified mail to the following address: Director, Water Management Division, NPDES and Biosolids Permits Section, U.S. EPA, Region 4, Atlanta Federal Center, 61 Forsyth Street, S.W., Atlanta, GA 30303-8960. Part III A. of the permit addresses the submittal process for monthly monitoring results and other related reports.

5. Photodocumentation Surveys (Part I.A.4(11), 63 FR 55747)

CWA. The general permit requires photodocumentation surveys for operational facilities in less than 100 meters water depth in the Central Planning Area, except facilities with current active discharges on the effective date of the general permit (November 16, 1998). EPA has been asked to clarify whether the exception includes “operational leases” as defined on page 55718 of the permit (operational leases are defined as “leases on which a discharge has taken place within two years of the effective dates of the general permits”). The answer is no.

As provided in the permit, only currently active dischargers are operational facilities and thus excluded from the NOI requirement for photodocumentation. The exemption only applies to “facilities” that have discharged within two years of the effective date of the permit, not the entire lease containing the facility (i.e., the “operational lease”). Such a lease-wide exemption would only be allowed if the entire block had been surveyed by photodocumentation.

However, EPA has reserved the right to deny this exemption for operational facilities if a significant increase in discharge volume will occur, or if a change in the nature (kind) of effluent to be discharged will occur where no previous photodocumentation has been done at said facility. EPA understands that some deviation from noticed surface locations is expected. Consistent with MMS protocol, EPA will allow flexibility in placement of a surface location. However, for notification purposes, the final surface location shall be placed no further than 500 feet from the proposed surface location. Should the final location be placed within 500 m of an area previously covered by a photodocumentation survey, then no additional survey is required.

6. Correction to Notification Requirements (Part I.A.4., 63 FR 55747)

The general permit requires the operator to submit a notice of commencement of operations (NCO) for several activities. EPA is providing the following typographical correction to the 6th paragraph under part I., section A.4. of the general permit as follows: “In addition, a notice of commencement of operations (NCO) is required to be submitted for each of the following activities: placing a production platform in the general permit coverage area (within 30 days after placement); and discharging produced water within the coverage area.”

7. Correction to the Sanitary Flow Measurement (Table 2, 63 FR 55758 and Table 3, 63 FR 55760).

The general permit requires the estimated flow to be recorded monthly. The tables entitled “Existing Sources-Effluent Limitations, Prohibitions, and Monitoring Requirements for the Eastern Gulf of Mexico NPDES General Permit” (Table 2) and “New Sources-Effluent Limitations, Prohibitions, and Monitoring Requirements for the Eastern Gulf of Mexico NPDES General Permit” (Table 3) do not include the requirement to report the estimated flow on the monthly reports.

EPA has corrected its inadvertent omission of the “Recorded/Reported Value” from Tables 2 (p. 55758) and 3 (p. 55760) of the permit for Sanitary Waste outfall. Consistent with the requirements of section B.7(c), the average flow in million gallons per day (MGD) must be estimated and recorded for the flow of sanitary wastes once per month and submitted on the DMR.

8. Correction to Oil and Grease Limitations of Produced Water Discharges (Part I.B.3., 63 FR 55749)

The reporting requirement for the monthly DMR, is clarified to read: “The highest daily maximum oil and grease concentration and the monthly average concentration shall be reported on the monthly DMR.”

9. Clarification to the (Exception) for Sanitary Waste Facilities (Part I.B.7., 63 FR 55749 and Part I.B.8., 63 FR 55750)

The exception to the permit limitations for sanitary waste is clarified to read: “(Exception) Any facility which properly operates and maintains a marine sanitation device (MSD) that complies with * * *.

10. Clarification to Monitoring Reports (Part III.A, 63 FR 55754)

Part III.A. deals with the proper labeling and submission of discharge monitoring reports (DMRs). EPA inadvertently stated that the operator of each “lease block” shall be responsible for submitting DMRs. Since Region 4 issues the general permit to an individual facility, and not a lease block, the operator of each facility is responsible for submitting the appropriate DMR. EPA is providing the following typographical change in the general permit:

The operator of each facility shall be responsible for submitting its monitoring results.

Start Printed Page 48509

11. Termination of Coverage Under the 1991 General Permit Issued (63 FR 55746)

The general permit, issued on October 16, 1998, required facilities covered under the previous general permit to submit a written notice of intent within 60 days of the effective date of the permit (November 16, 1998). NPDES permit coverage was terminated for those facilities with continuing operations after that deadline who had not submitted the requisite NOI. Therefore, those facilities which had not submitted the requsite NOI are currently operating without proper permit coverage.

V. Cost Estimate

The cost of compliance with a general permit is lower than that of an individual permit. Therefore, there is a comparative financial benefit to coverage under the general permit even with produced water requirements from coverage under an individual permit.

VI. Unfunded Mandates Reform Act

Section 201 of the Unfunded Mandates Reform Act (UMRA), Public Law 104-4, generally requires Federal agencies to assess the effects of their “regulatory actions” on State, local, and tribal governments and the private sector. UMRA uses the term “regulatory actions” to refer to regulations. (See, e.g., UMRA section 201, “Each agency shall * * * assess the effects of Federal regulatory actions * * * (other than to the extent that such regulations incorporate requirements specifically set forth in law)” (emphasis added)). UMRA section 102 defines “regulation” by reference to section 658 of Title 2 of the U.S. Code, which in turn defines “regulation” and “rule” by reference to section 601(2) of the Regulatory Flexibility Act (RFA). That section of the RFA defines “rule” as “any rule for which the agency publishes a notice of proposed rulemaking pursuant to section 553(b) of the Administrative Procedure Act (APA, or any other law * * *”

NPDES general permits are not “rules” under the APA and thus not subject to the APA requirement to publish a notice of proposed rulemaking. NPDES general permits also are not subject to such a requirement under the CWA. While EPA publishes a notice to solicit public comments on draft general permits, it does so pursuant to the CWA section 402(a) requirement to provide an “opportunity for a hearing.” Thus, NPDES general permits are not “rules” for RFA or UMRA purposes.

Title II of the Unfunded Mandates Reform Act of 1995, Public Law 104-4, establishes requirements for Federal agencies to assess the effects of their regulatory actions on State, local, and Tribal governments and the private sector. Under UMRA section 202, EPA generally must prepare a written statement, including a cost-benefit analysis, for proposed and final rules with “Federal mandates” that may result in expenditures to State, local, and Tribal governments, in the aggregate, or to the private sector, of $100 million or more in any one year. Before promulgating an EPA rule for which a written statement is needed, UMRA section 205 generally requires EPA to identify and consider a reasonable number of regulatory alternatives and adopt the least costly, most cost-effective or least burdensome alternative that achieves the objectives of the rule. The provisions of UMRA section 205 do not apply when they are inconsistent with applicable law. Moreover, UMRA section 205 allows EPA to adopt an alternative other than the least costly, most cost-effective or least burdensome alternative if the Administrator publishes an explanation with the final rule why the alternative was not adopted.

EPA has determined that the proposed permit modification would not contain a Federal requirement that may result in expenditures of $100 million or more for State, local and tribal governments, in the aggregate, or the private sector in any one year.

The Agency also believes that the permit would not significantly nor uniquely affect small governments. For UMRA purposes, “small governments” is defined by reference to the definition of “small government jurisdiction” under the RFA. (See UMRA section 102(1), referencing 2 U.S.C. 658, which references section 601(5) of the RFA.) “Small governmental jurisdiction” means government of cities, counties, towns, etc. with a population of less than 50,000, unless the agency establishes an alternative definition.

The permit modification, as proposed, also would not uniquely affect small governments because compliance with the proposed permit conditions affects small governments in the same manner as any other entities seeking coverage under the permit. Additionally, EPA does not expect small government to operate facilities authorized to discharge by this permit.

VII. Paperwork Reduction Act

The information collection required by these permits has been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., in submission made for the NPDES permit program and assigned OMB control numbers 2040-0086 (NPDES permit application) and 2040-0004 (discharge monitoring reports).

EPA did not prepare an Information Collection Request (ICR) document for today's permit modification because the information collection requirements in this permit have already been approved by the Office of Management and Budget (OMB) in submissions made for the NPDES permit program under the provisions of the CWA.

VIII. Regulatory Flexibility Act (RFA), as Amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 601 et seq.

Today's proposed general permit is not subject to the RFA, which generally requires an agency to prepare a regulatory flexibility analysis for any rule that will have a significant economic impact on a substantial number of small entities. The RFA only applies to rules subject to notice and comment rulemaking requirements under the Administrative Procedures Act (APA) or any other statute. As previously stated, the permit modification proposed today is not a “rule” subject to the RFA. Although this proposed general permit is not subject to the RFA, EPA nonetheless has assessed the potential of this rule to adversely impact small entities subject to this general permit and, in light of the facts presented above, I hereby certify pursuant to the provisions of the RFA that these proposed general permit modifications will not have a significant impact on a substantial number of small entities. This determination is based on the fact that the vast majority of the parties regulated by this permit have greater than 500 employees and are not classified as small businesses under the Small Business Administration regulations established at 49 FR 5024 et seq. (February 9, 1984). For those operators having fewer than 500 employees, this permit issuance will not have significant economic impact. These facilities are classified as Major Group 13—Oil and Gas Extraction SIC Crude Petroleum and Natural Gas.

Start Authority

Authority: Clean Water Act, 33 U.S.C. 1251 et seq.

End Authority Start Signature

Dated: June 30, 2000.

John H. Hankinson, Jr.,

Regional Administrator, Region 4.

End Signature Start Printed Page 48510

Draft Modification of the National Pollutant Discharge Elimination System (NPDES) General Permit for the Eastern Portion of the Outer Continental Shelf (OCS) of the Gulf of Mexico (GMG280000)

Draft Modification of National Pollutant Discharge Elimination System (NPDES) General Permit for the Eastern Portion of the Outer Continental Shelf (OCS) of the Gulf of Mexico (GMG280000)

For reasons set forth in the preamble, the NPDES General Permit for the Eastern Portion of the Outer Continental Shelf (OCS) of the Gulf of Mexico (GMG280000) is proposed to be modified as described below. EPA is proposing to delete the existing appendix A from the general permit along with several other additional modifications and clarifications. These proposed modifications and additional requirements will become effective on the date of Federal Register publication of the modifications.

General Permit Number [Modification]

(1) As of the effective date of the Federal Register publication of these modifications, the general permit number, originally identified as GMG280000, will be modified to read as GMG28AXXX, where the 6th significant figure will carry an alphabetic designation. The new numbering convention will be, e.g., GMG28A001-A999, GMG28B001-B999, GMG28C001-C999, etc.

Part I. Requirements for NPDES Permits

(2) On page 55747, paragraph (4) is modified to add additional information requirements and corrected to update the technical references, as follows:

Section A. Permit Applicability and Coverage Conditions

4. Notification Requirements (Existing Sources and New Sources) [Modified and Corrected]

Written notification of intent (NOI) to be covered in accordance with the general permit requirements shall state whether the permittee is requesting coverage under the existing source general permit or new source general permit, and shall contain the following information:

(1) The legal name and address of the owner or operator;

(2) The facility name and location, including the lease block assigned by the Department of the Interior, or if none, the name commonly assigned to the lease area;

(3) The number and type of facilities and activity proposed within the lease block;

(4) The waters into which the facility is or will be discharging; including a map with longitude and latitude of current or proposed outfall locations and expected discharges identified by the nomenclature used in part I., section B.1-10. Additional information may be requested by the Director regarding miscellaneous discharges.

* * * * *

(10) Technical information on the characteristics of the sea bottom in accordance with MMS Notice To Lessees 98-20, Shallow Hazard Requirements, or the most current MMS guidelines for shallow hazard investigation and analysis.

(11) MMS live bottom survey in accordance with MMS Notice To Lessees 99-G16 Live-Bottom Surveys and Reports, or the most current MMS guidelines for live-bottom surveys and reports, for facilities in less than 100 meters water depth in the Central Planning Area. (Exception: Current active discharging facilities on the effective date of the new general permit will be exempt from photo-documentation surveys for the life of that discharge: (Refer to Comment No. 69 for clarification)

* * * * *

(3) On page 55747, paragraph 4, is corrected to clarify NOI notification requirements for a newly acquired lease as follows:

For operating leases, the NOI shall be submitted within sixty (60) days after publication of the final determination on this action. Non-operational facilities are not eligible for coverage under these new general permits. No NOI will be accepted from either a non-operational or newly acquired lease until such time as an exploration plan or development production plan has been prepared.

* * * * *

(4) On page 55747, paragraph 4, is modified regarding NTD notice requirements and clarified to update the Agency address for submission of notices under the general permit follows:

For drilling activity, the operator shall submit a Notice to Drill (NTD) sixty (60) days, or lesser notice as approved by the Director, prior to the actual move-on date. This NTD shall contain: (1) The assigned NPDES general permit number assigned to the facility, (2) the latitude and longitude of the proposed discharge point, (3) the water depth, and (4) the estimated length of time the drilling operation will last. This NTD shall be submitted to Region 4 at the address above, by certified mail to: Director, Water Management Division, NPDES and Biosolids Permit Section, U.S. EPA, Region 4, Atlanta Federal Center, 61 Forsyth Street, S.W., Atlanta, GA 30303-8960.

* * * * *

All NOIs, NTDs, NCOs, and any subsequent reports required under this permit shall be sent by certified mail to the following address: Director, Water Management Division, NPDES and Biosolids Permits Section, U.S. EPA, Region 4, Atlanta Federal Center, 61 Forsyth Street, S.W., Atlanta, GA 30303-8960.

* * * * *

(5) On page 55747, paragraph 4, is modified to remove the reference to appendix A and corrected to remove two typographical errors as follows:

In addition, a notice of commencement of operations (NCO) is required to be submitted for each of the following activities: placing a production platform in the general permit coverage area (within 30 days after placement); and discharging produced water within the coverage area.

* * * * *

6. Intent To Be Covered by a Subsequent Permit [Corrected]

(6) On page 55747, paragraph 6, is clarified to update the Agency address for submission of notices under the general permit follows:

This permit shall expire on October 31, 2003. However, an expired general permit continues in force and effect until a new general permit is issued. Lease block operators authorized to discharge by this permit shall by certified mail notify the Director, Water Management Division, NPDES and Biosolids Permit Section, U.S. EPA, Region 4, Atlanta Federal Center, 61 Forsyth Street, S.W., Atlanta, GA 30303-8960, on or before April 30, 2003, that they intend to be covered by a permit that will authorize discharge from these facilities after the termination date of this permit on October 31, 2003.

Permittees must submit a new NOI in accordance with the requirements of this permit to remain covered under the continued general permit after the expiration of this permit. Therefore, facilities that have not submitted an NOI under the permit by the expiration date cannot become authorized to discharge under any continuation of this NPDES general permit. All NOI's from permittees requesting coverage under a Start Printed Page 48511continued permit should be sent by certified mail to: Director, Water Management Division, NPDES and Biosolids Permits Section, U.S. EPA, Region 4, Atlanta Federal Center, 61 Forsyth Street, S.W., Atlanta, GA 30303-8960.

* * * * *

7. Section 403(c) Reopener [New]

(7) On page 55747, a new paragraph 7, is added to address the mandatory Section 403(c) reopener clause, as follows:

7. Section 403(c) Reopener

In addition to any other grounds specified herein, this permit may be modified or revoked at any time if, on the basis of any new data or requirements, EPA determines that continued or increased discharges may cause unreasonable degradation of the marine environment or if EPA determines that additional conditions are necessary to protect the marine environment or special aquatic sites. Also, coverage under this permit may be denied or revoked and an individual NPDES permit application required such that any concerns, as stated, may be included in an individual NPDES permit.

* * * * *

Part I. Requirements for NPDES Permits

(8) On page 55749, Section B, paragraph (3) is modified to remove the reference to Appendix A, correct the arithmetic formula regarding limiting permissible concentrations, correct the reporting requirement for oil and grease limitation, and referencing the new produced water critical dilution tables, as follows:

Section B. Effluent Limitations and Monitoring Requirements

3. Produced Water [Modified]

(b) Limitations. Oil and Grease. Produced water discharges must meet both a daily maximum limitation of 42 mg/l and a monthly average limitation of 29 mg/l for oil and grease. A grab sample must be taken at least once per month. The daily maximum samples may be based on the average concentration of four grab samples taken within the 24-hour period. If only one sample is taken for any one month, it must meet both the daily and monthly limits. If more samples are taken, they may exceed the monthly average for any one day, provided that the average of all samples taken meets the monthly limitation. The gravimetric method is specified at 40 CFR part 136. The highest daily maximum oil and grease concentration and the monthly average concentration shall be reported on the monthly DMR.

Toxicity. Produced water discharges must meet a toxicity limitation projected to be the limiting permissible concentration (0.1 × LC50) at the edge of a 100-meter mixing zone. The toxicity limitation will be determined by the using the produced water critical dilutions in Tables 4- or 4-A.

* * * * *

(9) On page 55749, paragraph (7) is modified to further define the exemption for sanitary waste discharges, as follows:

7. Sanitary Waste (Facilities Continuously Manned by 10 or More Persons)

(b) Limitations. Residual Chlorine. Total residual chlorine is a surrogate parameter for fecal coliform. Discharges of sanitary waste must contain a minimum of 1 mg residual chlorine/l and shall be maintained as close to this concentration as possible. The approved analytical method is Hach CN-66-DPD. A grab sample must be taken once per month and the concentration reported.

(Exception) Any facility which properly operates and maintains a marine sanitation device (MSD) that complies with pollution control standards and regulations under section 312 of the Act shall be deemed in compliance with permit limitations for sanitary waste. The MSD shall be tested annually for proper operation and the test results maintained at the facility. The operator shall indicate use of an MSD on the monthly DMR.

* * * * *

(10) On page 55750, paragraph (8) is modified to further define the exemption for sanitary waste discharges, as follows:

8. Sanitary Waste (Facilities Continuously Manned by 9 or Fewer Persons or Intermittently by Any Number)

(a) Prohibitions. Solids. No floating solids may be discharged to the receiving waters. An observation must be made once per day when the facility is manned, during daylight in the vicinity of sanitary waste outfalls, following either the morning or midday meal and at a time during maximum estimated discharge. The number of days solids are observed shall be recorded.

(Exception) Any facility which properly operates and maintains a marine sanitation device (MSD) that complies with pollution control standards and regulations under section 312 of the Act shall be deemed in compliance with permit limitations for sanitary waste. The MSD shall be tested annually for proper operation and the test results maintained at the facility. The operator shall indicate use of an MSD on the monthly DMR.

* * * * *

(11) On page 55750, paragraph (10) is modified to include additional defined “miscellaneous discharges.” as follows:

10. Miscellaneous Discharges. Desalination Unit Discharge; Blowout Preventer Fluid; Uncontaminated Ballast Water; Uncontaminated Bilge Water; Mud, Cuttings, and Cement at the Seafloor; Uncontaminated Seawater; Boiler Blowdown; Source Water and Sand; Uncontaminated Freshwater; Excess Cement Slurry; Diatomaceous Earth Filter Media; chemically treated freshwater and seawater used for the hydrostatic testing of new piping and pipelines; and waters resulting from condensation.

* * * * *

(12) On page 55750, paragraph (10) is modified to include additional effluent limitations and monitoring requirements for chemically treated freshwater and seawater used for the hydrostatic testing of new piping and pipelines, as follows:

The discharge of miscellaneous discharges shall be limited and monitored by the permittee as specified in tables 2 and 3 and as below.

(a) Free Oil. No free oil shall be discharged. Monitoring shall be performed using the visual sheen test method once per day when discharging on the surface of the receiving water or by use of the static sheen method at the operator's option. Both tests shall be conducted in accordance with the methods presented at IV.A.3 and IV.A.4. Discharge is limited to those times that a visual sheen observation is possible. The number of days a sheen is observed must be recorded.

(Exception): Miscellaneous discharges may be discharged from platforms that are on automatic purge systems without monitoring for free oil when the facility is not manned. Discharge is not restricted to periods when observation is possible; however, the static (laboratory) sheen test method must be used during periods when observation of a sheen is not possible, such as at night or during inclement conditions. Static sheen testing is not required for miscellaneous discharges occurring at the sea floor.

(b) Treatment Chemicals. The concentration of treatment chemicals in discharged chemically treated freshwater and seawater shall not Start Printed Page 48512exceed the most stringent of the following three constraints:

(1) The maximum concentrations and any other conditions specified in the EPA product registration labeling if the chemical is an EPA registered product, or

(2) The maximum manufacturer's recommended concentration, or

(3) 500 mg/l.

(c) Toxicity. The toxicity of discharged chemically treated freshwater and seawater shall be limited as follows: the 48-hour minimum and monthly average minimum No Observable Effect Concentration (NOEC), or if specified the 7-day average minimum and monthly average minimum NOEC, must be equal to or greater than the critical dilution concentration specified in this permit in Table 5-A for seawater discharges and 5-B for freshwater discharges. Critical dilution shall be determined using Table 5 of this permit and is based on the discharge rate, discharge pipe diameter, and water depth between the discharge pipe and the bottom. The monthly average minimum NOEC value is defined as the arithmetic average of all 48-hour average NOEC (or 7-day average minimum NOEC) values determined during the month.

(d) Monitoring Requirements for discharged chemically treated freshwater and seawater:

Flow. Once per month, an estimate of the flow (MGD) must be recorded.

Toxicity. The required frequency of testing for continuous discharges shall be determined as follows:

Discharge rateToxicity testing frequency
0-499 bbl/dayOnce per year.
500-4,599 bbl/dayOnce per quarter.
4,600 bbl/day and aboveOnce per month.

Intermittent or batch discharges shall be monitored once per discharge but are required to be monitored no more frequently than the corresponding frequencies shown above for continuous discharges.

Samples shall be collected after addition of any added substances, including seawater that is added prior to discharge, and before the flow is split for multiple discharge ports. Samples also shall be representative of the discharge. Methods to increase dilution also apply to seawater and freshwater discharges which have been chemically treated.

If the permittee has been compliant with this toxicity limit for one full year (12 consecutive months) for a continuous discharge of chemically treated seawater or freshwater, the required testing frequency shall be reduced to once per year for that discharge.

* * * * *

Part III. Monitoring Reports and Permit Modification

(13) On page 55754, Section A is corrected to recognize that monitoring reports are to be submitted by the facility operator, as follows:

Section A. Monitoring Reports

The operator of each facility shall be responsible for submitting monitoring results for each facility within each lease block.

* * * * *

Appendix A [Modification]

(14) On page 55761, EPA is proposing to delete appendix A and replace it with two new Tables—Critical Dilution Tables 4 and 4-A, as follows.

Table 4.—Produced Water Critical Dilutions (Percent Effluent) for Water Depths of Less Than 200 Meters

Discharge rate (bbl/day)Pipe diameter
>0″ to 5″>5″ to 7″>7″ to 9″
>0 to 5000.110.110.11
501 to 10000.220.220.22
1001 to 20000.370.370.37
2001 to 30000.480.480.48
3001 to 40000.560.560.56
4001 to 50000.650.660.66
5001 to 60000.730.780.78
6001 to 70000.770.780.78
001 to 80000.840.860.86

Table 4-A.—Produced Water Critical Dilutions (Percent Effluent) for Water Depths of Greater Than 200 Meters

Discharge rate (bbl/day)Pipe diameter
>0″ to 5″>5″ to 7″>7″ to 9″
>0 to 5000.080.080.08
501 to 10000.120.120.12
1001 to 20000.180.180.18
2001 to 30000.220.220.22
3001 to 40000.240.250.25
4001 to 50000.280.280.28
5001 to 60000.300.300.31
6001 to 70000.320.320.32
7001 to 80000.350.350.35

(15) On pages 55757-55758, on Table 2 “Existing Sources-Effluent Limitations, Prohibitions, and Monitoring Requirements for the Eastern Gulf of Mexico NPDES General Permit” and Table 3 “New Sources-Effluent Limitations, Prohibitions, and Monitoring Requirements for the Eastern Gulf of Mexico NPDES General Permit” a correction is made to the Sanitary Flow Start Printed Page 48513Measurement reporting requirements to add a “Recorded/Reported Value” for “Estimated Flow”, as follows:

Table 2.—Effluent Limitations, Prohibitions, and Monitoring Requirements for the Eastern Gulf of Mexico NPDES General Permit

[Existing sources]

DischargeRegulated and monitored discharge parameterDischarge limitation/prohibitionMonitoring requirement
Measurement frequencySample type/methodRecorded/reported value
Drilling FluidsOil-based Drilling FluidsNo discharge
Oil-contaminated Drilling FluidsNo discharge
Drilling Fluids to Which Diesel Oil has been AddedNo discharge
Mercury and Cadmium in BariteNo discharge of drilling fluids if added barite contains Hg in excess of 1.0 mg/kg or Cd in excess of 3.0 mg/kg (dry wt)Once per new source of barite usedFlame and flameless AASmg Hg and mg Cd/kg in stock barite.
Toxicity \a\30,000 ppm daily minimumOnce/month Once/end of well \b\Grab/96-hr LC50 using Mysidopsis bahia; Method at 58 FR 12507Minimum LC50 of tests performed and monthly average LC50.
30,000 ppm monthly average minimumOnce/month
Free OilNo free oilOnce/day prior to dischargeStatic sheen; Method at 58 FR 12506Number of days sheen observed.
Maximum Discharge Rate1,000 barrels/hrOnce/hourEstimateMax. hourly rate in bbl/hr.
Mineral OilMineral oil may be used only as a carrier fluid, lubricity additive, or pill
Drilling Fluids InventoryRecordOnce/wellInventoryChemical constituents.
VolumeReportOnce/monthEstimateMonthly total in bbl/month.
Within 1000 Meters of an Areas of Biological Concern (ABC)No discharge
Drill CuttingsNote: Drill cuttings are subject to the same limitations/prohibitions as drilling fluids except Maximum Discharge Rate.
Free OilNo free oilOnce/day prior to dischargeStatic sheen; Method at 58 FR 12506Number of days sheen observed.
VolumeReportOnce/monthEstimateMonthly total in bbl/month.
Produced WaterOil and Grease42 mg/l daily maximum and 29 mg/l monthly averageOnce/month \c\Grab/GravimetricDaily max. and monthly avg.
ToxicityAcute toxicity (LC50); critical dilution as specified by the requirements at Part I.B.3(b) and Appendix A of this permitOnce/2 monthsGrab/96-hour LC50 using Mysidopsis bahia and inland silverside minnow (Method in EPA/600/4-90/027F)Minimum LC50 for both species and full laboratory report.
Flow (bbl/month)Once/monthEstimateMonthly rate.
Within 1000 meters of an Area of Biological Concern (ABC)No discharge
Deck DrainageFree OilNo free oilOnce/day when discharging \d\Visual sheenNumber of days sheen observed.
Volume (bbl/month)Once/monthEstimateMonthly total.
Produced SandNo Discharge
Well Treatment, Completion, and Workover Fluids (includes packer fluids) \e\Free OilNo free oilOnce/day when dischargingStatic sheenNumber of days sheen observed.
Start Printed Page 48514
Oil and Grease42 mg/l daily maximum and 29 mg/l monthly averageOnce/monthGrab/GravimetricDaily max. and monthly avg.
Priority PollutantsNo priority pollutantsMonitor added materials
Volume (bbl/month)Once/monthEstimateMonthly total.
Sanitary Waste (Continuously manned by 10 or more persons) \f\SolidsNo floating solidsOnce/day, in daylightObservationNumber of days solids observed.
Residual ChlorineAt least (but as close to) 1 mg/lOnce/monthGrab/Hach CN-66-DPDConcentration.
Flow (MGD)Once/monthEstimateMonthly ave.
Sanitary Waste (Continuously manned by 9 or fewer persons or intermittently by any) \f\SolidsNo floating solidsOnce/day, in daylightObservationNumber of days solids observed.
Domestic WasteSolidsNo floating solids; no food waste within 12 miles of land; comminuted food waste smaller than 25-mm beyond 12 milesOnce/day following morning or midday meal at time of maximum expected dischargeObservationNumber of days solids observed.
Miscellaneous Discharges—Desalination Unit; Blowout Preventer Fluid; Uncontaminated Ballast/Bilge Water; Mud, Cuttings, and Cement at the Seafloor; Uncontaminated Seawater; Boiler Blowdown; Source Water and Sand; Uncontaminated Fresh Water; Excess Cement Slurry; Diatomaceous Earth; Filter Media; Condensation waterFree OilNo free oilOnce/day when dischargingVisual sheenNumber of days sheen observed.
Miscellaneous discharges of seawater and freshwater to which treatment chemicals have been addedTreatment ChemicalsMost Stringent of: EPA label registration, maximum manufacturer's recommended dose, or 500 mg/l
Free OilNo Free Oil1/weekVisual SheenNumber of days sheen observed.
Toxicity48-hour ave. minimum NOEC and monthly ave. minimum NOECRate DependentGrabLowest NOEC observed for either of the two species.
a Toxicity test to be conducted using suspended particulate phase (SPP) of a 9:1 seawater:mud dilution. The sample shall be taken beneath the shale shaker, or if there are no returns across the shaker, the sample must be taken from a location that is characteristic of the overall mud system to be discharged.
b Sample shall be taken after the final log run is completed and prior to bulk discharge.
c The daily maximum concentration may be based on the average of up to four grab sample results in the 24 hour period.
d When discharging and facility is manned. Monitoring shall be accomplished during times when observation of a visual sheen on the surface of the receiving water is possible in the vicinity of the discharge.
e No discharge of priority pollutants except in trace amounts. Information on the specific chemical composition shall be recorded but not reported unless requested by EPA. Start Printed Page 48515
f Any facility that properly operates and maintains a marine sanitation device (MSD) that complies with pollution control standards and regulations under Section 312 of the Act shall be deemed to be in compliance with permit limitations for sanitary waste. The MSD shall be tested yearly for proper operation and test results maintained at the facility.

Table 3.—Effluent Limitations, Prohibitions, and Monitoring Requirements for the Eastern Gulf of Mexico NPDES General Permit

[New sources]

DischargeRegulated and monitored discharge parameterDischarge limitation/ prohibitionMonitoring requirement
Measurement frequencySample type/methodRecorded/reported value
Drilling FluidsOil-based Drilling FluidsNo discharge
Oil-contaminated Drilling FluidsNo discharge
Drilling Fluids to Which Diesel Oil has been AddedNo discharge
Mercury and Cadmium in BariteNo discharge of drilling fluids if added barite contains Hg in excess of 1.0 mg/kg or Cd in excess of 3.0 mg/kg (dry wt)Once per new source of barite usedFlame and flameless AASmg Hg and mg Cd/kg in stock barite.
Toxicitya30,000 ppm daily minimumOnce/month Once/end of wellbGrab/96-hr LC50 using Mysidopsis bahia; Method at 58 FR 12507Minimum LC50 of tests performed and monthly average LC50.
30,000 ppm monthly average minimumOnce/month
Free OilNo free oilOnce/day prior to dischargeStatic sheen; Method at 58 FR 12506Number of days sheen observed.
Maximum Discharge Rate1,000 barrels/hrOnce/hourEstimateMax. hourly rate in bbl/hr.
Mineral OilMineral oil may be used only as a carrier fluid, lubricity additive, or pill.
Drilling Fluids InventoryRecordOnce/wellInventoryChemical constituents.
VolumeReportOnce/monthEstimateMonthly total in bbl/month.
Within 1000 Meters of an Areas of Biological Concern (ABC)No discharge
Drill Cuttings(4) Note: Drill cuttings are subject to the same limitations/prohibitions as drilling fluids except Maximum Discharge Rate.
Free OilNo free oilOnce/day prior to dischargeStatic sheen; Method at 58 FR 12506Number of days sheen observed.
VolumeReportOnce/monthEstimateMonthly total in bbl/month.
Produced WaterOil and Grease42 mg/l daily maximum and 29 mg/l monthly averageOnce/monthcGrab/GravimetricDaily max. and monthly avg.
ToxicityAcute toxicity (LC50); critical dilution as specified by the requirements at Part I.B.3(b) and Appendix A of this permitOnce/2 monthsGrab/96-hour LC50 using Mysidopsis bahia and inland silverside minnow (Method in EPA/600/4-90/027F)Minimum LC50 for both species and full laboratory report.
Flow (bbl/month)Once/monthEstimateMonthly rate.
Within 1000 meters of an Area of Biological Concern (ABC)No discharge
Deck DrainageFree OilNo free oilOnce/day when dischargingdVisual sheenNumber of days sheen observed.
Volume (bbl/month)Once/monthEstimateMonthly total.
Produced SandNo Discharge
Well Treatment, Completion, and Workover Fluids (includes packer fluids)eFree OilNo free oilOnce/day when dischargingStatic sheenNumber of days sheen observed.
Start Printed Page 48516
Oil and Grease42 mg/l daily maximum and 29 mg/l monthly averageOnce/monthGrab/GravimetricDaily max. and monthly avg.
Priority PollutantsNo priority pollutantsMonitor added materials
Volume (bbl/month)Once/monthEstimateMonthly total.
Sanitary Waste (Continuously manned by 10 or more persons)fSolidsNo floating solidsOnce/day, in daylightObservationNumber of days solids observed.
Residual ChlorineAt least (but as close to) 1 mg/lOnce/monthGrab/Hach CN-66-DPDConcentration.
Flow (MGD)Once/monthEstimateMonthly ave.
Sanitary Waste (Continuously manned by 9 or fewer persons or intermittently by any)fSolidsNo floating solidsOnce/day, in daylightObservationNumber of days solids observed.
Domestic WasteSolidsNo floating solids; no food waste within 12 miles of land; comminuted food waste smaller than 25-mm beyond 12 milesOnce/day following morning or midday meal at time of maximum expected dischargeObservationNumber of days solids observed.
Miscellaneous Discharges—Desalination Unit; Blowout Preventer Fluid; Uncontaminated Ballast/Bilge Water; Mud, Cuttings, and Cement at the Seafloor; Uncontaminated Seawater; Boiler Blowdown; Source Water and Sand; Uncontaminated Freshwater; Excess Cement Slurry; Diatomaceous Earth Filter Media; Condensation waterFree OilNo free oilOnce/day when dischargingVisual sheenNumber of days sheen observed.
Miscellaneous discharges of seawater and freshwater to which treatment chemicals have been added.Treatment ChemicalsMost Stringent of: EPA label registration, maximum manufacturer's recommended dose, or 500 mg/l
Free OilNo Free Oil1/weekVisual SheenNumber of days sheen observed.
Toxicity48-hour ave. minimum NOEC and monthly ave. minimum NOEC.Rate DependentGrabLowest NOEC observed for either of the two species.
a Toxicity test to be conducted using suspended particulate phase (SPP) of a 9:1 seawater:mud dilution. The sample shall be taken beneath the shale shaker, or if there are no returns across the shaker, the sample must be taken from a location that is characteristic of the overall mud system to be discharged.
b Sample shall be taken after the final log run is completed and prior to bulk discharge.
c The daily maximum concentration may be based on the average of up to four grab sample results in the 24 hour period.
d When discharging and facility is manned. Monitoring shall be accomplished during times when observation of a visual sheen on the surface of the receiving water is possible in the vicinity of the discharge.
e No discharge of priority pollutants except in trace amounts. Information on the specific chemical composition shall be recorded but not reported unless requested by EPA. Start Printed Page 48517
f Any facility that properly operates and maintains a marine sanitation device (MSD) that complies with pollution control standards and regulations under Section 312 of the Act shall be deemed to be in compliance with permit limitations for sanitary waste. The MSD shall be tested yearly for proper operation and test results maintained at the facility.
End Further Info End Preamble

[FR Doc. 00-19913 Filed 8-7-00; 8:45 am]

BILLING CODE 6560-50-P