Section

[Code of Federal Regulations]
[Title 40, Volume 28]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR435.15]

[Page 303-336]

TITLE 40--PROTECTION OF ENVIRONMENT

CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

PART 435_OIL AND GAS EXTRACTION POINT SOURCE CATEGORY--Table of Contents

Subpart A_Offshore Subcategory

Sec. 435.15 Standards of performance for new sources (NSPS).

Any new source subject to this subpart must achieve the following
new source performance standards (NSPS):

New Source Performance Standards
------------------------------------------------------------------------
Pollutant
Waste source parameter NSPS
------------------------------------------------------------------------
Produced water................... Oil and grease.. The maximum for any
one day shall not
exceed 42 mg/l;
the average of
daily values for
30 consecutive
days shall not
exceed 29 mg/l.

[[Page 304]]

Drilling fluids and drill cut
tings:
(A) For facilities located within ................ No discharge.\1\
3 miles from shore.
(B) For facilities located beyond
3 miles from shore:
Water-based drilling fluids SPP Toxicity.... Minimum 96-hour
and associated drill LC50 of the SPP
cuttings. Toxicity Test \2\
shall be 3% by
volume.
Free oil........ No discharge.3
Diesel oil...... No discharge.
Mercury......... 1mg/kg dry weight
maximum in the
stock barite.
Cadmium......... 3 mg/kg dry weight
maximum in the
stock barite.
Non-aqueous drilling fluids.. ................ No charge.
Drill cuttings associated with
non-aqueous drilling fluids:
Stock Limitations (C16-C18 Mercury......... 1mg/kg dry weight
internal olefin. maximum in the
stock barite.
Cadmium......... 3 mg/kg dry weight
maximum in the
stock barite.
Polynuclear PAH mass ratio5
Aromatic shall not exceed
Hydrocarbons 1x10-5.
(PAH).
Sediment Base fluid sediment
toxicity. toxicity ratio 6
shall not exceed
1.0.
Biodegradation Biodegradation rate
rate. ratio7 shall not
exceed 1.0.
Discharge Limitations........ Diesel oil...... No discharge.
SPP Toxicity.... Minimum 96-hour
LC50 of the SPP
Toxicity Test \2\
shall be 3% by
volume.
Sediment Drilling fluid
toxicity. sediment toxicity
ratio 8 shall not
exceed 1.0.
Formation Oil... No discharge.9
Base fluid For NAFs that meet
retained on the stock
cuttings. limitations (C16-
C18 internal
olefin) in this
table, the maximum
weighted mass
ratio averaged
over all NAF well
sections shall be
6.9 g-NAF base
fluid/100 g-wet
drill cuttings.10
For NAFs that meet
the C12-C14 ester
or C8 ester stock
limitations in
footnote 11 of
this table, the
maximum weighted
mass ratio
averaged over all
NAF well sections
shall be 9.4 g-NAF
base fluid/100 g-
wet drill
cuttings.
Well treatment, completion, and Oil and grease.. The maximum for any
work over fluids. one day shall not
exceed 42 mg/l;
the average of
daily values for
30 consecutive
days shall not
exceed 29 mg/l.
Deck drainage.................... Free oil........ No discharge.\4\
Produced sand.................... ................ No discharge.
Sanitary M10..................... Residual Minimum of 1 mg/l
chlorine. and maintained as
close to this as
possible.
Sanitary M9IM.................... Floating solids. No discharge.
Domestic Waste................... Floating solids. No discharge.
Foam............ No discharge.
All other See 33 CFR part
domestic wastes. 151.
------------------------------------------------------------------------
\1\ All Alaskan facilities are subject to the drilling fluids and drill
cuttings discharge standards for facilities located more than three
miles offshore.
\2\ As determined by the suspended particulate phase (SPP) toxicity test
(Appendix 2 of subpart A of this part).
\3\ As determined by the static sheen test (appendix 1).
\4\ As determined by the presence of a film or sheen upon or a
discoloration of the surface of the receiving water (visual sheen).

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\5\ PAH mass ratio = Mass (g) of PAH (as phenanthrene)/Mass (g) of stock
base fluid as determined by EPA Method 1654, Revision A, (specified at
Sec. 435.11(u)) entitled ``PAH Content of Oil by HPLC/UV,'' December
1992, which is published in Methods for the Determination of Diesel,
Mineral, and Crude Oils in Offshore Oil and Gas Industry Discharges,
EPA-821-R-92-008. This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51. Copies may be obtained from the National Technical
Information Service, Springfield, VA 22161, 703-605-6000. Copies may
be inspected at the National Archives and Records Administration
(NARA). For information on the availability of this material at NARA,
call 202-741-6030, or go to: http://www.archives.gov/federal--register/
code--of--federal--regulations/ibr--locations.html. A copy may also be
inspected at EPA's Water Docket, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460.
\6\ Base fluid sediment toxicity ratio = 10-day LC50 of C16-C18 internal
olefin/10-day LC50 of stock base fluid as determined by ASTM E 1367-92
(specified at Sec. 435.11(ee)) method: ``Standard Guide for
Conducting 10-day Static Sediment Toxicity Tests with Marine and
Estuarine Amphipods,'' 1992, after preparing the sediment according to
the method specified in Appendix 3 of subpart A of this part. This
incorporation by reference was approved by the Director of the Federal
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies
may be obtained from the American Society for Testing and Materials,
100 Barr Harbor Drive, West Conshohocken, PA, 19428. Copies may be
inspected at the National Archives and Records Administration (NARA).
For information on the availability of this material at NARA, call 202-
741-6030, or go to: http://www.archives.gov/federal--register/code--
of--federal--regulations/ibr--locations.html. A copy may also be
inspected at EPA's Water Docket, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460.
\7\ Biodegradation rate ratio = Cumulative gas production (ml) of C16-
C18 internal olefin/Cumulative gas production (ml) of stock base
fluid, both at 275 days as determined by ISO 11734:1995 (specified at
Sec. 435.11(e)) method: ``Water quality--Evaluation of the
`ultimate' anaerobic biodegradability of organic compounds in digested
sludge--Method by measurement of the biogas production (1995
edition)'' as modified for the marine environment (Appendix 4 of
subpart A of this part). This incorporation by reference was approved
by the Director of the Federal Register in accordance with 5 U.S.C.
552(a) and 1 CFR part 51. Copies may be obtained from the American
National Standards Institute, 11 West 42nd Street, 13th Floor, New
York, NY 10036. Copies may be inspected at the National Archives and
Records Administration (NARA). For information on the availability of
this material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal--register/code--of--federal--regulations/ibr--
locations.html. A copy may also be inspected at EPA's Water Docket,
1200 Pennsylvania Ave., NW., Washington, DC 20460.
\8\ Drilling fluid sediment toxicity ratio = 4-day LC50 of C16-C18
internal olefin drilling fluid/4-day LC50 of drilling fluid removed
from drill cuttings at the solids control equipment as determined by
ASTM E 1367-92 (specified at Sec. 435.11(ee)) method: ``Standard
Guide for Conducting 10-day Static Sediment Toxicity Tests with Marine
and Estuarine Amphipods,'' 1992, after preparing the sediment
according to the method specified in Appendix 3 of subpart A of this
part. This incorporation by reference was approved by the Director of
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from the American Society for Testing and
Materials, 100 Barr Harbor Drive, West Conshohocken, PA, 19428. Copies
may be inspected at the National Archives and Records Administration
(NARA). For information on the availability of this material at NARA,
call 202-741-6030, or go to: http://www.archives.gov/federal--register/
code--of--federal--regulations/ibr--locations.html. A copy may also be
inspected at EPA's Water Docket, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460.
\9\ As determined before drilling fluids are shipped offshore by the GC/
MS compliance assurance method (Appendix 5 of subpart A of this part),
and as determined prior to discharge by the RPE method (Appendix 6 of
subpart A of this part) applied to drilling fluid removed from drill
cuttings. If the operator wishes to confirm the results of the RPE
method (Appendix 6 of subpart A of this part), the operator may use
the GC/MS compliance assurance method (Appendix 5 of subpart A of this
part). Results from the GC/MS compliance assurance method (Appendix 5
of subpart A of this part) shall supercede the results of the RPE
method (Appendix 6 of subpart A of this part).
\10\ Maximum permissible retention of non-aqueous drilling fluid (NAF)
base fluid on wet drill cuttings averaged over drilling intervals
using NAFs as determined by the API retort method (Appendix 7 of
subpart A of this part). This limitation is applicable for NAF base
fluids that meet the base fluid sediment toxicity ratio (Footnote 6),
biodegradation rate ratio (Footnote 7), PAH, mercury, and cadmium
stock limitations (C16-C18 internal olefin) defined above in this
table.
\11\ Maximum permissible retention of non-aqueous drilling fluid (NAF)
base fluid on wet drill cuttings average over drilling intervals using
NAFs as determined by the API retort method (Appendix 7 of subpart A
of this part). This limitation is applicable for NAF base fluids that
meet the ester base fluid sediment toxicity ratio and ester
biodegradation rate ratio stock limitations defined as: (a) Ester base
fluid sediment toxicity ratio = 10-day LC50 of C12-C14 ester or C8
ester /10-day LC50 of stock base fluid as determined by ASTM E 1367-92
[specified at Sec. 435.11(ee)] method: ``Standard Guide for
Conducting 10-day Static Sediment Toxicity Tests with Marine and
Estuarine Amphipods,'' 1992, after preparing the sediment according to
the method specified in Appendix 3 of subpart A of this part. This
incorporation by reference was approved by the Director of the Federal
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies
may be obtained from the American Society for Testing and Materials,
100 Barr Harbor Drive, West Conshohocken, PA, 19428. Copies may be
inspected at the National Archives and Records Administration (NARA).
For information on the availability of this material at NARA, call 202-
741-6030, or go to: http://www.archives.gov/federal--register/code--
of--federal--regulations/ibr--locations.html. A copy may also be
inspected at EPA's Water Docket, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460; (b) Ester biodegradation rate ratio = Cumulative
gas production (ml) of C12-C14 ester or C8 ester/Cumulative gas
production (ml) of stock base fluid, both at 275 days as determined by
ISO 11734:1995 (specified at Sec. 435.11(e)) method: ``Water
quality--Evaluation of the `ultimate' anaerobic biodegradability of
organic compounds in digested sludge--Method by measurement of the
biogas production (1995 edition)'' as modified for the marine
environment (Appendix 4 of subpart A of this part). This incorporation
by reference was approved by the Director of the Federal Register in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be
obtained from the American National Standards Institute, 11 West 42nd
Street, 13th Floor, New York, NY 10036. Copies may be inspected at the
National Archives and Records Administration (NARA). For information
on the availability of this material at NARA, call 202-741-6030, or go
to: http://www.archives.gov/federal--register/code--of--federal--
regulations/ibr--locations.html. A copy may also be inspected at EPA's
Water Docket, 1200 Pennsylvania Ave., NW., Washington, DC 20460; and
(c) PAH mass ratio (Footnote 5), mercury, and cadmium stock
limitations (C16-C18 internal olefin) defined above in this table.

[58 FR 12504, Apr. 13, 1979, as amended at 66 FR 6900, Jan. 22, 2001; 66
FR 33134, June 20, 2001; 69 FR 18803, Apr. 9, 2004]

Appendix 1 to Subpart A of Part 435--Static Sheen Test

1. Scope and Application

This method is to be used as a compliance test for the ``no
discharge of free oil'' requirement for discharges of drilling fluids,
drill cuttings, produced sand, and well treatment, completion and
workover fluids. ``Free oil'' refers to any oil contained in a waste
stream that when discharged will cause a film or sheen upon or a
discoloration of the surface of the receiving water.

2. Summary of Method

15-mL samples of drilling fluids or well treatment, completion, and
workover fluids, and 15-g samples (wet weight basis) of drill cuttings
or produced sand are introduced into ambient seawater in a container
having

[[Page 306]]

an air-to-liquid interface area of 1000 cm\2\ (155.5 in\2\). Samples are
dispersed within the container and observations made no more than one
hour later to ascertain if these materials cause a sheen, iridescence,
gloss, or increased reflectance on the surface of the test seawater. The
occurrence of any of these visual observations will constitute a
demonstration that the tested material contains ``free oil,'' and
therefore results in a prohibition of its discharge into receiving
waters.

3. Interferences

Residual ``free oil'' adhering to sampling containers, the magnetic
stirring bar used to mix the sample, and the stainless steel spatula
used to mix the sample will be the principal sources of contamination
problems. These problems should only occur if improperly washed and
cleaned equipment are used for the test. The use of disposable equipment
minimizes the potential for similar contamination from pipettes and the
test container.

4. Apparatus, Materials, and Reagents

4.1 Apparatus
4.1.1 Sampling Containers: 1-liter polyethylene beakers and 1-liter
glass beakers.
4.1.2 Graduated cylinder: 100-mL graduated cylinder required only
for operations where predilution of mud discharges is required.
4.1.3 Plastic disposable weighing boats.
4.1.4 Triple-beam scale.
4.1.5 Disposable pipettes: 25-mL disposable pipettes.
4.1.6 Magnetic stirrer and stirring bar.
4.1.7 Stainless steel spatula.
4.1.8 Test container: Open plastic container whose internal cross-
section parallel to its opening has an area of 1000 cm\2\50 cm\2\ (155.5 7.75 in\2\), and a
depth of at least 13 cm (5 inches) and no more than 30 cm (11.8 inches).
4.2 Materials and Reagents.
4.2.1 Plastic liners for the test container: Oil-free, heavy-duty
plastic trash can liners that do not inhibit the spreading of an oil
film. Liners must be of sufficient size to completely cover the interior
surface of the test container. Permittees must determine an appropriate
local source of liners that do not inhibit the spreading of 0.05 mL of
diesel fuel added to the lined test container under the test conditions
and protocol described below.
4.2.2 Ambient receiving water.

5. Calibration

None currently specified.

6. Quality Control Procedures

None currently specified.

7. Sample Collection and Handling

7.1 Sampling containers must be thoroughly washed with detergent,
rinsed a minimum of three times with fresh water, and allowed to air dry
before samples are collected.
7.2 Samples of drilling fluid to be tested shall be taken at the
shale shaker after cuttings have been removed. The sample volume should
range between 200 mL and 500 mL.
7.3 Samples of drill cuttings will be taken from the shale shaker
screens with a clean spatula or similar instrument and placed in a glass
beaker. Cuttings samples shall be collected prior to the addition of any
washdown water and should range between 200 g and 500 g.
7.4 Samples of produced sand must be obtained from the solids
control equipment from which the discharge occurs on any given day and
shall be collected prior to the addition of any washdown water; samples
should range between 200 g and 500 g.
7.5 Samples of well treatment, completion, and workover fluids must
be obtained from the holding facility prior to discharge; the sample
volume should range between 200 mL and 500 mL.
7.6 Samples must be tested no later than 1 hour after collection.
7.7 Drilling fluid samples must be mixed in their sampling
containers for 5 minutes prior to the test using a magnetic bar stirrer.
If predilution is imposed as a permit condition, the sample must be
mixed at the same ratio with the same prediluting water as the
discharged muds and stirred for 5 minutes.
7.8 Drill cuttings must be stirred and well mixed by hand in their
sampling containers prior to testing, using a stainless steel spatula.

8. Procedure

8.1 Ambient receiving water must be used as the ``receiving water''
in the test. The temperature of the test water shall be as close as
practicable to the ambient conditions in the receiving water, not the
room temperature of the observation facility. The test container must
have an air-to-liquid interface area of 1000 50
cm\2\. The surface of the water should be no more than 1.27 cm (.5 inch)
below the top of the test container.
8.2 Plastic liners shall be used, one per test container, and
discarded afterwards. Some liners may inhibit spreading of added oil;
operators shall determine an appropriate local source of liners that do
not inhibit the spreading of the oil film.
8.3 A 15-mL sample of drilling fluid or well treatment, completion,
and workover fluids must be introduced by pipette into the test
container 1 cm below the water surface. Pipettes must be filled and
discharged with

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test material prior to the transfer of test material and its
introduction into test containers. The test water/test material mixture
must be stirred using the pipette to distribute the test material
homogeneously throughout the test water. The pipette must be used only
once for a test and then discarded.
8.4 Drill cuttings or produced sand should be weighed on plastic
weighing boats; 15-g samples must be transferred by scraping test
material into the test water with a stainless steel spatula. Drill
cuttings shall not be prediluted prior to testing. Also, drilling fluids
and cuttings will be tested separately. The weighing boat must be
immersed in the test water and scraped with the spatula to transfer any
residual material to the test container. The drill cuttings or produced
sand must be stirred with the spatula to an even distribution of solids
on the bottom of the test container.
8.5 Observations must be made no later than 1 hour after the test
material is transferred to the test container. Viewing points above the
test container should be made from at least three sides of the test
container, at viewing angles of approximately 60[deg] and 30[deg] from
the horizontal. Illumination of the test container must be
representative of adequate lighting for a working environment to conduct
routine laboratory procedures. It is recommended that the water surface
of the test container be observed under a fluorescent light source such
as a dissecting microscope light. The light source shall be positioned
above and directed over the entire surface of the pan.
8.6 Detection of a ``silvery'' or ``metallic'' sheen or gloss,
increased reflectivity, visual color, iridescence, or an oil slick on
the water surface of the test container surface shall constitute a
demonstration of ``free oil.'' These visual observations include
patches, streaks, or sheets of such altered surface characteristics. If
the free oil content of the sample approaches or exceeds 10%, the water
surface of the test container may lack color, a sheen, or iridescence,
due to the increased thickness of the film; thus, the observation for an
oil slick is required. The surface of the test container shall not be
disturbed in any manner that reduces the size of any sheen or slick that
may be present.
If an oil sheen or slick occurs on less than one-half of the surface
area after the sample is introduced to the test container, observations
will continue for up to 1 hour. If the sheen or slick increases in size
and covers greater than one-half of the surface area of the test
container during the observation period, the discharge of the material
shall cease. If the sheen or slick does not increase in size to cover
greater than one-half of the test container surface area after one hour
of observation, discharge may continue and additional sampling is not
required.
If a sheen or slick occurs on greater than one-half of the surface
area of the test container after the test material is introduced,
discharge of the tested material shall cease. The permittee may retest
the material causing the sheen or slick. If subsequent tests do not
result in a sheen or slick covering greater than one-half of the surface
area of the test container, discharge may continue.

Appendix 2 to Subpart A of Part 435--Drilling Fluids Toxicity Test

I. Sample Collection

The collection and preservation methods for drilling fluids (muds)
and water samples presented here are designed to minimize sample
contamination and alteration of the physical or chemical properties of
the samples due to freezing, air oxidation, or drying.

I-A Apparatus

(1) The following items are required for water and drilling mud
sampling and storage:
a. Acid-rinsed linear-polyethylene bottles or other appropriate
noncontaminating drilling mud sampler.
b. Acid-rinsed linear-polyethylene bottles or other appropriate
noncontaminating water sampler.
c. Acid-rinsed linear-polyethylene bottles or other appropriate
noncontaminated vessels for water and mud samples.
d. Ice chests for preservation and shipping of mud and water
samples.

I-B. Water Sampling

(1) Collection of water samples shall be made with appropriate acid-
rinsed linear-polyethylene bottles or other appropriate non-
contaminating water sampling devices. Special care shall be taken to
avoid the introduction of contaminants from the sampling devices and
containers. Prior to use, the sampling devices and containers should be
thoroughly cleaned with a detergent solution, rinsed with tap water,
soaked in 10 percent hydrochloric acid (HCl) for 4 hours, and then
thoroughly rinsed with glass-distilled water.

I-C. Drilling Mud Sampling

(1) Drilling mud formulations to be tested shall be collected from
active field systems. Obtain a well-mixed sample from beneath the shale
shaker after the mud has passed through the screens. Samples shall be
stored in polyethylene containers or in other appropriate uncontaminated
vessels. Prior to sealing the sample containers on the platform, flush
as much air out of the container by filling it with drilling fluid
sample, leaving a one inch space at the top.
(2) Mud samples shall be immediately shipped to the testing facility
on blue or wet

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ice (do not use dry ice) and continuously maintained at 0-4 [deg]C until
the time of testing.
(3) Bulk mud samples shall be thoroughly mixed in the laboratory
using a 1000 rpm high shear mixer and then subdivided into individual,
small wide-mouthed (e.g., one or two liter) non-contaminating containers
for storage.
(4) The drilling muds stored in the laboratory shall have any excess
air removed by flushing the storage containers with nitrogen under
pressure anytime the containers are opened. Moreover, the sample in any
container opened for testing must be thoroughly stirred using a 1000 rpm
high shear mixer prior to use.
(5) Most drilling mud samples may be stored for periods of time
longer than 2 weeks prior to toxicity testing provided that proper
containers are used and proper condition are maintained.

II. Suspended Particulate Phase Sample Preparation

(1) Mud samples that have been stored under specified conditions in
this protocol shall be prepared for tests within three months after
collection. The SPP shall be prepared as detailed below.

II--A Apparatus

(1) The following items are required:
a. Magnetic stir plates and bars.
b. Several graduated cylinders, ranging in volume from 10 mL to 1 L
c. Large (15 cm) powder funnels.
d. Several 2-liter graduated cylinders.
e. Several 2-liter large mouth graduated Erlenmeyer flasks.
(2) Prior to use, all glassware shall be thoroughly cleaned. Wash
all glassware with detergent, rinse five times with tap water, rinse
once with acetone, rinse several times with distilled or deionized
water, place in a clean 10-percent (or stronger) HCl acid bath for a
minimum of 4 hours, rinse five times with tap water, and then rinse five
times with distilled or deionized water. For test samples containing
mineral oil or diesel oil, glassware should be washed with petroleum
ether to assure removal of all residual oil.
Note: If the glassware with nytex cups soaks in the acid solution
longer than 24 hours, then an equally long deionized water soak should
be performed.

II-B Test Seawater Sample Preparation

(1) Diluent seawater and exposure seawater samples are prepared by
filtration through a 1.0 micrometer filter prior to analysis.
(2) Artificial seawater may be used as long as the seawater has been
prepared by standard methods or ASTM methods, has been properly
``seasoned,'' filtered, and has been diluted with distilled water to the
same specified 202 ppt salinity and 202 [deg]C temperature as the ``natural'' seawater.

II-C Sample Preparation

(1) The pH of the mud shall be tested prior to its use. If the pH is
less than 9, if black spots have appeared on the walls of the sample
container, or if the mud sample has a foul odor, that sample shall be
discarded. Subsample a manageable aliquot of mud from the well-mixed
original sample. Mix the mud and filtered test seawater in a volumetric
mud-to-water ratio of 1 to 9. This is best done by the method of
volumetric displacement in a 2-L, large mouth, graduated Erlenmeyer
flask. Place 1000 mL of seawater into the graduated Erlenmeyer flask.
The mud subsample is then carefully added via a powder funnel to obtain
a total volume of 1200 mL. (A 200 mL volume of the mud will now be in
the flask).
The 2-L, large mouth, graduated Erlenmeyer flask is then filled to
the 2000 mL mark with 800 mL of seawater, which produces a slurry with a
final ratio of one volume drilling mud to nine volumes water. If the
volume of SPP required for testing or analysis exceeds 1500 to 1600 mL,
the initial volumes should be proportionately increased. Alternatively,
several 2-L drill mud/water slurries may be prepared as outlined above
and combined to provide sufficient SPP.
(2) Mix this mud/water slurry with magnetic stirrers for 5 minutes.
Measure the pH and, if necessary, adjust (decrease) the pH of the slurry
to within 0.2 units of the seawater by adding 6N HCl while stirring the
slurry. Then, allow the slurry to settle for 1 hour. Record the amount
of HCl added.
(3) At the end of the settling period, carefully decant (do not
siphon) the Suspended Particulate Phase (SPP) into an appropriate
container. Decanting the SPP is one continuous action. In some cases no
clear interface will be present; that is, there will be no solid phase
that has settled to the bottom. For those samples the entire SPP
solution should be used when preparing test concentrations. However, in
those cases when no clear interface is present, the sample must be
remixed for five minutes. This insures the homogeneity of the mixture
prior to the preparation of the test concentrations. In other cases,
there will be samples with two or more phases, including a solid phase.
For those samples, carefully and continuously decant the supernatant
until the solid phase on the bottom of the flask is reached. The
decanted solution is defined to be 100 percent SPP. Any other
concentration of SPP refers to a percentage of SPP that is obtained by
volumetrically mixing 100 percent SPP with seawater.
(4) SPP samples to be used in toxicity tests shall be mixed for 5
minutes and must not be preserved or stored.

[[Page 309]]

(5) Measure the filterable and unfilterable residue of each SPP
prepared for testing. Measure the dissolved oxygen (DO) and pH of the
SPP. If the DO is less than 4.9 ppm, aerate the SPP to at least 4.9 ppm
which is 65 percent of saturation. Maximum allowable aeration time is 5
minutes using a generic commercial air pump and air stone. Neutralize
the pH of the SPP to a pH 7.8.1 using a dilute HCl
solution. If too much acid is added to lower the pH saturated NaOH may
be used to raise the pH to 7.8.1 units. Record the
amount of acid or NaOH needed to lower/raise to the appropriate pH.
Three repeated DO and pH measurements are needed to insure homogeneity
and stability of the SPP. Preparation of test concentrations may begin
after this step is complete.
(6) Add the appropriate volume of 100 percent SPP to the appropriate
volume of seawater to obtain the desired SPP concentration. The control
is seawater only. Mix all concentrations and the control for 5 minutes
by using magnetic stirrers. Record the time; and, measure DO and pH for
Day 0. Then, the animals shall be randomly selected and placed in the
dishes in order to begin the 96-hour toxicity test.

III. Guidance for Performing Suspended Particulate Phase Toxicity Tests
Using Mysidopsis bahia

III-A Apparatus

(1) Items listed by Borthwick [1] are required for each test series,
which consists of one set of control and test containers, with three
replicates of each.

III-B Sample Collection Preservation

(1) Drilling muds and water samples are collected and stored, and
the suspended particulate phase prepared as described in section 1-C.

III-C Species Selection

(1) The Suspended Particulate Phase (SPP) tests on drilling muds
shall utilize the test species Mysidopsis bahia. Test animals shall be 3
to 6 days old on the first day of exposure. Whatever the source of the
animals, collection and handling should be as gentle as possible.
Transportation to the laboratory should be in well-aerated water from
the animal culture site at the temperature and salinity from which they
were cultured. Methods for handling, acclimating, and sizing bioassay
organisms given by Borthwick [1] and Nimmo [2] shall be followed in
matters for which no guidance is given here.

III-D Experimental Conditions

(1) Suspended particulate phase (SPP) tests should be conducted at a
salinity of 202 ppt. Experimental temperature
should be 202 [deg]C. Dissolved oxygen in the SPP
shall be raised to or maintained above 65 percent of saturation prior to
preparation of the test concentrations. Under these conditions of
temperature and salinity, 65 percent saturation is a DO of 5.3 ppm.
Beginning at Day 0-before the animals are placed in the test containers
DO, temperature, salinity, and pH shall be measured every 24 hours. DO
should be reported in milligrams per liter.
(2) Aeration of test media is required during the entire test with a
rate estimated to be 50-140 cubic centimeters/minute. This air flow to
each test dish may be achieved through polyethylene tubing (0.045-inch
inner diameter and 0.062-inch outer diameter) by a small generic
aquarium pump. The delivery method, surface area of the aeration stone,
and flow characteristics shall be documented. All treatments, including
control, shall be the same.
(3) Light intensity shall be 1200 microwatts/cm \2\ using cool white
fluorescent bulbs with a 14-hr light and 10-hr dark cycle. This light/
dark cycle shall also be maintained during the acclimation period and
the test.

III-E Experimental Procedure

(1) Wash all glassware with detergent, rinse five times with tap
water, rinse once with acetone, rinse several times with distilled or
deionized water, place in a clean 10 percent HCl acid bath for a minimum
of 4 hours, rinse five times with tap water, and then rinse five times
with distilled water.
(2) Establish the definitive test concentration based on results of
a range finding test. A minimum of five test concentrations plus a
negative and positive (reference toxicant) control is required for the
definitive test. To estimate the LC-50, two concentrations shall be
chosen that give (other than zero and 100 percent) mortality above and
below 50 percent.
(3) Twenty organisms are exposed in each test dish. Nytex[reg] cups
shall be inserted into every test dish prior to adding the animals.
These ``nylon mesh screen'' nytex holding cups are fabricated by gluing
a collar of 363-micrometer mesh nylon screen to a 15-centimeter wide
Petri dish with silicone sealant. The nylon screen collar is
approximately 5 centimeters high. The animals are then placed into the
test concentration within the confines of the Nytex cups.
(4) Individual organisms shall be randomly assigned to treatment. A
randomization procedure is presented in section V of this protocol. Make
every attempt to expose animals of approximately equal size. The
technique described by Borthwick [1], or other suitable substitutes,
should be used for transferring specimens. Throughout the test period,
mysids shall be fed daily with approximately 50 Artemia (brine shrimp)
nauplii per mysid. This will reduce stress and decrease cannibalism.

[[Page 310]]

(5) Cover the dishes, aerate, and incubate the test containers in an
appropriate test chamber. Positioning of the test containers holding
various concentrations of test solution should be randomized if
incubator arrangement indicates potential position difference. The test
medium is not replaced during the 96-hour test.
(6) Observations may be attempted at 4, 6 and 8 hours; they must be
attempted at 0, 24, 48, and 72 hours and must be made at 96 hours.
Attempts at observations refers to placing a test dish on a light table
and visually counting the animals. Do not lift the ``nylon mesh screen''
cup out of the test dish to make the observation. No unnecessary
handling of the animals should occur during the 96 hour test period. DO
and pH measurements must also be made at 0, 24, 48, 72, and 96 hours.
Take and replace the test medium necessary for the DO and pH
measurements outside of the nytex cups to minimize stresses on the
animals.
(7) At the end of 96 hours, all live animals must be counted. Death
is the end point, so the number of living organisms is recorded. Death
is determined by lack of spontaneous movement. All crustaceans molt at
regular intervals, shedding a complete exoskeleton. Care should be taken
not to count an exoskeleton. Dead animals might decompose or be eaten
between observations. Therefore, always count living, not dead animals.
If daily observations are made, remove dead organisms and molted
exoskeletons with a pipette or forceps. Care must be taken not to
disturb living organisms and to minimize the amount of liquid withdrawn.

IV. Methods for Positive Control Tests (Reference Toxicant)

(1) Sodium lauryl sulfate (dodecyl sodium sulfate) is used as a
reference toxicant for the positive control. The chemical used should be
approximately 95 percent pure. The source, lot number, and percent
purity shall be reported.
(2) Test methods are those used for the drilling fluid tests, except
that the test material was prepared by weighing one gram sodium lauryl
sulfate on an analytical balance, adding the chemical to a 100-
milliliter volumetric flask, and bringing the flask to volume with
deionized water. After mixing this stock solution, the test mixtures are
prepared by adding 0.1 milliliter of the stock solution for each part
per million desired to one liter of seawater.
(3) The mixtures are stirred briefly, water quality is measured,
animals are added to holding cups, and the test begins. Incubation and
monitoring procedures are the same as those for the drilling fluids.

V. Randomization Procedure

V-A Purpose and Procedure

(1) The purpose of this procedure is to assure that mysids are
impartially selected and randomly assigned to six test treatments (five
drilling fluid or reference toxicant concentrations and a control) and
impartially counted at the end of the 96-hour test. Thus, each test
setup, as specified in the randomization procedure, consists of 3
replicates of 20 animals for each of the six treatments, i.e., 360
animals per test. Figure 1 is a flow diagram that depicts the procedure
schematically and should be reviewed to understand the over-all
operation. The following tasks shall be performed in the order listed.
(2) Mysids are cultured in the laboratory in appropriate units. If
mysids are purchased, go to Task 3.
(3) Remove mysids from culture tanks (6, 5, 4, and 3 days before the
test will begin, i.e. Tuesday, Wednesday, Thursday, and Friday if the
test will begin on Monday) and place them in suitably large maintenance
containers so that they can swim about freely and be fed.
Note: Not every detail (the definition of suitably large containers,
for example) is provided here. Training and experience in aquatic animal
culture and testing will be required to successfully complete these
tests.

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[GRAPHIC] [TIFF OMITTED] TC01MY92.114

(4) Remove mysids from maintenance containers and place all animals
in a single container. The intent is to have homogeneous test population
of mysids of a known age (3-6 days old).
(5) For each toxicity test, assign two suitable containers (500-
milliliter (mL) beakers are recommended) for mysid separation/
enumeration. Label each container (A1, A2, B1, B2, and C1, C2, for
example, if two drilling fluid tests and a reference toxicant test are
to be set up on one day). The purpose of this task is to allow the
investigator to obtain a close estimate of the number of animals
available for testing and to prevent unnecessary crowding of the mysids
while they are being counted and assigned to test containers. Transfer
the mysids from the large test population container to the labeled
separation and enumeration containers but do not place more than 200
mysids in a 500-mL beaker. Be impartial in transferring the mysids;
place approximately equal numbers of animals (10-15 mysids is
convenient) in each container in a cyclic manner rather than placing the
maximum number each container at one time.
Note: It is important that the animals not be unduly stressed during
this selection and assignment procedure. Therefore, it will probably be
necessary to place all animals (except the batch immediately being
assigned to test containers) in mesh cups with flowing seawater or in
large volume containers with aeration. The idea is to provide the
animals with near optimal conditions to avoid additional stress.

[[Page 312]]

(6) Place the mysids from the two labeled enumeration containers
assigned to a specific test into one or more suitable containers to be
used as counting dishes (2-liter Carolina dishes are suggested). Because
of the time required to separate, count, and assign mysids, two or more
people may be involved in completing this task. If this is done, two or
more counting dishes may be used, but the investigator must make sure
that approximately equal numbers of mysids from each labeled container
are placed in each counting dish.
(7) By using a large-bore, smooth-tip glass pipette, select mysids
from the counting dish(es) and place them in the 36 individually
numbered distribution containers (10-ml beakers are suggested). The
mysids are assigned two at a time to the 36 containers by using a
randomization schedule similar to the one presented below. At the end of
selection/assignment round 1, each container will contain two mysids; at
the end of round 2, they will contain four mysids; and so on until each
contains ten mysids.

Example of a Randomization Schedule
------------------------------------------------------------------------
Place mysid in the numbered
Selection/assignment round (2 mysids each) distribution containers in
the random order shown
------------------------------------------------------------------------
1......................................... 8, 21, 6, 28, 33, 32, 1, 3,
10, 9, 4, 14, 23, 2, 34,
22, 36, 27, 5, 30, 35, 24,
12, 25, 11, 17, 19, 26, 31,
7, 20, 15, 18, 13, 16, 29.
2......................................... 35, 18, 5, 12, 32, 34, 22,
3, 9, 16, 26, 13, 20, 28,
6, 21, 24, 30, 8, 31, 7,
23, 2, 15, 25, 17, 1, 11,
27, 4, 19, 36, 10, 33, 14,
29.
3......................................... 7, 19, 14, 11, 34, 21, 25,
27, 17, 18, 6, 16, 29, 2,
32, 10, 4, 20, 3, 9, 1, 5,
28, 24, 31, 15, 22, 13, 33,
26, 36, 12, 8, 30, 35, 23.
4......................................... 30, 2, 18, 5, 8, 27, 10, 25,
4, 20, 26, 15, 31, 36, 35,
23, 11, 29, 16, 17, 28, 1,
33, 14, 9, 34, 7, 3, 12,
22, 21, 6, 19, 24, 32, 13.
5......................................... 34, 28, 16, 17, 10, 12, 1,
36, 20, 18, 15, 22, 2, 4,
19, 23, 27, 29, 25, 21, 30,
3, 9, 33, 32, 6, 14, 11,
35, 24, 26, 7, 31, 5, 13,
8.
------------------------------------------------------------------------

(8) Transfer mysids from the 36 distribution containers to 18
labeled test containers in random order. A label is assigned to each of
the three replicates (A, B, C) of the six test concentrations. Count and
record the 96 hour response in an impartial order.
(9) Repeat tasks 5-7 for each toxicity test. A new random schedule
should be followed in Tasks 6 and 7 for each test.
Note: If a partial toxicity test is conducted, the procedures
described above are appropriate and should be used to prepare the single
test concentration and control, along with the reference toxicant test.

V-B. Data Analysis and Interpretation

(1) Complete survival data in all test containers at each
observation time shall be presented in tabular form. If greater than 10
percent mortality occurs in the controls, all data shall be discarded
and the experiment repeated. Unacceptably high control mortality
indicates the presence of important stresses on the organisms other than
the material being tested, such as injury or disease, stressful physical
or chemical conditions in the containers, or improper handling,
acclimation, or feeding. If 10 percent mortality or less occurs in the
controls, the data may be evaluated and reported.
(2) A definitive, full bioassay conducted according to the EPA
protocol is used to estimate the concentration that is lethal to 50
percent of the test organisms that do not die naturally. This toxicity
measure is known as the median lethal concentration, or LC-50. The LC-50
is adjusted for natural mortality or natural responsiveness. The maximum
likelihood estimation procedure with the adjustments for natural
responsiveness as given by D.J. Finney, in Probit Analysis 3rd edition,
1971, Cambridge University Press, chapter 7, can be used to obtain the
probit model estimate of the LC-50 and the 95 percent fiducial
(confidence) limits for the LC-50. These estimates are obtained using
the logarithmic transform of the concentration. The heterogeneity factor
(Finney 1971, pages 70-72) is not used. For a test material to pass the
toxicity test, according to the requirements stated in the offshore oil
and gas extraction industry BAT effluent limitations and NSPS, the LC-
50, adjusted for natural responsiveness, must be greater than 3 percent
suspended particulate phase (SPP) concentration by volume unadjusted for
the 1 to 9 dilution. Other toxicity test models may be used to obtain
toxicity estimates provided the modeled mathematical expression for the
lethality rate must increase continuously with concentration. The
lethality rate is modeled to increase with concentration to reflect an
assumed increase in toxicity with concentration even though the observed
lethality may not increase uniformly because of the unpredictable animal
response fluctuations.
(3) The range finding test is used to establish a reasonable set of
test concentrations in order to run the definitive test. However, if the
lethality rate changes rapidly over a narrow range of concentrations,
the range finding assay may be too coarse to establish

[[Page 313]]

an adequate set of test concentrations for a definitive test.
(4) The EPA Environmental Research Laboratory in Gulf Breeze,
Florida prepared a Research and Development Report entitled Acute
Toxicity of Eight Drilling Fluids to Mysid Shrimp (Mysidopsis bahia),
May 1984 EPA-600/3-84-067. The Gulf Breeze data for drilling fluid
number 1 are displayed in Table 1 for purposes of an example of the
probit analysis described above. The SAS Probit Procedure (SAS
Institute, Statistical Analysis System, Cary, North Carolina, 1982) was
used to analyze these data. The 96-hour LC50 adjusted for the estimated
spontaneous mortality rate is 3.3 percent SPP with 95 percent limits of
3.0 and 3.5 percent SPP with the 1 to 9 dilution. The estimated
spontaneous mortality rate based on all of the data is 9.6 percent.

Table 1--Listing of Acute Toxicity Test Data (August 1983 to September
1983) with Eight Generic Drilling Fluids and Mysid Shrimp
[fluid N2=1]
------------------------------------------------------------------------
Number
Number Number alive
Percent concentration exposed dead (96 (96
hours) hours)
------------------------------------------------------------------------
0......................................... 60 3 57
1......................................... 60 11 49
2......................................... 60 11 49
3......................................... 60 25 35
4......................................... 60 48 12
5......................................... 60 60 0
------------------------------------------------------------------------

V-C. The Partial Toxicity Test for Evaluation of Test Material

(1) A partial test conducted according to EPA protocol can be used
economically to demonstrate that a test material passes the toxicity
test. The partial test cannot be used to estimate the LC-50 adjusted for
natural response.
(2) To conduct a partial test follow the test protocol for
preparation of the test material and organisms. Prepare the control
(zero concentration), one test concentration (3 percent suspended
particulate phase) and the reference toxicant according to the methods
of the full test. A range finding test is not used for the partial test.
(3) Sixty test organisms are used for each test concentration. Find
the number of test organisms killed in the control (zero percent SPP)
concentration in the column labeled X0 of Table 2. If the
number of organisms in the control (zero percent SPP) exceeds the table
values, then the test is unacceptable and must be repeated. If the
number of organisms killed in the 3 percent test concentration is less
than or equal to corresponding number in the column labeled
X1 then the test material passes the partial toxicity test.
Otherwise the test material fails the toxicity test.
(4) Data shall be reported as percent suspended particulate phase.

Table 2
------------------------------------------------------------------------
X0 X1
------------------------------------------------------------------------
0.......................................................... 22
1.......................................................... 22
2.......................................................... 23
3.......................................................... 23
4.......................................................... 24
5.......................................................... 24
6.......................................................... 25
------------------------------------------------------------------------

VI. References

1. Borthwick, Patrick W. 1978. Methods for acute static toxicity
tests with mysid shrimp (Mysidopsis bahia). Bioassay Procedures for the
Ocean Disposal Permit Program, [EPA-600/9-78-010:] March.
2. Nimmo, D.R., T.L. Hamaker, and C.A. Somers. 1978. Culturing the
mysid (Mysidopsis bahia) in flowing seawater or a static system.
Bioassay Procedures for the Ocean Disposal Permit Program, [EPA-600/9-
78-010]: March.
3. American Public Health Association et al. 1980. Standard Methods
for the Examination of Water and Wastewater. Washington, DC, 15th
Edition: 90-99.
4. U.S. Environmental Protection Agency, September 1991. Methods for
Measuring the Acute Toxicity of Effluents and Receiving Waters to
Freshwater and Marine Organisms. EPA/600/4-90/027. Washington, DC, 4th
Edition.
5. Finney, D.J. Probit Analysis. Cambridge University Press; 1971.
6. U.S. Environmental Protection Agency, May 1984. Acute Toxicity of
Eight Drilling Fluids to Mysid Shrimp (Mysidopsis bahia). EPA-600/3-84-
067.

Appendix 3 to Subpart A of Part 435--Procedure for Mixing Base Fluids
with Sediments

This procedure describes a method for amending uncontaminated and
nontoxic (control) sediments with the base fluids that are used to
formulate synthetic-based drilling fluids and other non-aqueous drilling
fluids. Initially, control sediments shall be press-sieved through a
2000 micron mesh sieve to remove large debris. Then press-sieve the
sediment through a 500 micron sieve to remove indigenous organisms that
may prey on the test species or otherwise confound test results.
Homogenize control sediment to limit the effects of settling that may
have occurred during storage. Sediments should be homogenized before
density determinations and addition of base fluid to control sediment.
Because base fluids are

[[Page 314]]

strongly hydrophobic and do not readily mix with sediment, care must be
taken to ensure base fluids are thoroughly homogenized within the
sediment. All concentrations are weight-to-weight (mg of base fluid to
kg of dry control sediment). Sediment and base fluid mixing shall be
accomplished by using the following method.
1. Determine the wet to dry ratio for the control sediment by
weighing approximately 10 g subsamples of the screened and homogenized
wet sediment into tared aluminum weigh pans. Dry sediment at 105 [deg]C
for 18-24 h. Remove sediment and cool in a desiccator until a constant
weight is achieved. Re-weigh the samples to determine the dry weight.
Determine the wet/dry ratio by dividing the net wet weight by the net
dry weight:

[Wet Sediment Weight (g)]/[Dry Sediment Weight (g)] = Wet to Dry Ratio
[1]

2. Determine the density (g/mL) of the wet control or dilution
sediment. This shall be used to determine total volume of wet sediment
needed for the various test treatments.

[Mean Wet Sediment Weight (g)]/[Mean Wet Sediment Volume (mL)] = Wet
Sediment Density (g/mL) [2]

3. To determine the amount of base fluid needed to obtain a test
concentration of 500 mg base fluid per kg dry sediment use the following
formulas:
Determine the amount of wet sediment required:

[Wet Sediment Density (g/mL)] x [Volume of Sediment Required per
Concentration (mL)] = Weight Wet Sediment Required per Conc. (g) [3]

Determine the amount of dry sediment in kilograms (kg) required for
each concentration:

{[Wet Sediment per Concentration (g)]/[Mean Wet to Dry Ratio]{time} x
(1kg/1000g) = Dry Weight Sediment (kg) [4]

Finally, determine the amount of base fluid required to spike the
control sediment at each concentration:

[Conc. Desired (mg/kg)] x [Dry Weight Sediment (kg)] = Base Fluid
Required (mg) [5]

For spiking test substances other than pure base fluids (e.g., whole
mud formulations), determine the spike amount as follows:

[Conc. Desired (mL/kg)] x [Dry Weight Sediment (kg)] x [Test Substance
Density (g/mL)] = Test Substance Required (g) [6]

4. For primary mixing, place appropriate amounts of weighed base
fluid into stainless mixing bowls, tare the vessel weight, then add
sediment and mix with a high-shear dispersing impeller for 9 minutes.
The concentration of base fluid in sediment from this mix, rather than
the nominal concentration, shall be used in calculating LC50
values.
5. Tests for homogeneity of base fluid in sediment are to be
performed during the procedure development phase. Because of difficulty
of homogeneously mixing base fluid with sediment, it is important to
demonstrate that the base fluid is evenly mixed with sediment. The
sediment shall be analyzed for total petroleum hydrocarbons (TPH) using
EPA Methods 3550A and 8015M, with samples taken both prior to and after
distribution to replicate test containers. Base-fluid content is
measured as TPH. After mixing the sediment, a minimum of three replicate
sediment samples shall be taken prior to distribution into test
containers. After the test sediment is distributed to test containers,
an additional three sediment samples shall be taken from three test
containers to ensure proper distribution of base fluid within test
containers. Base-fluid content results shall be reported within 48 hours
of mixing. The coefficient of variation (CV) for the replicate samples
must be less than 20%. If base-fluid content results are not within the
20% CV limit, the test sediment shall be remixed. Tests shall not begin
until the CV is determined to be below the maximum limit of 20%. During
the test, a minimum of three replicate containers shall be sampled to
determine base-fluid content during each sampling period.
6. Mix enough sediment in this way to allow for its use in the
preparation of all test concentrations and as a negative control. When
commencing the sediment toxicity test, range-finding tests may be
required to determine the concentrations that produce a toxic effect if
these data are otherwise unavailable. The definitive test shall bracket
the LC50, which is the desired endpoint. The results for the
base fluids shall be reported in mg of base fluid per kg of dry
sediment.

References

American Society for Testing and Materials (ASTM). 1996. Standard
Guide for Collection, Storage, Characterization, and Manipulation of
Sediments for Toxicological Testing. ASTM E 1391-94. Annual Book of ASTM
Standards, Volume 11.05, pp. 805-825.
Ditsworth, G.R., D.W. Schults and J.K.P. Jones. 1990. Preparation of
benthic substrates for sediment toxicity testing, Environ. Toxicol.
Chem. 9:1523-1529.
Suedel, B.C., J.H. Rodgers, Jr. and P.A. Clifford. 1993.
Bioavailability of fluoranthene in freshwater sediment toxicity tests.
Environ. Toxicol. Chem. 12:155-165.
U.S. EPA. 1994. Methods for Assessing the Toxicity of Sediment-
associated Contaminants with Estuarine and Marine Amphipods. EPA/600/R-
94/025. Office of Research and Development, Washington, DC.

[66 FR 6901, Jan. 22, 2001]

[[Page 315]]

Appendix 4 to Subpart A of Part 435--Determination of Biodegradation of
Synthetic Base Fluids in a Marine Closed Bottle Test System: Summary of
Modifications to ISO 11734:1995

The six modifications specified in this Appendix shall apply to the
determination of the biodegradability of synthetic base fluids as
measured by ISO 11734:1995. These modifications make the test more
applicable to a marine environment and are listed below:
1. The laboratory shall use sea water in place of freshwater media.
1.1 The sea water may be either natural or synthetic. The allowable
salinity range is 20-30 ppt.
1.2 To reduce the shock to the microorganisms in the sediment, the
salinity of the sediment's porewater shall be between 20-30 ppt.
2. The laboratory shall use natural marine or estuarine sediments in
place of digested sludge as an inoculum. The VS of the sediments must be
no less than 2%.
2.1 Sediment should be used for testing as soon as possible after
field collection. If required, the laboratory can store the sediment for
a maximum period of two months prior to use. The test sediment shall be
stored in the dark at 4 [deg]C.
2.2 The laboratory shall use the sediment mixing procedure specified
in Appendix 3 to Subpart A of part 435 to spike the test sediment with
base fluids. The final concentration will be 2000 mg carbon/Kg dry
weight sediment. No less than 25 g dry weight of the spiked sediment
shall be used per 125 ml serum bottle. The volume of sediment and
seawater in the bottle shall be 75 ml.
3. The temperature of incubation shall be 291
[deg]C.
4. The pH is maintained at the level of natural sea water, not at
7.0 as referenced in ISO 11734:1995.
5. The optional use of a trace metals solution as specified in
method ISO 11734:1995 shall not be used as part of these test
modifications.
6. The laboratory shall conduct the test for 275 days. The
laboratory may seek approval of alternate test durations under the
approval procedures specified at 40 CFR 136.4 and 136.5. Any
modification of this method, beyond those expressly permitted, shall be
considered a major modification subject to application and approval of
alternate test procedures under 40 CFR 136.4 and 136.5.

[66 FR 6901, Jan. 22, 2001]

Appendix 5 to Subpart A of Part 435--Determination of Crude Oil
Contamination in Non-Aqueous Drilling Fluids by Gas Chromatography/Mass
Spectrometry (GC/MS)

1.0 Scope and Application

1.1 This method determines crude (formation) oil contamination, or
other petroleum oil contamination, in non-aqueous drilling fluids (NAFs)
by comparing the gas chromatography/mass spectrometry (GC/MS)
fingerprint scan and extracted ion scans of the test sample to that of
an uncontaminated sample.
1.2 This method can be used for monitoring oil contamination of NAFs
or monitoring oil contamination of the base fluid used in the NAF
formulations.
1.3 Any modification of this method beyond those expressly permitted
shall be considered as a major modification subject to application and
approval of alternative test procedures under 40 CFR 136.4 and 136.5.
1.4 The gas chromatography/mass spectrometry portions of this method
are restricted to use by, or under the supervision of analysts
experienced in the use of GC/MS and in the interpretation of gas
chromatograms and extracted ion scans. Each laboratory that uses this
method must generate acceptable results using the procedures described
in Sections 7, 9.2, and 12 of this appendix.

2.0 Summary of Method

2.1 Analysis of NAF for crude oil contamination is a step-wise
process. The analyst first performs a qualitative assessment of the
presence or absence of crude oil in the sample. If crude oil is detected
during this qualitative assessment, the analyst must perform a
quantitative analysis of the crude oil concentration.
2.2 A sample of NAF is centrifuged to obtain a solids free
supernate.
2.3 The test sample is prepared by removing an aliquot of the solids
free supernate, spiking it with internal standard, and analyzing it
using GC/MS techniques. The components are separated by the gas
chromatograph and detected by the mass spectrometer.
2.4 Qualitative identification of crude oil contamination is
performed by comparing the Total Ion Chromatograph (TIC) scans and
Extracted Ion Profile (EIP) scans of test sample to that of
uncontaminated base fluids, and examining the profiles for
chromatographic signatures diagnostic of oil contamination.

[[Page 316]]

2.5 The presence or absence of crude oil contamination observed in
the full scan profiles and selected extracted ion profiles determines
further sample quantitation and reporting requirements.
2.6 If crude oil is detected in the qualitative analysis,
quantitative analysis must be performed by calibrating the GC/MS using a
designated NAF spiked with known concentrations of a designated oil.
2.7 Quality is assured through reproducible calibration and testing
of GC/MS system and through analysis of quality control samples.

3.0 Definitions

3.1 A NAF is one in which the continuous-- phase is a water
immiscible fluid such as an oleaginous material (e.g., mineral oil,
enhance mineral oil, paraffinic oil, or synthetic material such as
olefins and vegetable esters).
3.2 TIC--Total Ion Chromatograph.
3.3 EIP--Extracted Ion Profile.
3.4 TCB--1,3,5-trichlorobenzene is used as the internal standard in
this method.
3.5 SPTM--System Performance Test Mix standards are used to
establish retention times and monitor detection levels.

4.0 Interferences and Limitations

4.1 Solvents, reagents, glassware, and other sample processing
hardware may yield artifacts and/or elevated baselines causing
misinterpretation of chromatograms.
4.2 All Materials used in the analysis shall be demonstrated to be
free from interferences by running method blanks. Specific selection of
reagents and purification of solvents by distillation in all-glass
systems may be required.
4.3 Glassware shall be cleaned by rinsing with solvent and baking at
400 [deg]C for a minimum of 1 hour.
4.4 Interferences may vary from source to source, depending on the
diversity of the samples being tested.
4.5 Variations in and additions of base fluids and/or drilling fluid
additives (emulsifiers, dispersants, fluid loss control agents, etc.)
might also cause interferences and misinterpretation of chromatograms.
4.6 Difference in light crude oils, medium crude oils, and heavy
crude oils will result in different responses and thus different
interpretation of scans and calculated percentages.

5.0 Safety

5.1 The toxicity or carcinogenicity of each reagent used in this
method has not been precisely determined; however each chemical shall be
treated as a potential health hazard. Exposure to these chemicals should
be reduced to the lowest possible level.
5.2 Unknown samples may contain high concentration of volatile toxic
compounds. Sample containers should be opened in a hood and handled with
gloves to prevent exposure. In addition, all sample preparation should
be conducted in a fume hood to limit the potential exposure to harmful
contaminates.
5.3 This method does not address all safety issues associated with
its use. The laboratory is responsible for maintaining a safe work
environment and a current awareness file of OSHA regulations regarding
the safe handling of the chemicals specified in this method. A reference
file of material safety data sheets (MSDSs) shall be available to all
personnel involved in these analyses. Additional references to
laboratory safety can be found in References 16.1 through 16.3.
5.4 NAF base fluids may cause skin irritation, protective gloves are
recommended while handling these samples.

6.0 Apparatus and Materials

[[Page 317]]

6.3.1 Gas Chromatograph--An analytical system complete with a
temperature-programmable gas chromatograph suitable for split/splitless
injection and all required accessories, including syringes, analytical
columns, and gases.
6.3.1.1 Column--30 m (or 60 m) x 0.32 mm ID (or 0.25 mm ID) 1[mu]m
film thickness (or 0.25[mu]m film thickness) silicone-coated fused-
silica capillary column (J&W Scientific DB-5 or equivalent).
6.3.2 Mass Spectrometer--Capable of scanning from 35 to 500 amu
every 1 sec or less, using 70 volts (nominal) electron energy in the
electron impact ionization mode (Hewlett Packard 5970MS or comparable).
6.3.3 GC/MS interface--the interface is a capillary-direct interface
from the GC to the MS.
6.3.4--Data system--A computer system must be interfaced to the mass
spectrometer. The system must allow the continuous acquisition and
storage on machine-readable media of all mass spectra obtained
throughout the duration of the chromatographic program. The computer
must have software that can search any GC/MS data file for ions of a
specific mass and that can plot such ion abundance versus retention time
or scan number. This type of plot is defined as an Extracted Ion Current
Profile (EIP). Software must also be available that allows integrating
the abundance in any total ion chromatogram (TIC) or EIP between
specified retention time or scan-number limits. It is advisable that the
most recent version of the EPA/NIST Mass Spectral Library be available.

7.0 Reagents and Standards

7.1 Methylene chloride--Pesticide grade or equivalent. Use when
necessary for sample dilution.
7.2 Standards--Prepare from pure individual standard materials or
purchase as certified solutions. If compound purity is 96% or greater,
the weight may be used without correction to compute the concentration
of the standard.
7.2.1 Crude Oil Reference--Obtain a sample of a crude oil with a
known API gravity. This oil shall be used in the calibration procedures.
7.2.2 Synthetic Base Fluid--Obtain a sample of clean internal olefin
(IO) Lab drilling fluid (as sent from the supplier--has not been
circulated downhole). This drilling fluid shall be used in the
calibration procedures.
7.2.3 Internal standard--Prepare a 0.01 g/mL solution of 1,3,5-
trichlorobenzene (TCB). Dissolve 1.0 g of TCB in methylene chloride and
dilute to volume in a 100-mL volumetric flask. Stopper, vortex, and
transfer the solution to a 150-mL bottle with PTFE-lined cap. Label
appropriately, and store at -5 [deg]C to 20 [deg]C. Mark the level of
the meniscus on the bottle to detect solvent loss.
7.2.4 GC/MS system performance test mix (SPTM) standards--The SPTM
standards shall contain octane, decane, dodecane, tetradecane,
tetradecene, toluene, ethylbenzene, 1,2,4-trimethylbenzene, 1-
methylnaphthalene and 1,3-dimethylnaphthalene. These compounds can be
purchased individually or obtained as a mixture (i.e. Supelco, Catalog
No. 4-7300). Prepare a high concentration of the SPTM standard at 62.5
mg/mL in methylene chloride. Prepare a medium concentration SPTM
standard at 1.25 mg/mL by transferring 1.0 mL of the 62.5 mg/mL solution
into a 50 mL volumetric flask and diluting to the mark with methylene
chloride. Finally, prepare a low concentration SPTM standard at 0.125
mg/mL by transferring 1.0 mL of the 1.25 mg/mL solution into a 10-mL
volumetric flask and diluting to the mark with methylene chloride.
7.2.5 Crude oil/drilling fluid calibration standards--Prepare a 4-
point crude oil/drilling fluid calibration at concentrations of 0% (no
spike--clean drilling fluid), 0.5%, 1.0%, and 2.0% by weight according
to the procedures outlined in this appendix using the Reference Crude
Oil:
7.2.5.1 Label 4 jars with the following identification: Jar 1--
0%Ref-IOLab, Jar 2--0.5%Ref-IOLab, Jar 3--1%Ref-IOLab, and Jar 4--2%Ref-
IOLab.
7.2.5.2 Weigh 4, 50-g aliquots of well mixed IO Lab drilling fluid
into each of the 4 jars.
7.2.5.3 Add Reference Oil at 0.5%, 1.0%, and 2.0% by weight to jars
2, 3, and 4 respectively. Jar 1 shall not be spiked with Reference Oil
in order to retain a ``0%'' oil concentration.
7.2.5.4 Thoroughly mix the contents of each of the 4 jars, using
clean glass stirring rods.
7.2.5.5 Transfer (weigh) a 30-g aliquot from Jar 1 to a labeled
centrifuge tube. Centrifuge the aliquot for a minimum of 15 min at
approximately 15,000 rpm, in order to obtain a solids free supernate.
Weigh 0.5 g of the supernate directly into a tared and appropriately
labeled GC straight vial. Spike the 0.5-g supernate with 500 [mu]L of
the 0.01g/mL 1,3,5-trichlorobenzene internal standard solution (see
Section 7.2.3 of this appendix), cap with a Teflon lined crimp cap, and
vortex for ca. 10 sec.
7.2.5.6 Repeat step 7.2.5.5 except use an aliquot from Jar 2.
7.2.5.7 Repeat step 7.2.5.5 except use an aliquot from Jar 3.
7.2.5.8 Repeat step 7.2.5.5 except use an aliquot from Jar 4.
7.2.5.9 These 4 crude/oil drilling fluid calibration standards are
now used for qualitative and quantitative GC/MS analysis.
7.2.6 Precision and recovery standard (mid level crude oil/drilling
fluid calibration standard)--Prepare a mid point crude oil/

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drilling fluid calibration using IO Lab drilling fluid and Reference Oil
at a concentration of 1.0% by weight. Prepare this standard according to
the procedures outlined in Section 7.2.5.1 through 7.2.5.5 of this
appendix, with the exception that only ``Jar 3'' needs to be prepared.
Remove and spike with internal standard, as many 0.5-g aliquots as
needed to complete the GC/MS analysis (see Section 11.6 of this
appendix--bracketing authentic samples every 12 hours with precision and
recovery standard) and the initial demonstration exercise described in
Section 9.2 of this appendix.
7.2.7 Stability of standards
7.2.7.1 When not used, standards shall be stored in the dark, at -5
to -20 [deg]C in screw-capped vials with PTFE-lined lids. Place a mark
on the vial at the level of the solution so that solvent loss by
evaporation can be detected. Bring the vial to room temperature prior to
use.
7.2.7.2 Solutions used for quantitative purposes shall be analyzed
within 48 hours of preparation and on a monthly basis thereafter for
signs of degradation. A standard shall remain acceptable if the peak
area remains within 15% of the area obtained in
the initial analysis of the standard.

8.0 Sample Collection Preservation and Storage

8.1 Collect NAF and base fluid samples in 100- to 200-mL glass
bottles with PTFE- or aluminum foil lined caps.
8.2 Samples collected in the field shall be stored refrigerated
until time of preparation.
8.3 Sample and extract holding times for this method have not yet
been established. However, based on initial experience with the method,
samples should be analyzed within seven to ten days of collection and
extracts should be analyzed within seven days of preparation.
8.4 After completion of GC/MS analysis, extracts shall be
refrigerated at 4 [deg]C until further notification of sample disposal.

9.0 Quality Control

9.1 Each laboratory that uses this method is required to operate a
formal quality assurance program (Reference 16.4). The minimum
requirements of this program shall consist of an initial demonstration
of laboratory capability, and ongoing analysis of standards, and blanks
as a test of continued performance, analyses of spiked samples to assess
accuracy and analysis of duplicates to assess precision. Laboratory
performance shall be compared to established performance criteria to
determine if the results of analyses meet the performance
characteristics of the method.
9.1.1 The analyst shall make an initial demonstration of the ability
to generate acceptable accuracy and precision with this method. This
ability shall be established as described in Section 9.2 of this
appendix.
9.1.2 The analyst is permitted to modify this method to improve
separations or lower the cost of measurements, provided all performance
requirements are met. Each time a modification is made to the method,
the analyst is required to repeat the calibration (Section 10.4 of this
appendix) and to repeat the initial demonstration procedure described in
Section 9.2 of this appendix.
9.1.3 Analyses of blanks are required to demonstrate freedom from
contamination. The procedures and criteria for analysis of a blank are
described in Section 9.3 of this appendix.
9.1.4 Analysis of a matrix spike sample is required to demonstrate
method accuracy. The procedure and QC criteria for spiking are described
in Section 9.4 of this appendix.
9.1.5 Analysis of a duplicate field sample is required to
demonstrate method precision. The procedure and QC criteria for
duplicates are described in Section 9.5 of this appendix.
9.1.6 Analysis of a sample of the clean NAF(s) (as sent from the
supplier--i.e., has not been circulated downhole) used in the drilling
operations is required.
9.1.7 The laboratory shall, on an ongoing basis, demonstrate through
calibration verification and the analysis of the precision and recovery
standard (Section 7.2.6 of this appendix) that the analysis system is in
control. These procedures are described in Section 11.6 of this
appendix.
9.1.8 The laboratory shall maintain records to define the quality of
data that is generated.
9.2 Initial precision and accuracy--The initial precision and
recovery test shall be performed using the precision and recovery
standard (1% by weight Reference Oil in IO Lab drilling fluid). The
laboratory shall generate acceptable precision and recovery by
performing the following operations.
9.2.1 Prepare four separate aliquots of the precision and recovery
standard using the procedure outlined in Section 7.2.6 of this appendix.
Analyze these aliquots using the procedures outlined in Section 11 of
this appendix.
9.2.2 Using the results of the set of four analyses, compute the
average recovery (X) in weight percent and the standard deviation of the
recovery(s) for each sample.
9.2.3 If s and X meet the acceptance criteria of 80% to 110%, system
performance is acceptable and analysis of samples may begin. If,
however, s exceeds the precision limit or X falls outside the range for
accuracy, system performance is unacceptable. In this event, review this
method, correct the problem, and repeat the test.
9.2.4 Accuracy and precision--The average percent recovery (P) and
the standard deviation of the percent recovery (Sp) Express

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the accuracy assessment as a percent recovery interval from P-
2Sp to P+2Sp. For example, if P=90% and
Sp=10% for four analyses of crude oil in NAF, the accuracy
interval is expressed as 70% to 110%. Update the accuracy assessment on
a regular basis.
9.3 Blanks--Rinse glassware and centrifuge tubes used in the method
with 30 mL of methylene chloride, remove a 0.5-g aliquot of the solvent,
spike it with the 500 [mu]L of the internal standard solution (Section
7.2.3 of this appendix) and analyze a 1-[mu]L aliquot of the blank
sample using the procedure in Section 11 of this appendix. Compute
results per Section 12 of this appendix.
9.4 Matrix spike sample--Prepare a matrix spike sample according to
procedure outlined in Section 7.2.6 of this appendix. Analyze the sample
and calculate the concentration (% oil) in the drilling fluid and %
recovery of oil from the spiked drilling fluid using the methods
described in Sections 11 and 12 of this appendix.
9.5 Duplicates--A duplicate field sample shall be prepared according
to procedures outlined in Section 7.3 of this appendix and analyzed
according to Section 11 of this appendix. The relative percent
difference (RPD) of the calculated concentrations shall be less than
15%.
9.5.1 Analyze each of the duplicates per the procedure in Section 11
of this appendix and compute the results per Section 12 of this
appendix.
9.5.2 Calculate the relative percent difference (RPD) between the
two results per the following equation:

RPD = [D1 - D2]/[(D1 + D2)/
2] x 100 [1]

where:

D1 = Concentration of crude oil in the sample; and
D2 = Concentration of crude oil in the duplicate sample.

9.5.3 If the RPD criteria are not met, the analytical system shall
be judged to be out of control, and the problem must be immediately
identified and corrected, and the sample batch re-analyzed.
9.6 Prepare the clean NAF sample according to procedures outlined in
Section 7.3 of this appendix. Ultimately the oil-equivalent
concentration from the TIC or EIP signal measured in the clean NAF
sample shall be subtracted from the corresponding authentic field
samples in order to calculate the true contaminant concentration (% oil)
in the field samples (see Section 12 of this appendix).
9.7 The specifications contained in this method can be met if the
apparatus used is calibrated properly, and maintained in a calibrated
state. The standards used for initial precision and recovery (Section
9.2 of this appendix) and ongoing precision and recovery (Section 11.6
of this appendix) shall be identical, so that the most precise results
will be obtained. The GC/MS instrument will provide the most
reproducible results if dedicated to the setting and conditions required
for the analyses given in this method.
9.8 Depending on specific program requirements, field replicates and
field spikes of crude oil into samples may be required when this method
is used to assess the precision and accuracy of the sampling and sample
transporting techniques.

10.0 Calibration

10.1 Establish gas chromatographic/mass spectrometer operating
conditions given in Table 1 of this appendix. Perform the GC/MS system
hardware-tune as outlined by the manufacture. The gas chromatograph
shall be calibrated using the internal standard technique.
Note: Because each GC is slightly different, it may be necessary to
adjust the operating conditions (carrier gas flow rate and column
temperature and temperature program) slightly until the retention times
in Table 2 of this appendix are met.

Table 1--Gas Chromatograph/Mass Spectrometer (GC/MS) Operation
Conditions
------------------------------------------------------------------------
Parameter Setting
------------------------------------------------------------------------
Injection pot............................. 280 [deg]C
Transfer line............................. 280 [deg]C
Detector.................................. 280 [deg]C
Initial Temperature....................... 50 [deg]C
Initial Time.............................. 5 minutes
Ramp...................................... 50 to 300 [deg]C @ 5 [deg]C
per minute
Final Temperature......................... 300 [deg]C
Final Hold................................ 20 minutes or until all
peaks have eluted
Carrier Gas............................... Helium
Flow rate................................. As required for standard
operation
Split ratio............................... As required to meet
performance criteria
(1:100)
Mass range................................ 35 to 600 amu
------------------------------------------------------------------------

Table 2--Approximate Retention Time for Compounds
------------------------------------------------------------------------
Approximate
retention
Compound time
(minutes)
------------------------------------------------------------------------
Toluene.................................................... 5.6
Octane, n-C8............................................... 7.2
Ethylbenzene............................................... 10.3
1,2,4-Trimethylbenzene..................................... 16.0
Decane, -C10............................................... 16.1
TCB (Internal Standard).................................... 21.3
Dodecane, -C12............................................. 22.9
1-Methylnaphthalene........................................ 26.7
1-Tetradecene.............................................. 28.4
Tetradecane, -C14.......................................... 28.7
1,3-Dimethylnaphthalene.................................... 29.7
------------------------------------------------------------------------

10.2 Internal standard calibration procedure--1,3,5-trichlorobenzene
(TCB) has been shown to be free of interferences from diesel

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and crude oils and is a suitable internal standard.
10.3 The system performance test mix standards prepared in Section
7.2.4 of this appendix shall be used to establish retention times and
establish qualitative detection limits.
10.3.1 Spike a 500-mL aliquot of the 1.25 mg/mL SPTM standard with
500 [mu]L of the TCB internal standard solution.
10.3.2 Inject 1.0 [mu]L of this spiked SPTM standard onto the GC/MS
in order to demonstrate proper retention times. For the GC/MS used in
the development of this method, the ten compounds in the mixture had
typical retention times shown in Table 2 of this appendix. Extracted ion
scans for m/z 91 and 105 showed a maximum abundance of 400,000.
10.3.3 Spike a 500-mL aliquot of the 0.125 mg/mL SPTM standard with
500 [mu]L of the TCB internal standard solution.
10.3.4 Inject 1.0 [mu]L of this spiked SPTM standard onto the GC/MS
to monitor detectable levels. For the GC/MS used in the development of
this test, all ten compounds showed a minimum peak height of three times
signal to noise. Extracted ion scans for m/z 91 and 105 showed a maximum
abundance of 40,000.
10.4 GC/MS crude oil/drilling fluid calibration--There are two
methods of quantification: Total Area Integration (C8-
C13) and EIP Area Integration using m/z's 91 and 105. The
Total Area Integration method should be used as the primary technique
for quantifying crude oil in NAFs. The EIP Area Integration method
should be used as a confirmatory technique for NAFs. However, the EIP
Area Integration method shall be used as the primary method for
quantifying oil in enhanced mineral oil (EMO) based drilling fluid.
Inject 1.0 [mu]L of each of the four crude oil/drilling fluid
calibration standards prepared in Section 7.2.5 of this appendix into
the GC/MS. The internal standard should elute approximately 21-22
minutes after injection. For the GC/MS used in the development of this
method, the internal standard peak was (35 to 40)% of full scale at an
abundance of about 3.5e+07.
10.4.1 Total Area Integration Method--For each of the four
calibration standards obtain the following: Using a straight baseline
integration technique, obtain the total ion chromatogram (TIC) area from
C8 to C13. Obtain the TIC area of the internal
standard (TCB). Subtract the TCB area from the C8-
C13 area to obtain the true C8-C13
area. Using the C8-C13 and TCB areas, and known
internal standard concentration, generate a linear regression
calibration using the internal standard method. The r\2\ value for the
linear regression curve shall be greater than or equal to 0.998. Some
synthetic fluids might have peaks that elute in the window and would
interfere with the analysis. In this case the integration window can be
shifted to other areas of scan where there are no interfering peaks from
the synthetic base fluid.
10.4.2 EIP Area Integration--For each of the four calibration
standards generate Extracted Ion Profiles (EIPs) for m/z 91 and 105.
Using straight baseline integration techniques, obtain the following EIP
areas:
10.4.2.1 For m/z 91 integrate the area under the curve from
approximately 9 minutes to 21-22 minutes, just prior to but not
including the internal standard.
10.4.2.2 For m/z 105 integrate the area under the curve from
approximately 10.5 minutes to 26.5 minutes.
10.4.2.3 Obtain the internal standard area from the TCB in each of
the four calibration standards, using m/z 180.
10.4.2.4 Using the EIP areas for TCB, m/z 91 and m/z105, and the
known concentration of internal standard, generate linear regression
calibration curves for the target ions 91 and 105 using the internal
standard method. The r\2\ value for each of the EIP linear regression
curves shall be greater than or equal to 0.998.
10.4.2.5 Some base fluids might produce a background level that
would show up on the extracted ion profiles, but there should not be any
real peaks (signal to noise ratio of 1:3) from the clean base fluids.

11.0 Procedure

11.1 Sample Preparation--
11.1.1 Mix the authentic field sample (drilling fluid) well.
Transfer (weigh) a 30-g aliquot of the sample to a labeled centrifuge
tube.
11.1.2 Centrifuge the aliquot for a minimum of 15 min at
approximately 15,000 rpm, in order to obtain a solids free supernate.
11.1.3 Weigh 0.5 g of the supernate directly into a tared and
appropriately labeled GC straight vial.
11.1.4 Spike the 0.5-g supernate with 500 [mu]L of the 0.01g/mL
1,3,5-trichlorobenzene internal standard solution (see Section 7.2.3 of
this appendix), cap with a Teflon lined crimp cap, and vortex for ca. 10
sec.
11.1.5 The sample is ready for GC/MS analysis.
11.2 Gas Chromatography.
Table 1 of this appendix summarizes the recommended operating
conditions for the GC/MS. Retention times for the n-alkanes obtained
under these conditions are given in Table 2 of this appendix. Other
columns, chromatographic conditions, or detectors may be used if initial
precision and accuracy requirements (Section 9.2 of this appendix) are
met. The system shall be calibrated according to the procedures outlined
in Section 10 of this appendix, and verified every 12 hours according to
Section 11.6 of this appendix.

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11.2.1 Samples shall be prepared (extracted) in a batch of no more
than 20 samples. The batch shall consist of 20 authentic samples, 1
blank (Section 9.3 of this appendix), 1 matrix spike sample (9.4), and 1
duplicate field sample (9.5), and a prepared sample of the corresponding
clean NAF used in the drilling process.
11.2.2 An analytical sequence shall be analyzed on the GC/MS where
the 3 SPTM standards (Section 7.2.4 of this appendix) containing
internal standard are analyzed first, followed by analysis of the four
GC/MS crude oil/drilling fluid calibration standards (Section 7.2.5 of
this appendix), analysis of the blank, matrix spike sample, the
duplicate sample, the clean NAF sample, followed by the authentic
samples.
11.2.3 Samples requiring dilution due to excessive signal shall be
diluted using methylene chloride.
11.2.4 Inject 1.0 [mu]L of the test sample or standard into the GC,
using the conditions in Table 1 of this appendix.
11.2.5 Begin data collection and the temperature program at the time
of injection.
11.2.6 Obtain a TIC and EIP fingerprint scans of the sample (Table 3
of this appendix).
11.2.7 If the area of the C8 to C13 peaks
exceeds the calibration range of the system, dilute a fresh aliquot of
the test sample weighing 0.50-g and re-analyze.
11.2.8 Determine the C8 to C13 TIC area, the
TCB internal standard area, and the areas for the m/z 91 and 105 EIPs.
These shall be used in the calculation of oil concentration in the
samples (see Section 12 of this appendix).

Table 3--Recommended Ion Mass Numbers
------------------------------------------------------------------------
Typical
Selected ion mass numbers Corresponding aromatic rentention time
compounds (minutes)
------------------------------------------------------------------------
91............................ Methylbenzene 6.0
Ethylbenzene 10.3
1,4-Dimethylbenzene 10.9
1,3-Dimethylbenzene 10.9
1,2-Dimethylbenzene 11.9
105........................... 1,3,5-Trimethylbenzene 15.1
1,2,4-Trimethylbenzene 16.0
1,2,3-Trimethylbenzene 17.4
156........................... 2,6-Dimethylnaphthalene 28.9
1,2-Dimethylnaphthalene 29.4
1,3-Dimethylnaphthalene 29.7
------------------------------------------------------------------------

11.2.9 Observe the presence of peaks in the EIPs that would confirm
the presence of any target aromatic compounds. Using the EIP areas and
EIP linear regression calibrations compare the abundance of the aromatic
peaks, and if appropriate, determine approximate crude oil contamination
in the sample for each of the target ions.
11.3 Qualitative Identification--See Section 17 of this appendix for
schematic flowchart.
11.3.1 Qualitative identification shall be accomplished by
comparison of the TIC and EIP area data from an authentic sample to the
TIC and EIP area data from the calibration standards (Section 12.4 of
this appendix). Crude oil shall be identified by the presence of
C10 to C13 n-alkanes and corresponding target
aromatics.
11.3.2 Using the calibration data, establish the identity of the
C8 to C13 peaks in the chromatogram of the sample.
Using the calibration data, establish the identity of any target
aromatics present on the extracted ion scans.
11.3.3 Crude oil is not present in a detectable amount in the sample
if there are no target aromatics seen on the extracted ion scans. The
experience of the analyst shall weigh heavily in the determination of
the presence of peaks at a signal-to-noise ratio of 3 or greater.
11.3.4 If the chromatogram shows n-alkanes from C8 to
C13 and target aromatics to be present, contamination by
crude oil or diesel shall be suspected and quantitative analysis shall
be determined. If there are no n-alkanes present that are not seen on
the blank, and no target aromatics are seen, the sample can be
considered to be free of contamination.
11.4 Quantitative Identification--
11.4.1 Determine the area of the peaks from C8 to
C13 as outlined in the calibration section (10.4.1 of this
appendix). If the area of the peaks for the sample is greater than that
for the clean NAF (base fluid) use the crude oil/drilling fluid
calibration TIC linear regression curve to determine approximate crude
oil contamination.
11.4.2 Using the EIPs outlined in Section 10.4.2 of this appendix,
determine the presence of any target aromatics. Using the integration
techniques outlined in Section 10.4.2 of this appendix, obtain the EIP
areas for m/z 91 and 105. Use the crude oil/drilling fluid calibration
EIP linear regression curves to determine approximate crude oil
contamination.
11.5 Complex Samples--
11.5.1 The most common interferences in the determination of crude
oil can be from mineral oil, diesel oil, and proprietary additives in
drilling fluids.
11.5.2 Mineral oil can typically be identified by its lower target
aromatic content, and narrow range of strong peaks.
11.5.3 Diesel oil can typically be identified by low amounts of n-
alkanes from C7 to C9, and the absence of n-
alkanes greater than C25.
11.5.4 Crude oils can usually be distinguished by the presence of
high aromatics, increased intensities of C8 to C13
peaks, and/ or the presence of higher hydrocarbons of C25 and
greater (which may be difficult to see in some synthetic fluids at low
contamination levels).

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11.5.4.1 Oil condensates from gas wells are low in molecular weight
and will normally produce strong chromatographic peaks in the
C8-C13 range. If a sample of the gas condensate
crude oil from the formation is available, the oil can be distinguished
from other potential sources of contamination by using it to prepare a
calibration standard.
11.5.4.2 Asphaltene crude oils with API gravity 20 may not produce
chromatographic peaks strong enough to show contamination at levels of
the calibration. Extracted ion peaks should be easier to see than
increased intensities for the C8 to C13 peaks. If
a sample of asphaltene crude from the formation is available, a
calibration standard shall be prepared.
11.6 System and Laboratory Performance--
11.6.1 At the beginning of each 8-hour shift during which analyses
are performed, GC crude oil/drilling fluid calibration and system
performance test mixes shall be verified. For these tests, analysis of
the medium-level calibration standard (1-% Reference Oil in IO Lab
drilling fluid, and 1.25 mg/mL SPTM with internal standard) shall be
used to verify all performance criteria. Adjustments and/or re-
calibration (per Section 10 of this appendix) shall be performed until
all performance criteria are met. Only after all performance criteria
are met may samples and blanks be analyzed.
11.6.2 Inject 1.0 [mu]L of the medium-level GC/MS crude oil/drilling
fluid calibration standard into the GC instrument according to the
procedures in Section 11.2 of this appendix. Verify that the linear
regression curves for both TIC area and EIP areas are still valid using
this continuing calibration standard.
11.6.3 After this analysis is complete, inject 1.0 [mu]L of the 1.25
mg/mL SPTM (containing internal standard) into the GC instrument and
verify the proper retention times are met (see Table 2 of this
appendix).
11.6.4 Retention times--Retention time of the internal standard. The
absolute retention time of the TCB internal standard shall be within the
range 21.0 0.5 minutes. Relative retention times
of the n-alkanes: The retention times of the n-alkanes relative to the
TCB internal standard shall be similar to those given in Table 2 of this
appendix.

12.0 Calculations

The concentration of oil in NAFs drilling fluids shall be computed
relative to peak areas between C8 and C13 (using
the Total Area Integration method) or total peak areas from extracted
ion profiles (using the Extracted Ion Profile Method). In either case,
there is a measurable amount of peak area, even in clean drilling fluid
samples, due to spurious peaks and electrometer ``noise'' that
contributes to the total signal measured using either of the
quantification methods. In this procedure, a correction for this signal
is applied, using the blank or clean sample correction technique
described in American Society for Testing Materials (ASTM) Method D-
3328-90, Comparison of Waterborne Oil by Gas Chromatography. In this
method, the ``oil equivalents'' measured in a blank sample by total area
gas chromatography are subtracted from that determined for a field
sample to arrive at the most accurate measure of oil residue in the
authentic sample.
12.1 Total Area Integration Method
12.1.1 Using C8 to C13 TIC area, the TCB area
in the clean NAF sample and the TIC linear regression curve, compute the
oil equivalent concentration of the C8 to C13
retention time range in the clean NAF.
Note: The actual TIC area of the C8 to C13 is
equal to the C8 to C13 area minus the area of the
TCB.
12.1.2 Using the corresponding information for the authentic sample,
compute the oil equivalent concentration of the C8 to
C13 retention time range in the authentic sample.
12.1.3 Calculate the concentration (% oil) of oil in the sample by
subtracting the oil equivalent concentration (% oil) found in the clean
NAF from the oil equivalent concentration (% oil) found in the authentic
sample.
12.2 EIP Area Integration Method
12.2.1 Using either m/z 91 or 105 EIP areas, the TCB area in the
clean NAF sample, and the appropriate EIP linear regression curve,
compute the oil equivalent concentration of the in the clean NAF.
12.2.2 Using the corresponding information for the authentic sample,
compute its oil equivalent concentration.
12.2.3 Calculate the concentration (% oil) of oil in the sample by
subtracting the oil equivalent concentration (% oil) found in the clean
NAF from the oil equivalent concentration (% oil) found in the authentic
sample.

13.0 Method Performance

13.1 Specification in this method are adopted from EPA Method 1663,
Differentiation of Diesel and Crude Oil by GC/FID (Reference 16.5).
13.2 Single laboratory method performance using an Internal Olefin
(IO) drilling fluid fortified at 0.5% oil using a 35 API gravity oil
was:

Precision and accuracy 944%
Accuracy interval--86.3% to 102%
Relative percent difference in duplicate analysis--6.2%

14.0 Pollution Prevention

14.1 The solvent used in this method poses little threat to the
environment when recycled and managed properly.

[[Page 323]]

15.0 Waste Management

15.1 It is the laboratory's responsibility to comply with all
federal, state, and local regulations governing waste management,
particularly the hazardous waste identification rules and land disposal
restriction, and to protect the air, water, and land by minimizing and
controlling all releases from fume hoods and bench operations.
Compliance with all sewage discharge permits and regulations is also
required.
15.2 All authentic samples (drilling fluids) failing the RPE
(fluorescence) test (indicated by the presence of fluorescence) shall be
retained and classified as contaminated samples. Treatment and ultimate
fate of these samples is not outlined in this SOP.
15.3 For further information on waste management, consult ``The
Waste Management Manual for Laboratory Personnel'', and ``Less is
Better: Laboratory Chemical Management for Waste Reduction'', both
available from the American Chemical Society's Department of Government
Relations and Science Policy, 1155 16th Street NW, Washington, DC 20036.

16.0 References

16.1 Carcinogens--``Working With Carcinogens.'' Department of
Health, Education, and Welfare, Public Health Service, Centers for
Disease Control (available through National Technical Information
Systems, 5285 Port Royal Road, Springfield, VA 22161, document no. PB-
277256): August 1977.
16.2 ``OSHA Safety and Health Standards, General Industry [29 CFR
1910], Revised.'' Occupational Safety and Health Administration, OSHA
2206. Washington, DC: January 1976.
16.3 ``Handbook of Analytical Quality Control in Water and
Wastewater Laboratories.'' USEPA, EMSSL-CI, EPA-600/4-79-019.
Cincinnati, OH: March 1979.
16.4 ``Method 1663, Differentiation of Diesel and Crude Oil by GC/
FID, Methods for the Determination of Diesel, Mineral, and Crude Oils in
Offshore Oil and Gas Industry Discharges, EPA 821-R-92-008, Office of
Water Engineering and Analysis Division, Washington, DC: December 1992.

[66 FR 6901, Jan. 22, 2001]

Appendix 6 to Subpart A of Part 435--Reverse Phase Extraction (RPE)
Method for Detection of Oil Contamination in Non-Aqueous Drilling Fluids
(NAF)

1.0 Scope and Application

1.1 This method is used for determination of crude or formation oil,
or other petroleum oil contamination, in non-aqueous drilling fluids
(NAFs).
1.2 This method is intended as a positive/negative test to determine
a presence of crude oil in NAF prior to discharging drill cuttings from
offshore production platforms.
1.3 This method is for use in the Environmental Protection Agency's
(EPA's) survey and monitoring programs under the Clean Water Act,
including monitoring of compliance with the Gulf of Mexico NPDES General
Permit for monitoring of oil contamination in drilling fluids.
1.4 This method has been designed to show positive contamination for
5% of representative crude oils at a concentration of 0.1% in drilling
fluid (vol/vol), 50% of representative crude oils at a concentration of
0.5%, and 95% of representative crude oils at a concentration of 1%.
1.5 Any modification of this method, beyond those expressly
permitted, shall be considered a major modification subject to
application and approval of alternate test procedures under 40 CFR Parts
136.4 and 136.5.
1.6 Each laboratory that uses this method must demonstrate the
ability to generate acceptable results using the procedure in Section
9.2 of this appendix.

2.0 Summary of Method

2.1 An aliquot of drilling fluid is extracted using isopropyl
alcohol.
2.2 The mixture is allowed to settle and then filtered to separate
out residual solids.
2.3 An aliquot of the filtered extract is charged onto a reverse
phase extraction (RPE) cartridge.
2.4 The cartridge is eluted with isopropyl alcohol.
2.5 Crude oil contaminates are retained on the cartridge and their
presence (or absence) is detected based on observed fluorescence using a
black light.

3.0 Definitions

3.1 A NAF is one in which the continuous phase is a water immiscible
fluid such as an oleaginous material (e.g., mineral oil, enhance mineral
oil, paraffinic oil, or synthetic material such as olefins and vegetable
esters).

4.0 Interferences

4.1 Solvents, reagents, glassware, and other sample-processing
hardware may yield artifacts that affect results. Specific selection of
reagents and purification of solvents may be required.
4.2 All materials used in the analysis shall be demonstrated to be
free from interferences under the conditions of analysis by running
laboratory reagent blanks as described in Section 9.5 of this appendix.

5.0 Safety

5.1 The toxicity or carcinogenicity of each reagent used in this
method has not

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been precisely determined; however, each chemical shall be treated as a
potential health hazard. Exposure to these chemicals should be reduced
to the lowest possible level. Material Safety Data Sheets (MSDSs) shall
be available for all reagents.
5.2 Isopropyl alcohol is flammable and should be used in a well-
ventilated area.
5.3 Unknown samples may contain high concentration of volatile toxic
compounds. Sample containers should be opened in a hood and handled with
gloves to prevent exposure. In addition, all sample preparation should
be conducted in a well-ventilated area to limit the potential exposure
to harmful contaminants. Drilling fluid samples should be handled with
the same precautions used in the drilling fluid handling areas of the
drilling rig.
5.4 This method does not address all safety issues associated with
its use. The laboratory is responsible for maintaining a safe work
environment and a current awareness file of OSHA regulations regarding
the safe handling of the chemicals specified in this method. A reference
file of material safety data sheets (MSDSs) shall be available to all
personnel involved in these analyses. Additional information on
laboratory safety can be found in References 16.1-16.2.

6.0 Equipment and Supplies

Note: Brand names, suppliers, and part numbers are for illustrative
purposes only. No endorsement is implied. Equivalent performance may be
achieved using apparatus and materials other than those specified here,
but demonstration of equivalent performance that meets the requirements
of this method is the responsibility of the laboratory.
6.1 Sampling equipment.
6.1.1 Sample collection bottles/jars--New, pre-cleaned bottles/jars,
lot-certified to be free of artifacts. Glass preferable, plastic
acceptable, wide mouth approximately 1-L, with Teflon-lined screw cap.
6.2 Equipment for glassware cleaning.
6.2.1 Laboratory sink.
6.2.2 Oven--Capable of maintaining a temperature within 5 [deg]C in the range of 100-250 [deg]C.
6.3 Equipment for sample extraction.
6.3.1 Vials--Glass, 25 mL and 4 mL, with Teflon-lined screw caps,
baked at 200-250 [deg]C for 1-h minimum prior to use.
6.3.2 Gas-tight syringes--Glass, various sizes, 0.5 mL to 2.5 mL (if
spiking of drilling fluids with oils is to occur).
6.3.3 Auto pipetters--various sizes, 0.1 mL, 0.5 mL, 1 to 5 mL
delivery, and 10 mL delivery, with appropriate size disposable pipette
tips, calibrated to within 0.5%.
6.3.4 Glass stirring rod.
6.3.5 Vortex mixer.
6.3.6 Disposable syringes--Plastic, 5 mL.
6.3.7 Teflon syringe filter, 25-mm, 0.45[mu]m pore size--
Acrodisc[reg] CR Teflon (or equivalent).
6.3.8 Reverse Phase Extraction C18 Cartridge--Waters Sep-
Pak[reg]Plus, C18 Cartridge, 360 mg of sorbent (or
equivalent).
6.3.9 SPE vacuum manifold--Supelco Brand, 12 unit (or equivalent).
Used as support for cartridge/syringe assembly only. Vacuum apparatus
not required.
6.4 Equipment for fluorescence detection.
6.4.1 Black light--UV Lamp, Model UVG 11, Mineral Light Lamp,
Shortwave 254 nm, or Longwave 365 nm, 15 volts, 60 Hz, 0.16 amps (or
equivalent).
6.4.2 Black box--cartridge viewing area. A commercially available
ultraviolet viewing cabinet with viewing lamp, or alternatively, a
cardboard box or equivalent, approximately
14x7.5x7.5 in size and painted flat
black inside. Lamp positioned in fitted and sealed slot in center on top
of box. Sample cartridges sit in a tray, ca. 6 from lamp.
Cardboard flaps cut on top panel and side of front panel for sample
viewing and sample cartridge introduction, respectively.
6.4.3 Viewing platform for cartridges. Simple support (hand made
vial tray--black in color) for cartridges so that they do not move
during the fluorescence testing.

7.0 Reagents and Standards

7.1 Isopropyl alcohol--99% purity.
7.2 NAF--Appropriate NAF as sent from the supplier (has not been
circulated downhole). Use the clean NAF corresponding to the NAF being
used in the current drilling operation.
7.3 Standard crude oil--NIST SRM 1582 petroleum crude oil.

8.0 Sample Collection, Preservation, and Storage

8.1 Collect approximately one liter of representative sample (NAF,
which has been circulated downhole) in a glass bottle or jar. Cover with
a Teflon lined cap. To allow for a potential need to re-analyze and/or
re-process the sample, it is recommended that a second sample aliquot be
collected.
8.2 Label the sample appropriately.
8.3 All samples must be refrigerated at 0-4 [deg]C from the time of
collection until extraction (40 CFR Part 136, Table II).
8.4 All samples must be analyzed within 28 days of the date and time
of collection (40 CFR Part 136, Table II).

9.0 Quality Control

9.1 Each laboratory that uses this method is required to operate a
formal quality assurance program (Reference 16.3). The minimum
requirements of this program consist of an initial demonstration of
laboratory capability, and ongoing analyses of blanks and

[[Page 325]]

spiked duplicates to assess accuracy and precision and to demonstrate
continued performance. Each field sample is analyzed in duplicate to
demonstrate representativeness.
9.1.1 The analyst shall make an initial demonstration of the ability
to generate acceptable accuracy and precision with this method. This
ability is established as described in Section 9.2 of this appendix.
9.1.2 Preparation and analysis of a set of spiked duplicate samples
to document accuracy and precision. The procedure for the preparation
and analysis of these samples is described in Section 9.4 of this
appendix.
9.1.3 Analyses of laboratory reagent blanks are required to
demonstrate freedom from contamination. The procedure and criteria for
preparation and analysis of a reagent blank are described in Section 9.5
of this appendix.
9.1.4 The laboratory shall maintain records to define the quality of
the data that is generated.
9.1.5 Accompanying QC for the determination of oil in NAF is
required per analytical batch. An analytical batch is a set of samples
extracted at the same time, to a maximum of 10 samples. Each analytical
batch of 10 or fewer samples must be accompanied by a laboratory reagent
blank (Section 9.5 of this appendix), corresponding NAF reference blanks
(Section 9.6 of this appendix), a set of spiked duplicate samples blank
(Section 9.4 of this appendix), and duplicate analysis of each field
sample. If greater than 10 samples are to be extracted at one time, the
samples must be separated into analytical batches of 10 or fewer
samples.
9.2 Initial demonstration of laboratory capability. To demonstrate
the capability to perform the test, the analyst shall analyze two
representative unused drilling fluids (e.g., internal olefin-based
drilling fluid, vegetable ester-based drilling fluid), each prepared
separately containing 0.1%, 1%, and 2% or a representative oil. Each
drilling fluid/concentration combination shall be analyzed 10 times, and
successful demonstration will yield the following average results for
the data set:

0.1% oil--Detected in <20% of samples
1% oil--Detected in 75% of samples
2% oil--Detected in 90% of samples

9.3 Sample duplicates.
9.3.1 The laboratory shall prepare and analyze (Section 11.2 and
11.4 of this appendix) each authentic sample in duplicate, from a given
sampling site or, if for compliance monitoring, from a given discharge.
9.3.2 The duplicate samples must be compared versus the prepared
corresponding NAF blank.
9.3.3 Prepare and analyze the duplicate samples according to
procedures outlined in Section 11 of this appendix.
9.3.4 The results of the duplicate analyses are acceptable if each
of the results give the same response (fluorescence or no fluorescence).
If the results are different, sample non-homogenicity issues may be a
concern. Prepare the samples again, ensuring a well-mixed sample prior
to extraction. Analyze the samples once again.
9.3.5 If different results are obtained for the duplicate a second
time, the analytical system is judged to be out of control and the
problem shall be identified and corrected, and the samples re-analyzed.
9.4 Spiked duplicates--Laboratory prepared spiked duplicates are
analyzed to demonstrate acceptable accuracy and precision.
9.4.1 Preparation and analysis of a set of spiked duplicate samples
with each set of no more than 10 field samples is required to
demonstrate method accuracy and precision and to monitor matrix
interferences (interferences caused by the sample matrix). A field NAF
sample expected to contain less than 0.5% crude oil (and documented to
not fluoresce as part of the sample batch analysis) shall be spiked with
1% (by volume) of suitable reference crude oil and analyzed as field
samples, as described in Section 11 of this appendix. If no low-level
drilling fluid is available, then the unused NAF can be used as the
drilling fluid sample.
9.5 Laboratory reagent blanks--Laboratory reagent blanks are
analyzed to demonstrate freedom from contamination.
9.5.1 A reagent blank is prepared by passing 4 mL of the isopropyl
alcohol through a Teflon syringe filter and collecting the filtrate in a
4-mL glass vial. A Sep Pak[reg] C18 cartridge is then
preconditioned with 3 mL of isopropyl alcohol. A 0.5-mL aliquot of the
filtered isopropyl alcohol is added to the syringe barrel along with 3.0
mL of isopropyl alcohol. The solvent is passed through the
preconditioned Sep Pak[reg] cartridge. An additional 2-mL of isopropyl
alcohol is eluted through the cartridge. The cartridge is now considered
the ``reagent blank'' cartridge and is ready for viewing (analysis).
Check the reagent blank cartridge under the black light for
fluorescence. If the isopropyl alcohol and filter are clean, no
fluorescence will be observed.
9.5.2 If fluorescence is detected in the reagent blank cartridge,
analysis of the samples is halted until the source of contamination is
eliminated and a prepared reagent blank shows no fluorescence under a
black light. All samples shall be associated with an uncontaminated
method blank before the results may be reported for regulatory
compliance purposes.
9.6 NAF reference blanks--NAF reference blanks are prepared from the
NAFs sent from the supplier (NAF that has not been circulated downhole)
and used as the reference when viewing the fluorescence of the test
samples.

[[Page 326]]

9.6.1 A NAF reference blank is prepared identically to the authentic
samples. Place a 0.1 mL aliquot of the ``clean'' NAF into a 25-mL glass
vial. Add 10 mL of isopropyl alcohol to the vial. Cap the vial. Vortex
the vial for approximately 10 sec. Allow the solids to settle for
approximately 15 minutes. Using a 5-mL syringe, draw up 4 mL of the
extract and filter it through a PTFE syringe filter, collecting the
filtrate in a 4-mL glass vial. Precondition a Sep Pak[reg]
C18 cartridge with 3 mL of isopropyl alcohol. Add a 0.5-mL
aliquot of the filtered extract to the syringe barrel along with 3.0 mL
of isopropyl alcohol. Pass the extract and solvent through the
preconditioned Sep Pak[reg] cartridge. Pass an additional 2-mL of
isopropyl alcohol through the cartridge. The cartridge is now considered
the NAF blank cartridge and is ready for viewing (analysis). This
cartridge is used as the reference cartridge for determining the absence
or presence of fluorescence in all authentic drilling fluid samples that
originate from the same NAF. That is, the specific NAF reference blank
cartridge is put under the black light along with a prepared cartridge
of an authentic sample originating from the same NAF material. The
fluorescence or absence of fluorescence in the authentic sample
cartridge is determined relative to the NAF reference cartridge.
9.6.2 Positive control solution, equivalent to 1% crude oil
contaminated mud extract, is prepared by dissolving 87 mg of standard
crude oil into 10.00 mL of methylene chloride. Then mix 40 [mu]L of this
solution into 10.00 mL of IPA. Transfer 0.5 mL of this solution into a
preconditioned C18 cartridge, followed by 2 ml of IPA.

10.0 Calibration and Standardization

10.1 Calibration and standardization methods are not employed for
this procedure.

11.0 Procedure

This method is a screening-level test. Precise and accurate results
can be obtained only by strict adherence to all details.
11.1 Preparation of the analytical batch.
11.1.1 Bring the analytical batch of samples to room temperature.
11.1.2 Using a large glass stirring rod, mix the authentic sample
thoroughly.
11.1.3 Using a large glass stirring rod, mix the clean NAF (sent
from the supplier) thoroughly.
11.2 Extraction.
11.2.1 Using an automatic positive displacement pipetter and a
disposable pipette tip transfer 0.1-mL of the authentic sample into a
25-mL vial.
11.2.2 Using an automatic pipetter and a disposable pipette tip
dispense a 10-mL aliquot of solvent grade isopropyl alcohol (IPA) into
the 25 mL vial.
11.2.3 Cap the vial and vortex the vial for ca. 10-15 seconds.
11.2.4 Let the sample extract stand for approximately 5 minutes,
allowing the solids to separate.
11.2.5 Using a 5-mL disposable plastic syringe remove 4 mL of the
extract from the 25-mL vial.
11.2.6 Filter 4 mL of extract through a Teflon syringe filter (25-mm
diameter, 0.45 [mu]m pore size), collecting the filtrate in a labeled 4-
mL vial.
11.2.7 Dispose of the PFTE syringe filter.
11.2.8 Using a black permanent marker, label a Sep Pak[reg]
C18 cartridge with the sample identification.
11.2.9 Place the labeled Sep Pak[reg] C18 cartridge onto
the head of a SPE vacuum manifold.
11.2.10 Using a 5-mL disposable plastic syringe, draw up exactly 3-
mL (air free) of isopropyl alcohol.
11.2.11 Attach the syringe tip to the top of the C18
cartridge.
11.2.12 Condition the C18 cartridge with the 3-mL of
isopropyl alcohol by depressing the plunger slowly.
Note: Depress the plunger just to the point when no liquid remains
in the syringe barrel. Do not force air through the cartridge. Collect
the eluate in a waste vial.
11.2.13 Remove the syringe temporarily from the top of the
cartridge, then remove the plunger, and finally reattach the syringe
barrel to the top of the C18 cartridge.
11.2.14 Using automatic pipetters and disposable pipette tips,
transfer 0.5 mL of the filtered extract into the syringe barrel,
followed by a 3.0-mL transfer of isopropyl alcohol to the syringe
barrel.
11.2.15 Insert the plunger and slowly depress it to pass only the
extract and solvent through the preconditioned C18 cartridge.
Note: Depress the plunger just to the point when no liquid remains
in the syringe barrel. Do not force air through the cartridge. Collect
the eluate in a waste vial.
11.2.16 Remove the syringe temporarily from the top of the
cartridge, then remove the plunger, and finally reattach the syringe
barrel to the top of the C18 cartridge.
11.2.17 Using an automatic pipetter and disposable pipette tip,
transfer 2.0 mL of isopropyl alcohol to the syringe barrel.
11.2.18 Insert the plunger and slowly depress it to pass the solvent
through the C18 cartridge.
Note: Depress the plunger just to the point when no liquid remains
in the syringe barrel. Do not force air through the cartridge. Collect
the eluate in a waste vial.
11.2.19 Remove the syringe and labeled C18 cartridge from
the top of the SPE vacuum manifold.
11.2.20 Prepare a reagent blank according to the procedures outlined
in Section 9.5 of this appendix.

[[Page 327]]

11.2.21 Prepare the necessary NAF reference blanks for each type of
NAF encountered in the field samples according to the procedures
outlined in Section 9.6 of this appendix.
11.2.22 Prepare the positive control (1% crude oil equivalent)
according to Section 9.6.2 of this appendix.
11.3 Reagent blank fluorescence testing.
11.3.1 Place the reagent blank cartridge in a black box, under a
black light.
11.3.2 Determine the presence or absence of fluorescence for the
reagent blank cartridge. If fluorescence is detected in the blank,
analysis of the samples is halted until the source of contamination is
eliminated and a prepared reagent blank shows no fluorescence under a
black light. All samples must be associated with an uncontaminated
method blank before the results may be reported for regulatory
compliance purposes.
11.4 Sample fluorescence testing.
11.4.1 Place the respective NAF reference blank (Section 9.6 of this
appendix) onto the tray inside the black box.
11.4.2 Place the authentic field sample cartridge (derived from the
same NAF as the NAF reference blank) onto the tray, adjacent and to the
right of the NAF reference blank.
11.4.3 Turn on the black light.
11.4.4 Compare the fluorescence of the sample cartridge with that of
the negative control cartridge (NAF blank, Section 9.6.1 of this
appendix) and positive control cartridge (1% crude oil equivalent,
Section 9.6.2 of this appendix).
11.4.5 If the fluorescence of the sample cartridge is equal to or
brighter than the positive control cartridge (1% crude oil equivalent,
Section 9.6.2 of this appendix), the sample is considered contaminated.
Otherwise, the sample is clean.

12.0 Data Analysis and Calculations

Specific data analysis techniques and calculations are not performed
in this SOP.

13.0 Method Performance

This method was validated through a single laboratory study,
conducted with rigorous statistical experimental design and
interpretation (Reference 16.4).

14.0 Pollution Prevention

14.1 The solvent used in this method poses little threat to the
environment when recycled and managed properly.

15.0 Waste Management

15.1 It is the laboratory's responsibility to comply with all
Federal, State, and local regulations governing waste management,
particularly the hazardous waste identification rules and land disposal
restriction, and to protect the air, water, and land by minimizing and
controlling all releases from bench operations. Compliance with all
sewage discharge permits and regulations is also required.
15.2 All authentic samples (drilling fluids) failing the
fluorescence test (indicated by the presence of fluorescence) shall be
retained and classified as contaminated samples. Treatment and ultimate
fate of these samples is not outlined in this SOP.
15.3 For further information on waste management, consult ``The
Waste Management Manual for Laboratory Personnel,'' and ``Less is
Better: Laboratory Chemical Management for Waste Reduction,'' both
available from the American Chemical Society's Department of Government
Relations and Science Policy, 1155 16th Street, NW, Washington, DC
20036.

16.0 References

16.1 ``Carcinogen--Working with Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
16.2 ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
16.3 ``Handbook of Analytical Quality Control in Water and
Wastewater Laboratories,'' USEPA, EMSL-Ci, Cincinnati, OH 45268, EPA-
600/4-79-019, March 1979.
16.4 Report of the Laboratory Evaluation of Static Sheen Test
Replacements--Reverse Phase Extraction (RPE) Method for Detecting Oil
Contamination in Synthetic Based Mud (SBM). October 1998. Available from
API, 1220 L Street, NW, Washington, DC 20005-4070, 202-682-8000.

[66 FR 6901, Jan. 22, 2001; 66 FR 30811, June 8, 2001]

Appendix 7 to Subpart A of Part 435--API Recommended Practice 13B-2

1. Description

a. This procedure is specifically intended to measure the amount of
non-aqueous drilling fluid (NAF) base fluid from cuttings generated
during a drilling operation. This procedure is a retort test which
measures all oily material (NAF base fluid) and water released from a
cuttings sample when heated in a calibrated and properly operating
``Retort'' instrument.
b. In this retort test a known mass of cuttings is heated in the
retort chamber to vaporize the liquids associated with the sample. The
NAF base fluid and water vapors are then condensed, collected, and
measured in a precision graduated receiver.

Note: Obtaining a representative sample requires special attention
to the details of

[[Page 328]]

sample handling (e.g., location, method, frequency). See Addendum A and
B for minimum requirements for collecting representative samples.
Additional sampling procedures in a given area may be specified by the
NPDES permit controlling authority.

2. Equipment

a. Retort instrument--The recommended retort instrument has a 50-
cm³ volume with an external heating jacket.
Retort Specifications:
1. Retort assembly--retort body, cup and lid.
(a) Material: 303 stainless steel or equivalent.
(b) Volume: Retort cup with lid.
Cup Volume: 50-cm³.
Precision: 0.25-cm³.
2. Condenser--capable of cooling the oil and water vapors below
their liquification temperature.
3. Heating jacket--nominal 350 watts.
4. Temperature control--capable of limiting temperature of retort to
at least 930 [deg]F (500 [deg]C) and enough to boil off all NAFs.
b. Liquid receiver (10-cm³, 20-cm³)--the 10-
cm³ and 20-cm³ receivers are specially designed
cylindrical glassware with rounded bottom to facilitate cleaning and
funnel-shaped top to catch falling drops. For compliance monitoring
under the NPDES program, the analyst shall use the 10-cm³
liquid receiver with 0.1 ml graduations to achieve greater accuracy.
1. Receiver specifications:
Total volume: 10-cm³, 20-cm³.
Precision (0 to 100%): 0.05 cm³,
0.05 cm³.
Outside diameter: 10-mm, 13-mm.
Wall thickness: 1.50.1mm, 1.20.1mm.
Frequency of graduation marks (0 to 100%): 0.10-cm³,
0.10-cm³.
Calibration: To contain ``TC'' @ 20 [deg]C.
Scale: cm³, cm³
2. Material--Pyrex[reg] or equivalent glass.
c. Toploading balance--capable of weighing 2000 g and precision of
at least 0.1 g. Unless motion is a problem, the analyst shall use an
electronic balance. Where motion is a problem, the analyst may use a
triple beam balance.
d. Fine steel wool (No. 000)--for packing retort body.
e. Thread sealant lubricant: high temperature lubricant, e.g. Never-
Seez[reg] or equivalent.
f. Pipe cleaners--to clean condenser and retort stem.
g. Brush--to clean receivers.
h. Retort spatula--to clean retort cup.
i. Corkscrew--to remove spent steel wool.

3. Procedure

a. Clean and dry the retort assembly and condenser.
b. Pack the retort body with steel wool.
c. Apply lubricant/sealant to threads of retort cup and retort stem.
d. Weigh and record the total mass of the retort cup, lid, and
retort body with steel wool. This is mass (A), grams.
e. Collect a representative cuttings sample (see Note in Section 1
of this appendix).
f. Partially fill the retort cup with cuttings and place the lid on
the cup.
g. Screw the retort cup (with lid) onto the retort body, weigh and
record the total mass. This is mass (B), grams.
h. Attach the condenser. Place the retort assembly into the heating
jacket.
i. Weigh and record the mass of the clean and dry liquid receiver.
This is mass (C), grams. Place the receiver below condenser outlet.
j. Turn on the retort. Allow it to run a minimum of 1 hour.
Note: If solids boil over into receiver, the test shall be rerun.
Pack the retort body with a greater amount of steel wool and repeat the
test.
k. Remove the liquid receiver. Allow it to cool. Record the volume
of water recovered. This is (V), cm\3\.
Note: If an emulsion interface is present between the oil and water
phases, heating the interface may break the emulsion. As a suggestion,
remove the retort assembly from the heating jacket by grasping the
condenser. Carefully heat the receiver along the emulsion band by gently
touching the receiver for short intervals with the hot retort assembly.
Avoid boiling the liquids. After the emulsion interface is broken, allow
the liquid receiver to cool. Read the water volume at the lowest point
of the meniscus.
l. Weigh and record the mass of the receiver and its liquid contents
(oil plus water). This is mass (D), grams.
m. Turn off the retort. Remove the retort assembly and condenser
from the heating jacket and allow them to cool. Remove the condenser.
n. Weigh and record the mass of the cooled retort assembly without
the condenser. This is mass (E), grams.
o. Clean the retort assembly and condenser.

4. Calculations

a. Calculate the mass of oil (NAF base fluid) from the cuttings as
follows:
1. Mass of the wet cuttings sample (Mw) equals the mass
of the retort assembly with the wet cuttings sample (B) minus the mass
of the empty retort assembly (A).

Mw = B-A [1]

2. Mass of the dry retorted cuttings (MD) equals the mass
of the cooled retort assembly (E) minus the mass of the empty retort
assembly (A).

MD = E-A [2]

[[Page 329]]

3. Mass of the NAF base fluid (MBF) equals the mass of
the liquid receiver with its contents (D) minus the sum of the mass of
the dry receiver (C) and the mass of the water (V).

MBF = D-(C + V) [3]

Note: Assuming the density of water is 1 g/cm\3\, the volume of
water is equivalent to the mass of the water.
b. Mass balance requirement:
The sum of MD, MBF, and V shall be within 5%
of the mass of the wet sample.

(MD + MBF + V)/Mw = 0.95 to 1.05 [4]

The procedure shall be repeated if this requirement is not met.
c. Reporting oil from cuttings:
1. Assume that all oil recovered is NAF base fluid.
2. The mass percent NAF base fluid retained on the cuttings
(%BFi) for the sampled discharge ``i'' is equal to 100 times
the mass of the NAF base fluid (MBF) divided by the mass of
the wet cuttings sample (Mw).

%BFi = (MBF/Mw) x 100 [5]

Operators discharging small volume NAF-cuttings discharges which do
not occur during a NAF-cuttings discharge sampling interval (i.e.,
displaced interfaces, accumulated solids in sand traps, pit clean-out
solids, or centrifuge discharges while cutting mud weight) shall either:
(a) Measure the mass percent NAF base fluid retained on the cuttings
(%BFSVD) for each small volume NAF-cuttings discharges; or
(b) use a default value of 25% NAF base fluid retained on the cuttings.
3. The mass percent NAF base fluid retained on the cuttings is
determined for all cuttings wastestreams and includes fines discharges
and any accumulated solids discharged [see Section 4.c.6 of this
appendix for procedures on measuring or estimating the mass percent NAF
base fluid retained on the cuttings (%BF) for dual gradient drilling
seafloor discharges performed to ensure proper operation of subsea
pumps].
4. A mass NAF-cuttings discharge fraction (X, unitless) is
calculated for all NAF-cuttings, fines, or accumulated solids discharges
every time a set of retorts is performed (see Section 4.c.6 of this
appendix for procedures on measuring or estimating the mass NAF-cuttings
discharge fraction (X) for dual gradient drilling seafloor discharges
performed to ensure proper operation of subsea pumps). The mass NAF-
cuttings discharge fraction (X) combines the mass of NAF-cuttings,
fines, or accumulated solids discharged from a particular discharge over
a set period of time with the total mass of NAF-cuttings, fines, or
accumulated solids discharged into the ocean during the same period of
time (see Addendum A and B of this appendix). The mass NAF-cuttings
discharge fraction (X) for each discharge is calculated by direct
measurement as:

Xi = (Fi)/(G) [6]

where:

Xi = Mass NAF-cuttings discharge fraction for NAF-cuttings,
fines, or accumulated solids discharge ``i'', (unitless)
Fi = Mass of NAF-cuttings discharged from NAF-cuttings,
fines, or accumulated solids discharge ``i'' over a specified period of
time (see Addendum A and B of this appendix), (kg)
G = Mass of all NAF-cuttings discharges into the ocean during the same
period of time as used to calculate Fi, (kg)

If an operator has more than one point of NAF-cuttings discharge,
the mass faction (Xi) must be determined by: (a) Direct
measurement (see Equation 6 of this Appendix); (b) using the following
default values of 0.85 and 0.15 for the cuttings dryer (e.g., horizontal
centrifuge, vertical centrifuge, squeeze press, High-G linear shakers)
and fines removal unit (e.g., decanting centrifuges, mud cleaners),
respectively, when the operator is only discharging from the cuttings
dryer and the fines removal unit; or (c) using direct measurement of
``Fi'' (see Equation 6 of this Appendix) for fines and
accumulated solids, using Equation 6A of this Appendix to calculate
``GEST'' for use as ``G'' in Equation 6 of this Appendix, and
calculating the mass (kg) of NAF-cuttings discharged from the cuttings
dryer (Fi) as the difference between the mass of
``GEST'' calculated in Equation 6A of this appendix (kg) and
the sum of all fines and accumulated solids mass directly measured (kg)
(see Equation 6 of this Appendix).
GEST = Estimated mass of all NAF-cuttings discharges into the
ocean during the same period of time as used to calculate Fi
(see Equation 6 of this Appendix), (kg) [6A]
where:

GEST = Hole Volume (bbl) x (396.9 kg/bbl) x (1 + Z/100)
Z = The base fluid retained on cuttings limitation or standard (%) which
apply to the NAF being discharge (see Sec. Sec. 435.13. and 435.15).
Hole Volume (bbl) = [Cross-Section Area of NAF interval (in\2\)] x
Average Rate of Penetration (feet/hr) x period of time (min) used to
calculate Fi (see Equation 6 of this Appendix) x (1 hr/60
min) x (1 bbl/5.61 ft³) x (1 ft/12 in)\2\
Cross-Section Area of NAF interval (in\2\) = (3.14 x [Bit Diameter
(in)]\2\)/4
Bit Diameter (in) = Diameter of drilling bit for the NAF interval
producing drilling cuttings during the same period of time as used to
calculate Fi (see Equation 6 of this Appendix)
Average Rate of Penetration (feet/hr) = Arithmetic average of rate of
penetration into the formation during the same period

[[Page 330]]

of time as used to calculate Fi (see Equation 6 of this
Appendix)

Note: Operators with one NAF-cuttings discharge may set the mass
NAF-cuttings discharge fraction (Xi) equal to 1.0.

5. Each NAF-cuttings, fines, or accumulated solids discharge has an
associated mass percent NAF base fluid retained on cuttings value (%BF)
and mass NAF-cuttings discharge fraction (X) each time a set of retorts
is performed. A single total mass percent NAF base fluid retained on
cuttings value (%BFT) is calculated every time a set of
retorts is performed. The single total mass percent NAF base fluid
retained on cuttings value (%BFT) is calculated as:

%BFT,j = [Sigma](Xi)x(%BFi) [7]

where:

%BFT,j = Total mass percent NAF base fluid retained on
cuttings value for retort set ``j'' (unitless as percentage, %)
Xi = Mass NAF-cuttings discharge fraction for NAF-cuttings,
fines, or accumulated solids discharge ``i'', (unitless)
%BFi = Mass percent NAF base fluid retained on the cuttings
for NAF-cuttings, fines, or accumulated solids discharge ``i'' ,
(unitless as percentage, %)

Note: [Sigma]Xi = 1.
Operators with one NAF-cuttings discharge may set %BFT,j
equal to %BFi.
6. Operators performing dual gradient drilling operations may
require seafloor discharges of large cuttings (\1/4\[foot])
to ensure the proper operation of subsea pumps (e.g., electrical
submersible pumps). Operators performing dual gradient drilling
operations which lead to seafloor discharges of large cuttings for the
proper operation of subsea pumps shall either: (a) Measure the mass
percent NAF base fluid retained on cuttings value (%BF) and mass NAF-
cuttings discharge fraction (X) for seafloor discharges each time a set
of retorts is performed; (b) use the following set of default values,
(%BF=14%; X=0.15); or (c) use a combination of (a) and (b) (e.g., use a
default value for %BF and measure X).
Additionally, operators performing dual gradient drilling operations
which lead to seafloor discharges of large cuttings for the proper
operation of subsea pumps shall also perform the following tasks:
(a) Use side scan sonar or shallow seismic to determine the presence
of high density chemosynthetic communities. Chemosynthetic communities
are assemblages of tube worms, clams, mussels, and bacterial mats that
occur at natural hydrocarbon seeps or vents, generally in water depths
of 500 meters or deeper. Seafloor discharges of large cuttings for the
proper operation of subsea pumps shall not be permitted within 1000 feet
of a high density chemosynthetic community.
(b) Seafloor discharges of large cuttings for the proper operation
of subsea pumps shall be visually monitored and documented by a Remotely
Operated Vehicle (ROV) within the tether limit (approximately 300 feet).
The visual monitoring shall be conducted prior to each time the
discharge point is relocated (cuttings discharge hose) and conducted
along the same direction as the discharge hose position. Near-seabed
currents shall be obtained at the time of the visual monitoring.
(c) Seafloor discharges of large cuttings for the proper operation
of subsea pumps shall be directed within a 150 foot radius of the
wellbore.
7. The weighted mass ratio averaged over all NAF well sections
(%BFwell) is the compliance value that is compared with the
``maximum weighted mass ratio averaged over all NAF well sections'' BAT
discharge limitations (see the table in Sec. 435.13 and footnote 5 of
the table in Sec. 435.43) or the ``maximum weighted mass ratio averaged
over all NAF well sections'' NSPS discharge limitations (see the table
in Sec. 435.15 and footnote 5 of the table in Sec. 435.45). The
weighted mass ratio averaged over all NAF well sections
(%BFwell) is calculated as the arithmetic average of all
total mass percent NAF base fluid retained on cuttings values
(%BFT) and is given by the following expression:

%BFwell = [j=1 to j=n [Sigma] (%BFT,j)]/n [8]

where:

%BFwell = Weighted mass ratio averaged over all NAF well
sections (unitless as percentage, %)
%BFT,j = Total mass percent NAF base fluid retained on
cuttings value for retort set ``j'' (unitless as percentage, %)
n = Total number of retort sets performed over all NAF well sections
(unitless)

Small volume NAF-cuttings discharges which do not occur during a
NAF-cuttings discharge sampling interval (i.e., displaced interfaces,
accumulated solids in sand traps, pit clean-out solids, or centrifuge
discharges while cutting mud weight) shall be mass averaged with the
arithmetic average of all total mass percent NAF base fluid retained on
cuttings values (see Equation 8 of this Appendix). An additional
sampling interval shall be added to the calculation of the weighted mass
ratio averaged over all NAF well sections (%BFwell). The mass
fraction of the small volume NAF-cuttings discharges (XSVD)
will be determined by dividing the mass of the small volume NAF-cuttings
discharges (FSVD) by the total mass of NAF-cuttings
discharges for the well drilling operation (GWELL +
FSVD).

XSVD = FSVD / (GWELL + FSVD)
[9]

where:

XSVD = mass fraction of the small volume NAF-cuttings
discharges (unitless)

[[Page 331]]

FSVD = mass of the small volume NAF-cuttings discharges (kg)
GWELL = mass of total NAF-cuttings from the well (kg)

The mass of small volume NAF-cuttings discharges (FSVD)
shall be determined by multiplying the density of the small volume NAF-
cuttings discharges ([rho]svd) times the volume of the small
volume NAF-cuttings discharges (VSVD).

FSVD = [rho]svd x VSVD [10]

where:

FSVD = mass of small volume NAF-cuttings discharges (kg)
[rho]svd = density of the small volume NAF-cuttings
discharges (kg/bbl)
VSVD = volume of the small volume NAF-cuttings discharges
(bbl)
The density of the small volume NAF-cuttings discharges shall be
measured. The volume of small volume discharges (VSVD) shall
be either: (a) Be measured or (b) use default values of 10 bbl of SBF
for each interface loss and 75 bbl of SBM for pit cleanout per well.
The total mass of NAF-cuttings discharges for the well
(GWELL) shall be either: (a) Measured; or (b) calculated by
multiplying 1.0 plus the arithmetic average of all total mass percent
NAF base fluid retained on cuttings values [see Equation 8 of this
Appendix] times the total hole volume (VWELL) for all NAF
well sections times a default value for the density the formation of 2.5
g/cm³ (396.9 kg/bbl).
[GRAPHIC] [TIFF OMITTED] TR08JN01.001

where:

GWELL = total mass of NAF-cuttings discharges for the well
(kg)
[j = 1 to j = n [Sigma](%BFT,j)]/n = see Equation 8 of this
Appendix (unitless as a percentage)
VWELL = total hole volume (VWELL) for all NAF well
sections (bbl)

The total hole volume of NAF well sections (VWELL) will
be calculated as:
[GRAPHIC] [TIFF OMITTED] TR22JA01.170

For wells where small volume discharges associated with cuttings are
made, %BFWELL becomes:
[GRAPHIC] [TIFF OMITTED] TR08JN01.002

Note: See Addendum A and B to determine the sampling frequency to
determine the total number of retort sets required for all NAF well
sections.
8. The total number of retort sets (n) is increased by 1 for each
sampling interval (see Section 2.4, Addendum A of this appendix) when
all NAF cuttings, fines, or accumulated solids for that sampling
interval are retained for no discharge. A zero discharge interval shall
be at least 500 feet up to a maximum of three per day. This action has
the effect of setting the total mass percent NAF base fluid retained on
cuttings value (%BFT) at zero for that NAF sampling interval
when all NAF cuttings, fines, or accumulated solids are retained for no
discharge.
9. Operators that elect to use the Best Management Practices (BMPs)
for NAF-cuttings shall use the procedures outlined in Addendum B.

Addendum A to Appendix 7 to Subpart A of Part 435--Sampling of Cuttings
Discharge Streams for use with API Recommended Practice 13B-2

1.0 Sampling Locations

1.1 Each NAF-cuttings waste stream that discharges into the ocean
shall be sampled and analyzed as detailed in Appendix 7. NAF-

[[Page 332]]

cuttings discharges to the ocean may include discharges from primary
shakers, secondary shakers, cuttings dryer, fines removal unit,
accumulated solids, and any other cuttings separation device whose NAF-
cuttings waste is discharged to the ocean. NAF-cuttings wastestreams not
directly discharged to the ocean (e.g., NAF-cuttings generated from
shake shakers and sent to a cuttings dryer for additional processing) do
not require sampling and analysis.
1.2 The collected samples shall be representative of each NAF-
cuttings discharge. Operators shall conduct sampling to avoid the
serious consequences of error (i.e., bias or inaccuracy). Operators
shall collect NAF-cuttings samples near the point of origin and before
the solids and liquid fractions of the stream have a chance to separate
from one another. For example, operators shall collect shale shaker NAF-
cuttings samples at the point where NAF-cuttings are coming off the
shale shaker and not from a holding container downstream where
separation of larger particles from the liquid can take place.
1.3 Operators shall provide a simple schematic diagram of the solids
control system and sample locations to the NPDES permit controlling
authority.

2.0 Type of Sample and Sampling Frequency

2.1 Each NAF-cuttings, fines, or accumulated solids discharge has an
associated mass percent NAF base fluid retained on cuttings value (%BF)
and mass NAF-cuttings discharge fraction (X) for each sampling interval
(see Section 2.4 of this addendum). Operators shall collect a single
discrete NAF-cuttings sample for each NAF-cuttings waste stream
discharged to the ocean during every sampling interval.
2.2 Operators shall use measured depth in feet from the Kelly
bushing when samples are collected.
2.3 The NAF-cuttings samples collected for the mass fraction
analysis (see Equation 6, Appendix 7 of Subpart A of this part) shall
also be used for the retort analysis (see Equations 1-5, Appendix 7 of
Subpart A of this part).
2.4 Operators shall collect and analyze at least one set of NAF-
cuttings samples per day while discharging. Operators engaged in fast
drilling (i.e., greater than 500 linear NAF feet advancement of drill
bit per day) shall collect and analyze one set of NAF-cuttings samples
per 500 linear NAF feet of footage drilled. Operators are not required
to collect and analyze more than three sets of NAF-cuttings samples per
day (i.e., three sampling intervals). Operators performing zero
discharge of all NAF-cuttings (i.e., all NAF cuttings, fines, or
accumulated solids retained for no discharge) shall use the following
periods to count sampling intervals: (1) One sampling interval per day
when drilling is less than 500 linear NAF feet advancement of drill bit
per day; and (2) one sampling interval per 500 linear NAF feet of
footage drilled with a maximum of three sampling intervals per day.
2.5 The operator shall measure the individual masses (Fi,
kg) and sum total mass (G, kg) (see Equation 6, Appendix 7 of subpart A
of this part) over a representative period of time (e.g., <10 minutes)
during steady-state conditions for each sampling interval (see Section
2.4 of this addendum). The operator shall ensure that all NAF-cuttings
are capture for mass analysis during the same sampling time period
(e.g., <10 minutes) at approximately the same time (i.e., all individual
mass samples collected within one hour of each other).
2.6 Operators using Best Management Practices (BMPs) to control NAF-
cuttings discharges shall follow the procedures in Addendum B to
Appendix 7 of subpart A of 40 CFR 435.

3.0 Sample Size and Handling

3.1 The volume of each sample depends on the volumetric flow rate
(cm\3\/s) of the NAF-cuttings stream and the sampling time period (e.g.,
<10 minutes). Consequently, different solids control equipment units
producing different NAF-cuttings waste streams at different volumetric
flow rates will produce different size samples for the same period of
time. Operators shall use appropriately sized sample containers for each
NAF-cuttings waste stream to ensure no NAF-cuttings are spilled during
sample collection. Operators shall use the same time period (e.g., <10
minutes) to collect NAF-cuttings samples from each NAF-cuttings waste
stream. Each NAF-cuttings sample size shall be at least one gallon.
Operators shall clearly mark each container to identify each NAF-
cuttings sample.
3.2 Operators shall not decant, heat, wash, or towel the NAF-
cuttings to remove NAF base fluid before mass and retort analysis.
3.3 Operators shall first calculate the mass of each NAF-cuttings
sample and perform the mass ratio analysis (see Equation 6, Appendix 7
of subpart A of this part). Operators with only one NAF-cuttings
discharge may skip this step (see Section 4.c.4, Appendix 7 of subpart A
of this part).
3.4 Operators shall homogenize (e.g., stirring, shaking) each NAF-
cuttings sample prior to placing a sub-sample into the retort cup. The
bottom of the NAF-cuttings sample container shall be examined to be sure
that solids are not sticking to it.
3.5 Operators shall then calculate the NAF base fluid retained on
cuttings using the retort procedure (see Equations 1-5, Appendix 7 of
subpart A of this part). Operators shall start the retort analyses no
more than

[[Page 333]]

two hours after collecting the first individual mass sample for the
sampling interval .
3.6 Operators shall not discharge any sample before successfully
completing the mass and retort analyses [i.e., mass balance requirements
(see Section 4.b, Appendix 7 of subpart A of this part) are satisfied].
Operators shall immediately re-run the retort analyses if the mass
balance requirements (see Equation 4, Appendix 7 of subpart A of this
part) are not within a tolerance of 5% (see Section 4.b, Equation 4,
Appendix 7 of subpart A of this part).

4.0 Calculations

4.1 Operators shall calculate a set of mass percent NAF base fluid
retained on cuttings values (%BF) and mass NAF-cuttings discharge
fractions (X) for each NAF-cuttings waste stream (see Section 1.1 of
this addendum) for each sampling interval (see Section 2.4 of this
addendum) using the procedures outlined in Appendix 7 of subpart A of
this part.
4.2 Operators shall tabulate the following data for each individual
NAF-cuttings sample: (1) Date and time of NAF-cuttings sample
collection; (2) time period of NAF-cuttings sample collection (see
Section 3.1 of this addendum); (3) mass and volume of each NAF-cuttings
sample; (4) measured depth (feet) at NAF-cuttings sample collection (see
Section 2.2 of this addendum); (5) respective linear feet of hole
drilled represented by the NAF-cuttings sample (feet); and (6) the drill
bit diameter (inches) used to generate the NAF-cuttings sample cuttings.
4.3 Operators shall calculate a single total mass percent NAF base
fluid retained on cuttings value (%BFT) for each sampling
interval (see Section 2.4 of this addendum) using the procedures
outlined in Appendix 7 of Subpart A of this part.
4.4 Operators shall tabulate the following data for each total mass
percent NAF base fluid retained on cuttings value (%BFT) for
each NAF-cuttings sampling interval: (1) Date and starting and stopping
times of NAF-cuttings sample collection and retort analyses; (2)
measured depth of well (feet) at start of NAF-cuttings sample collection
(see Section 2.2 of this addendum); (3) respective linear feet of hole
drilled represented by the NAF-cuttings sample (feet); (4) the drill bit
diameter (inches) used to generate the NAF-cuttings sample cuttings; and
(5) annotation when zero discharge of NAF-cuttings is performed.
4.5 Operators shall calculate the weighted mass ratio averaged over
all NAF well sections (%BFwell) using the procedures outlined
in Appendix 7 of Subpart A of this part.
4.6 Operators shall tabulate the following data for each weighted
mass ratio averaged over all NAF well sections (%BFwell) for
each NAF well: (1) Starting and stopping dates of NAF well sections; (2)
measured depth (feet) of all NAF well sections; (3) total number of
sampling intervals (see Section 2.4 and Section 2.6 of this addendum);
(4) number of sampling intervals tabulated during any zero discharge
operations; (5) total volume of zero discharged NAF-cuttings over entire
NAF well sections; and (6) identification of whether BMPs were employed
(see Addendum B of Appendix 7 of subpart A of this part).

Addendum B to Appendix 7 to Subpart A of Part 435-- Best Management
Practices (BMPs) for use with API Recommended Practice 13B-2

1.0 Overview of BMPs

1.1 Best Management Practices (BMPs) are inherently pollution
prevention practices. BMPs may include the universe of pollution
prevention encompassing production modifications, operational changes,
material substitution, materials and water conservation, and other such
measures. BMPs include methods to prevent toxic and hazardous pollutants
from reaching receiving waters. Because BMPs are most effective when
organized into a comprehensive facility BMP Plan, operators shall
develop a BMP in accordance with the requirements in this addendum.
1.2 The BMP requirements contained in this appendix were compiled
from several Regional permits, an EPA guidance document (i.e., Guidance
Document for Developing Best Management Practices (BMP)'' (EPA 833-B-93-
004, U.S. EPA, 1993)), and draft industry BMPs. These common elements
represent the appropriate mix of broad directions needed to complete a
BMP Plan along with specific tasks common to all drilling operations.
1.3 Operators are not required to use BMPs if all NAF-cuttings
discharges are monitored in accordance with Appendix 7 of Subpart A of
this part.

2.0 BMP Plan Purpose and Objectives

2.1 Operators shall design the BMP Plan to prevent or minimize the
generation and the potential for the discharge of NAF from the facility
to the waters of the United States through normal operations and
ancillary activities. The operator shall establish specific objectives
for the control of NAF by conducting the following evaluations.
2.2 The operator shall identify and document each NAF well that uses
BMPs before starting drilling operations and the anticipated total feet
to be drilled with NAF for that particular well.
2.3 Each facility component or system controlled through use of BMPs
shall be examined for its NAF-waste minimization opportunities and its
potential for causing a discharge of NAF to waters of the United States
due to equipment failure, improper

[[Page 334]]

operation, natural phenomena (e.g., rain, snowfall).
2.4 For each NAF wastestream controlled through BMPs where
experience indicates a reasonable potential for equipment failure (e.g.,
a tank overflow or leakage), natural condition (e.g., precipitation), or
other circumstances to result in NAF reaching surface waters, the BMP
Plan shall include a prediction of the total quantity of NAF which could
be discharged from the facility as a result of each condition or
circumstance.

3.0 BMP Plan Requirements

3.1 The BMP Plan may reflect requirements within the pollution
prevention requirements required by the Minerals Management Service (see
30 CFR 250.300) or other Federal or State requirements and incorporate
any part of such plans into the BMP Plan by reference.
3.2 The operator shall certify that its BMP Plan is complete, on-
site, and available upon request to EPA or the NPDES Permit controlling
authority. This certification shall identify the NPDES permit number and
be signed by an authorized representative of the operator. This
certification shall be kept with the BMP Plan. For new or modified NPDES
permits, the certification shall be made no later than the effective
date of the new or modified permit. For existing NPDES permits, the
certification shall be made within one year of permit issuance.
3.3 The BMP Plan shall:
3.3.1 Be documented in narrative form, and shall include any
necessary plot plans, drawings or maps, and shall be developed in
accordance with good engineering practices. At a minimum, the BMP Plan
shall contain the planning, development and implementation, and
evaluation/reevaluation components. Examples of these components are
contained in ``Guidance Document for Developing Best Management
Practices (BMP)'' (EPA 833-B-93-004, U.S. EPA, 1993).
3.3.2 Include the following provisions concerning BMP Plan review.
3.3.2.1 Be reviewed by permittee's drilling engineer and offshore
installation manager (OIM) to ensure compliance with the BMP Plan
purpose and objectives set forth in Section 2.0.
3.3.2.2 Include a statement that the review has been completed and
that the BMP Plan fulfills the BMP Plan purpose and objectives set forth
in Section 2.0. This statement shall have dated signatures from the
permittee's drilling engineer and offshore installation manager and any
other individuals responsible for development and implementation of the
BMP Plan.
3.4 Address each component or system capable of generating or
causing a release of significant amounts of NAF and identify specific
preventative or remedial measures to be implemented.

4.0 BMP Plan Documentation

4.1 The operator shall maintain a copy of the BMP Plan and related
documentation (e.g., training certifications, summary of the monitoring
results, records of NAF-equipment spills, repairs, and maintenance) at
the facility and shall make the BMP Plan and related documentation
available to EPA or the NPDES Permit controlling authority upon request.

5.0 BMP Plan Modification

5.1 For those NAF wastestreams controlled through BMPs, the operator
shall amend the BMP Plan whenever there is a change in the facility or
in the operation of the facility which materially increases the
generation of those NAF-wastes or their release or potential release to
the receiving waters.
5.2 At a minimum the BMP Plan shall be reviewed once every five
years and amended within three months if warranted. Any such changes to
the BMP Plan shall be consistent with the objectives and specific
requirements listed in this addendum. All changes in the BMP Plan shall
be reviewed by the permittee's drilling engineer and offshore
installation manager.
5.3 At any time, if the BMP Plan proves to be ineffective in
achieving the general objective of preventing and minimizing the
generation of NAF-wastes and their release and potential release to the
receiving waters and/or the specific requirements in this addendum, the
permit and/or the BMP Plan shall be subject to modification to
incorporate revised BMP requirements.

6.0 Specific Pollution Prevention Requirements for NAF Discharges
Associated with Cuttings

6.1 The following specific pollution prevention activities are
required in a BMP Plan when operators elect to control NAF discharges
associated with cuttings by a set of BMPs.
6.2 Establishing programs for identifying, documenting, and
repairing malfunctioning NAF equipment, tracking NAF equipment repairs,
and training personnel to report and evaluate malfunctioning NAF
equipment.
6.3 Establishing operating and maintenance procedures for each
component in the solids control system in a manner consistent with the
manufacturer's design criteria.
6.4 Using the most applicable spacers, flushes, pills, and
displacement techniques in order to minimize contamination of drilling
fluids when changing from water-based drilling fluids to NAF and vice
versa.
6.5 A daily retort analysis shall be performed (in accordance with
Appendix 7 to

[[Page 335]]

subpart A of Part 435) during the first 0.33 X feet drilled with NAF
where X is the anticipated total feet to be drilled with NAF for that
particular well. The retort analyses shall be documented in the well
retort log. The operators shall use the calculation procedures detailed
in Appendix 7 to subpart A of part 435 (see Equations 1 through 8) to
determine the arithmetic average (%BFwell) of the retort
analyses taken during the first 0.33 X feet drilled with NAF.
6.5.1 When the arithmetic average (%BFwell) of the retort
analyses taken during the first 0.33 X feet drilled with NAF is less
than or equal to the base fluid retained on cuttings limitation or
standard (see Sec. Sec. 435.13 and 435.15), retort monitoring of
cuttings may cease for that particular well. The same BMPs and drilling
fluid used during the first 0.33 X feet shall be used for all remaining
NAF sections for that particular well.
6.5.2 When the arithmetic average (%BFwell) of the retort
analyses taken during the first 0.33 X feet drilled with NAF is greater
the base fluid retained on cuttings limitation or standard (see
Sec. Sec. 435.13 and 435.15), retort monitoring shall continue for the
following (second) 0.33 X feet drilled with NAF where X is the
anticipated total feet to be drilled with NAF for that particular well.
The retort analyses for the first and second 0.33 X feet shall be
documented in the well retort log.
6.5.2.1 When the arithmetic average (%BFwell) of the
retort analyses taken during the first 0.66 X feet (i.e., retort
analyses taken from first and second 0.33 X feet) drilled with NAF is
less than or equal to the base fluid retained on cuttings limitation or
standard (see Sec. Sec. 435.13 and 435.15), retort monitoring of
cuttings may cease for that particular well. The same BMPs and drilling
fluid used during the first 0.66 X feet shall be used for all remaining
NAF sections for that particular well.
6.5.2.2 When the arithmetic average (%BFwell) of the
retort analyses taken during the first 0.66 X feet (i.e., retort
analyses taken from first and second 0.33 X feet) drilled with NAF is
greater than the base fluid retained on cuttings limitation or standard
(see Sec. Sec. 435.13 and 435.15), retort monitoring shall continue for
all remaining NAF sections for that particular well. The retort analyses
for all NAF sections shall be documented in the well retort log.
6.5.3 When the arithmetic average (%BFwell) of the retort
analyses taken over all NAF sections for the entire well is greater that
the base fluid retained on cuttings limitation or standard (see
Sec. Sec. 435.13 and 435.15), the operator is in violation of the base
fluid retained on cuttings limitation or standard and shall submit
notification of these monitoring values in accordance with NPDES permit
requirements. Additionally, the operator shall, as part of the BMP Plan,
initiate a reevaluation and modification to the BMP Plan in conjunction
with equipment vendors and/or industry specialists.
6.5.4 The operator shall include retort monitoring data and dates of
retort-monitored and non-retort-monitored NAF-cuttings discharges
managed by BMPs in their NPDES permit reports.
6.6 Establishing mud pit and equipment cleaning methods in such a
way as to minimize the potential for building-up drill cuttings
(including accumulated solids) in the active mud system and solids
control equipment system. These cleaning methods shall include but are
not limited to the following procedures.
6.6.1 Ensuring proper operation and efficiency of mud pit agitation
equipment.
6.6.2 Using mud gun lines during mixing operations to provide
agitation in dead spaces.
6.6.3 Pumping drilling fluids off of drill cuttings (including
accumulated solids) for use, recycle, or disposal before using wash
water to dislodge solids.

[66 FR 6901, Jan. 22, 2001; 66 FR 30811, June 8, 2001]

Appendix 8 to Subpart A of Part 435--Reference C16-
C18 Internal Olefin Drilling Fluid Formulation

The reference C16-C18 internal olefin drilling
fluid used to determine the drilling fluid sediment toxicity ratio and
compliance with the BAT sediment toxicity discharge limitation (see
Sec. 435.13) and NSPS (see Sec. 435.15) shall be formulated to meet
the specifications in Table 1 of this appendix.
Drilling fluid sediment toxicity ratio = 4-day LC50 of
C16-C18 internal olefin drilling fluid/4-day
LC50 of drilling fluid removed from cuttings at the solids
control equipment as determined by ASTM E1367-92 [incorporated by
reference and specified at Sec. 435.11(ee)] and supplemented with the
sediment preparation procedure (Appendix 3 of subpart A of this part).

Table 1--Properties for Reference C16-C18 IOs SBF Used in Discharge Sediment Toxicity Testing
----------------------------------------------------------------------------------------------------------------
Reference C16-C18 IOs
Mud weight of SBF discharged with cuttings (pounds per gallon) Reference C16-C18 IOs SBF synthetic to water
SBF (pounds per gallon) ratio (%)
----------------------------------------------------------------------------------------------------------------
8.5-11........................................................ 9.0 75/25

[[Page 336]]

11-14......................................................... 11.5 80/20
14................................................. 14.5 85/15
===============================================================
Plastic Viscosity (PV), centipoise (cP)....................... 12-30
Yield Point (YP), pounds/100 sq. ft........................... 10-20
10-second gel, pounds/100 sq. ft.............................. 8-15
10-minute gel, pounds/100 sq. ft.............................. 12-30
Electrical stability, V....................................... 300
----------------------------------------------------------------------------------------------------------------

[66 FR 6901, Jan. 22, 2001]

Subpart B [Reserved]