2020 Hazardous Waste Disposal Injection Restrictions (HWDIR) Rubicon LLC Geismar Louisiana Facility Geismar, Louisiana April 6, 2023

April 6, 2023

FACT SHEET

EPA is proposing to approve the 2020 Hazardous Waste Disposal Injection Restrictions
(HWDIR) petition for an exemption to the land disposal restrictions for the following injection
well facility:

Applicant: Rubicon LLC

P.O. Box 517
Geismar, Louisiana 70734

Facility Location: Geismar Louisiana Facility

9156 Highway 75
Geismar, Louisiana 70734

Well: WDW-6

Summary of Decision Basis

The 2020 HWDIR petition submitted by Rubicon LLC Geismar Louisiana Facility requested the
approval to operate one new on-site, noncommercial Class I Hazardous Waste Disposal Injection
Well (WDW-6). Rubicon LLC currently operates four Class I hazardous injection wells under an
active No migration petition (WDW-1, 3, 4, 5, and proposed 6), all of which have the same waste
stream generated by manufacturing operations. Four wells operate under an existing approved
petition. Rubicon no longer operates a Class I hazardous injection well (WDW-2), plugged and
abandoned in July 2006. All wells have permits issued by the State of Louisiana Department of
Natural Resources (LDNR), Office of Conservation. Injection Well No. 6 was drilled in 2016
and completed in 2017. Rubicon LLC requests approval for WDW-6 to inject into two new
intervals: "L-2" Sand and "L-3" Sand. Rubicon LLC also proposes an operational injection rate
of 1,400 gpm for the "L-2" Sand interval, an operating injection rate of 4,500 gpm for the "L-3"
Sand injection interval, and a three-whole month running average specific gravity range of 0.996
to 1.089 at 77°F for injections intervals L-2" and "L-3" Sands. Rubicon LLC requests a
maximum cumulative injection volume of 7,460,000,000 gallons into the "L-2" Sand and
22,380,000,000 gallons into the "L-3" Sand intervals. The following explains the derivation of
the proposed decision, categorized according to the criteria outlined in 40 CFR Part 148. [53 Fed.
Reg., 28118, (7/26/88)]

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Summary of Decision Modeling Demonstration Results

Site geology consists of multiple stacked shales that provide barriers to fluid movement traveling
upward, and thick, porous, and permeable sandstones that provide excellent injection reservoirs;
the area's geologic details are summarized in the attached 2009 fact sheet. The site is operated by
Rubicon LLC and has been since 1987. Site geology and other associated information have
changed little since Rubicon LLC applied for reissuance of WDW-1, 3, 4, 5, and proposed 6 in
2005, which received EPA approval in 2009.

Modeled boundary conditions that may result in potential barriers to fluid flow within or near the
2.5-mile radius Area of Review include Fault "A" near Darrow dome. The drilling of WDW-6
did not change the previously modeled boundary conditions. A barrier or sealing fault of an
infinite extent is included in the modeling of all injection intervals. The modeled fault is placed
6,000 feet southwest of WDW-5. The modeled fault trends northwest-southeast and represents a
barrier extending from the trace of Fault "A" near the Darrow dome area to the northwest
through the Area of Review. The model fault location is such that most of the faulting in the
Darrow dome area is located on the south side of the modeled fault.

Interpretation of conventional and sidewall cores, borehole geophysical logs, pressure
measurements, and laboratory tests, used in conjunction with published and unpublished
literature, provides a comprehensive picture of the subsurface geology developed for the plant
site. Site-specific data was acquired during the drilling of WDW-6. Additionally, annual well
tests, mechanical integrity tests, and offset well information from all the site's wells were
reviewed to determine appropriate values for the no migration demonstration. Proper estimation
techniques and testing protocols were used per 40 CFR §148.21(a)(2). A range was assigned to
some parameters to maximize their impact on the demonstration. For example, for pressure
build-up and plume size, the injection interval thicknesses were decreased by 10% and 14% for
the L-2 and L-3 Sands. Another example is that the injection interval's permeability was
increased to 5 darcies to conservatively model the 10,000-year long-term plume movement. The
falloff test data for Well No. 6 was analyzed using pressure transient analysis methods. Results
of the September 28, 2022, falloff test identified a permeability value of 4.075 darcies and used
to help set bounds for upper and lower permeability values in the modeling. Higher
permeabilities were assigned to maximize the lateral waste plume movement. In comparison,
both intervals were assigned lower permeabilities to maximize the predicted pressure build-up
from injection operations.

A conservative 10,000-year plume migration model was constructed using worst-case reservoir
characteristics for each injection interval. The low and high-density plume models utilized the
thinner net thickness, conservative permeabilities based on historical pressure transient test
results, and historical and projected maximum injection volumes. Additionally, a limiting
concentration reduction factor was set to 1 x 10"7 for the constituents of concern, encompassing
the requested EPA hazardous waste numbers included in this petition and lower formation fluid
viscosity to predict an upper bound on the plume movement. Low-density plume modeling
utilized the requested low end of the density range for the waste stream and did not include a
background gradient to maximize up-dip plume movement. The higher density waste stream was
modeled using a conservative 1.0 feet/year as the maximum expected background gradient in the

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"L' Sands to maximize the downdip movement of the waste plume. These deviations are selected
to over-estimate the actual plume movement.

Artificial penetrations within the area of review are considered during the modeling. Rubicon is
one of five companies that have historically utilized Class I injection wells in the area. The
current facilities include Shell, Lion Copolymer (formerly Chemtura, Crompton, and Uniroyal),
BASF, and Borden Plastics and Chemicals. Additionally, several Class II saltwater disposal
wells are operating at Darrow dome. However, there are no Class I and II historical injection
wells sharing the same injection interval as WDW-6 in the area to be included in the modeling.

A vertical diffusion demonstration was included in this petition that calculated the maximum
vertical movement into intact strata and a mud-filled wellbore. The models (10,000-year and
diffusion) demonstrated that the injected waste stream for each interval would not migrate
vertically out of the injection zone or laterally within the injection zone to the point of discharge
or interface with an underground source of drinking water (USDW).

Rubicon LLC, Geismar Facility's Flow and Containment models conservatively modeled waste
fluid injections into the subsurface under certain modified conditions; these modifications make
the modeled parameters less ideal than the values measured. By over-matching model pressure
predictions, flowing downhole pressures, and formation shut-in pressures in the injection
reservoirs validated geologic parameters. The waste injected will be contained within the Area of
Review by the end of injection operations in 2040. Modeling through the end of 2040, using
maximum projected injection rates, results in the maximum horizontal extent of the waste in the
"L-2" and "L-3" Sands. The observed maximum vertical permeation into the aquiclude above the
"L-2" Sand is approximately 10.6 feet. No vertical permeation of fluids out of the "L-2" and "L-
3" Sands endangers USDWs.

The maximum requested injection rate for each injection interval was used from December 31,
2017, through December 31, 2040, to project the maximum pressure build-up. The pressure
build-up demonstration for the "L" Sands over-predicted well pressures compared to historical
static and flowing pressure measurements obtained from falloff tests conducted in WDW-6.
By the end of 2040, the maximum pressure build-up along the Area of Review boundary does
not exceed 302 psi within the "L-2" Sand at a maximum cumulative injection rate of 1,400 gpm
continuously into WDW-6. Also, the pressure build-up does not exceed 240 psi within the "L-3"
Sand at the same cumulative injection rate of 4,500 gpm continuously into WDW-6. The
pressure buildup model, extended past the end of injection operations, predicts the dissipation of
the Cone of Influence within one year of well closure due to decreased pressure build-up.

As pressure decreases within the formation, vertical permeation will decrease to below 6.6 feet in
the aquiclude layer above the "L-2" Sand. For the Rubicon LLC (Rubicon) Geismar Facility, the
radius of the "cone of influence" potentially falls outside of the 2.0-mile radius Area of Review
in the "L-2" Sand injection interval due to the very conservative modeling assumptions applied
(see Section 3.0). The extended areas in the cone of influence that lay beyond the fixed 2.0-mile
radius Area of Review were also searched for artificial penetrations. No additional wells are
contained within this extended area in this 2020 EPA No Migration Request. The most mobile
constituent within the waste stream will not diffuse beyond a total vertical extent of 131 feet of

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the 1,700 feet of shale overlying the "L-2" Sand. Over a 10,000-year evaluation period, the
High-Density Plume drift will extend approximately 26,500 feet down-dip to the southwest of
the operational plume perimeter. The Low-Density Plume drift over the 10,000-year evaluation
period will not exceed 73,000 feet to the site's northeast.

Rubicon LLC has successfully demonstrated site no migration through the results of the
modeling demonstrations in the 2020 HWDIR petition document and associated supporting
information, including recent mechanical integrity testing. Demonstration of modeling pressure
build-up effects, long-term horizontal plume movement distances, and vertical movement
modeling results are summarized below for the activation of WDW-6:

Operational Life

End of Operational Life: December 31, 2040

Modeled	Injection	Maximum Incremental

Well Location	Interval	Pressure Buildup (psi)

WDW-6	"L-2" Sand	302 psi

WDW-61	"L-3" Sand	240 psi

(^Currently completed in this injection interval)

Long Term Plume Movement

Maximum Up Dip Movement: 73,000 feet within the "L" Sand Injection Intervals
Maximum Down Dip Movement: 26,500 feet within "L" Sand Injection Intervals

Maximum Vertical Movement*

Within A Mud-Filled Borehole: 440 feet1

Through Intact Strata:	131 feet2

(*Includes uncertainty of 5% due to 10% uncertainty in the free water diffusion
coefficient.)

(1 Vertical diffusion distance through 9.0-lb/gal mud for Methylene Chloride)
(2Most mobile molecule Methylene Chloride)

Results from the most recent mechanical integrity tests for WDW-6 are summarized below:

Well Number	Annulus Pressure Test	Radioactive Tracer Survey

WDW-6	09/26/2022	09/28/2022

Proposed HWDIR Petition Request Approval Conditions

This proposed approval of an HWDIR petition request for an exemption to allow the injection of
restricted hazardous wastes is subject to the following conditions, which are necessary to assure
that the standard in 40 CFR § 148.20(a) is met. Noncompliance with any of these conditions is

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grounds for termination of the exemption per 40 CFR § 148.24(a)(1). This proposed exemption
applies to the Rubicon LLC Geismar Facility injection well: WDW-6, located at its Geismar,
Louisiana facility.

1. Injection of restricted waste shall be limited to the following injection zone(s):

Well Injection Interval Depth of Injection Zone

WDW-6 "L" Sand 5,590' - 7,846'*

('WDW-6 Injection Zone depths are referenced to Kelly Bushing (KB) depths (21' above
ground level) on WDW-6's Induction-SFL/Compensated Neutron-Density/Gamma/Sonic
Open hole log dated April 5, 2016)

The following correlative log depths shall define the injection intervals:

Well Injection Interval Depth of Injection Interval

WDW-6 "L-2" Sand 7,040'- 7,170'2

"L-3" Sand 7,230' - 7,770'2

(2WDW-6 Injection Interval depths are referenced to Kelly Bushing (KB) depths (21'
above ground level) on WDW-6's Induction-SFL/Compensated Neutron-
Density/Gamma/Sonic Open hole log dated April 5, 2016)

2. For WDW-6, the combined cumulative monthly volume injected into each of the
injection intervals shall not exceed that calculated as follows:

"L-2" Sand: (1,400 gpm)(1440 minutes/day)(number of days in that month)
"L-3" Sand: (4,500 gpm)(1440 minutes/day)(number of days in that month)

3. The facility shall cease injection into WDW-6 by December 31, 2040.

4. The characteristics of the injected waste stream for WDW-6 shall, at all times, conform to
those discussed in Section 1.2 of the 2020 No. 6 HWDIR Petition Request document for
WDW-6. The specific gravity of the waste stream injected into each interval shall remain
within the running volume-weighted three whole calendar-month range of 0.996 to 1.089
at 77 °F.

(The running three-whole calendar month average shall be calculated by multiplying each
day's specific gravity/density value by that day's injected volume, totaling those values
for the previous whole three-month period, and dividing by that three whole-month
injected volume. For the above calculation, each day's specific gravity/density value shall
be obtained by at least one representative grab sample for each active injection interval.)

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5.

The approval for injection is limited to the following hazardous waste codes:

D Codes

D001, D002, D003, D004, D005, D006, D007, D008, D009, D010,
D011, D018, DO 19, D021, D022, D023, D024, D025, D026, D027,
D028, D029, D030, D032, D033, D034, D035, D036, D037, D038,
D039, D040, D041, D042, D043

F Codes

F001, F002, F003, F004, F005, F006, F007, F008, F009, F010,
F011, F012, F019, F020, F021, F022, F023, F024, F025, F026,
F027, F028, F032, F034, F035, F037, F038, F039

K Codes

K001, K002, K003, K004, K005, K006, K007, K008, K009, K010,
KOI 1, K013, KOI4, K015, K016, K017, K018, K019, K020, K021,
K022, K023, K024, K025, K026, K027, K028, K029, K030, K031,
K032, K033, K034, K035, K036, K037, K038, K040, K042, K043,
K046, K048, K049, K050, K051, K052, K060, K061, K062, K069,
K071, K073, K083, K084, K085, K086, K087, K088, K093, K094,
K095, K096, K097, K099, K100, K101, K102, K103, K104, K105,
K106, Kill, K112, K113, K114, K115, K116, K117, K118, K136,
K141, K142, K143, K144, K145, K147, K149, K150, K151, K156,
K157, K158, K159, K161

P Codes

P010, P011, P012, P013, P015, P021, P022, P024, P028, P029, P030,
P036, P038, P047, P048, P056, P063, P065, P073, P074, P077, P092,
P095, P098, P099, P103, P104, P105, P106, PI 10, PI 13, PI 14, PI 15,
PI 19, P120, P121

U Codes

U002, U003, U006, U008, U012, U017, U019, U021, U030, U031,
U032, U037, U043, U044, U047, U048, U051, U052, U055, U056,
U057, U069, U070, U071, U072, U075, U076, U077, U078, U079,
U080, U083, U101, U102, U105, U106, U108, U112, U115, U117,
U120, U121, U122, U123, U127, U128, U130, U131, U133, U134,
U136, U140, U144, U145, U146, U147, U151, U154, U159, U161,
U165, U169, U170, U171, U181, U188, U190, U191, U196, U197,
U204, U205, U209, U210, U211, U213, U214, U215, U216, U217,
U218, U220, U221, U223, U225, U226, U227, U228, U235, U239,
U328, U353, U359, U404

6.	The facility must petition for approval to inject additional hazardous wastes not included
in Condition No. 5. The facility must also petition for approval to increase the
concentration of any waste, necessitating the recalculation of the limiting concentration
reduction factor and the extent of the waste plume. Petition reissuances and modifications
should be made according to 40 CFR §148.20 (e) or (f).

7.	Rubicon LLC Geismar Louisiana Facility shall annually submit to EPA the results of a
bottom hole pressure survey for WDW-6. These surveys shall be performed after shutting

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in each well for a sufficient period to allow the pressure in the injection interval to reach
equilibrium, per 40 CFR § 146.68(e)(1). The annual report should include a comparison
of reservoir parameters determined from the falloff test with parameters used in the
approved no migration petition. The information should consist of a comparison of the
current year's test results for the static and flowing bottomhole pressures with the values
demonstrated in the approved petition reissuance and a comparison of the test results for
transmissibility [Kh/|i (mD-ft/cP)] with the transmissibilities used in the approved
petition reissuance demonstration for the pressure build-up and 10,000-year plume
modeling.

8. Rubicon LLC Geismar Louisiana Facility shall also annually submit to the EPA a
radioactive tracer survey, an annulus pressure test, and a waste sample analysis for
WDW-6

9.	Rubicon LLC Geismar Louisiana Facility shall notify the EPA if WDW-6 loses
mechanical integrity before any well work on WDW-6 or Rubicon LLC Geismar
Louisiana Facility plans to plug WDW-6. If any well work or plugging is being planned,
Rubicon LLC Geismar Louisiana Facility shall also submit the procedures to EPA for
review before commencing any work.

10.	This exemption is subject to review upon the expiration, cancellation, reissuance, or
modification of the State of Louisiana Office on Conservation, Injection, and Mining
Division permit for WDW-6. A new demonstration may be required if information shows
that the basis of granting the exemption is no longer valid under 40 CFR §148.23 and §
148.24.

In addition to the above conditions, this proposed approval of an HWDIR petition request for an
exemption is contingent on the validity of the information submitted in the Rubicon LLC
Geismar Louisiana Facility HWDIR petition request for an exemption to the land disposal
restrictions. Any final decision is subject to termination when any of the conditions listed in 40
CFR § 148.24 occur, including noncompliance, misrepresentation of relevant facts, or a
determination that new information shows that the basis for approval is no longer valid.

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