United States District Court, D. Utah
MEMORANDUM DECISION AND ORDER
Waddoups, United States District Judge
the court are cross-motions for summary judgment filed by
Plaintiff Grand Canyon Trust (the Trust) and Defendants EFR
White Mesa LLC and Energy Fuels Resources (U.S.A.)
(collectively, the Mill). (Dkt. Nos. 67 & 60.) The
motions seek resolution of the five claims the Trust set
forth in its Amended Complaint, which seek declaratory and
injunctive relief as well as civil penalties for the
Mill's alleged violations of the EPA's radon emission
regulations. (Dkt. No. 29.) The court heard oral argument on
the motions on November 17, 2016. (Dkt. No. 89.) After
carefully considering the arguments presented in the briefing
and oral argument and reviewing the numerous exhibits and
declarations each party presented, the court now GRANTS the
Mill's motion, DISMISSES those claims with prejudice, and
DENIES the Trust's motion.
issue is whether the Mill complied with radon emission
regulations and, even if it did not, if the Trust's
enforcement action is proper under the Clean Air Act's
citizen-suit provision and Article III of the Constitution.
The following identifies the parties, provides an overview of
the relevant regulatory scheme, describes the conduct that
the Trust contends violated those regulations, and details
the purported effects those violations have had on Trust
Mesa Mill is a conventional uranium mill located six miles
south of Blanding, Utah near the Ute Mountain Ute tribal
community of White Mesa on the Colorado Plateau. (Dkt. No. 63
Ex. 14 EFR 457-58; Dkt. No. 68 Ex. 38 ¶ 6 & Ex. 40
¶¶ 1-2.) The Mill was first constructed in 1979 and
operations commenced there in 1980. (Dkt. No. 61 ¶ 5;
Dkt. No. 63 Ex. 14 EFR 459.) The Mill applies conventional
grinding and leaching processes to mined ore and byproduct
material in order to extract uranium and vanadium in the
forms of yellowcake and black flake, respectively. (Dkt. No.
61 ¶ 5; Dkt. No. 63 Ex. 11 EFR 306-07.) Production of
yellowcake and black flake results in a waste stream that
contains tailings solids and processing solutions. (Dkt. No.
61 ¶ 8; Dkt. No. 68 Ex. 5 & Ex. 12 pp.19-20.) That
waste then enters the tailings management system, which
separates liquid and solid waste. (Dkt. No. 61 ¶¶
6-10; Dkt. No. 63 Ex. 15 EFR 650.) Any liquids that may still
contain some ore-bearing solids are returned to the milling
process. (Dkt. No. 61 ¶¶ 6-10; Dkt. No. 63 Ex. 15
Mill was originally licensed under the Atomic Energy Act of
1954, as amended by the Uranium Mill Tailings Radiation
Control Act of 1978, by the Nuclear Regulatory Commission.
Energy Fuels Resources (USA) Inc., Utah Department
of Environmental Quality,
(last visited Sept. 15, 2017). In 2004, Utah became an
Agreement State, and oversight of the Mill transferred to the
Utah Division of Radiation Control that is now a part of the
Utah Division of Waste Management and Radiation Control
(UDWMRC). Id. The Mill also operates under a
Groundwater Discharge Permit, which UDWMRC oversees.
Id. The Mill's radon emissions are governed by
the Clean Air Act and regulations the Environmental
Protection Agency (EPA) set and that Utah's Department of
Air Quality (DAQ) administers. Id.
Grand Canyon Trust is a nonprofit advocacy organization with
over 3, 000 members. (Dkt. No. 68 Ex. 38 ¶ 2.) It is
based in Arizona with offices in Colorado and Utah.
(Id.) Its mission, according to its Executive
Director, William L. Hedden, is to “protect and restore
the Colorado Plateau, ” which “stretches
south-to-north from roughly the Mogollon Rim in northern
Arizona and the Uinta Mountains in northern Utah and
east-to-west from the Great Basin in Utah to the western side
of the Rocky Mountains in Colorado and northwestern New
Mexico” and encompasses the land upon which the Mill is
located. (Id. ¶ 3.)
Trust aims to protect the landscape, rivers, air, plant and
animal life, beauty, and solitude within the Colorado
Plateau. (Id.) The Trust opposes
“irresponsible uranium mining and milling on the
Plateau” and seeks to see contamination from uranium
mining removed and the area reclaimed. (Id. ¶
4.) As such, the Trust has worked to clean up abandoned
surface tailings piles on the former site of another mill;
campaigned to raise funds through legislation for cleanup
where reclamation bonds were insufficient; advocated an end
to uranium mining on the Plateau, including lobbying for
legislation that would permanently end the staking of new
claims around the Grand Canyon; developed a water quality
monitoring program; submitted comments on permitting
decisions for White Mesa Mill and other uranium operations on
the Plateau; lobbied for changes to uranium regulations; and
brought lawsuits aimed at protecting areas threatened by
pollution that can be linked to the uranium industry.
(Id. ¶¶ 4-6.)
Trust sued the Mill on April 2, 2014, to enforce violations
by the Mill of the Clean Air Act (CAA). (Dkt. No. 2 ¶
1.) The Trust contends that this action “seeks to
promote the same interests that underlie essentially all the
Trust's work, ” that is “to protect the
environment of the Colorado Plateau and the health of those
who live on or visit it.” (Dkt. No. 68 Ex. 38 ¶
enacted the CAA “to protect and enhance the quality of
the Nation's air resources so as to promote the public
health and welfare and the productive capacity of its
population.” 42 U.S.C. § 7401. In furtherance of
that goal, Congress identified a list of hazardous air
pollutants (HAPs), each of which is subject to the EPA's
review and revision. Id. § 7412. It listed
radionuclides, including radon, as HAPs. Id. §
7412(c). Congress also required the EPA to “promulgate
regulations establishing emission standards for . . . major
sources and area sources of hazardous air pollutants . . . in
accordance with” the CAA. Id. § 7412(d).
then promulgated the National Emission Standard for Hazardous
Air Pollutants (NESHAPs), which set emission limits for
listed HAPs according to category and subcategory of
potential polluters. See generally 40 C.F.R. §
61. Relevant to this case are the Subpart W NESHAPs, which
set out the “National Emission Standards for Radon
Emissions from Operating Mill Tailings” and which took
effect on December 15, 1989. See Subpart W-National
Emission Standards for Radon Emissions from Operating Mill
Tailings, 54 Fed. Reg. 51, 703 (December 15, 1989) (codified
at 40 C.F.R. § 61.250-256). Prior to December 1989,
Subpart W had previously been promulgated in 1986. Subpart
W-National Emission Standards for Radon Emissions from
Operating Mill Tailings, 51 Fed. Reg. 34, 056 (Sept. 24,
1986). And it was subsequently amended on March 21, 2017.
Revisions to National Emission Standards for Radon Emissions
from Operating Mill Tailings, 82 Fed. Reg. 5, 142 (Jan. 17,
W sets two standards-one for existing uranium mill tailings
piles and one that is triggered by newly built tailings
impoundments but that applies to all tailings impoundments
once it is triggered. 40 C.F.R. § 61.252. First, Subpart
W capped emission of radon-222 into the ambient air from
existing sources at 20 pCi/(m2-sec) (1.9 pCi/(ft2-sec).
Id. § 61.252(a). Compliance with this
limitation-the radon flux limit-is monitored according to
Method 115. Id. § 61.253. Method 115 requires
radon flux measurements to be taken from the following
regions of each tailings pile: (1) the water-saturated areas
or beaches; (2) the dry top-surface area; and (3) the sides,
unless they are made of dirt. 40 C.F.R. Pt. 61, Appx. B.
(“Method 115”) §§ 2.1.2 & 3. It
does not require measurement of “water covered
area[s].” Id. § 2.1.3.
such monitoring is conducted over a one-year period, the
facility must provide the EPA with a monitoring schedule
showing the “measurement frequency to be used.”
40 C.F.R. § 61.253. Measurements can be conducted once
per year or more frequently, so long as it is done on
“quarterly, monthly or weekly intervals.” Method
115 § 2.1.1. The schedule may be submitted before or
after the first measurement, and EPA must receive thirty
days' notice before any testing so that it may observe.
40 C.F.R. § 61.253. The test results, no matter how
frequently taken, must be reported to the EPA by March 31 of
the following year. Id. § 61.254. If the annual
report reveals that the facility is not in compliance with
the radon flux limit, the facility must make monthly reports
beginning the month immediately following the noncompliant
annual report. Id. § 61.254(b). And it must do
so until the EPA or state agency determines monthly reporting
is no longer necessary. Id. Such monthly reports
should include updated test results and plans to control or
modify operations to bring the facility into compliance.
Subpart W limits the total number of tailings impoundments
operated at a facility beginning from the time an impoundment
is newly built if it is constructed after 1989. Construction
of a new impound is not permitted unless it is designed,
constructed, and operated in compliance with the following:
does not exceed forty acres; meets the requirements of the
Nuclear Regulatory Commission set out in 40 CFR §
192.32(a); and does not cause the owner or operator to exceed
two total impoundments, including previously existing
impoundments, even those that were constructed prior to the
1989 version of Subpart W. Id. § 61.252(b). In
other words, once a new tailings impoundment is constructed,
all existing impoundments count toward the two cell limit, as
does the newly constructed impoundment. This is referred to
as the phased disposal work practice.
addition to delegating to the EPA the duties of maintaining
the list of HAPs and developing HAP regulations, Congress
also invited state involvement in HAP regulation. 42 U.S.C.
§ 7412(1)(1). Specifically, Congress authorized the
states to apply to the EPA for approval of a program to
implement and enforce emission standards. Id. State
programs “may provide for partial or complete
delegation of the Administrator's authorities and
responsibilities to implement and enforce emissions standards
and prevention requirements, ” so long as state
standards are no less than the EPA's. Id. The
CAA sets out criteria for approval of a state program and
allows for state revision if a program is not approved
initially. Id. § 7412(1)(5). The CAA also
provides for EPA oversight of state regulation, requiring the
Administrator to “withdraw approval of the
program” if “the Administrator determines, after
public hearing, that a State is not administering and
enforcing [its] program . . . in accordance with [EPA]
guidance . . . or the requirements of [the subsection]”
and if after notification the state fails to comply within
ninety days. Id. § 7412(1)(6). The statute
further says that “[n]othing in this subsection shall
prohibit the Administrator from enforcing any applicable
emission standard or requirement under this section.”
Id. § 7412(1)(7). In sum, the CAA invites state
involvement in HAP regulation, but it also vests significant
authority in the EPA to review state activity and to regulate
alongside the state where it sees fit.
satisfied all statutory and regulatory requirements for
delegation in 1995 and, effective May 15, 1995, the EPA
“delegate[d] its authority for the implementation and
enforcement of [many of the] . . . National Emission
Standards for Radionuclides for all sources located, or to be
located in the State of Utah, ” including Subpart W.
Approval of Delegation of Authority; National Emission
Standards for Hazardous Air Pollutants; Radionuclides; Utah,
60 Fed. Reg. 13, 912-13 (March 15, 1995). Thus, Subpart W was
administered in Utah by the EPA from 1989 until 1995 and then
by DAQ beginning in 1995. (Dkt. No. 64 ¶¶ 4-5.)
The Alleged Violations
Claim 2: Number of Tailings Impoundments
Mill operates as a zero-discharge facility, which means it is
required to dispose of waste, including tailings,
site as they are produced. (Dkt. No. 61 ¶¶ 10 &
12; Dkt. No. 63 Ex. 17 EFR 6369; Dkt. No. 68 Ex. 9 pp. 86-87
& 109-112.) To do so, the Mill operates a
tailings-management system for storing and disposing of waste
materials and liquids. (Dkt. 60 p. 15; Dkt. 60 Ex. 1; Dkt.
No. 68 Ex. 9 p. 45.) The tailings management system consists
of a series of evaporation ponds and tailings impoundments:
Cells 1, 2, 3, 4A, and 4B. (Dkt. No. 61 ¶ 6; Dkt. No. 63
Ex. 14 & Ex. 15; Dkt. No. 68 Ex. 9 p. 45.) A sixth basin,
Roberts Pond, was also on site until 2014. (Dkt. No. 61
¶ 28; Dkt. No. 68, Ex. 9 pp. 201-02, Ex. 10 EFR 21069,
Ex. 11 EFR 4562, & Ex. 2 p. 16');">12 p. 16.) Other than Roberts
Pond, each cell receives, or previously received, either
process solutions or a slurry containing tailings solids.
(Dkt. No. 61 ¶ 8; Dkt. No. 63 Ex. 14 EFR 459-62 &
Ex. 15 EFR 649-50.) The cells that receive the tailings
slurry hold the substance while the solids separate from the
liquid and settle at the bottom of the cell. (Dkt. No. 68 Ex.
9 p. 30.) The solids consist of a sand-like substance. (Dkt.
No. 68 Ex. 15 p. 7.) As the solids settle, they stabilize and
begin to fill the cell, allowing the Mill to install an
interim cover that prevents tailings from blowing out of
their impoundment and begins the reclamation process. (Dkt.
No. 61 ¶ 9; Dkt. No. 63 Ex. 15 EFR 650 & Ex. 17 EFR
6368-69.) Any excess liquid is then transferred to the
evaporation ponds. (Dkt. No. 68 Ex. 9 pp. 27-28.)
ponds hold the liquid, called raffinate or S/X (solvent
solution), either for evaporation as a method of disposal or
for temporary storage until the liquid can be further
processed for uranium and vanadium values. (Dkt. No. 61
¶¶ 8 & 10; Dkt. No. 68 Ex. 9 p. 32.) On
occasion, the evaporation ponds may become entirely dry,
revealing raffinate crystals at the bottom. (Dkt. No. 61
¶ 11; Dkt. No. 63 Ex. 14 EFR 459; Dkt. No. 68 Ex. 9 p.
50 & Ex. 16 pp. 147-148.) When this happens, the crystals
are removed and placed into the tailings impoundments. (Dkt.
No. 63 Ex. 14 EFR 459.) Raffinate crystals were removed from
Cell 4B in 2006 and disposed in Cell 3. (Id.)
Mill completed construction of Cell 1 in June 1981 and has
used it exclusively as an evaporation pond since that date.
(Dkt. No. 61 ¶ 14; Dkt. No. 63 Ex. 14 EFR 459.) Cell 1
receives raffinate solutions, process solutions from other
cells, liquids from the Mill's laboratory, and storm
water runoff. (Dkt. No. 61 ¶ 14.) Cell 1 has never
received tailings solids. (Dkt. No. 63 Ex. 14 EFR 467; Dkt.
No. 68 Ex. 12 pp. 17 & 22.)
Mill completed construction of Cell 2 in May 1980. (Dkt. No.
63 Ex. 14 EFR 459.) The parties do not dispute that Cell 2
received tailings solids from its construction and that it
was a tailings impoundment. (Dkt. No. 67 p. 37; Dkt. No. 76
p. 25.) Cell 2 received tailings solids until sometime after
the late 1980's but before 2008. (Dkt. No. 61 ¶ 15;
Dkt. No. 68 Ex. 16 pp. 164-66.) It stopped receiving tailings
when it was full to capacity pursuant to its Radioactive
Material License and Groundwater Discharge Permit. (Dkt. No.
61 ¶ 15; Dkt. No. 68 Ex. 9 pp. 83-84, Ex. 14 EFR 43535,
& Ex. 16 pp. 193-95.) Once Cell 2 was full and no longer
receiving tailings, the Mill began dewatering Cell 2
according to the final closure methods outlined in its
Reclamation Plan. (Dkt. No. 61 ¶ 16; Dkt. No. 68 Ex. 22
& Ex. 56.) The parties agree that some closure activity
has occurred, but they disagree on the legal issue of whether
Cell 2 has entered “final closure” as that term
is used in Subpart W. (Dkt. No. 67 pp. 60-64; Dkt. No. 76 pp.
Mill completed construction of Cell 3 in September 1982.
(Dkt. No. 61 ¶ 17; Dkt. No. 63 Ex. 14 EFR 459.) The
sides of Cell 3 are made of earthen material. (Dkt. No. 61
¶ 17; Dkt. No. 63 Ex. 14 EFR 464.) Since its
construction, Cell 3 has received tailings impoundments from
the tailings pipeline as well as process solutions from other
cells. (Dkt. No. 61 ¶ 17; Dkt. No. 63 Ex. 15 EFR 647,
650.) This began in the 1980s. (Dkt. No. 68 Ex. 14 EFR
43535.) The parties do not dispute that Cell 3 is a tailings
impoundment. (Dkt. No. 67 p. 36; Dkt. No. 76 p. 22.) In April
2016, the Mill reported that Cell 3 was almost full with
tailings but had a small area where new tailings were being
deposited. (Dkt. No. 61 ¶ 17; Dkt. No. 63 Ex. 15 EFR
Mill first proposed Cells 4A and 4B as a single eighty-acre
cell, but in anticipation of the adoption of the 1989
revisions to Subpart W, the Mill proposed splitting the cell
into two. (Dkt. No. 61 ¶ 18; Dkt. No. 63 Ex. 2 EFR 373;
Dkt. No. 68 Ex. 8 EFR 646-47.) The Mill then applied to the
Nuclear Regulatory Commission and the EPA for permission to
construct Cell 4A in 1989. (Dkt. No. 61 ¶ 18; Dkt. No.
63 Ex. 1.) The EPA approved the Mill's application under
the 1986 version of Subpart W on March 16, 1989. (Dkt. No. 61
¶ 19; Dkt. No. 63 Ex. 46.) The Approval Order for the
Mill was later updated on June 26, 1989, to authorize
construction of cells 4A and 4B. (Dkt. No. 61 ¶ 20; Dkt.
No. 63 Ex. 2.) Construction of Cell 4A was substantially
complete on November 30, 1989, and the NRC approved it to
receive process solutions on December 21, 1989. (Dkt. No. 61
¶ 21; Dkt. No. 63 Ex. 3 & Ex. 14 EFR 459.) The NRC
did not approve receipt of tailings at that time but then
amended the license to allow tailings on March 1, 1990. (Dkt.
No. 61 ¶ 21; Dkt. No. 63 Ex. 4.) Cell 4A received
process solutions in 1990. (Dkt. No. 61 ¶ 21; Dkt. No.
63 Ex. 14 EFR 459.) After 1990, Cell 4A was not used and the
liner suffered thermal stress as a result of direct sunlight.
(Dkt. No. 61 ¶ 22; Dkt. No. 63 Ex. 14 EFR 459.) This
drying caused raffinate crystals to form, which were removed
and disposed of in Cell 3 in the mid-2000s. (Dkt. No. 61
¶ 22; Dkt. No. 63 Ex. 14 EFR 459.) Cell 4A was relined
in 2007 and 2008 and, after DRC approved it for use on
September 17, 2008, began receiving tailings solids in
October 2008. (Dkt. No. 61 ¶ 22; Dkt. No. 68 Ex. 12 p.
23 & Ex. 16 p. 153.)
2008, the Mill applied for approval from DRC to construct
Cell 4B, which had originally been contemplated in 1989 but
was not constructed. (Dkt. No. 61 ¶ 23; Dkt. No. 63 Ex.
10 & Ex. 14 EFR 459-60.) Then on April 13, 2010, the Mill
applied for approval to construct Cell 4B from DAQ pursuant
to Subpart W; EPA also received a copy of the application.
(Dkt. No. 61 ¶ 24; Dkt. No. 63 Ex. 15.) The application
indicated that Cell 4B would not be used as a tailings
impoundment as long as Cells 3 and 4A were receiving tailings
solids and that it would instead be used as an evaporation
pond along with Cell 1. (Dkt. No. 61 ¶ 24; Dkt. No. 63
Ex. 15 EFR 649-50 & 653.) The Mill's application
assumed Cell 2 was in closure. (Dkt. No. 63 Ex. 15 EFR 653.)
DAQ approved the application, saying “our review
determined that these facilities will not cause emissions in
violation of the standard found in 40 C.F.R. 61.252, if
properly operated.” (Dkt. No. 61 ¶ 25; Dkt. No. 63
Ex. 16.) The Mill began construction of Cell 4B in November
2010. (Dkt. No. 68 Ex. 17 p. 6.) DRC granted the Mill final
approval to operate Cell 4B on January 31, 2011. (Dkt. No. 61
¶ 26; Dkt. No. 63 Ex. 18.) And in either January or
February of 2011, the Mill began moving processing solutions
from Cell 4A into Cell 4B. (Dkt. No. 68 Ex. 9 p. 26, Ex. 13
pp. 5-6, & Ex. 18 DEQ 52.) At the time the Trust filed
its motion for summary judgment, Energy Fuels continued to
operate Cell 4B as an evaporation pond. (Dkt. No. 68 Ex. 16
pp. 131-32 & 134.)
Pond is a one-acre retention basin that dates to the original
construction of the Mill in the early 1980's and that the
Mill took out of service in March of 2014 and backfilled and
regraded by early 2016. (Dkt. No. 61 ¶¶ 28 &
30; Dkt. No. 68 Ex. 9 pp. 193-94 & 197-98 & Ex. 12 p.
16.) Roberts Pond was used as a catch basin for process
upsets and overflows and to capture storm water runoff. (Dkt.
No. 61 ¶ 28; Dkt. No. 68 Ex. 9 pp. 193-95.) It is
undisputed that upon its closure, there were materials that
contained uranium in Roberts Pond, as evidenced by the
Mill's having returned such materials to the ore pad for
processing or deposited them into a tailings impoundment.
(Dkt. No. 61 ¶ 28; Dkt. No. 68 Ex. 9 pp. 201 &
204-06, Ex. 10 EFR 21069, & Ex. 19 EFR 23930.) The Mill
cleaned up Roberts Pond in July 2012 and again in 2014. (Dkt.
No. 68 Ex. 10 EFR 21069 & Ex. 11.)
it is undisputed that at the time of the briefing of the
instant motions, Cells 3 and 4A were serving as tailings
impoundments. It is also undisputed that Cells 1 and 4B were
at that time operating as a part of the tailings management
system as evaporation ponds and that evaporation ponds are a
necessary and approved part of its methods. (Dkt. No. 68 Ex.
9 85-87 & 90-92; Dkt. No. 77 Ex. 6 p. 6, 389.)
Claims 1, 3, 4, and 5: Radon Emissions Testing
tailings impoundments that existed before December 15, 1989,
are subject to monitoring requirements pursuant to Method 115
and the reporting requirements set out in Subpart W. 40
C.F.R. §§ 61.253-254; Method 115 §§
2.1.2-3. Although any “tailings pile” falls under
those reporting requirements, only testing of Cell 2 in 2012
and 2013 and Cell 3 in 2013 are now before the court.
4, 2012, the Mill notified DAQ and the EPA that it would
measure radon emissions from Cells 2 and 3 between June 11
and 15, 2012. (Dkt. No. 68 Ex. 23 EFR 35272.) The results of
those tests revealed that Cell 2 exceeded the regulatory
limit by emitting radon-222 at 23.1 pCi/(m2-sec), based on an
average of each of the tested areas. (Dkt. No. 68 Ex. 24 EFR
Mill then determined to conduct further testing during 2012.
(Dkt. No. 68 Ex. 16 pp. 49-52.) On August 3, 2012, it
notified DAQ and the EPA of this intention and that it would
retest Cell 2 in September and November or early December.
(Dkt. No. 68 Ex. 25 EFR 35274.) The September test again
exceeded the radon flux limit, this time measuring 26.6
pCi/(m2-sec). (Dkt. No. 68 Ex. 27 EFR 31861.) The Mill then
tested in October, which yielded still higher results of 27.7
pCi/(m2-sec), and November, which returned 26.1 pCi/(m2-sec).
(Dkt. No. 84 Ex. 1 p. 2.) Therefore, Cell 2 exceeded the
radon flux limit in 2012, averaging 25.9 pCi/(m2-sec). (Dkt.
No. 68 Ex. 26 GCT 8875.)
March 29, 2013, the Mill reported the 2012 radon flux results
for Cell 2 to DAQ. (Dkt. No. 62 ¶ 7; Dkt. No. 63 Ex.
21.) The report demonstrated an increase in radon flux and
included the Mill's proposed plan to bring the results
back under the standard by adding cover and engaging in
monthly sampling. (Dkt. No. 62 ¶ 7; Dkt. No. 68 Ex. 26
GCT 8875-83.) Pursuant to 40 C.F.R. § 61.254(b), the
Mill began monthly monitoring and reporting in April 2013.
(Dkt. No. 68 Ex. 26 GCT 8872 & 8883.)
Mill tested Cell 2 monthly in 2013 because of its 2012
violation. On April 3, 2014, the Mill reported that Cell 2
remained in violation of the radon flux limit and reported an
average of its radon-222 emissions between April and December
2013 of 20.4 pCi/(m2-sec). (Dkt. No. 68 Ex. 29 GCT 8226.) It
further reported that Cell 2 had reported emissions below
20.0 pCi/(m2-sec) since September 2013. (Id. GCT
8228.) It submitted a table of the monthly averages in its
annual compliance report, which showed that Cell 2's
radon-222 emissions were below 20.0 pCi/(m2-sec) for five of
the previous nine months and had not exceeded 20.0
pCi/(m2-sec) since August 2013. (Id. GCT 8237.) The
report attributed the high emissions levels to the dewatering
process mandated by its groundwater permit and identified
certain remediation measures it had already taken.
(Id. GCT 8234-35.)
remediate the Cell 2 radon flux violation, the Mill covered
“hot spots” where radon flux readings were
highest. (Dkt. No. 62 ¶ 8; Dkt. No. 63 Exs. 25-29.) It
also removed tailings that had blown from Cell 3 into Cell 2
and constructed a five-foot berm to reduce future windblown
tailings. (Dkt. No. 62 ¶ 8; Dkt. No. 63 Ex. 25 EFR
1000.) And the Mill covered large areas of Cell 2 with
additional cover to fortify the platform fill cover that was
already in place. (Dkt. No. 62 ¶¶ 8 & 14; Dkt.
No. 63 Ex. 40.) These efforts appear to have worked, as the
Mill reported below standard radon-222 levels in September
2013 and continuing until May 2014 when they submitted a
request to DAQ for permission to cease monthly monitoring.
(Dkt. No. 62 ¶¶ 10-11; Dkt. No. 84 Ex. 1.) DAQ
granted the Mill's request on July 23, 2014, and informed
the Mill that DAQ and DRC agreed that Cell 2 was closed and
therefore was not actually subject to Subpart W, but that it
would be required to conduct semiannual radon monitoring to
maintain its radiation permits. (Dkt. No. 62 ¶ 12; Dkt.
No. 63 Ex. 38.) While the Mill awaited DAQ's ...