DWQ-2024-003646

GROUND WATER QUALITY DISCHARGE PERMIT UGW570002
STATEMENT OF BASIS
Western Zirconium Plant Wastewater Evaporation Pond Area 10,000 West 900 South, Ogden, Utah 84404-9760
Introduction
The Division of Water Quality (DWQ) under the authority of the Utah Ground Water Quality Protection Rules (Ground Water Rules) issues ground water discharge permits to facilities which
have a potential to discharge contaminants to ground water. As defined by the Ground Water Rules, such facilities include mining operations. The Ground Water Rules are based on an anti-degradation
strategy for ground water protection as opposed to non-degradation; therefore, discharge of contaminants to ground water may be allowed provided that current and future beneficial uses
of the ground water are not impaired and the other requirements of Rule 317-6-6.4.A are met.Following this strategy, ground water is divided into classes based on its quality; and higher-quality
ground water is given greater protection due to the greater potential for beneficial uses.DWQ has developed permit conditions consistent with R317-6 and appropriate to the nature of
the mined materials, facility operations, maintenance, best available technology (BAT) and the hydrogeologic and climatic conditions of the site, to ensure that the operation would not
contaminate ground water.
Basis for Permit Renewal
This Permit is being renewed in accordance with R317-6-6.8 which states that a permit may be terminated, or a renewal denied if any one of the four items below applies:
Noncompliance by the permittee with any condition of the Permit where the permittee has failed to take appropriate action in a timely manner to remedy the Permit violation;
The permittee's failure in the application or during the Permit approval process to disclose fully all significant relevant facts at any time;
A determination that the permitted facility endangers human health or the environment and can only be regulated to acceptable levels by plan modification or termination; or
D. The permittee requests termination of the Permit.
Utah Admin. Code Rule 317-6
https://deq.utah.gov/ProgramsServices/programs/water/groundwater/docs/2008/08Aug/GWQP Permitlnfo.pdf 3 Utah Admin Code Rule 3 17-6-6. IA
Preamble to the Ground Water Quality Protection Regulations of the State of Utah, sec. 2.1, August, 1989
Utah Admin. Code Rule 317-6-3
Utah Admin. code Rule 317-6-4
Utah Admin. Code Rule 317-6-1(1.3)
Description of Facility
Western Zirconium is an operating unit of the Nuclear Fuels Business Unit of
Westinghouse Electric Company. The facility is located at the eastern base of Little Mountain, approximately 12 miles west of Ogden, Utah. The total Western Zirconium site encompasses
1,100 acres of land. Wastewater evaporation ponds cover approximately110 acres of the site. The Western Zirconium's wastewater evaporation ponds qualified as an existing facility under
the Utah Ground Water Protection Regulations, and a ground water discharge permit was not required until construction of new containment facilities in 2013.
Western Zirconium extracts zirconium and hafnium metals from raw materials, and then fabricates these metals into products used primarily by the nuclear fuels industry. The plant process
can be divided into three sections: l) Extraction, 2) Reduction/Melting, and 3) Fabrication.1.Extraction
The extraction portion of the process produces pure zirconium chloride from the starting raw material, zirconium oxychloride crystals. The first step is to dissolve zirconium oxychloride
crystals in water to produce a zirconyl chloride solution. At this point the zirconyl chloride solution contains approximately 10% hafnium, an element that is considered an impurity
in zirconium products. The hafnium content must be reduced to below 25 ppm in order for zirconium to be suitable for nuclear use. The zirconium and hafnium are separated in the second
step of the extraction process.
In the next step of the extraction process the zirconyl chloride solution, containing significant hafnium, is processed through a multi-stage liquid chemical separation process which
utilizes methyl iso-butyl ketone (MiBK), ammonia, nitric acid, and sulfuric acid to separate the zirconium and hafnium. The zirconium, which now exists as a sulfate, is fed into a rotary
kiln which produces a zirconium oxide powder which becomes the feed for the final extraction step, Chlorination.
In the chlorination step, zirconium oxide is combined with chlorine gas in a fluidized reactor at high temperature to produce zirconium tetrachloride, which becomes the starting raw
material feed for the Reduction/Melting portion of the Western Zirconium process.
Four aqueous waste streams are produced in the extraction process and are eventually sent to the evaporation/holding ponds. The first stream is produced in the separation step and contains
ammonia chloride, zirconium, hafnium, and methyl isobutyl ketone (MiBK). This stream is first sent to an elementary neutralization station where pH correction is made utilizing liquid
ammonia prior to entering the Plant Ammonia Drain (PAD) and eventual discharge into either Ammonia Chloride Pond #1 or #2 (Al, A2). The second stream is produced by the air pollution
control equipment scrubbing the off gas of the rotary kiln where zirconium sulfate is changed to zirconium oxide. This stream is a sodium sulfate solution that is discharged through
the Plant Upset Drain (PUD) to either Ammonia Chloride Pond #1 or #2 (Al, A2). The third and fourth aqueous waste streams are produced from the air pollution control equipment scrubbing
off gas from the chlorine fluidized reactors. The first of the scrubbers use water to remove zirconium particulate from the off gas and this stream is sent to an elementary neutralization
unit where the pH is adjusted using lime. This stream is then discharged through the Plant Calcium Drain (PCD) to evaporation/holding ponds Calcium Chloride #1 and #2 (C l , C2). The
second scrubbers use sodium hydroxide to remove residual chlorine from the off-gas stream. This aqueous sodium hypochlorite stream is discharged through the Plant Sulfate Drain (PSD)
to the Sodium Chloride Pond (S l).
Reduction/Melting
In the reduction process, zirconium tetrachloride powder from the separation process is placed in a vessel with magnesium metal. The vessel is then heated until the magnesium melts and
the zirconium powder convertinto a gas. A reaction then occurs where the chlorine is transferred from the zirconium to the magnesium producing zirconium metal and magnesium chloride
salt. This zirconium metal is then melted into ingots to serve as the raw material for the fabrication process.
Off gas from the reduction vessels is scrubbed with water to remove zirconium particulate. The effluent from the scrubbers is first sent to the lime elementary neutralization unit for
pH adjustment and then discharged through the PCD drain to evaporation/holding Ponds Cl and C2.
Fabrication
The fabrication process takes the zirconium ingots produced by the reduction/melting process and fabricates them into tubes, sheets, and wire for sale in the nuclear power generating
industry. Standard metal fabrication processes of forging, extrusion, rolling, and wire draw are utilized. Water quenching of heated zirconium as well as acid pickling utilizing nitric
and hydrofluoric acid is also performed. Aqueous waste streams from the quenching, pickling, and particulate scrubbers are sent to the lime elementary neutralization unit before being
discharged to ponds Cl and C2.
Additional Discharges

Additional materials, such as debris, soils and ground and surface water contaminated by Western Zirconium's process, and that have characterized through applicable investigations, may
be placed inside the subsurface barrier wall if authorized by DWQ and any other relevant regulatory agency.
Characteristics of Wastewater
All industrial wastewater at the plant is presently neutralized and transferred to one of the six operational ponds in the pond system. The operational pond system (shown in Figure 2
of the Evaporation Pond Area Ongoing Monitoring Plan) consists of two Ammonium Chloride Ponds (Al and A2), two Calcium Chloride Ponds (Cl and C2), one sodium Chloride Pond (S l), and
an emergency or upset pond (UI). Ponds Cl and C2 receive waste waters from the Chlorination, Reduction, and Fabrication processes. Ponds Al and A2 receive wastewater from the Separation
Department. Pond S1 receives wastewater from the Chlorination process caustic scrubber and blow down from the plant cooling towers. Pond UI presently does not receive any direct discharges.
However, liquid from the other evaporation ponds can be transferred to this pond if additional holding/evaporation space is needed. Wastewater may also be sent to other ponds as well.
Wastewater discharges from other manufacturing processes, equipment washdowns and cleaning operations are also sent to the wastewater ponds.
The average daily discharge to the ponds is 166,900 gallons per day (gpd). The largest amount of effluent comes from the Plant Calcium Drain (PCD) which discharges on average 127,072
gpd to ponds Cl and C2. The largest constituents of this effluent stream are calcium chloride salt, nitrate-nitrite, and fluoride. There are also trace amounts of zirconium and hafnium
metal, radionuclides, and some trace organics from the chlorination process. The Plant Ammonia Drain (PAD) discharges on average 28,942 gpd to ponds Al and A2. The largest constituents
of this effluent stream are ammonium chloride salt, zirconium and hafnium, and trace amounts of methyl iso-butyl ketone (MiBK). The Plant Sulfide Drain (PSD) discharges on average 9768
gpd to the S1 pond. The largest constituent of this effluent stream is sodium hypochlorite (bleach) from the caustic scrubbing of chlorine gas by the chlorination scrubbers. This drain
also receives blow down from the plant cooling towers.
The ponds were sampled from 2002 to 2004. The analytical data is summarized in DWQ's files. Only minor changes have occurred to the plant's process since that time, and pond constituents
should not have changed since that sampling. Note that effluent is transferred among ponds during the year to keep a constant level across the ponds to promote evaporation.
Description of Hydrogeology
The Western Zirconium site is located in western Weber County, in a salt flats area near the shore of the Great Salt Lake and at the eastern foot of Little Mountain, an isolated hill
composed of Precambrian bedrock. Little Mountain is almost certainly the surface expression of a Basin and Range fault block, and there are indications that a concealed fault occurs
in the subsurface along its eastern base, adjacent to the Western Zirconium site.
In a hydrogeologic sense, the site is part of the East Shore area of the Great Salt Lake. Like most areas along the Wasatch Front, ground water flow is controlled by geologic structure,
elevation differences between recharge and discharge areas, and stratigraphy of the thick valley-fill sediments that underlie the East Shore area. Ground water recharge takes place primarily
in areas of higher elevation in the Wasatch Mountains and particularly in the coarse-grained sediments that underlie the bench areas at the foot of the mountains. Low-lying areas to
the west of the mountain front are underlain by generally fine-grained lake sediments of low permeability. However, coarse-grained alluvial deposits were deposited underneath the lake
sediments, and they extend far to the west of the mountain front. These coarse-grained sedimentary layers are contiguous with, and at lower elevation than, the coarse-grained mountain
front deposits. As a result, they form confined aquifers in the East Shore area that are under artesian pressure because of the higher elevation of the recharge areas. In much of western
Weber County, two main confined aquifers are recognized, the Sunset Aquifer and the underlying Delta Aquifer. Near the Great Salt Lake, the aquifers are composed of thin alternating
layers of silt, clay, and sand, and are difficult to differentiate. (Clark, et. al., 1990)
The ground water affected by the facility is a shallow, unconfined aquifer contained in the fine-grained lake sediments immediately underlying the evaporation ponds. The sources of the
ground water in this aquifer are upward leakage from deeper confined aquifers, infiltration of precipitation and possibly recharge from Little Mountain. Ground water at the site occurs
at depths ranging from 0 to 20 feet below ground surface. Ground water from the shallow unconfined aquifer is not used due to its high dissolved solids concentration, poor quality and
low yield. (Western Zirconium RFI Phase I Report, 2003) Ground water elevations are higher on the western side of the site, near Little Mountain, possibly from enhanced upward flow from
deeper confined aquifers due to the concealed fault in the subsurface along the base of Little Mountain. Leakage from the evaporation ponds resulted in a ground water mound centered
on the ponds, which is documented in potentiometric contour maps contained in Western Zirconium's quarterly monitoring reports. Since construction of the subsurface barrier wall, the
mound has diminished.
Ground water movement in the fine-grained sediments of the shallow unconfined aquifer is very slow, as seen by the fact that significant contamination has not reached the "sentry" monitor
wells located approximately 700 to 1000 feet from the perimeter of the evaporation ponds after over thirty years of pond operation. However, because the water table is very shallow and
intersects the land surface at times, the shallow ground water can discharge to and become surface water in the salt flats environment east of the plant site. Partial erosion of the
sedimentary surface east of Little Mountain has produced knob-and-swale topography. The swales were former erosional channels that have been modified by construction of the wastewater
ponds, embankments, and other features at the plant site. These swales often hold surface water bodies, particularly during the colder part of the year. The main source of the surface
water is storm runoff and snowmelt, but water quality has been affected by upwelling shallow ground water and possibly by leaching from contaminated soils. Overland flow of contaminated
surface water is the dominant contaminant migration pathway to areas away from the ponds. (Western Zirconium Phase Il RFI Report, 2004). This contaminated surface water may also recharge
shallow ground water at locations far away from the ponds.
Because of the limited usefulness of shallow ground water at the site, the primary threat posed by Western Zirconium's wastewater evaporation ponds to waters of the state is the discharge
of contaminated surface water to the Great Salt Lake ecosystem.
Discharge Minimization Technology
The existing evaporation ponds were constructed in the late 1970s and early 1980s, under a Construction Permit issued on June 22, 1978, by the Bureau of Water Pollution Control. As such,
they are considered "existing facilities" under the Utah Ground Water
Protection Regulations, adopted in 1990. Initially, the first ponds had flexible membrane liners (FMLs) installed to line the ponds, but because of upwelling ground water under the site,
large bubbles or "whales" formed under the FMLs and the liners had to be removed. The existing ponds were constructed by building 12-foot-high dikes upon the existing ground surface
forming the ponds. The ponds are surrounded by a dike system that is mostly composed of silty sands and gravels, and with a gravel-surfaced road with little if any surface vegetation.
The dike crest ranges from a minimum width of about 12 feet to a maximum width of about 16 feet. The original pond drawings and specifications called for I to 2 feet of compacted impervious
silt to line the bottom of the ponds and to extend to form the body of the dikes. A 3-foot-wide cutoff trench constructed of the same material was to extend from the bottom of the dike
into the existing gumbo clays underlying the dike.
Since 1992, monitor wells located adjacent to the ponds have shown significantly elevated levels of ammonia, radium and other constituents found in the pond water. As a result of this,
on June 14, 1999, the Division of Water Quality issued a Notice of Violation and Order to Western Zirconium. The Order required Western Zirconium to conduct a Contaminant Investigation,
according to the provisions of UAC R317-6-6.15(D), and to repair the pond and liner to come into compliance with UCA 19-5-107(2) and the 1978 Construction Permit.
After investigation and consideration of alternatives, Western Zirconium proposed a subsurface barrier wall surrounding the evaporation ponds to minimize discharge to ground and surface
water. In combination with a low-permeability clay layer underneath the ponds, this wall should significantly cut off subsurface flow of wastewater from the ponds. Existing contamination

outside the wall should decrease by natural attenuation over time. This subsurface barrier is classified as a new facility under the Ground Water Protection Regulations, and this ground
water discharge permit was first issued to construct and operate it. DWQ issued a Construction Permit for the subsurface barrier on May 1 8, 2012. Construction of the barrier began in
October 2012 after Western Zirconium received approval from the Army Corps of Engineers to fill wetlands in the project area.
The composite subsurface barrier wall was constructed to have hydraulic conductivity of 1 x 10-7 cm/sec or less, and it surrounds the evaporation ponds to cut off horizontal flow of
wastewater that could impact shallow ground water and surface water. Western Zirconium's site investigations documented the presence of low-permeability clay layers underneath the pond
site. (WZ Phase I RFI Report, Sec. 6, Figures 6-1 and 6-2, 2003; WZ Phase Il RFI Report, Sec. 2, Figures 2-2 through 2-3, 2004) This low-permeable layer inhibits vertical subsurface
flow from the evaporation ponds.
New structures constructed as part of this wastewater containment system include a 10,800 foot long, 40-foot-wide work pad, the composite subsurface barrier wall, a new dike system and
access road surrounding the evaporation ponds. There is sufficient volume in the space between the new dike and existing pond dikes to provide for secondary containment in the event
of a pond dike breach.
Soil improvement was done under the work pad to provide seismic foundation support for the new exterior dike and wall that are underlain by liquefiable soils. The soil improvement consisted
of shallow soil-cement mixing where a Portland Cement grout was injected underneath the working pad and mixed with the native soils to a depth of approximately 3 to 5 feet.
Following installation of the work pad, the composite barrier wall was installed using slurry trench technology. A 3-foot-wide slurry trench was excavated through the work pad and underlying
soils. The trench was kept full of slurry during the entire excavation operation to maintain trench stability. The slurry trench was extended through a minimum of 10 feet to low-permeability
soils that underlie the pond area. The trench bottom ranged from an elevation of 4180 to 4200 feet above mean sea level (msl), corresponding to a depth of between 15 and 40 feet below
the then-existing ground surface, averaging 25 feet.
Excavated soils were placed on the work pad and mixed with the slurry and sepiolite clay to produce a low permeability backfill. The backfill was placed back into the trench in a controlled
fashion to displace the slurry and produce a continuous barrier around the evaporation ponds. Following backfill placement, interlocking high density polyethylene (HDPE) sheet piles
were inserted through the soil-sepiolite backfill. The HDPE sheeting extends above the former work pad surface is incorporated into the new dike section, providing containment of any
seepage or ponded water to elevation 4219 feet above msl. This composite barrier wall construction has been shown to meet long-term permeability requirements when subjected to the contaminated
pond water.
Following barrier wall installation, a new dike was constructed along the alignment to elevation 4220 feet above msl, providing 1 foot of freeboard above the elevation 4219 barrier wall.
The average height of the dike is about 5 feet above ground surface, and a 10-foot-wide access road was constructed along its exterior. The interior side of the dike consists of select
low-permeability core material placed and compacted against the HDPE sheet pile to protect above-grade portions of the sheet pile and maintain composite construction similar to that
installed in the slurry trench. The exterior of the dike consists of compacted granular soils with erosion protection rock on the inboard (pond) side. The dike provides 48 acre-feet
of spill containment in the event of a breach of a pond dike, meeting state Dam Safety regulations.
Surface water that has been affected by surfacing shallow ground water flows northward from the evaporation pond site in two swales that are impounded against a railroad grade to form
surface water bodies, designated SWB-3, and SWB-9. To prevent contaminated surface water from flowing off the property, Western Zirconium constructed earthen berms adjacent to the culverts
that run beneath the railroad grade. Contaminated ground water can potentially flow under the railroad grade, but at a much slower rate than surface water flow.
Basis for Permit Issuance
Ground water contamination has already occurred at this site and the permitted facilities are intended to cut off the source of the contamination. Compliance with permit conditions will
be demonstrated through monitored natural attenuation in the site's ground water, and no contamination in surface water off of Western Zirconium's property boundary that poses a risk
to the Great Salt Lake ecosystem. The compliance monitoring plan has been revised to reflect the findings of the 2022 Evaporation Pond Area Ongoing Monitoring Plan Review. Revisions
to the planare contained in the document "Evaporation Pond Area Ongoing Monitoring Plan", dated January 2023. Both documents are attached as Appendix A to the permit.
After completion of the barrier wall, if discharge of wastewater from the evaporation ponds to the subsurface has been effectively cut off, several changes should be observed in the
ground water surrounding the ponds. The existing ground water mound should dissipate, and ground water elevations outside the barrier wall should drop compared to ground water elevations
within the area enclosed by the wall. Contaminant concentrations within the existing plume of contaminated ground water should decrease. It may still be possible that the plume boundary
could expand outward, but by itself, that would not demonstrate that the contaminant source has not been cut off. Also, because of the very low permeability of the sediments surrounding
the evaporation ponds, any changes caused by the cutoff wall may happen very slowly. Review of quarterly monitoring data collected following the completion of the barrier wall in 2013
to fourth quarter 2021 indicate that the above-named changes are occurring as predicted.
This permit is founded on the concept that Western Zirconium has constructed a barrier wall that effectively isolates the evaporation ponds from the surrounding ground and surface water.
To demonstrate that the barrier wall is functioning as designed, it will be necessary to review different types of monitoring data from many different points and get an idea of site-wide
conditions. Because of this, permit compliance will not be tied to numeric levels of contaminant concentrations or ground water elevations, but rather on a review of all relevant data
needed to demonstrate barrier wall effectiveness.
Western Zirconium has constructed "sentry" monitor wells in uncontaminated ground water immediately outside of the plume of contaminated ground water. Previous ground water protection
levels were determined for these wells based on historic monitoring data but have been revised to reflect post barrier wall conditions. Other monitoring wells ("plume wells") were constructed
within the plume. Screening levels were determined for these wells using a single monitoring event post barrier wall from these wells. All monitoring well data will now be compared to
the standard groundwater protection levels developed as a result of the 2022 Evaporation Pond Area Ongoing Monitoring Plan review. Data obtained for sentry wells is used to detect contaminant
plume migration and plume well data is primarily used to track the attenuation of the groundwater plume contaminant concentrations.
Under anticipated conditions after the source of ground water contamination has been cut off, contaminated ground water may still migrate to the sites of the sentry wells and affect
the water chemistry observed in them. Therefore, if monitoring reveals that contaminated water from the wastewater ponds has influenced one of these wells for longer than four consecutive
monitoring events, Western Zirconium shall enter into discussion with DWQ as to whether the contaminant plume has reached the sentry well in question. If this has happened, DWQ will
require Western Zirconium to locate and construct a new sentry monitoring well in uncontaminated ground water as close as practical to the contaminated sentry well. This will monitor
any expansion of the contaminated ground water plume, and the old sentry well will continue to be monitored as a plume well. Contamination of a sentry well will not be considered noncompliance
with permit conditions, as long as the well is replaced in a timely fashion.
The following sources of information shall be monitored under this permit, and taken into consideration to determine whether Western Zirconium 's subsurface barrier wall is performing
in such a way as to minimize further releases of process water from the evaporation ponds:
Ground water elevation data from paired piezometers on either side of the subsurface barrier should continue to show significantly higher ground water static levels inside the area enclosed
by the barrier wall as compared to the levels outside the barrier. Ground water elevations within the existing ground water mound outside the barrier should continue to become lower
over time.

Levels of contaminant concentrations in plume monitor wells should continue to decrease over time in general, although levels in some wells may increase temporarily due to migration
of existing contaminated ground water.
Monitored surface water bodies, particularly those north of the evaporation ponds, should show results that are consistent with the source of contaminants being cut off by the subsurface
barrier. Existing contaminated surface water bodies on Western Zirconium's property should show a decrease in levels of contaminants associated with the wastewater.
Monitoring of sentry wells shows no significant increase in the areal extent of the existing plume of contaminated ground water.
The 2008 Ecological Risk Assessment identified concentrations of several parameters in surface water that would pose minimal risk for the ecology of the mud flats area where the evaporation
ponds are located. These parameters include ammonia, total cyanide, total barium, dissolved cadmium, dissolved selenium, dissolved uranium, total zirconium, nitrate + nitrate, radium
226 + 228, total dissolved solids and pH. The first version of this permit tied ground water protection levels to these concentrations, under the assumption that shallow ground water
would recharge surface water in the mudflats area under the prevailing upward hydraulic gradient. However, not all of these parameters are present in high concentrations in Western Zirconium's
wastewater, and not all of them are conservative tracers that would be the best indicators of wastewater migrating in the subsurface. Barium, one of these compliance parameters, exceeded
its protection level in sentry well S5 starting in the third quarter of 2014. Subsequent investigation [l] revealed that barium is not particularly concentrated in Western Zirconium's
wastewater, and the observed changes in its concentration were due to changes in the ground water flow system. Protection level exceedances for some other compounds related to ecological
risk may not be related to leakage of wastewater or contaminant plume expansion and may be difficult to investigate and explain. In this permit version, compliance parameters will be
used that would be directly related to plume expansion and would not be retarded in their movement in ground water by interaction with the aquifer matrix. These parameters are at high
concentrations in the wastewater or at low or undetectable concentrations in the uncontaminated ground water and would serve as best possible indicators of plume expansion. Compliance
parameters are ammonia, fluoride, nitrate + nitrite, total cyanide, thiocyanate as SCN, radium 226 + 228, and field pH. Monitoring for the Contaminants of Ecological Concern (COEC) parameters
of total barium, dissolved cadmium, dissolved selenium, dissolved uranium, and total zirconium will be done annually, but these parameters will be monitored for informational purposes
only and will not be used to evaluate permit compliance. Total dissolved solids and field eH will be monitored semi-annually, for informational purposes.
To evaluate effectiveness of the subsurface barrier wall and natural attenuation of the existing ground and surface water contamination, monitoring required in the first permit term
included quarterly sampling of sentry monitor wells, semi-annual sampling of surface water sampling points, annual sampling of plume monitor wells and quarterly collection of ground
water elevation data from the monitor wells and also from piezometers associated with the barrier wall.The second permit term included quarterly sampling of sentry wells, opportunistic
sampling of surface water when water is present, annual sampling of plume monitoring wells, quarterly sampling of the newly installed plume wells surrounding the barrier wall for ammonia
as N only, and quarterly collection of groundwater elevation data from all monitoring wells and piezometers identified for the Evaporation Pond Area.
Monitoring Results for First Term Compared to Second Term
Ground water elevation measurements in the paired piezometers on either side of the subsurface barrier wall have shown consistently higher static ground water levels within the area
enclosed by the barrier wall, except on the western side where ground water coming from the higher elevations of Little Mountain impinges on the barrier.[Paired Piezometer Data Compilation]
These measurements are consistent with containment of wastewater provided by the combination of the subsurface barrier wall and the low permeability clay layer underlying the wastewater
evaporation ponds.
Contaminant levels in plume wells have not risen significantly since 2013. [Permit Table 2] This is consistent with no significant additional release of contaminants to ground water.Overall,
contaminant levels in sentry wells remained below their protection levels. [Sentry Well Data Compilation] Sentrywell S-5 was out of compliance for barium, as described above. Sentry
well S-12 had four quarters out of compliance for ammonia as of the first quarter, 2018. Subsequent investigation [2] revealed that the increased concentration of ammonia within the
area of S-12 is strongly influenced by regional drought patterns and natural hydrologic factors rather than the expansion of the ammonia groundwater plume. Similar exceedances have been
observed in sentry well S-9, located southwest of S-12 as of 1st quarter 2019. These ammonia exceedances at S-9 are likely also due to regional drought patterns and hydrologic factors,
similar to ammonia concentrations observed at S-12.No sentry wells have been replaced according to permit conditions since the permit was first issued in 2013. In general, monitoring
of sentry wells is consistent with no significant increase in the area of the plume of contaminated ground water.
Surface water sampling in the six water bodies sampled since the permit was issued in 2013, all within approximately 1000 feet of the area enclosed within the subsurface barrier wall,
reveals that long-term surface water cleanup goals have not been achieved permanently in all of the water bodies. [Surface Water Data Compilation] These results are difficult to interpret,
however, and considering the other measures of containment structure performance described above, this may not be indicative of excessive, continuing discharge of wastewater into the
shallow ground water. The presence of wastewater contaminants in surface water may represent continued upwelling of ground water that was affected by wastewater discharges before construction
of the barrier wall, or stormwater runoff that was affected by solid waste management units at the plant site that have not been cleaned up yet. In many cases, also, any hydraulic connection
between the monitored surface water bodies and ground water previously contaminated by pond seepage is not obvious.
The ground surface in the area of the wastewater ponds slopes generally to the north. Surface water that was potentially affected by contaminated ground water or stormwater runoff ponds
against a railroad grade north of the plant site, in two drainages, monitored as SWB-3 (the stormwater pond) and SWB-9. Culverts exist under the railroad grade for these two drainages,
and Western Zirconium has installed rock-faced earthen berms to limit surface water flow and protect the culverts. Subsequent investigation [3] revealed contaminant concentrations found
in SWB-3 and SWB-9 located on site, south of the railroad grade were higher that concentrations found in SWB-10 and SWB-11, north of the railroad grade and outside Western Zirconium’s
property boundary. The concentration differences concluded that the rock-faced earthen berms installed to limit surface water flow off site are effective.
Two changes will be made in the permit monitoring requirements for surface water in order to better evaluate any impacts on surface water from pond wastewater:
Monitoring parameters will be changed to include fluoride and thiocyanate as SCN, the same as for well sampling, in order to detect any traces of lagoon wastewater.
Sampling frequency for surface water sites will be changed to opportunistically when water is present during a scheduled monitoring event.
In addition, Western Zirconium will take the following actions to minimize potential discharge of contaminants to surface water:
RCRA cleanup actions of historically contaminated areas on the plant site, overseen by the Division of Waste Management and Radiation Control, will be completed according to a schedule
agreed with the Division of WasteManagement and Radiation Control (DWMRC). This will minimize the potential for the formation of contaminated stormwater from contact of precipitation
with contaminated soils or other media. RCRA cleanup materials may be placed within the pond complex after characterization and approval by DWMRC and DWQ.
Monitoring Plan for the Revised Permit
Changes to the permit monitoring requirements for groundwater will be made to continue to track attenuation of the contaminant plume while eliminating redundancy, potential off-site
sources, and represent current site conditions following the installation of the barrier wall.Several different types of monitoring points will be used to determine compliance with permit
conditions:
Currently there are eight sentry monitoring wells located around the downgradient periphery of the site immediately outside the current extent of the plume of contaminated ground water.
During the second term permit, access restrictions and potential off-site influences were determined for sentry well S-11, located off-site, north of the Western Zirconium boundary.
Starting with this permit term, sentry well S-11 will no longer be monitored and will be decommissioned in accordance with Utah Annotated Code (UAC) R655-4-11.4. The remaining seven

wells will be sampled semi-annually for compliance parameters, TDS and field eH. Analytical results for nitrate-nitrite, total cyanide, fluoride, radium 226+228, total barium, dissolved
cadmium, dissolved selenium, and dissolved uraniumwill be compared to the standardized groundwater compliance levels based on Utah Division of Environmental Quality (UDEQ)groundwater
standards.Analytical results for total zirconium will be compared to the previously determined protection level as part of the Ecological Risk Assessment (ERA, 2008). Analytical results
for thiocyanate as SCN and ammonia as N will be compared to the calculated values of the mean concentration plus two times the standard deviation determined using the mean values for
all sentry well data post-barrier wall (excluding S-11).If analytical values exceed the standard permit compliance levels for four consecutive monitoringevents, Western Zirconium shall
conduct an evaluation, and if plume expansion is determined, shall install a new monitoring well close to the site of the contaminated well and immediately outside the plume of contaminated
ground water, as a means to track expansion of the plume. Sentry wells will be monitored annually forCOEC parameters used for informational purposes.
Plume monitoring wells are located within the plume of contaminated ground water originating from the ponds. These wells will be sampled annually for compliance parameters, COEC parameters,
TDS and field eH. The purpose of monitoring these wells is to track the natural attenuation of the plume. It is expected that following barrier wall construction and cutoff of subsurface
discharge from the ponds, contaminant concentrations in these wells will generally not increase and should continue to show a slow decrease over time, due to the low permeability of
the site's soils. Analytical results from this monitoring will be compared to the standardprotection levels. . This comparison is to evaluate dissipation of the contaminant plume and
not for permit compliance.
Surface water bodies SWB-3, SWB-7, SWB-8, SWB-9, SWB-10, AND SWB-11, defined in the Evaporation Pond Area Ongoing Monitoring Plan dated January 2023, will be monitored opportunistically
on a semi-annual basis, when water is present, for the both compliance parameters and COEC parameters. Monitoring results for ammonia, total barium, dissolved cadmium, and dissolved
selenium will be compared to the Ecological Risk-Based Cleanup Goals for the Mud Flat Area as determined in Western Zirconium'sJanuary 2008 Ecological Risk Assessment (ERA). Monitoring
results for totalcyanide will be compared to the ERA cleanup goal for free cyanide. Monitoring results for nitrate + nitrite will be compared to the water quality standard of 10 mg/l.
When sufficient data has been collected to define background concentrations of fluoride and thiocyanate as SCN are determined (eight samples), future monitoring results will be compared
to the mean plus twice the standard deviation of the data. It is not expected that these cleanup goals will be met immediately in all monitored surface water bodies, but cutoff of the
source of contaminated ground water that affects surface water quality should result in a decrease in contaminant concentrations in surface water over time Meeting the cleanup goals
in all surface water bodies outside of the subsurface barrier wall and dike is the long-term goal of this remedial action and would define successful containment of Western Zirconium
's wastewater. Accordingly, this monitoring will be for informational purposes and will not be tied to permit compliance, but rather, evaluated along with the other types of monitoring
date to determine whether the wastewater is being contained successfully.
Ground water elevations will be measured semi-annually in all monitor wells and piezometers. Twelve pairs of piezometers will be installed at equal distances around the barrier wall,
with one of the pair inside the wall and the other piezometer immediately outside the wall. Five existing nested piezometers will continue to be monitored to measure vertical hydraulic
gradient. If the subsurface barrier wall is successfully containing the evaporation pond wastewater, ground water elevations measured in the monitor wells should show dissipation of
the existing ground water mound over time; the paired piezometers around the barrier wall should show significantly higher ground water elevations inside the area enclosed by the barrier
wall compared to outside the wall; and the nested piezometers should show an upward vertical hydraulic gradient which would help to contain the contaminated ground water within the barrier
wall.
REFERENCES
Evaporation Pond Area Ongoing Monitoring Plan, Western Zirconium, August, 2018 DWQ-2018-009212
Quarterly Monitoring Reports, Western Zirconium, First through Fourth Quarters, 2002; First through Fourth Quarters 2003; Third Quarter 2004; Third Quarter 201 DWQ files
Clark, D.W., Appel, C.L., Lambert, P.M., and Puryear, R.L., 1990, Groundwater
Resources and Simulated Effects of Withdrawals in the East Shore Area of Great Salt Lake, Utah, Technical Publication No. 93, State of Utah Department of Natural Resources
Phase I RCRA Facility Investigation Report for Pond Solid Waste Management Units and Area of Concern Lowlands East of the Plant, Western Zirconium, February 2003, DWQ files
Phase Il RCRA Facility Investigation Report for Pond Solid Waste Management Units and Area of Concern Lowlands East of the Plant, Western Zirconium, August 2004, DWQ files
Ecological Risk Assessment, Western Zirconium, January 2008, DWQ-2008-010070
Paired Piezometer Data Compilation, DWQ-2018-005728 (Revised to include 2013-2022 data)
Sentry Well Data Compilation, DWQ-2018-005727 (Revised to include 2013-2022 data)
Surface Water Data Compilation, June 2018, DWQ-2018-007950 (Revised to include 2013-2022 data)
Technical Memorandum on Sentry Well Barium Concentrations, January 23, 2018,
DWQ-2018-009873
Ammonia Evaluation S-12 Area Report, January 2019
Western Zirconium North Area Barrier Evaluation, November 2019
Western Zirconium Evaporation Pond Area Ongoing Monitoring Plan Review (June 2022)