DWQ-2024-008089

STATEMENTOF BASIS
GroundWaterDischargePermitRenewal and Modification Permit UGW210010
New Castle Biogas, LLC
Holt Dairy
BarVHolding,LLC
PO Box 130
Enterprise,Utah84725
December XX, 2024
Purpose
Ground Water Discharge Permit UGW210010 for Holt Dairy, LLC was renewed for another 5-year term on September 16, 2019.The permit is now being modified to cover construction and operation
of a new covered lagoon Digester and a new revised storage lagoon.In the future, three additional staging lagoons may also be constructed. Monitoring during the previous permit term
has shown that the uppermost ground water underlying the siteisstillprotectedfromcontaminantsintroducedatthelandsurfacebyconfininglayersand an upward hydraulic gradient.In addition,
the dairy facility and waste handling systems were constructed to minimize discharge of contaminants to the subsurface.
FacilityDescription
Holt Dairy operates a 6000 cow dairy located approximately 1.5 miles west of New Castle, Utah.The facility is located in the southwest quarter of Section 18, Township 36 South, Range
15 West, SLBM.The facility includes:SixFreestallBarnsandExerciseCorrals,FlushLanes,andconnectingCross Alleys;FiveShadeBarnswithoutExercise Corrals;OneCorral fordry cows;TwoSickPens;One80cowCarouselParlorwithMilkingEquipment;One86cowCarouselParlorwithMilkingEquipment;OneHospitalParlorwithMilkingEquipment;OneCalvingBarn;TwoSandLanes;OneBiolinkFlushWater
System;OneReceptionPitandDuplexPumpSystem;Compostingand Mixing Areas;Asitegradedcompletewateranddrainagesystemforalloftheaboveitems; andThreeAnaerobicLagoonswith60-milHDPE LinerSystems.ASedimentationSettling
CellAPondSump/PumpSystem
ConstructionwasdoneaccordingtotheconditionsofaconstructionpermitissuedbytheDivision of Water Quality on September 16, 2009. A construction permit was also issued for approved additions.
The permit is being modified to accommodate a planned new flush manure covered lagoon Digester(Digester) to be constructed within the existing dairy footprint. Also, the permit is being
modified to redo and expand the current storage lagoons (95 and 16 acre-feet). The Digester lagoon will be lined on the bottom with an HDPE liner and also have an HDPE cover. The current
lagoons (95 and 16 acre-feet) have a footprint of approximately 1250 feet by 425 feet.The new Digester and storage lagoons will fit in a footprint of approximately 1400 ft by 500 feet
in the same location. The new Digester lagoon,large storage lagoon and small storage lagoon will have an estimated volume of approximately 300 acre-feet of storage. The new Digester
and large storage lagoon will be built above ground level by up to 16 feet. The depth of the Digester may be about 70 feet below grade. The depth of the new revised storage lagoons
may also be increased.
The Digester will accept thinned manure slurry after sand lanes and separation equipment, originating from the dairy’s flush lanes. The Digester, through an anaerobic process, will process
the suspended and volatile solids within the manure slurry into natural gas. The natural gas will either be sent to a generator for electrical production, a flare to receive emissions
reduction credits, or be processed and injected into a local utility pipeline. The effluent will be returned to the revised storage lagoon and the existing storage lagoon. Prior to
construction a complete set of stamped engineering plans and specifications will need to submitted to the Division of Water Quality (DWQ) and a Construction Permit will be issued.
Finalized and stamped engineered drawings will be sent to Iron County and the Utah Department of Natural Resources Division of Water Rights (“DWR”). Permittee is currently seeking a
conditional use permit from Iron County, and also a Dam Safety Permit from DWR. 
The Digester will accept thinned manure slurry after sand lanes and separation equipment, originating from the dairy’s flush lanes. The Digester, through an anaerobic process, will process
the suspended and volatile solids within the manure slurry into natural gas. The natural gas will either be sent to a generator for electrical production, a flare to receive emissions
reduction credits, or be processed and injected into a local utility pipeline. The effluent will be returned to the other storage lagoons.Prior to construction a complete set of stamped
engineering plans and specifications will need to submitted to the Division of Water Quality (DWQ) and a Construction Permit will be issued.The design is subject to change and has not
been finalized.
The milking parlors utilizes an estimated 600,000 gallons of water daily.The water is usedtopre-coolmilk,coolingofmilkingequipment,forcowcleaningand forcleaningof equipment and facilities.The
water is collected from the barn and is sent to a solids separator where the solids will be separated and the liquids are installed in the lagoon.
Water used for cooling is recycled by collecting the warmed water in storage until it is used for cleaning of the parlor and cows.Water used for cleaning contains milk residues and manure
as well as a small quantity of detergents and small amounts of disinfectants including iodine.
Wastewater that is collected from the milking parlor is piped to the solid separator.This equipment includes a series of gravity solid separating cells and a bio-link mechanical separator
system.These facilities separate 50% of the solids from the liquid stream.
The freestalls are bedded with sand or composted manure and they are cleaned by flushingthreetimes aday.The water from thefreestall flush is conveyed overaconcrete sand alley to remove
as much of the sand as possible, the remaining effluent is run through the separator.Solids are composted at the site to be land applied at the appropriate time.The flush lanes are flushed
with water taken from approximately6 feet below the surface of the process tank of the Biolink separation system that has been used during the current days’ wastewater production, for
odor reduction by using cleaner and aerobic water for flushing.
Theexerciselotandcloseuplotarelinedwithcompactednativesoilandgradedsuchthat the runoff from the lots are collected and directed to the Biolink separator via thedrainagesystem.Themanureandbeddingdepositedintheexercisepens,
closeuplotand calving barn are piled and hauled to the composting area as needed.
All the wastewater and runoff water flow through the gravity and mechanical separators, and then to the Digester lagoon (#1), which will overflow into the large storage lagoon (#2).
Runoff water that exceeds the system’s capacity will overflow to the smaller storage lagoon (#3).
The liquids are stored in four anaerobic lagoons, lined with a 60-mil high-density polyethylene (HDPE) flexible membrane liner installed on top of a compacted soil base. Digester Lagoon
(#1), large Storage Lagoon #2, and small overflow Storage Lagoon #3 will be built within the dimensions noted above, with final plans sent to DWQ and DWR. Storage Lagoon #4 is west of
the dairy, with a capacity of 200 acre-feet. During normal operation all the effluent is conveyed from the Biolink to Digester Lagoon #1 to allow for settling and eventual removal of
solids.Large Storage Lagoon #2 is used for evaporationandstorageofwastewaterpriortolandapplicationand will be built within the dimensions noted above.A transfer pipe at the normal high
water level conveys water from DigesterLagoon #1 to Storage Lagoon #2.During normal operation, only overflow from DigesterLagoon #1 and runoff from the site overflow directly to large
Storage Lagoon #2.In an abnormal event such as a large storm or power outage, effluent will be directed directlyto small overflow Storage Lagoon #3 from the reception pit.Operating depth
of the lagoons is expected to include two feet of freeboard.Lagoon #4, west of the dairy, is used for excess and winter storage, to dilute the wastewater, and for land application to
crops.
The lagoons are sized based on 600,000 gallons per day of milking parlor process water, storage for the winter season when the effluent cannot be land-applied, and runoff from the100-year,
24-hourstorm event.Duringthegrowingseason theliquids aremixed with clean water and applied to crops.A portion of the solids are composted and some of the compost may be exported to neighboring

farms.Composted and non-composted solids are land applied to crop land leased by Holt Farms, LLC DBA Holt Dairy with manure spreading equipment.
Hydrogeology
The facilities are located in Escalante Valley approximately two miles west of the point where Pinto Creek emerges from the mountain front.Sites where surface streams flow across coarse-grained
deposits along mountain fronts are often important sources of recharge for aquifers in the alluvial valley deposits.Information obtained after drilling and installing four ground water
monitoring wells revealed that materials under the site are predominantly silt and clay, with some minor lenses of sand and gravel.
While drilling the borings for the monitoring wells, uppermost ground water was encountered at approximately 250 feet below ground surface.After the wells were installed, static water
levels in the wells were measured at 175 to 185 feet below ground surface (bgs).More recent measurements indicate the static water levels is 200 feet below ground surface (bgs). This
indicates that the uppermost aquifer is under confined conditions and may be protected from contaminants introduced near the ground surface by nearly 300 feet of mostly fine-grained
sediments and an upward (artesian) hydraulic gradient. Upgradient monitoring well MW-1 had a ground water temperature of 100 degrees F at 300 feet below ground surface, which suggests
a geothermal source.The chemistry of ground watersampledat MW-1isalsodifferentfromthatindowngradientmonitor wells and the fourth monitoring well, which is upgradient from Lagoon #4.
Historically, ground water levels in Escalante Valley have been falling due to overpumping.Ground water withdrawals and overpumping in the Beryl Junction area has resulted in land subsidence
and earth fissures that were documented by the Utah Geological Survey.Additionally, overpumping may affect water levels in monitoring wells, vertical hydraulic gradients, and ground
water flow directions during the lifetimeof this facility.
Monitoring since this permit was first issued shows that while ground water levels in the monitor wells fluctuate over time, especially during the irrigation season. A measurement from
irrigation season shows that the levels have not dropped below 211 feet bgs. (Well MW-2, August 2024 measurement).
The monitoring well drilled at the 200 acre-foot Storage Basin #4 site, west of the dairy, approved in 2019 shows a water level of 193.2 feet bgs on the well driller’s report. Permittee’s
most recent report shows from April of 2024 (the same month as the well-driller’s log) shows the water level at 196.0 bgs. The report further shows mostly clay to 200 feet with some
silt.
BestAvailable Technology
The wastewater lagoons are lined with 60-mil HDPE flexible membrane liners over a one-foot subbase of compacted soil. The covered Lagoon will include the same liner and compaction.
All facilities with sustained hydrostatic conditions, including reception pits and the milking parlor, are constructed with concrete and have water stops in all joints.
All open lots have a minimum of 12 inches of native soil compacted to 95% proctor, and this soil has a clay content greater than 18%.
Land application of solids and liquids will be done under a Comprehensive Nutrient Management Plan developed by a certified nutrient management planner.
BackgroundGroundWaterQuality,GroundWaterClass,andProtection Levels
In order to better understand variability of ground water quality and pressure head in the ground water flow system, eight sets of water quality samples and water level measurements
were collected from each of the three original monitoring wells over a one-year period, as well as the fourth and fifth monitoring well for Storage Lagoon #4.Based on the accelerated
water quality monitoring data, background water quality for key parameters has been established as summarized in Table 1.
Table1:BackgroundGroundWaterQuality (mg/L)
MonitoringWell
TDS
Nitrate+ Nitrite
Ammonia
MW-1(upgradient)
1,090
1.6
0.06
MW-2
604
0.5
0.05
MW-3
829
0.2
0.05
MW-4
244
0.6
0.5
MW-5
240
0.7
0.5
Based on laboratory analytical results of eight samples collected in 2010 and 2011 from the three monitoring wells installed at the dairy site, the uppermost ground water is classified
as Class II Drinking Water Quality with total dissolved solids (TDS) ranging from 600 to 1,100 mg/L.
Based on laboratory analytical results of eight samples collected in 2019 and 2020 from the two monitoring wells at the site of Storage Lagoon #4, the uppermost ground water is classified
as Class IA Drinking Water Quality with total dissolved solids (TDS) ranging from 240to 250 mg/L.
Table 2 summarizes well-specific ground water protection levels, which were derived from background water quality data in accordance with UAC R317-6-4.
Table2:Ground Water ProtectionLevels(mg/L)
MonitoringWell
TDS

Nitrate+ Nitrite
Ammonia(c)
MW-2
1,007 (a)
2.5(b)
7.5 (b)
MW-3
1,127 (a)
2.5(b)
7.5 (b)
MW-5
3031
2.5 (b)
7.5 (b)BasedonmeanconcentrationX1.25(UACR317-6-4).Basedon0.25Xgroundwaterqualitystandard(UACR317-6-4).AmmoniastandardbasedonEPALifetimeHealthAdvisoryof30mg/L.
Ground water protection levels will only apply to changes in ground water quality due to contaminants introduced into the uppermost aquifer by the dairy facility (i.e., not from naturally-occurring
geothermal effects).
Groundwaterfromthe monitorwellswassampledonApril 18, 2024asapermitcondition. Results of this sampling are shown in Table 3.Protection levels were not exceeded in downgradientwells.WhilewellMW-1exceededbackgroundconcentrationsforNitrate
+ Nitrite in this sample event, it is an upgradient well that samples ground water from a geothermal source, and its static water levels have not dropped below the confining layers.
Table3:GroundWaterChemistry,SampledApril 18, 2024.(mg/L)
MonitoringWell
TDS
Nitrate+ Nitrite
Ammonia
MW-1
955
9.55
<.5
MW-2
730
2.38
<.5
MW-3
788
2.68
<.5
MW-4
225
1.71
<.5
MW-5
215
.96
<.5
ComplianceGroundWaterMonitoring
During construction in 2010, ground water conditions at the site were unknown during the permit application process. Based on the assumption that hydrogeologic conditions would be similar
to most valley and bench locations in Utah, Holt Dairy was required to drill one upgradient monitoring well (MW-1) and two downgradient monitoring wells (MW-2 and MW-3) located along
the presumed direction of ground water flow. Later, to construct Storage Lagoon #4, one upgradient monitoring well was drilled (MW-4), and a downgradient well also was required (MW-5).When
the wells were drilled, including MW-4, it was discovered that the upper 300 feet of the subsurface was predominantly silt and clay, and the uppermost ground water was encountered beneath
these layers under confined (artesian) conditions.Under these confined conditions, contaminants introduced near the ground surface at the dairy site are not likely to affect the uppermost
ground water.
Based on the presence of confined conditions, sampling and analysis of ground water quality from the site monitoring wells would not be useful to evaluate compliance with permit conditions.Instead
of ground water quality monitoring, compliance monitoring will be based on measurement of depth to water and ground water elevations in the monitoring wells.The depth to ground water
data will be used to evaluate whether static ground water levels in the confined aquifer are dropping during the operation of the dairy facility, which could change the existing upward
hydraulic gradient and make downward contaminant migration possible.
If static ground water elevations measured in the monitoring wells drop to or below the initial elevationwhere groundwaterwasfirstencounteredduringdrilling(250feetbelow ground surface),
water quality monitoring of the wells will be resumed.Ground water quality monitoring may also be resumed at any time upon notification by the Executive Secretary.The Permittee shall
also sample all three monitoring wells six months before the expiration date of this permit term, as part of the permit renewal application.
Compliance with permit conditions at the existing facilities will be demonstrated by monitoring static water levels in the confined aquifer as described above, water quality monitoring
if necessary, maintaining best available technology of containment facilities appropriate for the site conditions, and following the approved Comprehensive Nutrient Management Plan for
land application.

One monitoring well was constructed at the Storage Lagoon #4 location (the west 200 acre-foot lagoon) that appears to be upgradient of the basin, and an irrigation well was approved
as a downgradient monitoring well. Background ground water quality and protection levels were defined for the permit based on eight independent samples taken from the downgradient well
over at least one year.
Up to three staging lagoons have been designated in the 2024 Groundwater Discharge Permit.
Notes
Engineered drawings have been submitted for construction of the new Digester. Final plans and specifications will be submitted when complete. DWQ will issue a Construction Permit at
that time.