m ground water pollution control sdeq.mt.gov/portals/112/water/wqinfo/documents/mt-19-11/...water...

Water Protection Bureau P.O. Box 200901

Helena, MT 59620-0901

PERMIT FACT SHEET MTX000249

MONTANA GROUND WATER POLLUTION CONTROL SYSTEM (MGWPCS) Permittee: M.Y. Global Property LLC

Permit Number: MTX000249 Permit Type: Domestic wastewater

Application Type: New Permit Facility Name: Microtel Inn and Suites, West Yellowstone

Facility Location: Section 15, T. 12S., R. 5E., Gallatin County Latitude: 44.789182ᵒ Longitude: -111.112809ᵒ

Facility Address: Facility Contact: C&H Engineering, Bozeman, Mike Hausauer

Treatment Type: Advanced treatment, SepticNet pre-fabricated fixed film bioreactor Receiving Water: Class I Ground Water

Number of Outfalls: 1 Outfall / Type: 001, subsurface pressure dose drainfield Effluent Type: Domestic strength wastewater Mixing Zone: 150 foot Mixing Zone

Effluent Limit Type: WQBEL Load limit Effluent Limits: Total nitrogen: .79 lbs/day

Flow Rate: Design maximum: 8,640 gpd (reported average and Max design flow the same). Design average: 8,640 gpd

Effluent sampling: Quarterly Sampling at EFF 001, located at dose tank prior to discharge. Ground water sampling: No ground water sampling required.

Fact Sheet Date: March 15, 2019 Prepared By: Rich Morse

FACT SHEET: MGWPCS Permit No. MTX000249– Microtel Inn and Suites, West Yellowstone

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1.0 PERMIT INFORMATION

DEQ issues MGWPCS permits for a period of five years. The permit may be reissued at the end of the period, subject to reevaluation of the receiving water quality and permit limitations. This fact sheet provides the basis for DEQ’s decision to issue a MGWPCS wastewater discharge permit M.Y. Global LLC for the Microtel Inns and Suites, West Yellowstone wastewater treatment system.

1.1 APPLICATION DEQ received an application for the permit on February 19, 2019. Fees accompanied the application. DEQ reviewed the submittal and issued a completeness letter on March 5, 2019.

2.0 FACILITY INFORMATION

2.1 LOCATION The Microtel Inn and Suites is a 50-room motel facility located four miles north of the Town of West Yellowstone and Yellowstone National Park on HWY 191 (Figure 1, 2 and 3).

2.2 Operations

System operations are summarized in Table 1. Table 1. Collection, Treatment, and Disposal Summary Collection

Contributing sources: 50 room motel facility (non-industrial)

Standard industrial code(s) of sources: 7011

Collection method: Gravity-driven sewer lines Flow volume: Average daily design flow: 8,640 gallons per day

Maximum daily design flow: 8,640 gallons per day Treatment Treatment level: Advanced Treatment

Treatment technology: Fixed film bioreactor, SepticNET SC-10K

Treatment location: 44.788834, -111.112551 Disposal

Method of disposal: Infiltration to ground water

Disposal structure: Pressure dosed subsurface drainfield (Outfall 001)

Outfall location: 44.788468, -111.11298

The effluent at the Microtel site gravity feeds to a 25,000-gallon primary treatment septic tank with effluent filter. Treatment consists of a SepticNET pre-fabricated fixed film bioreactor. Treated effluent is dosed to an adjacent drainfield. Effluent is treated to below 7.5 mgL TN prior to discharge. See Figure 4. for system diagram.


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Effluent sampling is done in the dose tank prior to discharge. Monitoring and sampling requirements are further discussed in Section 6. Maximum discharge from the facility is 8,640 gallons per day. Discharge is domestic-in-nature. Treatment on the Microtel site is a Level II SepticNET SC-10K treatment unit. Outfall 001 is a pressurized drainfield.

Figure 1. Location of the Microtel Inn and Suites, and West Yellowstone.


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Figure 2. Microtel vicinity map and relation to surface water.


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FIGURE 3. MICROTEL SITE MAP


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Figure 4. System diagram of the Microtel Inn and Suites collection, treatment, and disposal

process.


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Figure 5: Flow diagram of Microtel Inn and Suites, West Yellowstone, MTX000249


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2.3 EFFLUENT CHARACTERISTICS DEQ requires a permit applicant to disclose the quality of the effluent so that DEQ may evaluate the potential for pollution of state water. The applicant provided estimated effluent quality based on best professional judgement and effluent characteristics from equivalent facilities. These data are summarized below in Table 2. The majority of the concentrations are reported in units of milligrams per liter (mg/L), which is equivalent to one part per million. Table 2.

2.4 GEOLOGY The Microtel Inn and Suites site is located in volcanic tuff deposits related to the volcanic origins of the Yellowstone Park caldera. The tuff deposits that are contained in two members of the Huckleberry Ridge Tuff deposits. The upper member is a nonwelded pink and poorly compacted tuff with pumice fragments. The lower member of the Huckleberry Ridge Tuff is dark-gray welded tuff. The base of this unit is a phenocrystic, rhyolitic vitrophyre. The well log for GWIC well Id #295520 located on this site, indicates the presence of the Huckleberry Ridge Tuff to at least 138 feet. There is approximately twenty feet of poorly sorted (Pleistocene) glacial outwash and young (Holocene) alluvial fan deposits overlying the Huckleberry Ridge Tuff deposits.

2.5 HYDROGEOLOGY The applicant provided hydrogeologic information for the site. A summary of that information is contained in Table 3. The water bearing unit for GWIC #295520 is the Huckleberry Tuff. Static water level is 65 feet below ground surface. Hydraulic gradient and flow direction was determined using a three point analysis included in Appendix A. Important hydrogeologic characteristics are summarized in Table 3.

Parameter(1) Location UnitsReported Minimum

Value

Reported Average

Value

Reported Maximum(2)

Value

Source of Data(3)(4)

Nitrogen, Total Ammonia (as N) EFF-001 mg/L 0.11 1.11 3.01 Applicant

Nitrogen, Total Kjeldahl (as N ) EFF-001 mg/L 0.50 3.30 6.80 Applicant

Nitrogen, Total (as N) EFF-001 mg/L 1.27 3.75 9.50 Applicant

(3) Best professional judgement by manufacturer.

Period of Record: Maufacturer supplied data from 2013 through 2018.

(2) Maximum value recorded of all reported values.

(4) Data from other similar plants.

(1) Conventional and nonconventional pollutants only, table does not include all possible toxics.

Estimated Effluent Quality– Outfall 001 Microtel Inns and Suites, MTX000249

Footnotes:


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Table 3. Hydrogeologic Summary Average depth to ground water 65 feet General ground water flow direction South 58˚ West Hydraulic conductivity 6.8 feet per day Hydraulic gradient 0.021 feet/feet Nearest downgradient surface water Duck Creek (3,300 feet)

2.6 GROUND WATER MONITORING WELLS There is one ambient monitoring well (MW-1) associated with this permit. This well is plotted in Figure 2. Monitoring well construction details are provided in Table 4. This is an upgradient monitoring well that is included in the monitoring schedule. Driller’s log for this well is attached as Appendix A.

Table 4. Monitoring Well Summary Upgradient Monitoring Well MW-1 MBMG GWIC ID: ID #295520 Location- latitude/longitude: 44.7895ᵒ Longitude: -111.11241ᵒ Location- narrative: Northeast corner of site, adjacent to MT Highway 191 Rationale: Ambient receiving water quality Depth; screened interval: Total depth of 138 feet, screened from 118-138 feet. Notes: This is a PWS with static water level= 65 ft. Continued

monitoring will be required.

Down Gradient Monitoring Well MW-2 MBMG GWIC ID: Not yet drilled. See special conditions. Location- latitude/longitude: To be decided. Location- narrative: Possibly between zone 1 and 2 of replacement

drainfield on adjacent property. Rationale: Downgradient end of mixing zone. Depth; screened interval: Plan to be submitted to DEQ. Notes: This well shall sample the first 15 feet of the shallow

aquifer. If a DEQ-approved monitoring well is abandoned, destroyed or decommissioned, or is no longer able to be sampled due to fluctuations in the ground water table, the permittee must install or designate a new well to replace the abandoned, destroyed, decommissioned, or non-viable well.


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2.7 GROUND WATER QUALITY CHARACTERISTICS Water sampling results from MW-1 are provided in Table 5. Based on the 169 microsiemens per centimeter (µS/cm) specific conductance, the receiving water is Class I ground water.

Table 5. Ambient Water Quality Reported From Monitoring Well MW-1 (GWIC #ID 295520) MW-1 represents shallow ground water 100 feet upgradient of Outfall 001

Parameter Units Reported values Reporting Limit # of

Samples Minimum Maximum Average Chloride (as Cl) mg/L 2.96 3.24 3.1 0.15 2 Total dissolved solids mg/L 95 122 108 1.0 2 Escherichia coli bacteria CFU/100mL


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3.2 WATER QUALITY STANDARDS DEQ’s ground water standard for nitrate is 10.0 mg/L, as is the standard for nitrate + nitrite (as nitrogen). Class I ground water must be maintained suitable for use as a drinking water supply with little or no treatment, and therefore must meet the corresponding human health standard of 10.0 mg/L total nitrogen. These water quality standards may not be exceeded outside a designated mixing zone (Section 4).

3.3 NONDEGRADATION Montana’s nondegradation policy is intended to preserve high-quality state waters. Any water whose existing condition is better than the water quality standards must be maintained in that high quality. Nondegradation policy states that certain types of common activities cause nonsignificant changes in water quality, and also provides criteria for determining whether changes in water quality are significant.

Nonsignificant changes do not require further nondegradation review. Therefore, DEQ must determine whether the proposed discharge will result in significant changes in water quality.

3.4 NONSIGNIFICANCE This section establishes whether or not a significance determination is required for this action. The proposed activity is a new source resulting in a change of existing water quality. DEQ must determine whether these water quality changes are significant. Some nonsignificant activities are specified in the Administrative Rules of Montana; other activities are evaluated for significance according to a process provided in the Rules. DEQ evaluated the significance of this discharge using the criteria and methods described below. 3.4.1 Ground Water Nonsignificance Criteria For this discharge to ground water, the following nonsignificance criteria are relevant:


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Nitrogen Under Montana statute, ground water total nitrogen at or below 7.5 mg/L at the downgradient end of the mixing zone (see Section 4) is a nonsignificant change in water quality, so long as the discharge does not cause degradation of surface water. Using the nonsignificance criterion of 7.5 mg/L, DEQ established effluent limits that cause the discharge to comply with ground water nonsignificance/nondegradation criteria at the end of the mixing zone. This is discussed in detail in Section 5.1. Phosphorus A total phosphorus surface water breakthrough time of greater than 50 years is a nonsignificant change in water quality. The phosphorus criterion requires an analysis to determine a breakthrough time. Breakthrough occurs when the subsurface soils lose their capability to adsorb any more phosphorus, and it reaches surface water. Using these conservative estimates, DEQ’s phosphorus breakthrough analysis estimates that phosphorus discharged to ground water from Outfall 001 may reach surface water in 107 years. Predicted phosphorus breakthrough within 50 years is considered significant. Calculations for this analysis are included in Appendix B.

4.0 MIXING ZONE

DEQ authorizes a department modified standard mixing zone for total nitrogen discharged from Outfall 001. A mixing zone is a specifically defined area of the receiving water where water quality standards may be exceeded. DEQ evaluates the suitability according to criteria established in the Administrative Rules of Montana. The mixing zone is then defined in the permit. This mixing zone extends 150 feet downgradient from the source. The upgradient boundary is equal to the width of the source (measured perpendicular to the of ground water flow direction). The mixing zone widens in the downgradient direction by 5ᵒ on either side. The width of the downgradient boundary is calculated by adding the increased width for each side (the tangent of 5ᵒ (0.0875) times the mixing zone length) to the width of the upgradient boundary. Mixing zones extend 15 feet below the ground water table.


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The volume of ground water (QGW) available to mix with the effluent is calculated using Darcy’s Equation: QGW = KIA

Where: QGW = ground water flow volume (feet3/day) K = hydraulic conductivity (feet/day) I = hydraulic gradient (feet/feet) A = cross-sectional area (feet2) at the downgradient boundary of the mixing zone.

Table 6 summarizes the variables used in Darcy’s equation and the resulting volume of ground water available to mix at Outfall 001. These values are drawn from recent investigation and the permit application.

Table 6. Mixing Zone for Total Nitrogen Discharged from Outfall 001 Parameter Units Value Receiving water nitrogen concentration 1.23 mg/L Ground water flow direction S58W Bearing Length of mixing zone 150 Feet Thickness/depth of mixing zone 15 Feet Upgradient width of mixing zone 288 Feet Downgradient width of mixing zone 301 Feet Cross-sectional area of mixing zone (A) 4,515 Square feet Hydraulic conductivity (K) 6.8 Feet per day Hydraulic gradient (I) 0.021 Feet per feet Volume of ground water available for mixing (QGW) 645 Cubic feet per day

In order to determine whether a mixing zone is allowable, DEQ calculates a predicted concentration at the downgradient end of the mixing zone. This mixing calculation follows the following procedure:

• Volume of ground water times the concentration of the parameter = existing load; • Volume of discharge times the concentration of the parameter = waste load; and • (Existing load + waste load) / total volume = predicted concentration.

Because the predicted concentration must satisfy the most stringent nonsignificance criterion (Section 3), DEQ can calculate water quality based effluent limits (WQBELs) by rearranging the equation and solving for the effluent concentration (Section 5).

5.0 PERMIT CONDITIONS

Discharge permits include conditions that ensure compliance with the Montana Water Quality Act and the regulations used to implement it. These conditions include effluent limits as well as any special conditions that DEQ deems necessary to protect the quality of the receiving water. Montana’s numeric water quality standards are published in Circular DEQ-7. Water quality criteria applicable to this permit are summarized below in Table 7. The permit establishes effluent limits that will meet water quality standards and nondegradation criteria, thereby protecting beneficial uses and existing high quality waters. The most restrictive criteria in Table 7 provide the basis for the effluent limits.


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Table 7. Applicable Ground Water Quality Criteria Parameter Human Health Standard Beneficial Use Support Nondegradation Criteria Nitrate plus nitrite (as Nitrogen[N])

10 mg/L - -

Total Nitrogen - 10 mg/L 7.5 mg/L Total Phosphorus - - >50 year breakthrough

This discharge permit includes numeric WQBELs that restrict the strength and volume of the discharge. The ground water nonsignificance criteria (Section 3.4.1) provide the basis for the limits. DEQ calculates WQBELs by rearranging the mixing zone equation (Section 4) and solving for the effluent concentration that satisfies the water quality criteria. DEQ evaluates and recalculates the limits using updated water quality data as part of every permit renewal cycle. In this way, DEQ protects the receiving water quality by continually assessing cumulative impacts to the receiving water.

5.1 TOTAL NITROGEN EFFLUENT LIMIT The nonsignificance criterion of 7.5 mg/L TN is the most restrictive of the water quality criteria applicable to this permit; therefore it is the water quality target for this effluent limit. DEQ established the final WQBEL for this discharge by back-calculating the effluent concentration that results in 7.5 mg/L at the end of the mixing zone, given the available dilution. Available dilution is determined by recent ground water quality sampling of the receiving water. Ambient total nitrogen averaged 1.23 mg/L (Section 2). DEQ calculates an effluent limit that protects receiving water quality and beneficial uses according to the following equation:

Equation 1: Clmt = Cstd + D(Cstd - Cgw) Where:

Clmt = effluent limitation concentration Cstd = limiting water quality criterion Cgw = ambient receiving ground water concentration D = dilution ratio (Qgw ∕ Qeff) Qgw =ground water flux at the end of the mixing zone Qeff = average maximum daily discharge

Using the values provided above in Table6, the result for Clmt is 11.0 mg/L. This is the final WQBEL expressed as a concentration. Load limits are more appropriate for discharges to ground water since the long-term loading is the greater concern in absence of aquatic life considerations. Additionally, load limits inherently control both the strength and volume of the discharge. A discharge of 8,640 gallons per day containing 11.0 mg/L total nitrogen is equivalent to 0.79 pounds per day. The limit calculations are provided in detail in Appendix II.


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5.2 TOTAL PHOSPHORUS EFFLUENT LIMIT DEQ determined that phosphorous discharged to ground water would reach the surface water Duck Creek in 107 years. A phosphorous breakthrough time of less than 50 years is considered significant. Based on the information and analyses presented above, DEQ proposes the following numerical effluent limitations in Table 8 below.

Table 8. Final effluent limit

5.3 SPECIAL CONDITIONS In accordance with ARM 17.30.1031, this section contains the basis for special permit conditions that are necessary to assure compliance with the ground water quality standards and the Montana Water Quality Act. The following special condition(s) will be included in the permit. A. Monitoring Well Installation

Within one year of the effective date of the permit, a monitoring well must be installed 150 feet downgradient of the proposed discharge structure (Outfall 001). Monitoring well will be constructed to allow sampling of the upper 15 feet of the shallow aquifer. Installation and reporting requirements are further described in the ground water monitoring and special condition sections of this fact sheet (Section 6. and Table 10 and Table 11 of this fact sheet).

A compliance schedule is included to allow a reasonable opportunity for the permittee to attain compliance with permit requirements and to stay in compliance with the Water Quality Act and the Administrative Rules of Montana. The actions listed in Table 12 must be completed on or before the respective scheduled completion date. A report documenting each respective action must be received by DEQ on or before the scheduled reporting date. Completion of all actions or deliverables must be reported to DEQ in accordance with Part II.D and Part IV.G of the permit.

Nitrogen, Total (as N) lbs/day 0.79

Beneficial Uses: ARM 17.30.1006Footnotes:

(1) See definition in Part V of permit.

Proposed Final Effluent Limits – Outfall 001, MTX000249

Parameter Units Daily Maximum(1)


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6.0 MONITORING AND REPORTING REQUIREMENTS

DEQ requires effluent monitoring to assure compliance with the effluent limitations and therefore water quality standards. Effluent monitoring is required as a condition of this permit. All monitoring and sampling required by this permit must be representative; therefore the permit identifies specific monitoring locations. Monitoring requirements and rationale are summarized below.

6.1 EFFLUENT MONITORING This permit includes numeric effluent limitations with specific magnitudes and durations to ensure the discharge will not cause or contribute to an exceedance of an applicable water quality standard (see Section 3). Accordingly, the permittee is required to monitor and report at a specified frequency in order to demonstrate compliance with these limitations. Effluent samples and discharge flow measurements must be representative of the nature and volume of the effluent. The effluent sample location (EFF-001) is located at dose tank prior to discharge as shown in Figure 5. The permittee is required to install, maintain and report flow measurements using a flow-measuring device capable of measurements that are within 10 percent of the actual flow. The flow measuring device (FM-001) is located in the metering vault prior to distribution valve (Figure 5). The flow measuring device must be installed and in operating condition prior to discharge. Effluent monitoring and reporting requirements are summarized in Table 9. All analytical methods must be in accordance with the Code of Federal Regulations, 30 CFR Part 136 for each monitored parameter.


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Table 9: Effluent Monitoring Requirements

Effluent Monitoring and Reporting Requirements – Outfall 001, MTX000249, Microtel Inn and Suites

Analyte/Measurement/Method Monitor Location Units Sample Type(1)

Minimum Sample

Frequency

Reporting Requirements(1)(2)(3)(4)

Report Freq

Flow Rate, Effluent(5) FM-001 gpd Contin- uous Contin-

uous Daily Maximum

Quarterly Average Quarterly

Nitrogen, Nitrite+Nitrate (as N) EFF-001 mg/L Grab 1/Quarter Daily Maximum Quarterly Average Quarterly

Nitrogen, Total Ammonia (as N) EFF-001 mg/L Grab 1/Quarter Daily Maximum Quarterly Average Quarterly

Nitrogen, Total Kjeldahl (TKN)(as N) EFF-001 mg/L Grab 1/Quarter

Daily Maximum Quarterly Average Quarterly

Nitrogen, Total (as N)(6) EFF-001 mg/L Calculate 1/Quarter Daily Maximum Quarterly Average Quarterly

lbs/day(7) Calculate 1/Quarter Daily Maximum(8)

Quarterly Average(9) Quarterly

Phosphorus, Total (as P) EFF-001 mg/L Grab 1/Quarter Quarterly Average Quarterly

Footnotes: EFF-001: Description provided in Table 5. INF-001: Description provided in Table 5. FM-001: Description provided in Table 5. If no discharge occurs during the reporting period, “no discharge” shall be recorded on the effluent Discharge Monitoring Report (DMR) report forms. Grab sample will represent concentration for a 24 hour period. Parameter analytical methods shall be in accordance with the Code of Federal Regulations, 40 CFR Part 136, unless specified above. (1) See definitions in Part V of the permit. (2) Daily Maximum: Report highest measured daily value for the reporting period on Discharge Monitoring Report (DMR) form. (3) Daily Minimum: Report lowest measured daily value for the reporting period on Discharge Monitoring Report (DMR). (4) The geometric mean must be reported if multiple samples are taken during a reporting period. (5) Requires recording device or totalizing meter, must be capable of recording daily effluent volume. (6) Total Nitrogen is the sum of Nitrate + Nitrite and Total Kjeldahl Nitrogen. (7) Load calculation: lbs/day = (mg/L) x flow (gpd) x [8.34 x 10-6]. (8) Daily Maximum Load calculation: lbs/day = the maximum of all calculated individual daily average loads (lbs/day) recorded during the reporting period. (9) Quarterly Average Load calculation: lbs/day = the average of all calculated individual daily average loads (lbs/day) recorded during the reporting period.

6.2 GROUND WATER MONITORING As a condition, this permit requires ground water monitoring to provide long term ambient and downgradient characterization of the aquifer. Ground water monitoring will be required at monitoring wells MW-1 and MW-2. Data collected via ground water monitoring will be used for mixing zone evaluation and aquifer characterization in future permit renewals. Ground water monitoring and reporting requirements are summarized in the table below. Sampling and reporting requirements shall commence upon the effective date of the permit.


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Ground water monitoring and reporting requirements are summarized in Table 10 and Table 11. All analytical methods must be in accordance with the Code of Federal Regulations, 40 CFR Part 136 for each monitored parameter.

Table 10 – Upgradient Monitoring

Analyte/MeasurementMonitor

Location(1)Units

SampleType(2)

Minimum Sampling Frequency

Reporting(2)(3)(4)

RequirementsReporting Frequency

Chloride (as Cl)MW-1

mg/L Grab 1/Quarter Quarterly Average Quarterly

Count of Daily Samples Collected During Reporting Period

MW-1- - - Count Quarterly

Escherichia coli Bacteria MW-1 CFU/100ml Grab 1/QuarterDaily Maximum

Quarterly Average(5)Quarterly

Nitrogen, Nitrate + Nitrite(as N)

MW-1mg/L Grab 1/Quarter

Daily MaximumQuarterly Average Quarterly

Nitrogen, Total Ammonia(as N)

MW-1mg/L Grab 1/Quarter


Nitrogen, Total Kjeldahl (TKN)(as N)

MW-1 mg/L Grab 1/Quarter Daily MaximumQuarterly Average

Quarterly

pH MW-1 s.u. Instant-aneous

1/Quarter Quarterly Average Quarterly

Specific Conductivity @ 25°CMW-1

µS/cmInstant-aneous 1/Quarter Quarterly Average Quarterly

Static Water Level (SWL)(6)MW-1 ft-bmp Instant-

aneous1/Quarter Quarterly Average Quarterly

TemperatureMW-1

°CInstant-aneous 1/Quarter Quarterly Average Quarterly

Upgradient Ground Water Monitoring and Reporting Requirements

(1) Refer to Section 2.2 and Section 2.6 of the Fact Sheet for the existing or proposed location of the monitoring wells.

(2) See definitions in Part V of the permit.

(4) Daily Maximum: Report highest measured daily value for the reporting period on Discharge Monitoring Report (DMR).

(6) Measuring point (point of reference) for SWL measurements shall be from top of casing and measured to within 1/100th of one foot.

(3) Submittal of DMRs will be required, regardless of the installation status of each individual monitoring well. If the monitoring well(s) is not installed for an individual monitoring period, the following shall be stated upon each applicable DMR: “monitoring well has not been installed”.

(5) The geometric mean must be reported if more than one sample is taken during a reporting period.


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Table 11: Down Gradient Monitoring

Analyte/MeasurementMonitor

Location(1)Units

SampleType(2)

Minimum Sampling Frequency

Reporting(2)(3)(4)

RequirementsReporting Frequency

Chloride (as Cl) MW-2 mg/L Grab 1/Quarter Quarterly Average Quarterly

Count of Daily Samples Collected During Reporting Period

MW-2 - - - Count Quarterly

Escherichia coli Bacteria MW-2 CFU/100ml Grab 1/QuarterDaily Maximum

Quarterly Average(5)Quarterly

Nitrogen, Nitrate + Nitrite(as N) MW-2 mg/L Grab 1/Quarter


Nitrogen, Total Ammonia(as N)


Quarterly

Nitrogen, Total Kjeldahl (TKN)(as N)


Quarterly

pH MW-2 s.u. Instant-aneous

1/Quarter Quarterly Average Quarterly

Specific Conductivity @ 25°C MW-2 µS/cmInstant-aneous 1/Quarter Quarterly Average Quarterly

Static Water Level (SWL)(6) MW-2 ft-bmpInstant-aneous 1/Quarter Quarterly Average Quarterly

Temperature MW-2 °CInstant-aneous 1/Quarter Quarterly Average Quarterly

(4) Daily Maximum: Report highest measured daily value for the reporting period on Discharge Monitoring Report (DMR).(5) The geometric mean must be reported if more than one sample is taken during a reporting period.

(6) Measuring point (point of reference) for SWL measurements shall be from top of casing and measured to within 1/100th of one foot.

Down gradient Ground Water Monitoring and Reporting Requirements

(1) Refer to Section 2.2 and Section 2.6 of the Fact Sheet for the existing or proposed location of the monitoring wells.(2) See definitions in Part V of the permit.(3) Submittal of DMRs will be required, regardless of the installation status of each individual monitoring well. If the monitoring well(s) is not installed for an individual monitoring period, the following shall be stated upon each applicable DMR: “monitoring well has not been installed”.


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COMPLIANCE SCHEDULE

The actions listed in Table 12 must be completed on or before the respective scheduled completion date. A report documenting each respective action must be received by DEQ on or before the scheduled reporting date. Completion of all actions or deliverables must be reported to DEQ in accordance with Part II.D and Part IV.G of the permit. Table 12– Compliance Schedule

Action Freq.Scheduled Completion Date of Action(1)

Scheduled Report Due Date.(2)

Complete a Monitoring Well Installation Plan.(3)

Single event

Within 180 days of the effective date of the permit.

Due on or before the 28th day of the month following the completion date.

Complete the installation of the monitoring well(s).(4)

Single event

Within one (1) year of the effective date of the permit.


Commence monitoring and reporting of the newly installed monitoring well(s). (5)

Single event

Within fifteen (15) months of the effective date of the permit.


(5) Sampling parameters required for each respective monitoring well as listed within Table 3 of the permit.

(4) The written report documenting monitoring well installation must include: drilling methods used; borehole lithologic logs; diagram of well construction details; measuring point details; surveyed base location of monitoring well; depth to the top contact of the first saturated ground water bearing zone; well development records; depth to static water level (post development).

Compliance Schedule Microtel Inn and Suties, MTX000249

(2) Reports must be received by DEQ on or before the scheduled report due dates. The reports must include all information as required for each applicable action as listed in Section II.D. of the permit.

(1) The actions must be completed on or before the scheduled completion dates.

(3) The completed plan (action), in place of a written report, must be received by the DEQ on or before the scheduled "report" due date.

Footnotes:


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PUBLIC NOTICE

Legal notice information for water quality discharge permits are listed at the following website: http://deq.mt.gov/Public/notices/wqnotices. Public comments on this proposal are invited any time prior to close of business on June 5, 2019. Comments may be directed to: [email protected] or to: Montana Department of Environmental Quality Water Protection Bureau PO Box 200901 Helena, MT 59620 All comments received or postmarked prior to the close of the public comment period will be considered in the formulation of the final permit. DEQ will respond to all substantive comments pertinent to this permitting action and may issue a final decision within thirty days of the close of the public comment period. All persons, including the applicant, who believe any condition of the draft permit is inappropriate, or that DEQ’s tentative decision to deny an application, terminate a permit, or prepare a draft permit is inappropriate, shall raise all reasonably ascertainable issues and submit all reasonably available arguments supporting their position by the close of the public comment period (including any public hearing). All public comments received for this draft permit will be included in the administrative record and will be available for public viewing during normal business hours. Copies of the public notice are mailed to the applicant, state and federal agencies, and interested persons who have expressed interest in being notified of permit actions. A copy of the distribution list is available in the administrative record for this draft permit. Electronic copies of the public notice, draft permit, fact sheet, and draft environmental assessment are available at the following website: http://deq.mt.gov/Public/notices/wqnotices. Any person interested in being placed on the mailing list for information regarding this permit may contact the DEQ Water Protection Bureau at (406) 444-5546 or email [email protected]. All inquiries will need to reference the permit number (MTX000249), and include the following information: name, address, and phone number. During the public comment period provided by the notice, DEQ will accept requests for a public hearing. A request for a public hearing must be in writing and must state the nature of the issue proposed to be raised in the hearing.


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APPENDIX A – AMBIENT WELL LOG & HYDROGEOLOGIC CALCULATIONS


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Appendix B – Nonsignificance Projections Phosphorus Breakthrough:

MONTANA DEPARTMENT OF ENVIRONMENTAL QUALITY (DEQ)

PHOSPHOROUS BREAKTHROUGH ANALYSIS

SITE NAME: Microtel Inn and Suites, West YellowstoneCOUNTY: GallatinPermit #: MTX000249NOTES: Variables used are based on conservative measurements

Design Capacity = 8,640 gpd = 1155 ft³/day

VARIABLES DESCRIPTION VALUE UNITSLg Length of Primary Drainfield as Measured Perpendicular to Ground 288 ft Water Flow L Length of Primary Drainfield's Long Axis 280 ftW Width of Primary Drainfield's Short Axis 120 ftB Depth to Limiting Layer from Bottom of Drainfield Laterals* 15 ftD Distance from Drainfield to Surface Water 3379 ftT Phosphorous Mixing Depth in Ground Water (0.5 ft for coarse soils, 0.5 ftNe 1.0 ft for fine soils)** Sw Soil Weight (usually constant) 100 lb/ft3Pa Phosphorous Adsorption Capacity of Soil (usually constant) 200 ppm#l Number of proposed wastewater treatment systems 1

CONSTANTSPl Phosphorous Load per proposed wastewater treatment system 278 lbs/yrX Conversion Factor for ppm to percentage (constant) 1.0E+06

EQUATIONSPt Total Phosphorous Load = (Pl)(#l) 278 lbs/yrW1 Soil Weight under Drainfield = (L)(W)(B)(Sw) 50400000 lbsW2 Soil Weight from Drainfield to Surface Water 98609779 lbs

= [(Lg)(D) + (0.0875)(D)(D)] (T)(Sw)P1 Total Phosphorous Adsorption by Soils = (W1 + W2)[(Pa)/(X)] 29802 lbs SOLUTIONBT Breakthrough Time to Surface Water = P / Pt 107 years

BY:DATE:

NOTES: * Depth to limiting layer is typically based on depth to water in a test pit or bottom ofa dry test pit minus two feet to account for burial depth of standard drainfield laterals.

REV. 04/2000


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APPENDIX C – EFFLUENT LIMIT CALCULATIONS

The Microtel Inn and Suites treatment system consisting of level II treatment using a SepticNET aerobic nitrification reactor which discharges effluent below 7.5 mg/L. Effluent is pressure dosed to an infiltrator chamber drainfield. To protect beneficial uses [ARM 17.30.1006(1)(b)(ii)], there shall be no increase of a parameter to a level that renders the waters harmful, detrimental, or injurious to the beneficial uses. Therefore, no wastes may be discharged such that the waste either alone or in combination with other wastes will violate or can reasonably be expected to violate any standard. DEQ establishes the effluent limitations for nitrogen based on the projection that the entire nitrogen load in the wastewater stream may ultimately be converted to nitrate (USEPA, 2002a). Nitrogen: The allowable discharge concentrations are derived from a mass-balance equation (ARM 17.30.517) which is a simple steady-state model, used to determine concentration after accounting for other sources of pollution in the receiving water and any dilution as provided by a mixing zone. The mass-balance equation (Equation 1) derived for ground water is as follows:

The mass-balance equation has been arranged to calculate effluent limits so that the discharge does not cause or contribute to an exceedance of the most restrictive water quality standard. This equation can be applied to any effluent and receiving water where the applicable dilution ratio is known. This equation will only be used for nitrogen which has been authorized a load limit (Section 4).

ground water available for mixing ambient receiving ground water concentration maximum design capacity of wastewater system effluent pollutant concentration combined ground water and effluent (Qcomb = Qgw + Qeff) projected pollutant concentration (after available mixing)

Qgw = Cgw = Qeff = Ceff = Qcomb = Cproj =

Where:

Equation 1: QgwCgw + QeffCeff = QcombCproj


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Clmt =8,640 gpd (7.5 mg/L – 1.23 mg/L) = 11.0 mg/L A mass-balance approach is used to calculate the effluent quality of the discharge that meets the most restrictive water quality standard at the end of the mixing zone. Numeric effluent limitations are expressed as loads since this type of limitation inherently regulates both volume and strength of the effluent as prescribed by 75-5-402(3), MCA. Load limits ensure compliance with the ground water standards at the end of the mixing zone. Based on the proposed design capacity, the respective load effluent limitation is:

.79 lb/day [(8.34*10-6)* 11.0 mg/L*8,640 gpd] as based on the following equation:

The Final Effluent Limits for Outfall 001 are summarized in Table 8.

Equation 2:

Clmt =Cstd + D(Cstd -Cgw)

Where: Clmt = effluent limitation concentration Cstd = water quality standard concentration = 7.5 mg/L Cgw = ambient receiving ground water concentration = 1.23 mg/L

Equation 3:

Llmt =CON * Ceff *

DCeff Where: Llmt = effluent limitation-load

Ceff = allowable effluent concentration DCeff = design capacity of wastewater treatment system

(gpd) CON = conversion factor [8.34*10-6]

Permit Fact Sheet MTX000249Montana Ground Water Pollution Control System (MGWPCS)

1.0 Permit Information1.1 Application

2.0 Facility Information2.1 LocationFigure 3. Microtel site map2.3 Effluent Characteristics2.4 Geology2.5 Hydrogeology2.6 Ground Water Monitoring Wells2.7 Ground Water Quality Characteristics

Table 1. Collection, Treatment, and Disposal SummaryTable 3. Hydrogeologic SummaryTable 4. Monitoring Well SummaryTable 5. Ambient Water Quality Reported From Monitoring Well MW-1 (GWIC #ID 295520) 3.0 Water Quality Standards and Nondegradation3.1 Beneficial Uses3.2 Water Quality Standards3.3 Nondegradation3.4 Nonsignificance3.4.1 Ground Water Nonsignificance CriteriaNitrogen

4.0 Mixing ZoneTable 6. Mixing Zone for Total Nitrogen Discharged from Outfall 0015.0 Permit Conditions5.1 Total Nitrogen Effluent Limit5.2 Total Phosphorus Effluent Limit5.3 Special Conditions

Table 7. Applicable Ground Water Quality CriteriaIn accordance with ARM 17.30.1031, this section contains the basis for special permit conditions that are necessary to assure compliance with the ground water quality standards and the Montana Water Quality Act. The following special condition(s) will...A. Monitoring Well InstallationWithin one year of the effective date of the permit, a monitoring well must be installed 150 feet downgradient of the proposed discharge structure (Outfall 001). Monitoring well will be constructed to allow sampling of the upper 15 feet of the shallow...Installation and reporting requirements are further described in the ground water monitoring and special condition sections of this fact sheet (Section 6. and Table 10 and Table 11 of this fact sheet).A compliance schedule is included to allow a reasonable opportunity for the permittee to attain compliance with permit requirements and to stay in compliance with the Water Quality Act and the Administrative Rules of Montana. The actions listed in Tab...6.0 Monitoring And Reporting Requirements6.1 Effluent Monitoring6.2 Ground Water Monitoring

COMPLIANCE SCHEDULEPUBLIC NOTICEAppendix A – Ambient Well Log & Hydrogeologic CalculationsAppendix C – Effluent Limit Calculations

m ground water pollution control sdeq.mt.gov/portals/112/water/wqinfo/documents/mt-19-11/...water...

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