PERMIT RATIONALE FOR REISSUANCE
CF Industries Nitrogen LLC
Yazoo County
Yazoo City, Mississippi
Water NPDES No. MS0000574
October 2024

I.	FACILITY INFORMATION

Facility Name:     CF Industries Nitrogen LLC
Facility Address:  4612 Highway 49 East 
 Yazoo City, MS  39194
    
Permit No.:  MS0000574
SIC:  2873
Permit Writer:  Samar I. Patel
EPD Branch:  Chemical Branch

II.	NATURE OF BUSINESS

Manufacture of nitrogen fertilizers (anhydrous ammonia, ammonium nitrate, urea solutions, and N-SOL that is an aqueous blend of urea and ammonia nitrate solutions), nitric acid, dinitrogen tetroxide, and the by-product carbon dioxide (CO2). 

III.	EFFLUENT AND RECEIVING STREAM FLOW DATA

A.	Outfall 001 (MS0000574 001) – This outfall consists of the following wastewater streams: 0.547 million gallons per day (mgd) of process wastewater from ammonia production; 0.182 mgd of process wastewater from nitric acid production, 0.431 mgd of process wastewater from ammonium nitrate production, 0.055 mgd of process wastewater of urea production, 0.004 mgd of process wastewater from dinitrogen tetroxide production, 1.379 mgd of wastewater from steams for various plant operations, 0.196 mgd of wastewater from demineralization/regeneration processes, 0.04 mgd of sanitary wastewater from internal outfall 102 and 103, 1.223 mgd of non- contact cooling water blowdown, including wastewater from the co-generation of electricity, equipment wash racks, and storm water. Long-term average flow = 5.27 MGD. Maximum 30-day average flow of 6.40 MGD is calculated based on the historical DMR data for last 59 months (i.e., Sep 2018 through July 2023). 

B.	Outfall 101 (MS0000574 101) – This outfall pipe is permitted to discharge to Martin Creek only during excessive rainfall events and during the testing of flood pumps as required by the permit. The excessive rainfall event is one that adds enough water to the facility’s wastewater system so that the total wastewater rate exceeds the maximum pumping capacity for Outfall 001 to be discharged to the river (about 5800 gpm), resulting in excessive water levels within the facility. 

This outfall includes an overland weir set at a height just below flood level for the wastewater system. Water passing over the weir flows through three short gated conduits leading beneath the railroad tracks and into Martin Creek. Note that if the water level in the creek becomes so high that it blocks the drainage from the weir, the conduit gates are closed and one of two flood pumps is used to move wastewater into the creek.

C.	Internal Outfall 102 (MS0000574 102) – Sanitary wastewater from areas within ammonia production, carbon dioxide liquefaction, urea production, and nitric acid production plants along with minimal amount of laboratory wastes from the facility testing lab. The sanitary wastewater is treated via aerated sewage treatment system prior to being discharged to Outfall 001. Long term average flow = 0.03 MGD. 

D.	Internal Outfall 103 (MS0000574 103) – Sanitary wastewater from areas within ammonium nitrate production / prilling plant. The sanitary wastewater is treated via aerated sewage treatment system prior to being discharged to Outfall 001. Long term average flow = 0.0016 MGD.

RECEIVING WATERS

A.	Outfall 001 (MS0000574 001) – Yazoo River (7Q10 flow = 1160 cfs = 749.73 MGD)

B.	Outfall 101 (MS0000574 101) – Martin Creek

C.	Outfall 102 (MS0000574 102) – Internal outfall discharging to final Outfall 001.

D.	Outfall 103 (MS0000574 103) – Internal outfall discharging to final Outfall 001.

IV.	303(d) ISSUES

Yazoo River: The 7Q10 of the receiving stream is 1160 cfs (749.73 MGD); this along with the facility’s calculated maximum 30-day average flow of 6.40 MGD results in an Instream Waste Concentration (IWC) of 0.846%. The receiving stream is in the Yazoo River Basin, and is classified as fish and wildlife. The section of the receiving stream segment where Outfall 001 discharges into the Yazoo River, Water body ID No. MSYAZR2E, from confluence at North end of Lower Auxiliary Channel to confluence with Big Sunflower River, does not appear on the updated State of Mississippi 303(d) List of Impaired Water bodies. However, this site is listed in a State of Mississippi Yazoo River Basin TMDL for Total Nitrogen (TN) and Total Phosphorous (TP) for selected Large Rivers in the Delta, which was completed in June of 2008. No flow or nutrient loading increases have been proposed in this draft permit.  This draft permit proposes effluent limitations for TN and TP consistent with that TMDL and the corresponding waste load allocation found in Section VIII of this draft permit rationale. 

Martin Creek: The receiving stream at the point of discharge is not listed on the 303(d) list of evaluated, impaired water bodies in the State of Mississippi 2024 List of water bodies. The receiving stream is in the Yazoo River drainage basin. The receiving stream is classified as Fish and Wildlife at the discharge location.

V.	TYPE OF WASTEWATER TREATMENT:

A.	Outfall 001 (MS0000574 001) – Ion exchange (process wastewater treatment).

B.	Outfall 102 (MS0000574 102) – Sewage treatment system receives sanitary waste water from the immediate surrounding area for treatment via an aeration lagoon with microbes (or bugs) and steam (to kill off any residual microbes).  

C.	Outfall 103 (MS0000574 103) – Sewage treatment system receives sanitary waste water from the immediate surrounding area for treatment via an aeration lagoon with microbes (or bugs) and steam (to kill off any residual microbes).  

VI.	EPA APPLICABLE CATEGORICAL GUIDELINES

40 CFR 418 – Fertilizer Manufacturing Point Source Category; Subpart B – Ammonia Subcategory, Subpart C – Urea Subcategory, and Subpart E – Nitric Acid Subcategory.

VII.	DATA FROM APPLICATION FORM 2C

A.	Outfall 001 (MS0000574 001)

Parameter	Maximum Daily Value, mg/L (lb/day)	Long Term Average, mg/L	No of Analysis	
BOD (5 day)	6.01 mg/L	--	1	
TSS	7.26 mg/L	--	1	
Ammonia (as N)	31.60 (2408.79)	8.48 (372.71)	59	
pH	7.20 SU	6.0 SU (Min.)	Continuous Recorder	
Nitrate-Nitrite (as N)	8.50 (647.93)	--	1	
Nitrogen, Total Organic (as N)	23.20 (1768.48)	1.23 (54.06)	59	
Nitrogen-Nitrate Total (as N)	35.50 (2004.50)	8.29 (382.29)	59	
Total Phosphorous (as P)	53.40 lb/day	35.77 lb/day	59	
Total Iron	0.184 mg/L 	--	1	
Total Arsenic	0.000687 mg/L			
Total Coper	0.00492 mg/L	--	1	
Total Zinc	<0.00796 mg/L	--	1	
Total Nickel	<0.000514 mg/L	-	1	
Total Chromium	<0.00560 mg/L	-	1	
Total Lead	<0.000513 mg/L	-	1	
Total Mercury	0.000000314 mg/L	-	1	
Total Selenium	<0.000437 mg/L	-	1	
Total Silver	<0.000144	-	1	

B.	Outfall 102 (MS0000574 102)

Parameter	Maximum Daily Value, mg/L 	Long Term Average, mg/L	No. of Analysis	
BOD (5 day)	23.00	8.62	20	
TSS	35.00	7.79	20	
Fecal Coliform1	35 col./100 ml	1.0 col./100 ml	244	
Chlorine, Total Residual	0.80	0.13	61	

C.	Outfall 103 (MS0000574 103)

Parameter	Maximum Daily Value, mg/L	Long Term Average, mg/L	No. of Analysis	
BOD (5 day)	38.0	13.67	20	
TSS	20.0	9.48	20	
Fecal Coliform1	5.0 col./100 ml	1.0 col./100 ml	244	
Chlorine, Total Residual	0.52	0.10	61	

1       The fecal coliform count at the internal outfalls 102 and 103 is essentially low since the facility began using                  thermal sterilization. Therefore, any fecal coliform count reported at the main outfall will likely be from natural             sources due to the wastewater collection system consisting of extensive sections of open ditches around the                   facility.  

VIII. 	WATER QUALITY LIMITATIONS BASED ON WASTELOAD ALLOCATION 

Parameter	WLA Limitation	
Minimum DO	6.0 mg/l	
TN (lbs/day)2	4773.0	
TP (lbs/day)2	50.0	
pH (SU)	6-9	
 
2       Limits of TN and TP are based on nutrient allowance for Selected Large Rivers in the Delta and represent the total        maximum daily load (TMDL).

IX        TOXICITY SCREENING

See Attachment I.

X.	PROPOSED FINAL LIMITATIONS 

1.	Average Permit Limitations

Outfall	Parameter	Categorical Limitation
(previously Calculated)	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Basis	
Outfall 001
MS0000574 00111	- Flow

- Ammonia     Nitrogen3

- Nitrate
  Nitrogen3

- Organic
  Nitrogen3

- pH (continuous)4

- Total Nitrogen5,6
(TN)

- Total Phosphorous7 (TP)

Minimum DO8	-

816.2
 lb/day

1101.20
lb/day

362.40
lb/day

-

-

-

-	-

-

-

-

6.0 S.U. (min)

2279.8 lb/day

50 
lb/day

6.0	Report

816.20 lb/day

1101.20 lb/day

362.40
lb/day

6.0 SU (min.)

-

-

-	Report

816.2 lb/day

1101.2
lb/day

362.40
lb/day

6.0 SU (min.)

2279.8 lb/day

50
 lb/day

6.0	Engineering (Engr) Judgment

Anti-backsliding /  Existing Permit 

Anti-backsliding / Existing Permit

Anti-backsliding / Existing Permit

WLA / MSWQS / Existing Permit / 40 CFR §401.17

TMDL / WLA

TMDL / WLA

MSWQS / WLA	
Outfall 101
MS0000574 10111	- Flow

Minimum DO8

- pH (continuous)4	-

-

-

	-

6.0 mg/l (min.)

-	Report

6.0 mg/l (min.)

6.0 SU (min.)	Report

6.0 mg/l (min.)

6.0 SU
(min.)
	Engr Judgment

MSWQS / WLA

MSWQS	
Outfall 102
MS0000574 10211	- Flow

- BOD510

- TSS10

- E.Coli10	-

-

-

-	-

-

-

-
	Report

30 mg/l

30 mg/l

-	Report

30 mg/l

30 mg/l

126
col./100ml	Engr Judgment

Anti-backsliding / Existing Permit 
Anti-backsliding / Existing Permit 
MSWQS	
Outfall 103
MS0000574 10311

	- Flow

- BOD510

- E.Coli10	-

-

-

	-

-

-
	Report

30

-
	Report

30

126
col./100ml	Engr Judgment

Anti-backsliding / Existing Permit 
MSWQS	

2.	Maximum Permit Limitations

Outfall	Parameter	Categorical Limitation
(PreviouslyCalculated)	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Basis	
Outfall 001
MS0000574 00111	- Flow

- Ammonia   Nitrogen3

- Nitrate
  Nitrogen3

- Organic
  Nitrogen3

- pH (continuous)4

- Total Nitrogen5,6 (TN)

- Total Phosphorous7 (TP)

Temperature9 (ºF)	-

1672.3
 lb/day

2372.6
lb/day

728.1
lb/day

-

-

-

-	-

-

-

-

9.0 SU (max.)

4773.0 lb/day

86.67 lb/day

90ºF	Report

1672.3 lb/day

2372.6
lb/day

728.1
lb/day

9.0 SU (max.)

-

-

Report	Report

1672.3 lb/day

2372.6
lb/day

728.1
lb/day

9.0 SU (max.)

4773.0 lb/day

86.67 lb/day

Report	Engr Judgment

Anti-backsliding / Existing Permit 

Anti-backsliding / Existing Permit 

Anti-backsliding / Existing Permit

WLA / MSWQS / Existing Permit / 40 CFR §401.17

TMDL / WLA

Anti-backsliding / Existing Permit

MSWQS	
Outfall 101
MS0000574 10111	- Flow

- Ammonia  
  Nitrogen4
 
- pH (continuous)4	-
-

-	-

12.0 mg/l (max.)

-	Report

12.0 mg/l (max.)

9.0 SU (min.)	Report

12.0 mg/l (max.)

9.0 SU
(min.)	Engr Judgment

MSWQS & Existing Permit

MSWQS 	
Outfall 102
MS0000574 10211	- Flow

- BOD510

- TSS10

- Chlorine    Residual10

- E.Coli10
	-

-

-

-

-
	-

-

-

-

-	Report

45 mg/l

45 mg/l

1.0 mg/l (max.)

-	Report

45 mg/l

45 mg/l

1.0 mg/l (max.)

410
col./100ml	Engr Judgment

Anti-backsliding / Existing Permit 
Anti-backsliding / Existing Permit 
Anti-backsliding / Existing Permit 

MSWQS
	
Outfall 103
MS0000574 10311

	- Flow

- BOD510

- Chlorine    
   Residual10

-E.Coli10
	-

-

-

-
	-

-

-

-
	Report

45

1.0 mg/l (max.)

-	Report

45

1.0 mg/l (max.)

410
col./100ml	Engr Judgment

Anti-backsliding / Existing Permit 
Anti-backsliding / Existing Permit 

MSWQS
	
MSWQS =  Mississippi Water Quality Standard, TMDL = Total Maximum Daily Load, TSD = Technical Support Document, WLA = Waste Load Allocation (issued on August 28, 2012), FEG = Federal Effluent Guidelines (Categorical, Technology-Based)
 
3  For Outfall 001, the numeric mass loadings for ammonia nitrogen (NH3-N), Nitrate Nitrogen        (NO3-N), and Organic Nitrogen (Org-N) were originally set in the permit based upon the 40 CFR    418 (Fertilizer Manufacturing Point Source Category): Subpart B (Ammonia Subcategory),          Subpart C – (Urea Subcategory), and Subpart E (Nitric Acid Subcategory and will remain in the    proposed permit due to the anti-backsliding provisions found under 11 Miss. Admin. Code Pt. 6,    R.1.1.4.A(4)(e). of the Wastewater Regulations for NPDES Permits. Since these loadings were     considered at the time the Yazoo River Basin Nutrient TMDL was developed, MDEQ has     
   decided to limit NH3-N, NO3-N, and Org-N up to the allowable loadings permitted to the      
   facility under the TMDL (See item 5 below). For Outfall 101, the proposed limitation for 
   Ammonia Nitrogen is based upon 11 Miss. Admin. Code Pt. 6, R.2.2.F(3). of the State Water    
   Quality Criteria (i.e.,ammonia toxicity) and the existing permit.

4   For Outfall 001 and 101, the proposed limitations for pH are based upon 11 Miss. Admin. Code Pt. 6, R. 2.2.D. of the State of Mississippi Water Quality Criteria. Since pH shall be        monitored continuously at these outfalls, the Permitee shall be limited to excursions from the  pH range set forth in the permit as defined in 40 CFR §401.17. Note that for Outfall 101, the pH shall be reported utilizing the continuous monitoring equipment permanently installed in   Outfall 001, since wastewater discharging at Outfall 001 is representative of that exiting Outfall 101.

5   The proposed limitation for TN is based upon the Yazoo River Basin TMDL for nutrients for      selected Large Rivers in the Delta. The TMDL was completed in June of 2008. The TMDL          for TN has accounted for the maximum daily permitted loads for NH3-N, NO3-N, and org N         from the permit issued December 11, 2007 and was derived as follows:
   
       TMDL for TN = NH3-Nlb/day + NO3-Nlb/day + Org Nlb/day = 1672.3+2372.6+728.1 = 4773.0 lb/day

    Similarly, we have derived the average allowance for TN by totaling up the average mass             loadings for NH3-N, NO3-N, and org N as permitted in the previous permit. 

6    NH3-N, NO3-N, and Org N must be monitored and the results added together to obtain a value for          TN.

7   The proposed limitation for TP is based upon the Yazoo River Basin TMDL for nutrients for             selected Large Rivers in the Delta. 

8 The proposed limit for dissolved oxygen is based on the Water Quality Criteria as                                     determined by a Waste Load Allocation from the Standards, Modeling, and TMDL Branch                      (SMTB). 

9  Temperature – In accordance with the State of Mississippi Water Quality Criteria, the maximum water temperature shall not exceed 90ºF (32.2ºC) in streams,  lakes, and reservoirs . In addition, the discharge of any heated waters into a stream, lake, or reservoir shall not raise temperatures more than 5ºF (2.8ºC) above natural conditions for temperatures. 

      The proposed NPDES permit contains instream monitoring requirements for temperature which will allow the facility to discharged heated waters (in excess of 90ºF) during the summer and winter months as long as the temperature of the effluent does not cause the background temperature of the receiving stream to exceed 90ºF after mixing nor shall it cause it to rise more than 5ºF above natural conditions.  Instream monitoring is required to verify compliance. Conditions were added that require monitoring of the receiving stream upstream and downstream of the effluent discharge point to ensure that the effluent temperature does not cause an exceedance of the State’s temperature criteria for the receiving stream. 

10   For BOD5 at Outfall 102 and 103, and TSS at Outfall 102, limitations are based on our engineering 
     judgment and demonstrate compliance with the secondary treatment requirements will be good 
     confirmation of the performance and treatment efficiency for the two small Activated Sludge 
     package plants operating at the facility. The permit limits for Total Residual Chlorine is proposed 
     based on the anti-backsliding provisions of 11 Miss.Admin. Code Pt. 6, R.1.1.4.A(4)(e). of the 
     Wastewater Regulations for NPDES Permits and the existing permit since these outfalls collect 
     primarily the sanitary wastewater for the production areas around the facility. The E. coli limits 
     are based on Mississippi State Water Quality Standards. TSS limit has been removed from Outfall 
     103 since the flow recorded at this outfall is significantly low compared to facility’s long-term 
     average flow of 5.27 mgd. The monitoring of total residual chlorine (TRC), BOD5, and E. coli is 
     sufficed for indicating the performance and treatment efficiency of the unit operation at Outfall 
     103. 

11   Outfall 001 shall be monitored for flow and pH with a continuous recorder. All other parameters,      with the exception of Total Phosphorous, DO, and temperature shall be monitored three                     times per week with a 24-hour composite sampling of the effluent. TP shall be monitored twice per     month with a 24-hour composite sampling of the effluent. DO shall be monitored twice per month     with a grab sample of the effluent. Permit conditions have been added that require daily monitoring     of effluent temperature, as well as monitoring once per quarter upstream and downstream of the        effluent  discharge point to ensure that the effluent temperature does not cause an exceedance of       the State’s temperature criteria for the receiving stream.

     The monitoring and reporting requirements for Outfalls 101, 102, and 103, were                                 established in previous permitting actions and are retained in the proposed permit based on the 
     anti-backsliding provisions of 11 Miss. Admin. Code Pt. 6, R. 1.1.4.A(4)(e). of the Wastewater          Regulations for NPDES Permits.

ATTACHMENT I

TOXICITY SCREENING