Public Notice Draft
Date: 09/07/2022

PRETREATMENT RATIONALE FOR ISSUANCE

Custom Commodities Transport
Hancock County
Bay St. Louis, MS
Water I Branch
Agency Interest (AI) No. 81023
	MSP092458
SIC: 4213
September 7, 2022
Permit Engineer: Thomas Kelly
	
I.	FACILITY INFORMATION

A.	Nature of Business: Bulk transportation

B.	Process Wastewater Description: Wastewater generated from interior and exterior tank truck washing. 

C.	Process Wastewater Treatment:  <5 mm mesh screening, Air Mixing, and pH adjustment.

D.	Proposed Flowrate: 	0.010 MGD

E.	Applicable Federal Guidelines:  40 CFR 442 Subpart A - Tank Trucks and Intermodal Tank Containers Transporting Chemical and Petroleum Cargos; Section 442.16- Pretreatment standards for new sources (PSNS).

II.	RECEIVING POTW INFORMATION

A.	POTW and Permit Number: Hancock County Water and Sewer District, Port Bienville Industrial Park (MS0059501-001), AI# 5911 

B.	POTW Treatment Type: Port Bienville Industrial Park collects and treats wastewater biologically by means of an activated sludge process and UV disinfection. Outfall 001 discharges treated Industrial/Domestic wastewater. 

C.	POTW Design Flowrate:  POTW #1 (0.150 MGD)

D.	POTW Receiving Stream: Mulatto Bayou thence to the Pearl River 

E.	POTW Receiving Stream 7Q10 (Q7Q10): Mulatto Bayou and Pearl River are both tidally influenced. The State Regulations indicate that for oceans, bays, estuaries, and lakes where a mixing zones evaluation is not available, dilution will be assumed to be one part effluent to six parts receiving water body.  This dilution ratio will be used to calculate the instream wastewater concentration (IWC).

III.	PERTINENT FLOWRATE AND LOADING DATA

A.	POTW 12-month Average Flowrate (QPOTW): 0.182 MGD

POTW Monthly Average flowrate values using 12 months of recently available DMR data (MGD): (June 2021 – March 2022)

B.	Industrial Facilities Flowrate Data: (Dec 2020-Dec 2021)

1 the largest Monthly Average value listed on the DMRs. The above listed facility submits their DMRs on a semi-annual basis.

C.	Current Maximum Permitted Loads (Xta)2: 

2 quantities listed in units of lb/day.  

D.	Maximum 30-day Average Discharge Value (Xt)2 using the most recent 
12-months of DMR data: (June 2020 - May 2021)

IV.	BACKGROUND/DOMESTIC LOADING CALCULATIONS

Background Loading (BGL), lb/d = 8.34 x BGC(mg/L)(1) x (QPOTW - QINDUSTRIAL(2))(MGD)

1 BGC = Background concentration of domestic sewage.  Calculated from actual POTW data as shown in Appendix A or literature values from Appendix V of EPA’s Local Limits Development Guidance (EPA 833-R-04-002A, July 2004) for those pollutants with insufficient data. 

2 QINDUSTRIAL = QW1 + QW2 + …
where QW is the largest average flowrate from the DMR over the last twelve months. (Maximum daily flow data may be used when monthly average data is not available.)

The background concentrations (BGc) for Cr, Hg, and Zn could not be calculated because the influent and effluent monitoring data from the POTW is not available. Consequently, the BGL loading values could not be calculated.

V.	WATER QUALITY ANALYSIS

A.	Instream Wastewater Concentration(1)

IWC = QPOTW /(QPOTW + Q7Q10) x 100   = 1/(1+6) 

Q7Q10 = (QPOTW/IWC) - QPOTW = (0.182/(1/7)) - 0.182 = 1.092 MGD

B.	Allowable Water Quality Criteria (AWQC) Headworks Loading Calculations

AWQC, lb/day = [8.34 x CCRITICAL(mg/L)(2) x (Q7Q10 + QPOTW, MGD)] / (1 – RPOTW(3))

Acute Calculations:  (Based on acute water quality criteria)

Chronic Calculations:  (Based on chronic water quality criteria)

1 If IWC ≤ 1%, only an acute screening is developed.  If IWC > 1%, an acute and chronic screening are developed.
2 CCRITICAL = State of Mississippi Water Quality Criteria (adopted October 24, 2002) or EPA Water Quality Criteria, if there is no state criteria.
3 RPOTW = Removal efficiency. Because the POTW influent and effluent data was not available, the literature values from Appendix R of EPA’s Local Limits Development Guidance (EPA 833-R-04-002A, July 2004) was used for those pollutants. 
VI.	POTW INHIBITION ANALYSIS (HEADWORKS INHIBITION, HWI)

HWI, lb/day = 8.34 x QPOTW(MGD) x CINH(mg/L)(1)

1 CINH = Activated Sludge Inhibition Threshold Levels, from EPA Guidance Manual on the Development and Implementation of Local Discharge Limitations Under the Pretreatment Program: Table 3-2 Activated Sludge Inhibition Threshold Levels.  

VII.	LIMITING CASE (LC) SUMMARY TABLE

*If AWQC < HWI, then LC = AWQC; if AWQC > HWI, then LC = HWI
 
VIII.	DEVELOPMENT OF ALLOWABLE CONCENTRATIONS

The remaining industrial wasteload allocation will be used in calculating allowable acute and chronic concentrations using the “Industrial User (IU) Contributory Flow” method as described in EPA’s Local Limits Development Guidance (EPA 833-R-04-002A, July 2004).

PAI, lb/day = (LC, lb/day – BGL, lb/day) (QI, MGD / QT, MGD)

CALLOW, mg/L = (PAI, lb/day) / (8.34 x QI, MGD)

Where,
PAI 	=	Permit allocation for indirect discharger
CALLOW=	Allowable concentration for indirect discharger
QI	=	Applicant’s permitted process discharge 
QT	=	Total industrial contributory flow for pertinent pollutants
LC	=	Limiting case loading
BGL	=	Background/domestic loading

   1Since this discharge is proposed new discharge, the maximum daily flow from the application was used for these pollutants.
2These are the permitted flow limits for those outfalls containing these pollutants.

1There are currently no industrial facilities permitted to discharge chromium and mercury, so the background loading (BGL) values will be assumed zero in the following calculations. 

2SABIC Innovative Plastics US LLC is the only industrial source currently contributing zinc to the POTW. Although the BGC and BGL values could not be calculated, the background domestic loading (BGL) will be assumed to be 0.538 lb/day in the following calculations. This loading value was obtained from their June 2021 discharge monitoring report (DMR). 

ACUTE:

CHRONIC:

IX.	FEDERAL EFFLUENT LIMITATIONS GUIDELINES (ELGs)

Part 442 – TRANSPORATION EQUIPMENT CLEANING POINT SOURCE CATEGORY
Subpart A – Tank Trucks and Intermodal Tank Containers Transporting Chemical and Petroleum Cargos
	
§ 442.16  Pretreatment standards for new sources (PSNS)

Regulated parameter 	Maximum daily1 	
Non-polar material (SGT-HEM)	26 	
Copper	0.84 	
Mercury	0.0031 	
1mg/L (ppm).

X.	NOTABLE SAMPLING DATA FROM PERMIT APPLICATION:  (Form 2P)

1Actual pollutant data was not available, so the facility has estimated these values using effluent data from a similar 
discharge at their sister facility in Baytown, TX with similar operations.
XI.	PROPOSED PERMIT LIMITATIONS

Outfall 001

Parameter	Reported Max. Conc. (mg/L)1	Allowable Concentration 	Categorical Limits	Current Permit Limits	Proposed Permit Limits	Sampling Frequency 	Sample Type	Basis of Decision1	
		Acute (mg/L)	Chronic (mg/L)	Max (mg/L)	Avg. (mg/L)	Max. (mg/L)	Avg. (mg/L)	Max. (mg/L)	Avg. (mg/L)				
Copper (TR)	0.0583 	18.23	18.23	0.84	---	---	---	0.84	Report	Monthly	Grab Sampling	CAT, TJ	
Mercury, (TR)	0.00068 	5.01	5.01	0.0031	---	---	---	0.0031	Report	Monthly	Grab Sampling	CAT, TJ	
Oil and Grease, Non-polar material	4.56 	---	---	26	---	---	---	26	Report	Monthly	Grab Sampling	CAT, TJ	
Flow (MGD)	0.010	---	---	---	---	---	---	Report	Report	Monthly	Flow Estimate	TJ	
pH (SU)	9.0 	---	---	---	---	---	---	9.0 (max)	6.0 (min)	Monthly	Grab Sampling	TJ	
1 Basis of Decision: CAT= Categorical Limitations; TJ=Technical Judgment

Wastewater Treatment

The permittee shall screen the process wastewater utilizing the <5MM mesh screen as described in the permit application.

Submit a Permit Application

Within 6 months (180 days) of commencing discharge of effluent, the permittee shall submit to the MDEQ Environmental Permits Division a completed Form 2P application containing results of data collected from the facility's process wastewater discharge. The sampling data shall be representative of typical washing activities. Based upon the results of the sampling, the permit may be reopened to address additional limits or requirements as deemed necessary to protect the POTW or water quality.

Electronic DMR submission to the POTW

The permittee shall submit the quarterly Discharge Monitoring Report (DMR) via email to the Hancock County Water and Sewer District, Port Bienville Industrial Park (hcsport@bellsouth.net). The DMR submission shall be done through the MDEQ NetDMR system due no later than the 28th day of the month following the completed reporting period. The DMR recipient's email address (hcsport@bellsouth.net) should be added in the "DMR Submissions Notification" section of NetDMR.

X.	STATEMENT OF BASIS 

The foregoing limitations are based on technical judgment (TJ), the Categorical (CAT) Standards of 40 CFR 40 CFR 442 Subpart A, and the requested limitations from the Hancock County Water and Sewer District - Port Bienville Industrial Park (POTW) specified in their letter dated August 15, 2022.

APPENDIX A

ADEQUACY OF TREATMENT