PRETREATMENT RATIONALE FOR REISSUANCE

Rohm and Haas Chemicals LLC
Jackson
Moss Point, MS
Chemical Branch

MSP092041
SIC: 2822
June 26, 2015
Permit Engineer: Ryan Ozment

I.	FACILITY INFORMATION

A.	Nature of Business: Site of a closed and dismantled industrial plant (since 2001) with contaminated groundwater from hazardous disposal operations.  The only activities on site are those associated with remediation.
B.	Process Wastewater Description:  Wastewater results only from groundwater remediation.  Treatment includes: 1) pH adjustment (utilizing potassium hydroxide), 2) aeration, 3) solids removal via lamella clarifier, 4) multi-media filtration, and 5) two carbon beds in series.  
C.	Proposed Flowrate: 250,000 gallons per day
D.	Applicable Federal Guidelines: 40 CFR 403 General Pretreatment Regulations

II.	RECEIVING POTW INFORMATION

A.	POTW and Permit Number: Jackson County Utility Authority, Escatawpa WWTP (Permit No. MS0021521)
B.	POTW Treatment Type: Activated sludge followed by UV disinfection
C.	POTW Design Flowrate: 3 MGD (4.65 cfs)
D.	POTW Receiving Stream: Escatawpa River (fish & wildlife classification)
E.	POTW Receiving Stream 7Q10 (Q7/10):  100 cfs

III.	PERTINENT FLOWRATE AND LOADING DATA

A.	POTW 12-month Average Flowrate (QPOTW): 1.2 MGD (See Appendix A: POTW DMR Data)
B.	Industrial Facilities Flowrate Data:

Facility	Average Flow (MGD)1	Maximum Daily Flow (MGD)	Permitted Maximum Daily Flow (MGD)	
Rohm & Haas Chemicals LLC	0.090	0.112	0.2502	
Omega Protein Inc	0.026	0.131	0.108	
Macland Disposal Center Inc.	0.018	0.085	0.174	
Total	0.134	0.328	0.532	
1 The average flow from DMR Data following the installation of the new groundwater treatment system (July 2013 —October 2014).
2 Rohm & Haas is permitted to report its daily maximum flow.  Value chosen based on treatment system design capacity.

C.	Current Maximum Permitted Loads (Xtat): 
Parameter	Permitted Concentration	Xtat (using design flow rate, 0.25 MGD)	
Units	mg/L	lb/d	
1,2-dichloroethane	0.574	1.200	
1,1-dichloroethane	0.059	0.123	
1,1,1-trichloroethane	0.059	0.123	
1,1-dichloroethylene	0.060	0.125	
1,2-transdichloroethylene	0.066	0.138	
Benzene	0.134	0.279	
Bis (2-ethylhexyl) Phthalate	0.258	0.538	
Ethyl Benzene	0.380	0.792	
Methylene Chloride	0.170	0.354	
Toluene	0.074	0.154	
Vinyl Chloride	0.172	0.360	

D.	Maximum 30-day Average Discharge Value (Xtt) using the most recent 12 months of DMR data: 

Parameter	Application Data	DMR Data	Xtt (using 0.25 MGD and largest concentration)	
Units	mg/L	lb/d	
1,2-dichloroethane	0.029	0.034	0.071	
1,1-dichloroethane	ND	ND	--	
1,1,1-trichloroethane	ND	ND	--	
1,1-dichloroethylene	ND	ND	--	
1,2-transdichloroethylene	ND	ND	--	
Benzene	ND	ND	--	
Bis (2-ethylhexyl) Phthalate	ND	ND	--	
Ethyl Benzene	ND	ND	--	
Methylene Chloride	ND	ND	--	
Toluene	ND	ND	--	
Vinyl Chloride	ND	ND	--	
Mercury	0.000074	--	0.0002	
Cyanide	0.0035	--	0.0073	
  	       ND = Non-detect

IV.	BACKGROUND/DOMESTIC LOADING CALCULATIONS

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

QPOTW = 1.2 MGD
QIN = 0.134 MGD
∆Q = 1.066 MGD

Parameter	BGC (mg/L)	BGL (lb/d)	
1,1-dichloroethane	0.026	0.231	
1,2-transdichloroethylene	0.013	0.116	
Methylene Chloride	0.055	0.489	
Mercury	0.054	0.480	
Cyanide	0.370	3.290	

Example (Mercury): BGL (lb/d) = 8.34 × 0.054 × 1.066 = 0.480 lb/d

1 BGC = Background concentration of domestic sewage.  Literature values from Appendix V of EPA’s Local Limits Development Guidance (EPA 833-R-04-002A, July 2004).  Only these five parameters had background concentration data available.

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.)

V.	WATER QUALITY ANALYSIS

A.	Instream Wastewater Concentration(1)

IWC, % = QPOTW / (QPOTW + Q7/10) x 100
	
QPOTW = 4.65 cfs
	Q7/10  = 100 cfs

	IWC (%) = 4.65 / (4.65 + 100) × 100 = 4.44%

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

AWQC, lb/d = 8.34 x CCRITICAL(mg/L)(2) x (Q7/10 + QPOTW, MGD) / (1 – RPOTW(3))

Parameter	CAcute	CChronic	RPOTW	AWQCAcute	AWQCChronic	
Mercury	0.0018	0.000025	0.60	3.93	0.055	

Example (Acute, mercury): 
AWQCAcute = (8.34 × 0.0018 × 104.65) / (1 – 0.60) = 3.93 lb/d

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).  No other parameters have acute and/or chronic water quality criteria established by MDEQ or EPA.  

3 RPOTW = Removal efficiencies in decimal form from an MDEQ removal study and Appendix R of EPA’s Local Limits Development Guidance (EPA 833-R-04-002A, July 2004). 

VI.	POTW INHIBITION ANALYSIS (HEADWORKS INHIBITION, HWI)

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

	QPOTW  = 1.2 MGD

Parameter	CINH	HWI	
Units	mg/L	lb/d	
Benzene	100	1000.8	
Ethyl Benzene	200	2001.6	
Toluene	200	2001.6	
Mercury	0.1	1.0008	
Cyanide	0.1	1.0008	

	Example (Mercury): HWI (lb/d) = 8.34 × 1.2 × 0.1 = 1.0008 lb/d

1 CINH = Activated Sludge Inhibition Threshold Levels, from Appendix G of EPA’s Local Limits Development Guidance (EPA 833-R-04-002A, July 2004).  Only these five parameters had inhibition data available. 

I.	
VII.	LIMITING CASE (LC) SUMMARY TABLE

Parameter	HWI (lb/d)	Acute AWQC (lb/d)	Chronic AWQC (lb/d)	POTW LC (lb/d)1	LC (lb/d)	BGL (lb/d)	Xtat (lb/d)	Xtt (lb/d)	BGL < LC (Pass/Fail)	Xtat < LC (Pass/Fail)	Xtt < LC (Pass/Fail)	
1,2-dichloroethane	--	--	--	--	--	--	1.200	0.071	--	--	--	
1,1-dichloroethane	--	--	--	--	--	0.231	0.123	--	--	--	--	
1,1,1-trichloroethane	--	--	--	--	--	--	0.123	--	--	--	--	
1,1-dichloroethylene	--	--	--	--	--	--	0.125	--	--	--	--	
1,2-transdichloroethylene	--	--	--	--	--	0.116	0.138	--	--	--	--	
Benzene	1000.8	--	--	--	1000.8	--	0.279	--	--	Pass	--	
Bis (2-ethylhexyl) Phthalate	--	--	--	--	--	--	0.538	--	--	--	--	
Ethyl Benzene	2001.6	--	--	--	2001.6	--	0.792	--	--	Pass	--	
Methylene Chloride	--	--	--	--	--	0.489	0.354	--	--	--	--	
Toluene	2001.6	--	--	--	2001.6	--	0.154	--	--	Pass	--	
Vinyl Chloride	--	--	--	--	--	--	0.360	--	--	--	--	
Mercury	1.0008	3.93	0.055	--	0.055	0.480	--	0.0002	Fail	--	Pass	
Cyanide	1.0008	--	--	--	1.0008	3.290	--	0.0073	Fail	--	Pass	

1 If the POTW has a limit for a specific parameter, industrial loading is limited to the amount the POTW can accept and still meet the limit.  If there is no specific limit, this column does not apply.  POTW LC (lb/d) = (8.34 x CPOTW(mg/L) x QPOTW (MGD)) / (1 – RPOTW), where CPOTW is the POTW concentration limit in mg/L.  
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/d = (LC, lb/d – BGL, lb/d) (QI, MGD / QT, MGD)

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

	Not applicable.	

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

I.	
IX.	PROPOSED PERMIT LIMITATIONS
Parameter	Reported Max. Conc. (mg/L)	Allowable Concentration 	414.111 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)				
1,1,1-trichloroethane	ND	--	--	0.059	0.022	0.059	0.022	0.059	0.022	Monthly	Grab Sampling	TBEL	
1,1-dichloroethane	ND	--	--	0.059	0.022	0.059	0.022	0.059	0.022	Monthly	Grab Sampling	TBEL	
1,1-dichloroethylene	ND	--	--	0.06	0.022	0.06	0.022	0.06	0.022	Monthly	Grab Sampling	TBEL	
1,2-dichloroethane	0.034	--	--	0.574	0.18	0.574	0.18	0.574	0.18	Monthly	Grab Sampling	TBEL	
1,2-transdichloroethylene	ND	--	--	0.066	0.025	0.066	0.025	0.066	0.025	Monthly	Grab Sampling	TBEL	
1,4-dioxane (1,4-diethyleneoxide)	1.6	--	--	--	--	Report	Report	Report	Report	Monthly	Grab Sampling	PPL	
Benzene	ND	--	--	0.134	0.057	0.134	0.057	0.134	0.057	Monthly	Grab Sampling	TBEL	
bis(2-Chloroethoxy)methane	0.0052	--	--	--	--	Report	Report	Report	Report	Monthly	Grab Sampling	PPL	
Bis(2-ethylhexyl) phthalate	ND	--	--	0.258	0.095	0.258	0.095	0.258	0.095	Monthly	Grab Sampling	TBEL	
Dichloroethyl ether (Bis(2-chloroethyl)ether)	ND	--	--	--	--	Report	Report	Report	Report	Monthly	Grab Sampling	PPL	
Ethyl benzene	ND	--	--	0.38	0.142	0.38	0.142	0.38	0.142	Monthly	Grab Sampling	TBEL	
Ethylene chlorohydrin	1	--	--	--	--	Report	Report	Report	Report	Monthly	Grab Sampling	PPL	
Methylene chloride	ND	--	--	0.17	0.036	0.17	0.036	0.17	0.036	Monthly	Grab Sampling	TBEL	
Toluene	ND	--	--	0.074	0.028	0.074	0.028	0.074	0.028	Monthly	Grab Sampling	TBEL	
Vinyl chloride	ND	--	--	0.172	0.097	0.172	0.097	0.172	0.097	Monthly	Grab Sampling	TBEL	
Flow	250 MGD	--	--	--	--	Report	0.23 MGD	Report	0.23	Continuously	Continuous Recorder	PPL	
BOD5	28	--	--	--	--	500	400	500	400	Weekly	24-hr Composite	PPL	
Parameter	Reported Max. Conc. (mg/L)	Allowable Concentration 	414.111 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)				
pH	5.7—9.1 S.U.	--	--	5.0—9.5 S.U.	6.0—9.0 S.U.	Continuously	Continuous Recorder	PPL	
TSS	31	--	--	--	--	300	200	300	200	Weekly	24-hr Composite	PPL	
1,2,3-trichloropropane	ND	--	--	--	--	--	--	Report	Report	Monthly	Grab Sampling	 CBP	
1,2-dichloropropane	ND	--	--	0.794	0.196	--	--	0.794	0.196	Monthly	Grab Sampling	TBEL, CBP	
1,3-dichloropropane	ND	--	--	--	--	--	--	Report	Report	Monthly	Grab Sampling	 CBP	
Chloroethane	ND	--	--	0.295	0.11	--	--	0.295	0.11	Monthly	Grab Sampling	TBEL, CBP	
Ethylene Glycol	ND	--	--	--	--	--	--	Report	Report	Monthly	Grab Sampling	 CBP	
Chloroactetaldehyde	ND	--	--	--	--	--	--	Report	Report	Monthly	Grab Sampling	 CBP	
Acetaldehyde	ND	--	--	--	--	--	--	Report	Report	Monthly	Grab Sampling	 CBP	
Formaldehyde	ND	--	--	--	--	--	--	Report	Report	Monthly	Grab Sampling	CBP	
Mercury	0.000074	3.93	0.055	--	--	--	--	--	--	--	--	EJ	
Cyanide	0.0035	--	--	--	--	--	--	--	--	--	--	EJ	
ND = Non-detect
1 Basis of Decision: WQC = Water Quality Criteria; TBEL = Technology-Based Effluent Limitation; CBP = Compounds Believed Present; PPL = Previous Permit Limit; EJ = Engineering Judgement; etc.

X.	STATEMENT OF BASIS (narrative)

	The majority of monitoring and reporting requirements for this permit will remain the same as the previous permit.  The only changes to the permit include the addition of reporting requirements for six (6) compounds believed to be present and limitations on two (2) others that may cause a detectable concentration in the effluent. 
•	BOD, TSS, and pH limits were established by the POTW, and they are still willing to accept the discharge with these limitations.
•	Many of the pollutants included in the permit were established using 40 CFR 414.111: Toxic Pollutant Standards for Indirect Discharge Point Sources for Manufacturers of Organic Chemicals, Plastics, and Synthetic Fibers (OCPSF).  This was determined due to the similar characteristics between the recovered groundwater and facilities described in 40 CFR Part 414.  Also, Rohm & Haas has adequate treatment installed to meet these technology-based standards.
•	A few nonconventional pollutants believed to be present in the groundwater are not included on the 2-P application.  The permittee provided a list of these eight compounds with their application.  Two of these (1,2-dichloropropane and chloroethane) also have standards in the OCPSF list and have been added to the permit, while the other six will only be required to monitor and report at the same frequency as the other nonconventional pollutants.
•	No limitation or reporting requirements will be included for cyanide or mercury due to the reported concentrations being over 500 orders of magnitude smaller than the allowable concentration.  Also, the detected concentrations were well below the background concentrations for mercury and cyanide that are estimated to be in domestic wastewater, further substantiating no need for monitoring of these two pollutants. 
•	At the request of the Jackson County Utility Authority, the pH limits will be adjusted from 5.0 – 9.5 S.U. to 6.0 – 9.0 S.U.  

APPENDIX A

POTW DMR DATA