PERMIT RATIONALE FOR REISSUANCE
Crowson Thornton, LLC, Crowson Auto World
Winston County
Louisville, Mississippi
Water NPDES No. MS0059650
August 1, 2018

I.	FACILITY INFORMATION

Facility Name:  Crowson Thornton, LLC, Crowson Auto World
Facility Address:  541 Highway 15 North, Louisville, Mississippi 39339
Permit No.:  MS0059650 (NPDES Minor Industrial)
SIC:  7538
Permit Writer:  Sherryl Couch
EPD Branch:  Water II

II.	NATURE OF BUSINESS

This is a manned car wash operation at an automotive dealership with discharge of treated carwash effluent only; no domestic wastewater is allowed.

III.	AVAILABILITY OF WASTEWATER DISCHARGE VIA CITY SEWER

	No available connection is apparent.

IV.	EFFLUENT AND RECEIVING STREAM FLOW DATA

The discharge is to an unnamed ditch thence into Tallahaga Creek.  (Located in the Pearl River drainage basin.)  (Not specifically listed/designated; therefore, classified as Fish and Wildlife.)

V.	TOTAL MAXIMUM DAILY LOAD AND 303(d) ISSUES

None, per the 2016 Section 303(d) list of impaired water bodies.

VI.	TYPE OF WASTEWATER TREATMENT:

Treatment methods include sedimentation and oil/water separator.

VII.	EPA APPLICABLE CATEGORICAL GUIDELINES

Not applicable.

VIII.	DATA FROM APPLICATION SHORT FORM D

	A Short Form D was utilized; thus, no detailed data is provided.

IX. 	WATER QUALITY LIMITATIONS BASED ON WASTELOAD ALLOCATION 

	Not applicable.

X.	CATEGORICAL GUIDELINE LIMITATIONS CALCULATIONS

Not applicable.

XI.	TOXICITY SCREENING

Not applicable.

XII.	PROPOSED FINAL LIMITATIONS 

1.	Average Permit Limitations:  Outfall 001

Parameter	Categorical Limitation	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Basis	
TSS (mg/l)	-----	-----	30	30	Domestic Guidelines	
Oil & Grease (mg/l)	-----	No visible sheen.	10	10	WQC; Domestic Guidelines	
Flow (MGD)	-----	-----	0.001	0.001	BTJ	

2.	Maximum Permit Limitations:  Outfall 001

Parameter	Categorical Limitation	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Basis	
TSS (mg/l)	-----	-----	45	50	Domestic Guidelines	
Oil & Grease (mg/l)	-----	No visible sheen.	15	15	WQC; Domestic Guidelines	
Flow (MGD)	-----	-----	0.001	0.001	BTJ	
WQC: Water Quality Criteria; BTJ: Best Technical Judgement

There is no monitoring proposed for this permitted discharge. Effluent limits have been developed such that the waste treatment system should protect water quality.  However, this permit is subject to modification if future evidence, monitoring results, or nuisance conditions indicate a higher degree of treatment is required to maintain water quality in the receiving stream.

XIII.	BTJ STATEMENT

The permit conditions and requirements are based on water quality standards and Mississippi wastewater regulations.  Permit conditions and requirements are representative of those contained in similar permits in the state for car wash facilities.