PERMIT RATIONALE
DEEPROCK DISPOSAL SERVICES LLC., WAYNESBORO
WAYNESBORO, WAYNE COUNTY
NPDES PERMIT NO. MS0046531
August 20, 2019

I.	INDUSTRIAL CLASSIFICATION: The facility has two Standard Industrial Classification (SIC) Codes.  They are 1389 - Oil and Gas Field Services and 2421 - Sawmills and Planing Mills.  The facility has the following operations at the site: Oilfield service, vehicle maintenance, hardwood saw milling, and pine chip milling.

II.	GENERAL DESCRIPTION OF WASTEWATER AND DISCHARGE FLOW:
The facility has one outfall which they have applied to be permitted for.  Effluent from outfall 001 consists of storm water overflow from the facility’s log spray re-circulation sump.  Discharge from sump does not occur during normal operations at the site.  Discharge from the sump is rainfall dependent. 
  
III.	DESCRIPTION OF WASTEWATER TREATMENT:  The facility has a 28,000 gallon log spray re-circulation sump where water which is sprayed on the logs is recaptured and reused.  Sedimentation and settling occur in the log spray re-circulation sump.  Discharge from the sump occurs only during a rainfall event.     

IV.	RECEIVING WATERS:	Unnamed tributary of the Chickasawhay River
(7Q10 of unnamed tributary = 0 MGD)

There are no 303(d) issues for the site.  In 2005, a TMDL was finalized for the Chickasawhay River for Organic Enrichment/Low DO and Nutrients.  Also in 2005, a TMDL was finalized for Sediment.  Deeprock Disposal Services is not discussed in either TMDL nor is a reduction in the pollutant loadings discharged from this facility proposed. 
	
V.	APPLICABLE GUIDELINES:	"State of Mississippi Water Quality Criteria", 40 CFR Part 429 - Timber Products Processing Point Source Category; Subpart I - Wet Storage Subcategory; Section 429.103 and Subpart K - Sawmills and Planing Mills Subcategory; Section 429.123.

VI.	 PERTINENT DATA FROM FORM 2C:

				Maximum 		Number            
	Parameter		Daily Value		of Samples	
	BOD (5-Day)		25.1 ppm		1
	COD			181 ppm		1
	TOC			30.3 ppm		1
	TSS			400 ppm		1
	Ammonia (as N)	0.069 ppm		1
	Flow			1.35 MGD		3
				
				Maximum 		Number            
	Parameter		Daily Value		of Samples	
	pH			7.1-7.3 s.u.		19
	
VII.	SUMMARY OF WATER QUALITY LIMITATIONS , CATEGORICAL 	            LIMITATIONS, EXISTING PERMIT LIMITATIONS, AND PROPOSED            EFFLUENT PERMIT LIMITATIONS		

	Average Limitations

			Water				Existing	Proposed
			Quality		Categorical	Permit		Permit	
Paramter	Limitations	Limitations	Limitations	Limitations	Basis
	pH		6.0 - 9.0 s.u.	6.0 - 9.0 s.u.	6.0-9.0 s.u.	6.0-9.0 s.u.	MSWQS
	
	Maximum Limitations

			Water				Existing	Proposed
			Quality		Categorical	Permit 		Permit		
	Parameter	Limitations	Limitations	Limitations	Limitations	Basis	
	pH		6.0 - 9.0 s.u.	6.0 - 9.0 s.u.	6.0-9.0 s.u.	6.0-9.0 s.u.	MSWQS
	
The pH limits are based on the “State of Mississippi Water Quality Criteria”.  pH shall be monitored once per year with a grab sample of the effluent.  One special condition of the permit, as per 40 CFR Part 429, Subpart I, shall be that there shall be no discharge of debris from the log spray sump.  Another special condition of the permit, as per 40 CFR Part 429, Subpart K, shall be that there shall be no discharge of process wastewater from the sump.  In order to ensure that no discharge occurs from the sump except as a result of rainfall, two other special conditions of the permit shall be as follows:

1.)	The log spray sump shall be operated and maintained such that there shall be no          discharge except during rainfall conditions.

2.)	A daily inspection log shall be maintained at the facility to indicate freeboard level and daily rainfall events.

The facility also has a truck washout pit at the site from which no discharge occurs.  Two conditions of the permit regarding the truck washout operation shall be that there shall be no discharge to waters of the State from the truck washout pit and that a minimum of 2 feet of freeboard shall be maintained in the truck washout pit during normal operations.  The facility recycles this wastewater.

As is found in the existing permit, the facility will be required to estimate flow from Outfall 001 using the rationale equation.  Two special conditions of the permit for flow shall be as follows:

1.)	The permittee shall maintain a rain gauge on the site.

2.)	The permittee shall estimate discharge from Outfall 001 using the rationale equation.

The facility was previously known as Deepwell Energy Services.  The name change for the NPDES Permit is being handled as part of the reissuance process.