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The full text of certain NPDES permits and the associated fact sheets has been made available to 

provide online access to this public information. EPA is making permits and fact sheets available 

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permit writers. The ownership of these documents lies with the permitting authority, typically a 

State with an authorized NPDES program. 

While EPA makes every effort to ensure that this web site remains current and contains the final 

version of the active permit, we cannot guarantee it is so. For example, there may be some delay 

in posting modifications made after a permit is issued. Also note that not all active permits are 

currently available electronically. Only permits and fact sheets for which the full text has been 

provided to Headquarters by the permitting authority may be made available. Headquarters has 

requested the full text only for permits as they are issued or reissued, beginning November 1, 

2002. 

Please contact the appropriate permitting authority (either a State or EPA Regional office) prior to 

acting on this information to ensure you have the most up-to-date permit and/or fact sheet. EPA 

recognizes the official version of a permit or fact sheet to be the version designated as such and 

appropriately stored by the respective permitting authority. 

The documents are gathered from all permitting authorities, and all documents thus obtained are 

made available electronically, with no screening for completeness or quality. Thus, availability 

on the website does not constitute endorsement by EPA. 
E. I. du Pont de Nemours & Company NPDES Permit No. DE 0000051 

Chemical & Pigments Department State Permit No. WPCC 3193C/76 

104 Hay Road 

Edge Moor, Delaware 19809 

The E. I. du Pont de Nemours & Company Edge Moor (DuPont) facility has applied for reissuance of its National 

Pollutant Discharge Elimination System (NPDES) permit No. DE 0000051 issued on September 29, 1989 and 

amended on March 8, 1990 and October 20, 1993 to discharge noncontact cooling water, treated process waste 

waters, and storm water to the Delaware River and Shellpot Creek. 

DNREC published public notice for reissuance of this permit on June 10, 1998. EPA Region III at that time 

rescinded intake provisions in Delaware’s SWQS, and objected to the draft permits inclusion of allowances for 

pollutants, total suspended solids (TSS) and iron, in the intake from the Delaware River water used in the site’s noncontact cooling water system. The reissued Delaware “Regulations Governing the Control of Water Pollution”1 

(RGCWP) include the required provisions addressing pollutants in the intake in §8.04(d). 

This permit expired on September 28, 1994. In accordance with State and federal regulations, their NPDES permit 

renewal application was submitted 3/20/94. That application information is old, and the discussion below reflects 

that. Where available (e.g., DMR data), more recent data were used in the following permit renewal review. 

Proposed Changes2 

1. PCBs, dioxins, and furans. 

a. Add numeric limits for Outfall 001 for the total of congeners of PCBs, dioxins and furans, as “Toxic 

Equivalents to 2,3,7,8 TCDD”. 

b. Require quarterly monitoring for outfall 001 and annual monitoring for Outfall 004. 

c. Require maintenance of a ”Pollutant Minimization Plan” (PMP)3 for PCBs, dioxins, and furans for entire site. 

2. Outfalls 001, 002, and 003 – Grant request for changes in temperature and flow limits.- In a letter dated August 

14, 2006, DuPont requested increases in temperature limits. The increased temperature limits will be offset by 

decreases in flow limits, such that the total permitted heat discharge (measured as BTU) will be reduced 

slightly. See Table below for existing and proposed limits: 

1

2

 Effective Date May 14, 2003. 

 Changes are compared to the currently effective permit, not the 6/10/98 Public Notice draft permit. 3 From §4.30.0.E.6.C of DRBC’s “Rule For Establishing Pollutant Minimization Plan (PMP) Requirements For Point 

And Non-Point Source Dischargers Of Toxic Pollutants Following Issuance Of A TMDL Or Assimilative Capacity 

Determination, 4.30.9 Pollutant Minimization Plans for Toxic Pollutants,” adopted May 18, 2005. See 

http://www.state.nj.us/drbc/PMPrule-May05.pdf. 

Permit Effective Date: January 1, 2007 
DuPont Edge Moor, Fact Sheet Page 2 of 11 Pages 

Table 1 -- Proposed Flow and Temperature Limit Changes 

Outfall Temperature (°F) Flow (mgd) Change in Heat 

Current Proposed Current Proposed Discharged (BTU) 

001 110 112 5.20 5.20 88 

002 110 110 3.00 2.89 -100 

003 110 112 6.00 5.90 7 

Total 14.2 13.99 -6 

3. Outfall 001 – Discharge of treated process wastewater 

a. Considering treatment plant performance and RGCWP §7.03(a), 

i. Reduce the average iron limit from 3.0 to 2.0 mg/L. 

ii. Delete Special Condition No. 3. It required six months monitoring of Outfall 001 for ammonia, 

aluminum, copper, silver, mercury, hardness, chlorides, conductivity, and alkalinity. The monitoring has 

been completed. 

iii. Grant request (in 3/20/94 renewal application) to reduce chromium monitoring from weekly to monthly. 

iv. Delete Special Condition No. 4. It required the permittee to “identify valance equilibrium coefficients 

typical for chromium in discharge 001". That is, identify total vs. hexavalent chromium (chromium+6, the 

much more toxic form) in the 001 discharge. 

b. Whole Effluent Toxicity 

i. Add a compliance schedule to eliminate acute whole effluent toxicity within three years. 

ii. Acute biomonitoring should remain at quarterly frequency. 

iii. Add chronic biomonitoring, per the DRBC’s request. 

iv. Add final limits for acute whole effluent toxicity. 

c. Add quarterly monitoring for 1,2 dichloroethane, trichloroethene, Tetrachloroethene, using U.S. EPA test 

method 601 GC/HAL for purgeable halocarbons, as requested by the Delaware River Basin Commission 

(DRBC). The DRBC is gathering information regarding loads of these pollutants from multiple potential 

sources to the Delaware River. 

4. Outfalls 002 and 003 - Intake is from the Delaware River. Both discharges are predominantly single-pass 

noncontact cooling water, with some storm water. 

a. For total suspended solids (TSS) and iron, 

i. Delete current permit’s final limits based on “intake + analytical variability” for iron and TSS. 

ii. Current monitoring frequency is once per month. Increase frequency to twice per month simultaneous 

samples on intake, 002, and 003 for TSS and iron. 

iii. Add a reopener clause into the special conditions that specifically allows reopening the permit to update 

the iron and TSS limits for 002 and 003, based on analysis of data if needed 

iv. Require yearly submittal of paired sample results (since the permit effective date) in electronic format 

(Excel, Lotus, etc.). 

v. Add Special Condition requiring PMP for iron to identify and reduce possible iron sources to the river for 

outfall 002 and 003. 

b. Delete Special Condition No. 11. It required controls for storm water runoff from the ilmenite storage pile in 

the area of Outfall 003. In the future, these controls should be included in the Storm Water Plan (SWP). 

5. Outfall 004 – Added monitoring requirements for dissolved organic carbon, total organic carbon, and total 

suspended solids. This monitoring is intended to evaluate the usefulness of these parameters as surrogate 

indicators of the presence of PCBs, dioxins, and furans. 

6. Require submittal of updated NPDES application Forms 2C and 2F, considering the date of the original permit 

application (1994). 

7. Add Special Condition requiring a storm water plan (SWP) to prevent and minimize contamination of storm 

water runoff from the site. 

Permit Effective Date: January 1, 2007 
DuPont Edge Moor, Fact Sheet Page 3 of 11 Pages 

Background Information 

Activity Description 

DuPont Edge Moor manufactures titanium dioxide, ferric chloride, and titanium tetrachloride. 

Statutory and Regulatory Basis 

The Delaware Department of Natural Resources and Environmental Control (DNREC) proposes to reissue an 

NPDES permit to discharge the wastewater subject to certain effluent discharge limitations, monitoring 

requirements and other terms and conditions identified in the draft permit. Section 402 of the federal Clean Water 

Act, as amended, and 7 Del. C. Chapter 60 provide the authority for permit issuance. Federal and state regulations 

promulgated pursuant to these statutes are the regulatory bases for permit issuance. 

Receiving Stream Classification 

DuPont Edge Moor’s storm water and non-storm water effluents discharge to the Delaware River. The Delaware 

River Basin Commission assesses attainment of designated uses for these receiving waters. Zone 5 of the 

Delaware River does show some nonattainment of designated uses. 

Regulatory agencies classify water bodies according to their designated uses (e.g., aquatic life protection, fishing, 

swimming, etc.). Agencies assess whether each body supports (“attains”) each of its designated uses, and report 

their assessments in “305(b)” Reports1

 (See Table 1, “Use Support in Estuary Assessment Units 

from 2004 Integrated Assessment”). When a stream is in non-attainment of a designated use, it must be listed on a 

“303(d) List” (See Table 2, “Final Determination For The State Of Delaware, 2002 Clean Water Act Section 303(d) 

List Of Waters Needing TMDLs”, for the Delaware River waters), which shows the cause of the impairment, and a 

schedule for agencies to address those impairments, usually via the TMDL5

. 

Table 2 -- 2 Use Support in Estuary Assessment Units 

from 2004 Integrated Assessment 

Parameter Assessment Unit 

5A 5B 5C 

Designated Use Use Support Level 

Aquatic Life ID Not Supported Not Supported 

Recreation Supported Supported Supported 

Drinking Water NA NA NA 

Fish Consumption Not Supported Not Supported Not Supported 

Final Assessment Category3

 5 5 5 

Notes: 

NA: Ambient criteria not applied in these zones 

ID: Insufficient Data 

Aquatic Life Use Support Assessed by: DO, Temperature, pH, TDS, Alkalinity, 

Turbidity, Toxicity4

, Toxic Parameters 

Recreation Use Support Assessed by: Fecal Coliform 

Drinking Water Use Assessed by: TDS, Turbidity, Chloride in Zones 2 and 3, 

Sodium in Zone 3, Toxic Parameters 

Fish Consumption Use Assessed by: Presence of Advisories. See “2004 Delaware 

River and Bay Integrated List Water Quality Assessment", Tables 3.14 through 

3.16, beginning on Pages 57, September 2004, DRBC 

(http://www.state.nj.us/drbc/04IntegratedList/EntireReport.pdf). 

1 Called “305(b) Reports” because they are required under Section 305(b) of the Federal Clean Water Act. 2

3 

 “2004 Delaware River and Bay Integrated List Water Quality Assessment", Table 1.2, Page 4, September 2004, DRBC. 

“The water quality standard is not attained. The AU is impaired or threatened for one or more designated uses by a pollutant(s), and requires a 

TMDL.” From “2004 Delaware River and Bay Integrated List Water Quality Assessment", §3.3.5, “Method For Assigning Assessment Units to 

Integrated List Categories”, Page 47, September 2004, DRBC. 4

 The protocol for gathering chronic toxicity data and related information has been questioned. There is a need to collect supplementary data in 

order to determine the validity of the data used for this listing and the extent of the impairment, which may exist in the river segment. 5

 “TMDL” is the “Total Maximum Daily Load” from point, nonpoint, and natural background sources that a water body can assimilate and still 

support designated uses. 

Permit Effective Date: January 1, 2007 
DuPont Edge Moor, Fact Sheet Page 4 of 11 Pages 

Maps of Assessment Units are available at http://www.state.nj.us/drbc/04IntegratedList/background2.2.pdf, "Figure 

2.3: Main Stem Water Quality Zones for the Delaware River". 

Table 3. 2004 Delaware Surface Water Attainment for Shellpot Creek1 

Watershed Segment 

ID 

Segment 

Name 

Segment Length 

(miles) or area 

(acres or sq. 

miles) 

Attainment Fish advisory 

contaminants, 

metals or 

ammonia 

Min 

DO 

Avg 

DO Bacterial N P Overall 

Shellpot 

Creek 

DE 300-

001-01 

Lower 

Shellpot 

Creek 

1.0m 1 3 5 5 5 5 PCBs, 

Chlordane 

KEY for Attainment Code2 

1 = Fully Supporting for this parameter 

3 = Information is insufficient to make a determination 

4a = TMDL has been completed and approved by EPA 

4B = Management Actions are expected to solve impairment 

5 = TMDL Needed 

Table 4 -- 2006 Delaware Fish Consumption Advisories 

Waterbody Species Geographical Extent Contaminants of 

Concern* ** Advice 

Delaware River All Finfish Delaware State Line to the C&D 

Canal 

PCBs, Dioxin, Mercury, 

Chlorinated Pesticides No Consumption 

Lower Delaware 

River and 

Delaware Bay 

Weakfish-all sizes; Bluefish-14 inches 

or less 

Chesapeake & Delaware Canal to 

the Mouth of the Delaware Bay PCBs No more than one 8­

ounce meal per month 

Striped Bass, White Perch, American 

Eel, Channel Catfish, White Catfish, 

Bluefish-greater than 14 inches 

Chesapeake & Delaware Canal to 

the Mouth of the Delaware Bay PCBs, Mercury No more than one 8­ounce meal per year*** 

Shellpot Creek All Finfish Philadelphia Pike to the De. River PCBs No 

From http://www.fw.delaware.gov/Fisheries/AdvisoriesChart.htm 

Notes: 

* The pollutant listed first is of the greatest concern in this system. 

** Proper trimming and cooking of fish can reduce but not eliminate the risk associated with PCBs, dioxins, and 

chlorinated pesticides. Trimming and cooking does not reduce the risk associated with mercury. 

*** Women of childbearing age and children should not consume any amount of these fish. 

 “State of Delaware 2004 Combined Watershed Assessment Report (305(b)) and Determination for the Clean Water Act Section 303(d) List of 

Waters Needing TMDLs”, Delaware Department of Natural Resources and Environmental Control, February 25, 2005, Table III-5: 

(http://www.dnrec.state.de.us/water2000/Sections/Watershed/TMDL/2004%20305_b.pdf, pg 130 of 254 of .pdf file) 2

 Ibid. pg 163 of 254 of the .pdf file 

Permit Effective Date: January 1, 2007 

1
DuPont Edge Moor, Fact Sheet Page 5 of 11 Pages 

Table 5 -- “Final Determination for The State of Delaware, 

2004 Clean Water Act Section 303(d) List Of Waters Needing TMDLs” 

SEGMENT 

(TOTAL SIZE) DESCRIPTION SIZE 

AFFECTED 

POLLUTANT(S) 

AND / OR 

STRESSOR(S) 

PROBABLE 

SOURCE(S) 

YEAR 

LISTED 

TARGET DATE FOR 

TMDL 

Pollutant 

CALM 

Code 

Shellpot Creek 

Lower Shellpot 

Creek 

(1.0 mile) 

From the head of tide 

below the east set of 

railroad tracks to the 

mouth of the Delaware 

River 

1.0 mile 

Nutrients, DO NPS 

Delaware 

River 

1996 2004 (Nutrients, DO 

and Bacteria) 

2009 

(PCBs, Chlordane) 

5 

Bacteria, PCBs, 

Chlordane 2002 5 

Shellpot Creek 

Upper Shellpot 

Creek 

(14.2 miles) 

From the headwaters to 

the head of tide below 

the east set of railroad 

tracks 

7.7 miles Bacteria, Nutrients, NPS 1996 2004 5 

Western tributary of the 

headwaters to the 

confluence of the next 

larger stream order 

1.4 miles Biology and Habitat NPS 1998 2009 5 

From the headwaters of 

Matson Run to the 

confluence with 

mainstem Shellpot 

Creek 

1.3 miles Biology and Habitat NPS 1998 2009 5 

Delaware 

River DRBC 

Zone 51 

(59.0 sq. mi.) 

From the PennsylvaniaDelaware line to Liston 

Point, Delaware. 

59.0 sq. mi. 

Bacteria PS, NPS 1996 2006 (Bacteria) 5 

PCBs 

PS, NPS, SF 

2005 (PCBs) 5 

Arsenic, Dioxin, 

Mercury, Chlorinated 

Pesticides 

2002 

2011 (Arsenic, Dioxin, 

Mercury, Chlorinated 

Pesticides) 

5 

Chronic Toxicity PS, NPS, SF 2002 (See Note 1) 3 

Iron 2004 (See Note 2) 3 

Delaware Bay 

DRBC Zone 6 

(782.0 sq. 

mi.) 

From Liston Point to the 

confluence with the 

Atlantic Ocean 

782.0 sq. mi. 

PCBs, Bacteria 

PS, NPS, SF 

1996 2005 (for Bacteria) 

2006 (for PCBs) 5 

Mercury, Dieldrin 2002 2012 5 

KEY for Probable 

Source(s): 

NPS = Nonpoint Source(s) 

PS = Point Source(s) 

SF = Superfund Site(s) 

KEY for CALM Codes: 

1= Fully Supporting for this parameter 

3= Information is insufficient to make a determination 

Note 1. The protocol for gathering chronic toxicity data and related information has been questioned. There is a need to collect 

supplementary data in order to determine the validity of the data used for this listing and the extent of impairment which may exist in the 

river segment. 

Note 2. Surface water levels of iron in the segment sometimes exceed the applicable criterion. The Department believes further study of 

surface water iron levels and a determination of whether a use impairment is resulting from those levels is an appropriate response to the 

available information. 

Discharge Description 

Ten discharges (Outfalls 001, 002, 003, 004, 005, 006, 007, 008, 009, and 010) are identified in the permit. All of 

the discharges go directly to the Delaware River except outfall 005 and 010 which discharge to Shellpot Creek then 

to the Delaware River. Page 2 of the permit lists the constituents of these outfalls: 

Outfall 001 - Effluent from the wastewater treatment system. 

Outfall 002 - Noncontact cooling water from the ferric chloride heat exchanger and storm water. 

Outfall 003 - Noncontact cooling water from Line II (reaction, purification, oxidation, finishing activities, and

hydrocyclone) operations and storm water. 

Outfall 004 - Storm Water discharge from plant areas to Delaware River 

Outfall 005 - Storm Water discharge from plant areas to ditch along I495; the ditch discharges into 

Shellpot Creek. 

Outfalls 006, 007, 008, and 009 - Storm Water discharge from plant areas to Delaware River. 

Outfall 010 - Storm Water discharge from plant areas to highway catch basin; the catch basin discharges 

into Shellpot Creek. 

1

 Also see “2004 Delaware River and Bay Integrated List Water Quality Assessment", Table 1.7, Page 8, September 

2004, DRBC (http://www.state.nj.us/drbc/04IntegratedList/EntireReport.pdf). 

Permit Effective Date: January 1, 2007 
-- 

-- -- 

-- -- 

-- -- -- 

DuPont Edge Moor, Fact Sheet Page 6 of 11 Pages 

The following table summarizes general types of discharge constituents. 

Table 6 – Summary of Discharges Constituents 

Outfall 

Flow 

Limit 

(mgd) 

Intake 

Discharge Components 

Process Sanitary 

Wastewater 

Noncontact 

Cooling Water Storm Water 

15.9% Public Water 

001 5.2 Supply & 84.1% De. Yes -- Yes 

River Water 

002 3.0 De. River Yes Approximately

2% 

003 6.0 De. River Yes Approximately 

20% 

004, 005, 006, 

007, 008, 009, & 

010 

NA (Storm Water 

Discharge Only) 100% 

In October 2004, DuPont ceased discharging non-contact cooling water through outfall 002. DuPont has requested 

keeping Outfall 002 listed as non-contact cooling water based on the current flow basis, to retain an option to send 

non-contact cooling water through outfall 002 again. The Department agrees to leave Outfall 002 in the permit as 

requested. Stormwater monitoring requirements will apply to Outfall 002, as long as it consists only of stormwater. 

DuPont must notify the Department if it will restart nonstormwater discharges via Outfall 002, and the permit’s 

requirements for nonstormwater discharges via Outfall 002 will become effective. 

Bases for Effluent Limitations 

DNREC has examined the application, recent discharge monitoring data, and related information. The Department 

proposes to reissue the facility’s NPDES permit for a period not to exceed five (5) years, subject to the effluent 

discharge limitations and monitoring requirements shown in the attached permit. The following table outlines the 

bases for the proposed effluent limitations. 

Table 7 -- Summary of Bases for Proposed Effluent Limitations and Monitoring 

Outfall Parameter Limits or Monitoring 

Only 

Water QualityBased1 

Technology-Based 

DRBC2 Effluent Limitation 

Guidelines 

PerformanceBased3 RGCWP4 

001 

Flow Limits 9

BOD5 Limits §7.03(a) 

TSS Limits 40 CFR §415.222 9

Lead Limits 9

Iron Limits 9 §7.03(a) 

Chromium Limits 40 CFR §415.222 §7.03(a) 

Nickel Limits 9 40 CFR §415.222 

pH5 Limits 9 40 CFR §415.222 & 

40 CFR §401.17 

Temperature Limits 9

PCBs Narrative Limits 9 9

Dioxins and Furans Limits 9

Biomonitoring Limits 9

“Free from ...” Limits 9

1

2

 State of Delaware Surface Water Quality Standards, as amended August 11, 1999. 

 Delaware River Basin Commission 

3

 Performance-based limits are based on the provisions of 40 CFR 122.45(b)(2)(i). 

4

 “State of Delaware Regulations Governing the Control of Water Pollution” (RGCWP), effective May 14, 2003: 

§7.03(a), “Effluent Limitations Based on a Practicable Level of Pollutant Removal Technology”; and §8.04(d) 

“Consideration for Pollutants in Intake Waters When Assessing Reasonable Potential”. 

Permit Effective Date: January 1, 2007 
DuPont Edge Moor, Fact Sheet Page 7 of 11 Pages 

Table 7 -- Summary of Bases for Proposed Effluent Limitations and Monitoring(Continued) 

Outfall Parameter Limits or 

Monitoring Only 

Water QualityBased1 

Technology-Based 

DRBC2 Effluent Limitation 

Guidelines 

PerformanceBased3 RGCWP4 

002 

Flow Limits 9

TSS Monitor 9 §8.04(d) 

Iron Monitor 9 §8.04(d) 

pH Limits 9 40 CFR §401.17 

Temperature Limits 9

PCBs Narrative 

Limits 

9

Dioxins and Furans 9

“Free from ...” Limits 9

003 

Flow Limits 9

TSS Monitor 9 §8.04(d) 

Iron Monitor 9 §8.04(d) 

pH Limits 9 40 CFR §401.17 

Temperature Limits 9

PCBs Narrative 

Limits 

9

Dioxins and Furans 9

“Free from ...” Limits 9

004 

Dissolved Organic Carbon Monitor 9

Total Organic Carbon Monitor 9

Total Suspended Solids Monitor 9

004, 005, 

006, 007, 

008, 009, 

& 010 

PCBs Narrative 

Limits 

9

Dioxins and Furans 9

“Free from ...“ Limits 9

ELG’s exist under 40 CFR §415.222 for TSS, Chromium, Nickel, and pH. Stricter criteria exist for TSS, Chromium, and Ni, so the ELG’s are 

not the bases for the limit numbers, although the existence of ELG’s does mean that numeric limits are required. 

For Outfalls 001, 002, and 003, the allowable pH range of 6.0 to 9.0 SU. is based on SWQS. 40 CFR §401.17 allows the discharge to be 

outside the 6.0 to 9.0 S.U. range 1% of the time and is the basis for the “individual excursion time” (I.E.T.) and “total excursion time” (T.E.T.) 

provisions of the pH limit. 

Bases for Effluent Limitations – Discussion 

The following provides additional details beyond the mention under “Proposed Changes” section, beginning on 

page 1 of this Fact Sheet. 

PCBs, Dioxins, and Furans 

New permit requirements for PCBs, dioxins, and furans (PD&F) affect the entire site. The permit includes a general 

requirement for a “Pollutant Minimization Plan” to track down and eliminate discharges of PD&F. Further, the permit 

includes numeric limits for PD&F discharge from Outfall 001. 

On December 15, 2003 the US EPA Regions II and II adopted a Total Maximum Daily Load (TMDL) for PCBs) for 

Zones 2,3,4, and 5 of the tidal Delaware River. This TMDL requires that facilities identified as discharging PCBs to 

the Delaware River prepare and implement a Pollutant Minimization Plan (PMP). DRBC has issued guidance 

documents for completing the PMPs. 

Narrative limits for PCBs follow the DRBC’s pollutant minimization plan5

 (PMP) requirements for point and nonpoint discharges of toxic pollutants following issuance of a TMDL or assimilative capacity determination. The TMDL 

for PCBs, “Stage 1 Total Maximum Daily Loads (TMDLs) for polychlorinated biphenyls (PCBs) for Zones 2 through 

1

2

 State of Delaware Surface Water Quality Standards, as amended August 11, 1999. 

 Delaware River Basin Commission 

3

 Performance-based limits are based on the provisions of 40 CFR 122.45(b)(2)(i). 

4

 “State of Delaware Regulations Governing the Control of Water Pollution” (RGCWP), effective May 14, 2003: 

§7.03(a), “Effluent Limitations Based on a Practicable Level of Pollutant Removal Technology”; and §8.04(d) 

“Consideration for Pollutants in Intake Waters When Assessing Reasonable Potential”. 5

 DRBC’s Resolution No. 2005-9 was adopted on May 18, 2005 (http://www.state.nj.us/drbc/PMP_info.htm), 

Permit Effective Date: January 1, 2007 
DuPont Edge Moor, Fact Sheet Page 8 of 11 Pages 

5 of the Delaware Estuary”, was established on December 15, 2003 by The United States Environmental Protection 

Agency (EPA) Regions II and III. Promulgation of a TMDL for dioxins and furans is scheduled off 2011. The 

TMDLs will establish Waste Load Allocations (WLAs) and load allocations for point sources and non-point sources, 

respectively, and will result in achieving the water quality standards for the waterbody. The Department will 

reevaluate effluent limitations for this Discharger, to be consistent with WLAs that are derived from new TMDLs. 

40 CFR §122.4(k)(4) allows the use of non-numeric, BMP-based water quality-based effluent limitations where a 

BMP approach is the most appropriate means to control pollutants to achieve the goals of the Clean Water Act. 

Minimizing the sources of these PCBs is an effective and efficient method by which to reduce PCB loading to the 

Delaware River. A PMP approach that includes sensitive monitoring, pollutant trackdown, and mitigation of 

contamination is the most appropriate means to protect water quality and achieve the goals of the Clean Water Act. 

The permit also includes new numeric limits for total PCBs, dioxins and furans as “toxic equivalents”, which 

considers the toxicity of the different congeners of PCBs, dioxins and furans. The PD&F limit is based on the 

“Human Carcinogens, Fish Ingestion” water quality standard, as promulgated in the July 11, 2004 amendments to 

the “State of Delaware Surface Water Quality Standards” 1 (DeSWQS). Federal NPDES regulations at 40 CFR 

122.44(d)(1) specify that water quality based limits must be included in the permit when the regulatory agency 

determines that a discharge causes, has the reasonable potential to cause, or contributes to an excursion above a 

numeric or narrative water quality criterion within a State water quality standard. Monitoring results from Outfall 001 

and DuPont’s landfill waste indicate that PCBs, dioxins, and furans are produced in the process and have the 

potential to generate PCBs, dioxins, and furans in their effluent greater than the water quality criteria. 

Attachment A shows monitoring results for Outfall 001 monitoring for PD&F, both as total of concentrations of all 

congeners, and as total of toxic equivalents for all congeners. DuPont has achieved significant reductions of 

discharges of total PD&Fs, from a high of 879 pg/L2

 to the most recent value of 58.1 pg/L (“Sum of Conc’s” on the 

attachment A graph). DuPont has also managed to reduce Outfall 001 discharge of the more toxic congeners, as 

measured by total toxic equivalents (“Sum of TEQs” on the attachment A graph). 

As for details regarding PD&F requirements, the permit requires the following: 

1. Analyze all congeners for PCBs, and some congeners for dioxins and furans. 

2. Use draft Method 1668A for PCBs, per modifications from DRBC3

. Because the method is still “draft”, PCBs will 

not count towards compliance with the “Toxic Equivalents” limits until the method is finalized and approved 

under 40 CFR 136, and the permit is modified to include requirements under that method. 

3. Use Method 1613b for dioxins and furans. 

4. A site-wide Pollutant Minimization Plan (PMP) to track down sources and implement Best Management 

Practices (BMPs) to reduce pollutant discharges to the maximum extent practicable for PCBs, dioxins, and 

furans 

5. PMP efforts may rely upon analytical methods other than draft Methods 1668A and 1613b as required above, 

for purposes of screening or identification of pollutant sources. 

Whole Effluent Toxicity 

“Whole Effluent Toxicity” measures total toxicity of a wastewater discharge by exposing organisms to the effluent at 

various dilutions with clean water, then measuring the effects. For example, if a sample with 10% effluent and 90% 

clean water kills all of the test organisms, it is much more toxic than a sample with 90% effluent and 10% clean 

water with the same effect. “Acute toxicity” tests measure survival. “Chronic toxicity” tests will measure additional 

effects, such as growth and reproduction. 

After failing acute biomonitoring tests for Daphnia Magna, the DuPont completed a “Toxicity Identification 

Evaluation” (TIE) and “Toxicity Reduction Evaluation” (TRE), submitting their results to the Department in 

September, 1993. DuPont’s TIE identified calcium chloride (CaCl) as the cause of acute toxicity. The TRE 

1 See pages 31 and 32 of the DeSWQS, pages 31 and 32, available at 

http://www.dnrec.state.de.us/DNREC2000/Divisions/Water/WaterQuality/WQStandard.pdf. 2 A picogram (pg) is 0.000000001 milligrams (mg). 3 Monitoring, analyses, and reporting shall be according to DRBC requirements at 

http://www.state.nj.us/drbc/PCB_info.htm. 

Permit Effective Date: January 1, 2007 
DuPont Edge Moor, Fact Sheet Page 9 of 11 Pages 

suggested two alternatives to eliminate acute toxicity in the acute mixing zone: source reduction of the CaCl, or 

install a diffuser to increase dilution in the acute mixing zone. DuPont has elected to install the diffuser, and 

submitted a “Phase II Diffuser Design Study” Report in September, 2001. 

The proposed diffuser will include a multiport design using 3 ports, each with a diameter of 6 inches, spaced 7.5 

meters apart. Applying the Department’s and the Delaware River Basin Commission's (DRBC) most restrictive 

mixing zone criterion of 50 times the discharge length scale results in a mixing zone with a radius of 6.8 meters from 

each diffuser port. This diffuser design would achieve a dilution ratio of 32.1 to 1 at the edge of this mixing zone at 

an effluent flow rate of 3.14 MGD. 

Utilizing the DRBC’s acute whole effluent toxicity (WET) water quality criterion of 0.3 Toxic Units (acute) or TUa, the 

resulting wasteload allocation would be 9.6 TUa. Using the recommended permit derivation procedures contained 

in the EPA's Technical Support Document (“TSD”) for Water Quality-Based Toxics Control (U.S. EPA, 1991) and a 

coefficient of variation (CV) of 0.443 based upon actual effluent data collected from the period 1993 to 2005, the 

calculated average limit is 5.5 TUa. 

The permit includes an average limit of 5.5 TUa for whole effluent toxicity, requires quarterly sampling for Daphnia 

magna, and determines compliance with the limit using a 4 quarter running average. The “Schedule of Compliance” 

under Part I.A.1.a) of this permit provides three years, starting on the permit effective date, for the permittee to 

complete reduction of acute toxicity. “Acute Biomonitoring, Interim Requirements” under Special Condition No. 6 

refers to requirements that apply until the sooner of three years after the permit effective date, or the permittee has 

achieved compliance with the “Schedule of Compliance”, Part I.C.1.a), “Acute Toxicity”. 

DuPont submitted a request for an alternative mixing zone under Section 4.20.5A.1.f. of the DRBC's Water Quality 

Regulations by letter dated August 14, 2006. Specifically, DuPont requested a site-specific mixing zone with a 12.1 

meter radius around each port, for a dilution ratio of 40 to 1 at the edge of the acute mixing zone. Using the EPA’s 

recommended TSD procedures as discussed above, a 40 to 1 dilution ratio results in an average limit of 6.9 TUa. 

Page 6 of the permit, “Outfall 001 – Final Effluent Limitations And Monitoring Requirements” includes a footnote that 

provides for the 6.9 TUa average limit to become effective, conditioned upon DRBC approval of the site-specific 

mixing zone. 

At the same time, the Delaware River Basin Commission (DRBC) is gathering information to evaluate the combine 

chronic toxicity effects of multiple wastewater discharges to the Delaware River. Toward this end, the permit also 

requires chronic toxicity testing for Outfall 001. 

Special Conditions 

Special Condition No. 1 states that this permit supersedes the State Permit WPCC 3193B/76 and NPDES Permit 

DE 0000051 issued on September 29, 1989, as amended on March 8, 1990 and October 20, 1993. 

Special Condition No. 2 is a permit reopener clause. 

Special Condition No. 3 states the DRBC's allocation for oxygen demanding substances. 

Special Condition No. 4 requires submittal of updated NPDES application Forms. 

Special Conditions No. 5, 6, and 7 list requirements for testing and reporting acute whole effluent toxicity for Outfall 

001. 

Special Condition No. 8 lists requirements for testing and reporting chronic effluent toxicity for Outfall 001. This 

chronic toxicity monitoring is required per DRBC efforts to assess the possible need for chronic toxicity TMDL for 

the Delaware River. This Special Condition does not include a Chronic Instream Waste Concentration (IWCc) that 

would require Toxicity Reduction Evaluation since appropriate levels of chronic toxicity reduction would be based 

upon a DRBC allocation. 

Special Condition No. 9 provides for some limited monitoring frequency reductions and testing changes for 

biomonitoring. 

Permit Effective Date: January 1, 2007 
DuPont Edge Moor, Fact Sheet Page 10 of 11 Pages 

Special Condition No. 10 requires a Pollutant Minimization Plan for iron. 

Special Condition No. 11 provides details for reporting of analytical results for “Toxic Equivalents” , especially 

regarding of calculation compliance with the numeric limit for dioxins and furans. 

Special Condition No. 12 requires a Pollutant Minimization Plan PCBs, dioxins, and furans. 

Special Condition No. 13 states monitoring requirements for congeners of PCBs, dioxins, and furans. 

Special Condition No. 14 lists monitoring requirements for background levels of iron for Outfalls 001, 002, and 003 

at the intake and the discharges. 

Special Condition No. 15 lists intake monitoring requirements for background levels of iron for Outfalls 001, 002, 

and 003 at the intake and the discharges. 

Special Conditions No. 16, 17, and 18 list requirements for sludges generated in the NPDES wastewater treatment 

process. 

Special Condition No 19 requires the permittee to implement and maintain a Storm Water Plan (SWP) to minimize 

discharge of contaminated storm water from its facility. 

Public Notice and Process for Reaching a Final Decision 

The public notice of the Department’s receipt of the application and of reaching the tentative determinations outlined 

herein will be published in the Wilmington News Journal on ______. Interested persons are invited to submit their 

written views on the draft permit and the tentative determinations made with respect to this NPDES permit 

application. The Department will not hold a public hearing on this application unless the Department receives a 

meritorious request to do so or unless the notice of this proposal generates substantial public interest. A public 

hearing request shall be deemed meritorious if it exhibits a familiarity with the application and a reasoned statement 

of the permit's probable impact. The request for a public hearing shall be in writing and shall state the nature of the 

issues to be raised at the hearing. All comments received by the close of business on (a date at least 30 days 

following the date the notice is published) will be considered by the Department in preparing the final permit. 

Department Contact for Additional Information: 

Name: John R. DeFriece, P.E. 

Telephone Number: (302) 739-9946 

Permit Effective Date: January 1, 2007 
Attachment A – Outfall 001 Congener Monitoring Resu

(Includes estimated concentrations below the Method Detection Limits for some conge

Outfall 001, Totals for Detected PCB, Dioxin, & Furan Congeners 

879 

9.1 

20.8 

57.9 

144.6 

107.0 

29.2 

21.6 

10.1 

0.091 

0.055 

0.0058 

25.15 

0.011 

0.0029 

0.0022 

00 00

1 

0 00 

1 

000 

1 

0 0 

1

00

1 

00 

1 

0

1 

2 

0 

1 

2 

3 

00

1 

2 

0

1 

0 

1 

2 

3 

4 

5 

6 

7 

8 

0.0010 0.0100 0.1000 1.0000 

10.0000 

100.0000 

1,000.0000 

08/31/03 11/30/03 02/29/04 05/30/04 08/30/04 11/29/04 02/28/05 05/30/05 08/30/05 11/29/Note: Dots on SW QS line (red dashed) indicate dates when samples were taken. 

picograms/Liter 

ΣConc's (pg/L) 

ΣTEQs 

SW QS (pg/L) Conc. L

Permit Effe