7 Del. Admin. Code § 7401-4.0

Current through Reigster Vol. 28, No. 6, December 1, 2024

Section 7401-4.0 - Criteria To Protect Designated Uses

4.1 All surface waters of the State (except as detailed in Sections 7.0 and 8.0) shall meet the following minimum criteria:

4.1.1 Waters shall be free from substances that are attributable to wastes of industrial, municipal, agricultural or other human-induced origin. Examples include but are not limited to the following:

4.1.1.1 Floating debris, oil, grease, scum, foam, or other materials on the water surface that may create a nuisance condition, or that may in any way interfere with attainment and maintenance of designated uses of the water,

4.1.1.2 Settleable solids, sediments, sludge deposits, or suspended particles that may coat or cover submerged surfaces and create a nuisance condition, or that may in any way interfere with attainment and maintenance of designated uses of the water,

4.1.1.3 Any pollutants, including those of a thermal, toxic, corrosive, bacteriological, radiological, or other nature, that may interfere with attainment and maintenance of designated uses of the water, may impart undesirable odors, tastes, or colors to the water or to aquatic life found therein, may endanger public health, or may result in dominance of nuisance species.

4.2 Narrative Criteria for Waters With the Public Water Supply Designated Use

4.2.1 Streams with a designated use of public water supply shall provide waters of acceptable quality for use for drinking, culinary or food processing purposes after application of approved treatment equivalent to coagulation, filtration, and disinfection (with additional treatment as necessary to remove naturally occurring impurities). The untreated waters are subject to the following limitations:

4.2.1.1 Waters shall be free from substances (except natural impurities) that, alone or in combination with other substances, result in:

4.2.1.1.1 Unacceptable levels of taste or odor in the treated water;

4.2.1.1.2 Significant disruption of the treatment processes at the treatment facility; or

4.2.1.1.3 Concentrations of toxic substances in the treated water that may be harmful to human health. The requirements of subsection 4.6.3 shall apply.

4.3 Certain waters of the State are subject to natural variations in salinity such that those waters meet the definition of fresh at some times and marine at other times. For such waters, the more stringent of fresh or marine water quality criteria or standards as detailed throughout this document shall apply at all times unless otherwise specified by the Department.

4.4 Coordination with Delaware River Basin Commission:

For waters of the Delaware River and Delaware Bay, duly adopted Delaware River Basin Commission (DRBC) Water Quality Regulations shall be the applicable criteria. If the DRBC has not developed an applicable regulatory standard or criteria for these waters, and Delaware has, Delaware's criteria shall be applicable.

4.5 The following criteria shall apply outside approved regulatory mixing zones unless otherwise specified:

4.5.1 Temperature, measured as Fahrenheit Degrees

4.5.1.1 Fresh Waters

4.5.1.1.1 Maximum increase above natural conditions shall be 5°F.

4.5.1.1.2 No human-induced increase of the true daily mean temperature above 82°F shall be allowed.

4.5.1.1.3 No human-induced increase of the daily maximum temperature above 86°F shall be allowed.

4.5.1.2 Marine Waters

4.5.1.2.1 Maximum increase above natural conditions shall be 4°F from October through May. Temperature rise during June through September shall be limited by the following conditions:

4.5.1.2.2 No human-induced increase of the true daily mean temperature above 84°F shall be allowed; and

4.5.1.2.3 No human-induced increase of the daily maximum temperature above 87°F shall be allowed.

4.5.1.3 Cold Water Fisheries (Put and Take)

4.5.1.3.1 Maximum increase above natural conditions shall be 5°F.

4.5.1.3.2 No human-induced increase of the true daily mean temperature above 75°F, shall be allowed

4.5.1.4 In all waters of the state, the Department may mandate additional limitations on a site-specific or seasonal basis in order to provide incremental protection for early life stages of fish.

4.5.2 Dissolved Oxygen, measured as milligrams per liter (mg/L)

4.5.2.1 Fresh Waters

4.5.2.1.1 Daily average shall not be less than 5.5 mg/L.

4.5.2.1.2 Instantaneous minimum shall not be less than 4.0 mg/L

4.5.2.2 Marine Waters

4.5.2.2.1 Daily average shall not be less than 5.0 mg/L.

4.5.2.2.2 Instantaneous Minimum shall not be less than 4.0 mg/L

4.5.2.3 Cold Water Fisheries (Put and Take)

4.5.2.3.1 Daily average shall not be less than 6.5 mg/L during the applicable period.

4.5.2.3.2 Instantaneous Minimum shall not be less than 5.0 mg/L during the applicable period.

4.5.2.4 The Nanticoke River from the upstream-most limits of the City of Seaford to the Maryland State Line and Broad Creek from the upstream-most limits of the Town of Laurel to the confluence with the Nanticoke River

At water temperatures greater than 84 degrees Fahrenheit, instantaneous minimum shall not be less than 4.3 mg/L

4.5.2.4.1 For the period February 1- May 31:

4.5.2.4.1.1 7-Day mean shall not be less than 6.0 mg/L

4.5.2.4.1.2 Instantaneous minimum shall not be less than 5.0 mg/L

4.5.2.4.2 For June 1- January 31

4.5.2.4.2.1 30 Day mean shall not be less than 5.5 mg/L

4.5.2.4.2.2 7-Day mean shall not be less than 4.0 mg/L

4.5.2.4.2.3 Instantaneous minimum shall not be less than 3.2 mg/L

4.5.2.5 The Murderkill River from the Route 1 Bridge to the Confluence with the Delaware Bay

4.5.2.5.1 For the period from May 16 through September 30:

4.5.2.5.1.1 Daily average shall not be less than 3.0 mg/L

4.5.2.5.1.2 One Hour Minimum: one hour average shall not be less than 1.0 mg/L

4.5.2.5.2 For the period October 1 through May 15, applicable criteria for all waters of the State shall apply.

4.5.2.6 All Waters

4.5.2.6.1 In cases where natural conditions prevent attainment of these criteria, allowable reduction in dissolved oxygen levels as a result of human activities shall be determined through application of the requirements of Sections 5.0 and 9.0 of these Standards.

4.5.2.6.2 The Department may mandate additional limitations on a site specific or seasonal basis in order to provide incremental protection for early stages of fish.

4.5.3 pH, measured in standard units, in all waters of the state

4.5.3.1 Shall be between 6.5 and 8.5 unless outside this range due solely to natural conditions. Where within this range, maximum human-induced change from background shall be 0.5 Standard Units; pH which results from human-induced change must remain within this range.

4.5.3.2 Where pH is below 6.5 or above 8.5 due solely to natural conditions, it shall not be lowered (where below 6.5) or raised (where above 8.5) more than 0.3 Standard Units due to human-induced changes.

4.5.4 Alkalinity, measured as mg/L as CaCO3, in all waters of the State shall not be less than 20 mg/L unless due solely to natural conditions. If less than 20 mg/L due solely to natural conditions, no reduction due to human-induced changes is allowed.

4.5.5 Turbidity Measured as Nephelometric or Formazin Turbidity Units, in all waters of the State shall not exceed natural levels by more than 10 units.

4.5.6 Water Clarity in the Nanticoke River from the upstream-most limits of the City of Seaford to the Maryland State Line and Broad Creek from the upstream-most limits of the Town of Laurel to the confluence with the Nanticoke River:

During the period of April 1 to October 31 the minimum seasonal averaged secchi depth shall be 1.0 m.

4.5.6.1 Chlorophyll-a criteria for the Nanticoke River from the upstream-most limits of the City of Seaford to the Maryland State Line and Broad Creek from the upstream-most limits of the Town of Laurel to the confluence with the Nanticoke River:

Concentrations of chlorophyll-a in free-floating microscopic aquatic plants (algae) shall not exceed levels that result in ecologically undesirable consequences - such as reduced water clarity, low dissolved oxygen, food supply imbalances, proliferation of species deemed potentially harmful to aquatic life or humans or aesthetically objectionable conditions or otherwise render tidal waters unsuitable for designated uses.

4.5.7 Bacterial Water Quality Criteria

4.5.7.1 Primary and Secondary Contact Recreation Waters:

The following criteria shall apply:

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The purpose of these criteria is to provide the Department with a basis to assess water quality trends and pollution control needs with regard to primary and secondary contact recreation in waters of the State and to meet Federal Beaches Environmental Assessment and Coastal Health (BEACH) Act Requirements. The criteria apply to enterococcus bacteria determined by the Department to be of non-wildlife origin based on best scientific judgment using available information. Swimming in waters affected by runoff during runoff periods may present an elevated risk of gastrointestinal illness and is not recommended.

4.5.7.2 Harvestable Shellfish waters:

The total coliform median MPN of the water shall not exceed 70/100 mL, nor shall more than 10% of the samples have an MPN in excess of 330/100 mL for a 3 decimal dilution test (or 230/100 mL where the 5 tube decimal test is used). These criteria shall be verified through sampling of those portions of the shellfish area most probably exposed to fecal contamination for those tidal and climatic conditions most likely to result in contamination of the shellfish area.

4.5.8 Nutrients

Nutrient overenrichment is recognized as a significant problem in some surface waters of the State.

4.5.8.1 It shall be the policy of this Department to minimize nutrient input to surface waters from point and human induced non-point sources.

4.5.8.2 The types of, and need for, nutrient controls shall be established on a site-specific basis. Nutrient controls may include, but shall not be limited to, discharge limitations or institution of best management practices.

4.5.8.3 For lakes and ponds, controls shall be designed to eliminate overenrichment.

4.5.8.4 For tidal portions of the stream basins of Indian River, Rehoboth Bay, and Little Assawoman Bay, controls needed to attain submerged aquatic vegetation growth season (approximately March 1 to October 31) average levels for dissolved inorganic nitrogen of 0.14 mg/L as N, for dissolved inorganic phosphorus of 0.01 mg/L as P, and for total suspended solids of 20 mg/L shall be instituted.

4.5.8.5 The specific measures to be employed by existing NPDES facilities to meet the aforementioned criteria shall be as specified in subsection 5.6.3.4 of these standards.

4.5.9 Toxic Substances

4.5.9.1 Applicability: Criteria set forth in this section apply to all surface waters of the State, except as provided in Section 6.0, Regulatory Mixing Zones, Section 7.0, Critical Flows, and Section 8.0, Criteria for Low Flow Waters.

4.5.9.2 General Provisions:

4.5.9.2.1 Waters of the State shall not exhibit acute toxicity to fish, aquatic life, and wildlife, except in special cases applying to regulatory mixing zones as provided in Section 6.0.

4.5.9.2.2 Waters of the State shall not exhibit chronic toxicity to fish, aquatic life, and wildlife, except in regulatory mixing zones as provided in Section 6.0, at flows less than critical flows as provided in Section 7.0, or in low flow waters as provided in Section 8.0.

4.5.9.2.3 Waters of the State shall be maintained to prevent adverse toxic effects on human health resulting from ingestion of chemically contaminated aquatic organisms and drinking water.

4.5.9.2.4 The Department may consider synergistic, antagonistic, and additive impacts of combinations of toxicants to fish, aquatic life, and wildlife, and human health in assessing aggregate environmental impacts and mandating point and nonpoint source controls.

4.5.9.3 Specific Numerical Criteria:

4.5.9.3.1 Aquatic Life Criteria:

4.5.9.3.1.1 Aquatic Life Criteria for Aluminum, Iron, and Selenium in Table 1 are expressed on a total recoverable basis. Criteria for Cyanide in Table 1 are expressed as free cyanide at the lowest pH occurring in the receiving water, or cyanide amenable to chlorination. Criteria for all other metals in Table 1 are expressed on a total dissolved basis. For toxic substances where the relationship of toxicity is defined as a function of pH or hardness, numerical criteria are presented as an equation based on this relationship. Appropriate pH or hardness values for such criteria shall be determined on a case-by-case basis by the Department.

4.5.9.3.1.2 Specific numerical acute criteria as presented in Table 1 are applied as one-hour average concentrations not to be exceeded more than once in any three-year period. Specific numerical chronic criteria as presented Table 1 are applied as four-day average concentrations not to be exceeded more than once in any three-year period.

4.5.9.3.1.3 For toxic substances for which specific numerical criteria are not listed in Table 1, concentrations shall not exceed those which are chronically toxic (as determined from appropriate chronic toxicity data or calculated as 0.1 of LC50 values) to representative, sensitive aquatic organisms, except as provided in Section 6.0, Regulatory Mixing Zones, Section 7.0, Critical Flows, or Section 8.0, Criteria for Low Flow Waters. Concentrations so determined shall be applied as four-day average concentrations not to be exceeded more than once in any three-year period.

4.5.9.3.2 Human Health Criteria

4.5.9.3.2.1 Water quality criteria appearing in Table 2 for pollutants identified as carcinogens have been established at an upper bound worst case risk management level of one excess cancer in a population of one million (1 x 10-6) over a 70 year lifetime. Criteria listed under the columns header "Fish and Water Ingestion" apply only to surface waters of the State designated as Public Water Supply Sources in Section 3.0 of these Standards. Criteria listed under columns headed "Fish Ingestion Only" apply to all surface waters of the State not designated as Public Water Supply Sources in Section 3.0 of these Standards.

4.5.9.3.2.2 For compounds in Table 2 which are considered as both systemic toxicants and human carcinogens, criteria based on both human health concerns are presented. In determining pollution control requirements, the more stringent criterion, after consideration of critical (design) flows in Section 7.0, shall be utilized.

TABLE 1

WATER QUALITY CRITERIA FOR PROTECTION OF AQUATIC LIFE

(All Values Are Listed or Calculated in Micrograms Per Liter)

Parameter	Fresh Acute Criterion	Fresh Chronic Criterion	Marine Acute Criterion	Marine Chronic Criterion
Aldrin	3.0	--	1.3	--
Acrolein	3.0	3.0
Aluminum pH6.5-9.0	750.	87.	--	--
Ammonia	Temperature and pH dependent, see formula after this table	Temperature and pH dependent, see formula after this table
Arsenic (III)*	340.	150	69.	36.
Cadmium*	EXP^(0.9789LN(hardness)-3.866)(1.136672-((LN(hardness)*(0.041838))))	EXP^(0.7977LN(hardness)-3.909)(1.101672-((LN(hardness)*(0.041838))))	33	7.9
Carbaryl	2.1	2.1	1.6
Chlordane	2.4	0.0043	0.09	0.004
Chlorine	19	11.	13	7.5
Chlorpyrifos (Dursban)	0.083	0.041	0.011	0.0056
Chromium (III)*	0.316EXP(0.819LN(hardness)+3.7256)	0.86EXP(0.819LN(hardness)+0.6848)	C	--
Chromium (VI)*	16.	11.	1,100.	50.
Copper*	Freshwater criteria calculated using the EPA Biotic Ligand Model	Freshwater criteria calculated using the EPA Biotic Ligand Model	4.8	3.1
Cyanide1	22.	5.2	1.0	--
DDT and Metabolites (DDD and DDE)	1.1	0.0010	0.13	0.0010
Demeton	--	0.10	--	0.10
Diazanon	0.17	0.17	0.82	0.82
Dieldrin	0.24	.056	0.71	0.0019
Endosulfan	0.22	0.056	0.034	0.0087
Endrin	.086	.036	0.037	0.0023
Guthion	--	0.01	--	0.01
Heptachlor	0.52	0.0038	0.053	0.0036
Hexachloro-cylclohexane	.095	0.08	0.16	--
Iron	--	1000.	--	--
Lead*	(1.46203-LN(hardness)0.145712) EXP(1.273*LN(hardness)-1.460)	(1.46203-LN(hardness)0.145712) EXP(1.273*LN(hardness)-4.705)	210.	8.1
Malathion	--	0.1	--	0.1
Mercury (II)*	1.4	.77	1.8	0.94
Methoxychlor	--	0.03	--	0.03
Mirex	--	0.001	C	0.001
Nickel*	0.998EXP(0.8460LN(hardness)+2.255)	0.997EXP(0.8460LN(hardness)+0.0584)	74.	8.2
Nonylphenol	28	6.6	7	1.7
Total PCBs	0.014	0.03
Parathion	0.065	0.013	--	--
Pentachlorophenol	EXP(1.005*pH-4.869)	EXP(1.005*pH-5.134)	13.	7.9
Selenium	20	5.0	290	71.
Silver*	0.85EXP(1.72LN(hardness)-6.59)	--	1.9	--
Toxaphene	0.73	0.0002	0.21	0.0002
Tributyltin (TBT)	0.46	0.072	0.42	0.0074
Zinc*	0.978EXP(0.8473LN(hardness)+0.884)	0.986EXP(0.8473LN(hardness)+0.884)	90	81

Notes:

1Cyanide measured as free cyanide at the lowest pH occurring in the receiving water, or cyanide amenable to chlorination.

Formulas in the table have been formatted so that they can be copied directly into spreadsheets to calculate criteria. Criteria are calculated to two significant figures.

LN = natural log base e

EXP = e = 2.71828

Hardness is expressed as mg/L as CaCO3

pH is expressed as Standard Units

* Criteria is for total dissolved form

Calculation of Freshwater Acute Ammonia Criterion:

The one-hour average concentration of total ammonia nitrogen (in mg TAN/L) is not to exceed, more than once every three years on the average, the CMC (acute criterion magnitude) calculated using the following equation:

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Where:

pH=pH of interest

t= temperature degrees Celsius

Calculation of Freshwater Chronic Ammonia Criterion:

The thirty-day rolling average concentration of total ammonia nitrogen (in mg TAN/L) is not to exceed, more than once every three years on the average, the chronic criterion magnitude (CCC) calculated using the following equation:

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Where:

pH=pH of interest

t= temperature degrees Celsius

In addition, the highest four-day average within the 30-day averaging period should not be more than 2.5 times the CCC more than once in three years on average.

TABLE 2

WATER QUALITY CRITERIA FOR PROTECTION OF HUMAN HEALTH

(All Values Are Listed in Micrograms per Liter)

Pollutant	Human Health for the consumption of Organism Only (ug/l)	Human Health for the consumption of Water + Organism (ug/l)
Acenaphthene	90	70
Acrolein	400	3
Acrylonitrile	7	0.061
Aldrin	0.00000077	0.00000077
alpha-Hexachlorocyclohexane (HCH)	0.00039	0.00036
alpha-Endosulfan	30	20
Anthracene	400	300
Antimony	640	5.6
Arsenic	10 (mcl)
Asbestos	7 million fibers/L
Barium	1,000
Benzene	16	0.58
Benzidine	0.011	0.00014
Benzo(a)anthracene	0.18	0.038
Benzo(a)pyrene	0.018	0.0038
Benzo(b)fluoranthene	0.18	0.038
Beryllium	4 (MCL)
beta-Hexachlorocyclohexane (HCH)	0.014	0.008
beta-Endosulfan	40	20
Bis(2-Chloro-1-methylethyl) Ether	4000	200
Bis(2-Chloroethyl) Ether	2.2	0.03
Bis(2-Ethylhexyl) Phthalate	0.37	0.32
Bis(Chloromethyl) Ether	0.017	0.00015
Bromoform	120	7
Butylbenzyl Phthalate	0.1	0.1
Cadmium	5 (MCL)
Carbon Tetrachloride	5	0.4
Chlordane	0.00032	0.00031
Chlorobenzene	800	100
Chlorodibromomethane	21	0.8
Chloroform	2,000	60
Chlorophenoxy Herbicide (2,4-D)	70 (MCL)
Chlorophenoxy Herbicide (2,4,5-TP) [Silvex]	50 (MCL)
Chromium (III)	100 (MCL)
Chromium (VI)	100 (MCL)
Chrysene	0.13	0.12
Copper	1300 (MCL)
Cyanide	400	4
Dibenzo(a,h)anthracene	0.018	0.0038
Dichlorobromomethane	27	0.95
Dieldrin	0.0000012	0.0000012
Diethyl Phthalate	600	600
Dimethyl Phthalate	2,000	2,000
Di-n-Butyl Phthalate	30	20
Dinitrophenols	1,000	10
Endosulfan Sulfate	40	20
Endrin	0.03	0.03
Endrin Aldehyde	1	1
Ethylbenzene	130	68
Fluoranthene	20	20
Fluorene	70	50
gamma-Hexachlorocyclohexane (HCH) [Lindane]	4.4	0.2 (MCL)
Heptachlor	0.0000059	0.0000059
Heptachlor Epoxide	0.000032	0.000032
Hexachlorobenzene	0.000079	0.000079
Hexachlorobutadiene	0.01	0.01
Hexachlorocyclohexane (HCH) -Technical	0.01	0.0066
Hexachlorocyclopentadiene	4	4
Hexachloroethane	0.1	0.1
Indeno(1,2,3-cd)pyrene	0.0013	0.0012
Isophorone	1,800	34
Methylmercury	0.3 mg/kg	-
Methoxychlor	0.02	0.02
Methyl Bromide	10000	100
Methylene Chloride	1,000	5 (MCL)
Nickel	4,600	610
Nitrates	10,000 (MCL)
Nitrobenzene	600	10
Nitrosodibutylamine	0.22	0.0063
Nitrosodiethylamine	1.24	0.0008
Nitrosopyrrolidine	34	0.016
N-Nitrosodimethylamine	3	0.00069
N-Nitrosodi-n-Propylamine	0.51	0.005
N-Nitrosodiphenylamine	6	3.3
Pentachlorobenzene	0.1	0.1
Pentachlorophenol	0.04	0.03
Phenol	300,000	4,000
Polychlorinated Biphenyls (PCBs)	0.000064	0.000064
Pyrene	30	20
Selenium	4200	50 (MCL)
Tetrachloroethylene	29	5 (MCL)
Thallium	0.47	0.24
Toluene	520	57
Toxaphene	0.00071	0.0007
Trichloroethylene	7	0.6
Vinyl Chloride	1.6	0.022
Zinc	26,000	7,400
1,1,1-Trichloroethane	200,000	200 (MCL)
1,1,2,2-Tetrachloroethane	3	0.2
1,1,2-Trichloroethane	8.9	0.55
1,1-Dichloroethylene	20,000	7 (MCL)
1,2,4,5-Tetrachlorobenzene	0.03	0.03
1,2,4-Trichlorobenzene	0.076	0.071
1,2-Dichlorobenzene	3,000	600(MCL)
1,2-Dichloroethane	650	5 (MCL)
1,2-Dichloropropane	31	0.9
1,2-Diphenylhydrazine	0.2	0.03
Trans-1,2-Dichloroethylene	4,000	100
1,3-Dichlorobenzene	10	7
1,3-Dichloropropene	12	0.27
1,4-Dichlorobenzene	900	75 (MCL)
2,3,7,8-TCDD (Dioxin) (as TEQ1)	5.10E-09	5.00E-09
2,4,5-Trichlorophenol	600	300
2,4,6-Trichlorophenol	2.8	1.5
2,4-Dichlorophenol	60	10
2,4-Dimethylphenol	3,000	100
2,4-Dinitrophenol	300	10
2,4-Dinitrotoluene	1.7	0.049
2-Chloronaphthalene	1000	800
2-Chlorophenol	800	30
2-Methyl-4,6-Dinitrophenol	30	2
3,3'-Dichlorobenzidine	0.15	0.049
3-Methyl-4-Chlorophenol	2,000	500
p,p'-Dichlorodiphenyldichloroethane (DDD)	0.00012	0.00012
p,p'-Dichlorodiphenyldichloroethylene (DDE)	0.000018	0.000018
p,p'-Dichlorodiphenyltrichloroethane (DDT)	0.00003	0.00003

The columns labeled "Fish and Water Ingestion" shall apply only to waters of the State designated Public Water Supply sources in these standards.

The column labeled "Fish Ingestion Only" shall apply to all waters of the State not designated Public Water Supply sources in this document.

Values shown with "(MCL)" under header "Fish and Water Ingestion" are Primary Maximum Contaminant Levels (MCLs) as given in the State of Delaware Regulations Governing Public Drinking Water Systems that became effective September 10, 2001

Criteria is for the "total toxic equivalence (TEQ) to 2, 3, 7, 8 - TCDD". The toxic equivalence for a sample is the sum of the concentration for each congener multiplied by its associated Toxicity Equivalence Factor (TEF) listed in table below.

TEQ = ((Concentration of Congener in sample) x (TEF))

where the TEF is unitless and the concentration is in ug/l.

Congener	TEF value	Congener	TEF value
Dibenzo-p-dioxins	Non-ortho PCBs
2,3,7,8-TCDD	1	PCB 77	0.0001
1,2,3,7,8-PnCDD	1	PCB 81	0.0003
1,2,3,4,7,8-HxCDD	0.1	PCB 126	0.1
1,2,3,6,7,8-HxCDD	0.1	PCB 169	0.03
1,2,3,7,8,9-HxCDD	0.1
1,2,3,4,6,7,8-HpCDD	0.01	Mono-ortho PCBs
OCDD	0.0003	PCB 105	0.00003
PCB 114	0.00003
Dibenzofurans	PCB 118	0.00003
2,3,7,8-TCDF	0.1	PCB 123	0.00003
1,2,3,7,8-PnCDF	0.03	PCB 156	0.00003
2,3,4,7,8-PnCDF	0.3	PCB 157	0.00003
1,2,3,4,7,8-HxCDF	0.1	PCB 167	0.00003
1,2,3,6,7,8-HxCDF	0.1	PCB 189	0.00003
1,2,3,7,8,9-HxCDF	0.1
2,3,4,6,7,8-HxCDF	0.1
1,2,3,4,6,7,8-HpCDF	0.01
1,2,3,4,7,8,9-HpCDF	0.01
OCDF	0.0003

7 Del. Admin. Code § 7401-4.0

14 DE Reg. 1392 (06/01/11)
18 DE Reg. 312 (10/1/2014)
21 DE Reg. 241 (9/1/2017)
26 DE Reg. 608 (1/1/2023) (Final)