Delaware Administrative Code
Title 7 - Natural Resources and Environmental Control
5000 - Division of Watershed Stewardship
7400 - Watershed Assessment Section
7401 - Surface Water Quality Standards
Section 7401-9.0 - Exceptions, Modifications and Conditions
Universal Citation: 7 DE Admin Code 7401-9.0
Current through Register Vol. 28, No. 3, September 1, 2024
9.1 Exceptions and Modifications
9.1.1 Request for Removal of Designated Uses:
The Department shall consider scientifically reasonable requests for the
removal of a designated use which is not an existing use, or the establishment
of sub-categories of a use for a water body or segment of specific waters of
the State based upon the demonstration by means of a Use Attainability Analysis
that attainment of the designated use is not feasible because:
9.1.1.1 Naturally occurring pollutant
concentrations prevent the attainment of the use; or;
9.1.1.2 Natural, ephemeral, intermittent or
low flow conditions or water levels prevent the attainment of the use, unless
these conditions may be compensated for by the discharge of sufficient volume
of effluent discharges without violating State water conservation requirements
to enable uses to be met; or
9.1.1.3 Human caused conditions or sources of
pollution prevent the attainment of the use and cannot be remedied or would
cause more environmental damage to correct than to leave in place; or
9.1.1.4 Dams, diversions or other types of
hydrologic modifications preclude the attainment of the use, and it is not
feasible to restore the water body to its original condition or to operate such
modification in a way that would result in the attainment of the use;
or
9.1.1.5 Physical conditions
related to the natural features of the water body, such as the lack of a proper
substrate, cover, flow, depth, pools, riffles, and the like, unrelated to water
quality, preclude attainment of aquatic life protection uses; or
9.1.1.6 Controls more stringent than those
required by sections 301(b) and 306 of the Clean Water Act would result in
substantial and widespread economic and social impact.
A request for removal of designated uses shall be deemed a scientifically reasonable request if it is demonstrated that the Use Attainability Analysis prepared and submitted by the requestor is based upon sound scientific rationale and is supported by substantial scientific and technical evidence and analysis as to the existence of one or more of the factors listed above. If the Department finds any request for removal to be frivolous or to be flawed as to the methods used to obtain evidence or perform analysis to such an extent that the validity of the conclusions would be challenged by most persons trained and competent in the use and interpretation of the technical or scientific methods employed, it may dismiss such request for removal without further action. If the Department determines that a scientifically reasonable request has been made, it shall make a preliminary determination as to the proposed change and hold a public hearing in accordance with 7 Del.C. § 6006. The removal or establishment of sub-categories of a designated use completed under this Section are deemed to be duly adopted components of the State of Delaware Surface Water Quality Standards.
The Department will not consider requests for the removal of a designated use, for a water body or segment of specific waters of the State if:
9.1.1.7 They are
existing uses unless a use requiring more stringent criteria is added;
or
9.1.1.8 The designated use will
be attained by implementing effluent limits required under sections 301(b) and
306 of the Clean Water Act and by implementing cost-effective and reasonable
best management practices for nonpoint source control.
9.1.2 Request for Modification of Water
Quality Criteria: The Department shall consider scientifically reasonable
requests for modification of water quality criteria contained herein for
portions of specific waters of the State. A request for modification shall be
deemed to be a scientifically reasonable request if it is based upon a sound
rationale, and supported by substantial scientific evidence and analysis. This
evidence and analysis must demonstrate the existence of site-specific
differences in the chemical, physical, or biological characteristics of the
surface water, and must propose alternate site-specific water quality criteria.
Scientific studies for the development of these alternate criteria shall be
designed and conducted in accordance with the guidelines set forth in the Water
Quality Standards Handbook Second Edition, EPA 823/B-94-005 or other
scientifically defensible methodologies approved by the Department. If the
Department finds any request for modification to be frivolous, to be flawed as
to the methods used to obtain evidence and to perform analysis to such an
extent that the validity of the conclusions would be challenged by most persons
trained and competent in the use and interpretation of the technical and
scientific methods employed, or to contain reasonable evidence that a reduction
in the number, quality, or river or stream mileage of designated uses would
occur, it may dismiss such request for modification without further action. If
the Department determines that a scientifically reasonable request has been
made, the Department shall make a preliminary determination as to the proposed
change and shall hold a public hearing in accordance with 7 Del.C. §
6006.
If the Department determines that a scientifically reasonable request has been
made pursuant to this Section and such request could result in a change in
discharge limits, then the public hearings for the discharge limitation change
and the criteria modification shall be held concurrently. In such case, the
Department shall provide separate public notices for the discharge limitation
change and the criteria modification. Criteria modification completed under
this Section are deemed to be duly adopted components of the State of Delaware
Surface Water Quality Standards.
9.1.2.1 In
the absence of pollutants corroded and eroded from the facility's water
distribution piping and appurtenances, there would be no violation of the
surface water quality criteria in the receiving water; and
9.1.2.2 The normal corrosion and erosion
associated with the intake water used by the facility is sufficient to be the
sole cause of the violation. For purposes of this determination, intake water
characteristics shall be used in assessing normal corrosion and erosion;
and
9.1.2.3 No other activity,
condition or method of operation, or materials used or produced at the
facility, which results in the addition to erosion and corrosion based
pollutants into the facility's discharge, significantly contributes to the
violations of surface water quality criteria in the receiving waters. Such
activities, conditions or methods of operation, or materials used or produced
at the facility include entrainment of pollutants previously discharged or
disposed by the facility; and
9.1.2.4 No practicable alternative water
supply or treatment methodology or system which would yield statistically
significant lower corrosivity or erosiveness is available to the facility;
and
9.1.2.5 The discharger
demonstrates that controls more stringent than technology-based limits and
Section 306 of the Clean Water Act that would result in substantial and
widespread economic and social impact. The analysis of economic impacts must
demonstrate that:
9.1.2.5.1 The discharger
would face substantial financial impacts due to the costs of the necessary
pollution controls or water treatment (substantial impacts of which would
interfere with development), and
9.1.2.5.2 The affected community will bear
significant adverse impacts if the entity is required to meet existing or
proposed water quality standards (widespread impacts of important
development).
9.2 Conditions
9.2.1 Any person who shall apply for a permit
to discharge to the waters of the State shall have the opportunity to submit an
analysis to the Department at the time of application to demonstrate that said
discharge will not cause, have the reasonable potential to cause, or contribute
to an excursion of the receiving stream's water quality standards. The
Department shall consider any analysis submitted by the applicant and also
conduct its own analysis in making a determination whether the discharge
causes, has the reasonable potential to cause, or contributes to an excursion
of standards. Analyses performed under subsection 9.2 .1 shall be conducted in
concert with the requirements of Section 3.0, as applicable. A public hearing,
pursuant to 7 Del.C. §
6004 and 6006, may be held to gather public comment
on any analysis submitted by an applicant in conjunction with subsection 9.2
.1.
9.2.2 Consistency with Other
State and Federal Requirements: Nothing in Section 9.0 relieves or reduces the
obligation of any person to comply with other applicable provisions of these
Standards, federal or state laws and
regulations.
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