7 Del. Admin. Code § 7401-9.0

Current through Register Vol. 28, No. 7, January 1, 2025

Section 7401-9.0 - Exceptions, Modifications and Conditions

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.

7 Del. Admin. Code § 7401-9.0

21 DE Reg. 241 (9/1/2017) (Final)