Virginia Administrative Code › Title 9 - ENVIRONMENT › Agency 25 - STATE WATER CONTROL BOARD › Chapter 31 - VIRGINIA POLLUTANT DISCHARGE ELIMINATION SYSTEM (VPDES) PERMIT REGULATION › Part VII - General Pretreatment Regulations for Existing and New Sources of Pollution › Section 9VAC25-31-790 - Removal credits

Current through Register Vol. 40, No. 24, July 15, 2024
A. General.
1. Definitions for the purpose of this
				  section:
"Removal" means a reduction in the amount of a pollutant in
					 the POTW's effluent or alteration of the nature of a pollutant during treatment
					 at the POTW. The reduction or alteration can be obtained by physical, chemical
					 or biological means and may be the result of specifically designed POTW
					 capabilities or may be incidental to the operation of the treatment system.
					 Removal as used in this subpart shall not mean dilution of a pollutant in the
					 POTW.
"Sludge requirements" means the following statutory
					 provisions and regulations or permits issued thereunder (or more stringent
					 Virginia or local regulations): § 405 of the CWA; the Solid Waste Disposal
					 Act (SWDA) ( 42 USC § 6901 et seq.) (including Title II more commonly
					 referred to as the Resource Conservation Recovery Act (RCRA) ( 42 USC §
					 6901 et seq.) and Virginia regulations contained in any Virginia sludge
					 management plan prepared pursuant to Subtitle D of SWDA); the Clean Air Act (
					 42 USC § 4701 et seq.); the Toxic Substances Control Act ( 15 USC §
					 2601 et seq.); and the Marine Protection, Research and Sanctuaries Act ( 33 USC
					 § 1401 et seq.).
2.
				  General. Any POTW receiving wastes from an industrial user to which a
				  categorical pretreatment standards applies may, at its discretion and subject
				  to the conditions of this section, grant removal credits to reflect removal by
				  the POTW of pollutants specified in the categorical pretreatment standards. The
				  POTW may grant a removal credit equal to or, at its discretion, less than its
				  consistent removal rate. Upon being granted a removal credit, each affected
				  industrial user shall calculate its revised discharge limits in accordance with
				  subdivision 4 of this subsection. Removal credits may only be given for
				  indicator or surrogate pollutants regulated in a categorical pretreatment
				  standard if the categorical pretreatment statement so specifies.
3. Conditions for authorization to give
				  removal credits. A POTW is authorized to give removal credits only if the
				  following conditions are met;
a. Application.
				  The POTW applies for, and receives, authorization from the director to give a
				  removal credit in accordance with the requirements and procedures specified in
				  subsection E of this section;
b.
				  Consistent removal determination. The POTW demonstrates and continues to
				  achieve consistent removal of the pollutant in accordance with subsection B of
				  this section;
c. POTW local
				  pretreatment program. The POTW has an approved pretreatment program in
				  accordance with and to the extent required by this part; provided, however, a
				  POTW which does not have an approved pretreatment program may, pending approval
				  of such a program, conditionally give credits as provided in subsection D of
				  this section;
d. Sludge
				  requirements. The granting of removal credits will not cause the POTW to
				  violate the local, state and federal sludge requirements which apply to the
				  sludge management method chosen by the POTW. Alternatively, the POTW can
				  demonstrate to the director that even though it is not presently in compliance
				  with applicable sludge requirements, it will be in compliance when the
				  industrial users to whom the removal credit would apply is required to meet its
				  categorical pretreatment standards as modified by the removal credit. If
				  granting removal credits forces a POTW to incur greater sludge management costs
				  than would be incurred in the absence of granting removal costs, the additional
				  sludge management costs will not be eligible for EPA grant assistance. Removal
				  credits may be made available for the following pollutants:
(1) For any pollutant listed in Appendix G-I
				  of the regulation incorporated by reference in
				  9VAC25-31-750 for the use or
				  disposal practice employed by the POTW, when the requirements of Part VI of
				  this chapter for that practice are met;
(2) For any pollutant listed in Appendix G-II
				  of the regulation incorporated by reference in
				  9VAC25-31-750 for the use or
				  disposal practice employed by the POTW when the concentration for a pollutant
				  listed in Appendix G-II of the regulation incorporated by reference in
				  9VAC25-31-750 in the sewage sludge
				  that is used or disposed does not exceed the concentration for the pollutant in
				  Appendix G-II of the regulation incorporated by reference in
				  9VAC25-31-750; and
(3) For any pollutant in sewage sludge when
				  the POTW disposes all of its sewage sludge in a municipal solid waste landfill
				  that meets the criteria in the Code of Virginia and the Solid Waste Management
				  Regulations, 9VAC20-81;
e. VPDES permit limitations. The granting of
				  removal credits will not cause a violation of the POTW's permit limitations or
				  conditions. Alternatively, the POTW can demonstrate to the director that even
				  though it is not presently in compliance with applicable limitations and
				  conditions in its VPDES permit, it will be in compliance when the industrial
				  user or users to whom the removal credit would apply is required to meet its
				  categorical pretreatment standard or standards, as modified by the removal
				  credit provision.
4.
				  Calculation of revised discharge limits. Revised discharge limits for a
				  specific pollutant shall be derived by use of the following formula:
y =
x
1 - r
where:
x = pollutant discharge limit specified in the applicable
					 categorical pretreatment standard
r = removal credit for that pollutant as established under
					 subsection B of this section (percentage removal expressed as a proportion,
					 i.e., a number between 0 and 1)
y = revised discharge limit for the specified pollutant
					 (expressed in same units as x)