Virginia Administrative Code › Title 9 - ENVIRONMENT › Agency 25 - STATE WATER CONTROL BOARD › Chapter 31 - VIRGINIA POLLUTANT DISCHARGE ELIMINATION SYSTEM (VPDES) PERMIT REGULATION › Part III - Permit Conditions › Section 9VAC25-31-230 - Calculating VPDES permit conditions

Current through Register Vol. 40, No. 24, July 15, 2024
A. Permit
				  effluent limitations, monitoring requirements, standards and prohibitions shall
				  be established for each outfall or discharge point of the permitted facility,
				  except as otherwise provided under
				  9VAC25-31-220
				  and subsection H of this section (limitations on internal waste
				  streams).
B. Production-based
				  limitations.
1. In the case of POTWs, permit
				  effluent limitations, standards, or prohibitions shall be calculated based on
				  design flow.
2.
a. Except in the case of POTWs or as provided
				  in subdivision 2 b of this subsection, calculation of any permit limitations,
				  standards, or prohibitions which are based on production (or other measure of
				  operation) shall be based not upon the designed production capacity but rather
				  upon a reasonable measure of actual production of the facility. For new sources
				  or new dischargers, actual production shall be estimated using projected
				  production. The time period of the measure of production shall correspond to
				  the time period of the calculated permit limitations; for example, monthly
				  production shall be used to calculate average monthly discharge limitations.
b.
(1)
(a) The
				  department may include a condition establishing alternate permit limitations,
				  standards, or prohibitions based upon anticipated increased (not to exceed
				  maximum production capability) or decreased production levels.
(b) For the automotive manufacturing industry
				  only, the department may establish a condition under subdivision 2 b (1) (a) of
				  this subsection if the applicant satisfactorily demonstrates to the department
				  at the time the application is submitted that its actual production, as
				  indicated in subdivision 2 a of this subsection, is substantially below maximum
				  production capability and that there is a reasonable potential for an increase
				  above actual production during the duration of the permit.
(2) If the department establishes permit
				  conditions under subdivision 2 b (1) of this subsection:
(a) The permit shall require the permittee to
				  notify the department at least two business days prior to a month in which the
				  permittee expects to operate at a level higher than the lowest production level
				  identified in the permit. The notice shall specify the anticipated level and
				  the period during which the permittee expects to operate at the alternate
				  level. If the notice covers more than one month, the notice shall specify the
				  reasons for the anticipated production level increase. New notice of discharge
				  at alternate levels is required to cover a period or production level not
				  covered by prior notice or, if during two consecutive months otherwise covered
				  by a notice, the production level at the permitted facility does not in fact
				  meet the higher level designated in the notice;
(b) The permittee shall comply with the
				  limitations, standards, or prohibitions that correspond to the lowest level of
				  production specified in the permit, unless the permittee has notified the
				  department under subdivision 2 b (2) (a) of this subsection, in which case the
				  permittee shall comply with the lower of the actual level of production during
				  each month or the level specified in the notice; and
(c) The permittee shall submit with the DMR
				  the level of production that actually occurred during each month and the
				  limitations, standards, or prohibitions applicable to that level of
				  production.