Current through Register Vol. 46, No. 39, September 25, 2024
(a)
Basinwide.
Where necessary to maintain stream quality objectives or
protect water uses in a given zone, the waste assimilative capacity of the
receiving waters shall be allocated by the commission among individual
dischargers in accordance with the doctrine of equitable apportionment.
(1) Commission procedure.
(i) Whenever the commission determines that
allocations of a stream's waste assimilative capacity are necessary in a zone,
the executive director shall find and determine an allocation for each waste
discharge in that zone.
(ii) Such
determination shall be governed by the Commission's Rules of Practice
and Procedure relating to review, hearing and decision of objections
thereto.
(2) Allocations
not a property right. Allocations are not transferable except upon consent of
the commission.
(3) Limitations.
(i) No allocation will exceed the residual
after treatment as required in accordance with section
861.9 of this Part.
(ii) No allocation will exceed the residual
after treatment necessary to meet any other requirements.
(4) Reserve.
In each zone, as part of the initial allocation, and each
subsequent reallocation, a reserve may be set aside by the commission.
(i) The reserve in each zone shall be
utilized to accommodate new discharges or major revisions to an allocation, or
any reallocation, when appropriate in the judgment of the commission.
(ii) Individual allocations or portions
thereof which are no longer needed because use of the facilities to which they
are assigned is discontinued or substantially decreased shall be returned to
the reserve.
(iii) Where improved
waste management practice results in a reduction of the load discharged to less
than the allocation, the unused portion of the allocation shall not revert to
the reserve.
(5)
Reallocations.
(i) Carbonaceous oxygen demand.
(a) All allocations shall be subject to
review by the commission and, after such review, the commission may make such
reallocation as it deems necessary.
(b) If any factors upon which an individual
allocation is based change significantly, application shall be made to the
executive director for a revised allocation.
(c) Whenever the reserve in a zone approaches
depletion, or when the full use of the assimilative capacity is approached, or
when in the judgment of the commission, the allocations existing at that time
are no longer equitable, the capacity in the zone, minus a reserve, will be
reallocated among the waste dischargers in that zone.
(ii) Toxic Pollutants
(a) All allocations shall be subject to
review by the commission and, after such review, the commission may make such
reallocation as it deems necessary.
(b) If any factors upon which an individual
allocation is based change significantly, application shall be made to the
executive director for a revised allocation. The executive director shall
provide notice to interested and affected parties prior to establishing the
revised allocation.
(c) Allocations
shall, as a minimum, be reviewed and, if required, revised every five years, or
as directed by the commission.
(6) Regionalization.
Whenever two or more waste dischargers with separate
allocations formulate a regional plan for water quality control, allocations
may be revised by the commission.
(7) Design streamflow.
For the purpose of determining the waste assimilative
capacity of a stream, the following design minimum streamflows will be
used:
(i) Unregulated streams. Where
streams are unregulated, a minimum consecutive seven-day (average) flow with a
10-year recurrence interval shall be the design flow.
(ii) Regulated streams. Where the pattern of
regulation is such as to result in weekly, daily, or hourly variations in flow
significantly different from the natural pattern of variation, the above design
flow may reflect the effects of these variations.
(iii) Lakes and reservoirs. Wherever waste
discharges may affect the protected uses of lakes and reservoirs, the
commission, after consultation with the appropriate states, will determine the
characteristics upon which to base effluent quality requirements in relation to
the special characteristics of the receiving body of water.
(iv) Tidal waters. Wherever waste discharges
may affect the protected uses or the water quality criteria of tidal waters,
the commission, after consultation with the appropriate states, will determine
the characteristics upon which to base effluent quality requirements in
relation to the special characteristics of the receiving body of
water.
(8) Design
effluent flow.
For the purpose of determining the waste assimilative
capacity of a stream and the wasteload allocations for discharges of toxic
pollutants, the following design effluent flows will be used:
(i) For industrial wastewater treatment plant
discharges covered by Effluent Limitations Guidelines (ELG) promulgated by the
U.S. EPA, the effluent design flow shall be the average daily flow associated
with:
(a) the month having the highest monthly
production rate of the previous 12 months or, if greater;
(b) the year having the highest annual
production rate of the previous five years.
(ii) If the discharge from an industrial
wastewater treatment plant is not covered by Effluent Limitations Guidelines
(ELG) promulgated by the U.S. EPA, is mixed with stormwater or cooling water or
production data are not available, the effluent design flow shall be the
average daily flow associated with:
(a) the
month with the highest monthly flow rate of the previous 12 months, or if
greater;
(b) the year having the
highest annual flow rate of the previous five years.
(iii) For municipal wastewater treatment
plant discharges, the effluent design flow shall be the higher of:
(a) the average daily flow of the plant for
the previous three years including a growth factor based upon a five-year
projection, if available; or
(b)
the capacity of the plant that was used to establish effluent limitations for
the NPDES permit expressed as the annual average flow.
(b)
Delaware River
Estuary.
(1) Carbonaceous oxygen
demand.
Pursuant to the provisions of section
860.4(e) of this
Title, the commission determines that the 1964 carbonaceous oxygen demand of
the effluent load to zones 2, 3, 4 and 5 exceeded the waste assimilative
capacity of those zones to meet the stream quality objectives. Accordingly, the
total carbonaceous oxygen demand exerted by the sum of all waste discharges to
each of these zones shall be reduced to the following:
Zone 2 |
18,600 pounds per day |
Zone 3 |
144,800 pounds per day |
Zone 4 |
91,000 pounds per day |
Zone 5 |
67,600 pounds per day |
(i)
Reserve. In zones 2, 3, 4 and 5, as a part of the initial allocation, and each
subsequent reallocation, a reserve of about 10 percent of the total permissible
load to the zone may be set aside by the commission.
(ii) Allocation to individual dischargers.
(a) Within zones 2, 3, 4 and 5, the pounds of
carbonaceous oxygen demand prescribed above, minus the reserve, will be
allocated among individual dischargers.
(b) Allocations will be based upon the
concept of uniform reduction of raw waste in a zone.
(c) Upon application, in special cases, for
dilute industrial process wastewater, an allocation may be assigned consistent
with section
861.9(b)(3) of
this Part.
(iii)
Allowable variations.
(a) The number of pounds
in the discharge permitted by the allocation will be determined by an average
of samples taken over each period of 30 consecutive days of the year.
(b) It is recognized that optimum efficiency
may not be achieved with certain secondary treatment facilities during the
colder months. A discharge exceeding the allocation may be permitted by the
commission when it results from reduced plant efficiency caused by temperatures
below 59°F (15°C), provided that the pounds discharged by any individual
discharger shall not exceed its allocation by more than an average of
two-thirds over any consecutive 10 days.
(iv) Allocations from the reserve.
Allocations from the reserve will be made upon the same principles as provided
in subparagraph (ii) of this paragraph, based upon the concept of uniform raw
waste reduction in a zone at the time the allocation is made.
(v) Reallocations. Reallocations will be made
upon the same principles as provided by subparagraph (ii) of this paragraph,
provided that where the waste reduction by any discharger results in lower
poundage input than it has been allocated such poundage differential will not
be returned to the reserve in the absence of conditions requiring a
reallocation for the zone.
(vi)
Tidal tributaries.
(a) Wastes discharged to
the portions of tributaries of the Delaware River Estuary affected by tidal
action are included in the total permissible load in each zone, and poundage
allocations will be assigned to these dischargers on the same basis as
effluents discharged directly to the estuary.
(b) However, additional requirements may be
imposed if any one or group of waste dischargers complying with estuary load
allocations exceeds the waste assimilative capacity of the tidal
tributary.
(2)
Toxic pollutants.
Pursuant to section
860.4(e) of this
Title and section
861.13(a) of this
Part, the commission shall establish wasteload allocations and other effluent
requirements that may be necessary to meet the stream quality objectives for
toxic pollutants contained in section
860.26 -860.31 of this
Title.
(i) Reserve. A reserve
allocation of five percent of the total maximum daily load (TMDL) shall be
established as a part of an allocation or reallocation, by increasing the
effluent design flow by five percent.
(ii) Margin of safety. As part of an
allocation or reallocation, a proportion of the total maximum daily load shall
be established as a margin of safety. The proportion established shall reflect
the degree of uncertainty in the data and resulting water quality-based
controls.
(iii) Allocation to
discharges.
(a) Wasteload allocations shall be
established for Phase 1 continuous point source discharges to address acute
aquatic life protection, chronic aquatic life protection and both carcinogenic
and systemic toxicants.
(1) The water quality
objective for the establishment of any allocation or reallocation shall be the
stream quality objectives contained in section
860.26 -860.31 of this Title. If
the background concentration of a toxic pollutant at the appropriate criteria
duration exceeds the stream quality objective as a result of loadings from
sources not subject to control, then the water quality objective shall be the
background concentration of the pollutant.
(2) The minimum flows for aquatic life
protection and to protect the taste and odor of ingested water and fish are
based on a minimum consecutive 7-day flow with a 10-year recurrence interval
for all tributaries; and for the Delaware River, a flow of 2500 cfs at Trenton.
For the protection of human health, the harmonic mean flow shall be used for
carcinogens, and the minimum consecutive 30-day flow with a 5-year recurrence
interval shall be used for systemic toxicants.
(b) Allocations shall be determined by the
executive director using the procedure described in clause (
d)
of this subparagraph or alternative procedures that are consistent with the
doctrine of equitable apportionment, and achieve the following:
(1) assure compliance with applicable stream
quality objectives;
(2) provide
maximum equity among competing discharges; and
(3) minimize the overall cost of
compliance.
(c) The
loadings of toxic pollutants identified in this subparagraph shall be allocated
among individual phase 1 continuous point source discharges which meet any of
the following criteria:
(1) the discharge has
an existing permit limit for the parameter;
(2) effluent data indicates the presence of
the parameter; or
(3) the
reasonable potential exists for the parameter to occur in the
discharge.
(d)
Allocations for phase 1 continuous point source discharges will be based upon
the equal marginal percent reduction procedure which has been determined to be
consistent with the requirements of clause (
b) of this
subparagraph. This procedure requires all dischargers, whether they are part of
a multiple discharge wasteload allocation scenario or not, to provide treatment
of their wastewater to achieve the applicable water quality standard; and in
addition, requires some dischargers to provide additional treatment due to the
cumulative impact of all discharges.
(1)
Alternative wasteload allocation procedures may be considered by the Commission
if they provide timely compliance with clause (b) of this
subparagraph and include the consent of all dischargers affected by the
alternative procedure.
(2)
Discharges meeting any of the requirements of clause (
c) of
this subparagraph will be assigned an initial loading based upon the following
information in order of preference:
(i) the
average monthly limit obtained from effluent guideline limitations promulgated
by the U.S. Environmental Protection Agency for the point source category
applicable to the discharge;
(ii)
any average monthly limitation for the parameter in the current discharge
permit;
(iii) monitoring data of
sufficient quantity and quality, as determined by the executive director, to
characterize the concentration of the parameter in the discharge; or
(iv) minimum performance standards
established by the executive director for industrial and municipal wastewater
treatment plants discharging to the tidal Delaware River.
In assigning the initial loading, the average loading at
the appropriate criteria duration will be calculated using the coefficient of
variation (CV) calculated from monitoring data or a default value of 0.6 in the
absence of data of sufficient quantity and quality, as determined by the
executive director.
(3) Discharges contributing to an exceedance
of a stream quality objective due to the cumulative effect of all discharges
may not be required to provide additional treatment or loading reduction if the
discharge does not represent a significant proportion of the marginal
loading.
(e) Allocations
established by the executive director and reallocations required under clause
(a)(5)(ii)(b) of this section shall be published in a document
containing the specific procedures, tools and assumptions used to derive the
allocations.
(f) Wasteload
allocations established under subparagraph (iii) of this paragraph shall be
referred to the appropriate agency of the signatory parties, respectively, for
use, as appropriate, in developing effluent limitations, schedules of
compliance, and other requirements in permits.
(iv) Adjustment for pollutants in intake
water. Wasteload allocations established for an industrial discharge may be
adjusted by the executive director, in consultation with the appropriate agency
of the signatory parties, to account for pollutants present in water withdrawn
for use by the facility from the receiving water provided that the following
conditions are met:
(a) in the absence of
pollutants in the water withdrawn, there would be no exceedance of the stream
quality objectives for toxic pollutants;
(b) pollutants in the discharge resulting
from any other activity, operation or materials used or produced at the
facility do not significantly contribute to an exceedance of the stream quality
objectives for toxic pollutants contained in sections
860.26 -860.31 of this
Title;
(c) no statistically
significant difference can be detected between the intake and effluent
concentrations and loadings of a toxic pollutant based upon a rigorous analysis
of data representative of operating and ambient conditions at the facility;
and
(d) no practicable alternative
source of intake water is available.
(c)
Definitions.
(1)
Wasteload allocation.
The portion of the total maximum daily load of a body of water or section
thereof that is allocated to an existing or future point source of pollution.
Or, any limitation on the loading and/or concentration of a pollutant
discharged from a point source required to ensure that stream quality
objectives are not exceeded.
(2)
Total maximum daily load (TMDL). The maximum daily loading of
a pollutant from all sources which still ensures that water quality objectives
are met.
(3)
Margin of
safety. A factor that takes into account any uncertainty or lack of
knowledge about the relationship between pollutant loadings and the quality of
the receiving water.
(4)
Marginal load. The portion of the loading of a pollutant that
contributes to an exceedance of a stream quality objective when the cumulative
loading from all point sources is considered.
(5)
Effluent limitations
guidelines. Effluent limitations for pollutants for categories and
classes of point sources promulgated by the U.S. Environmental Protection
Agency under section 301 of the Clean Water Act which reflect the best
available treatment technology.
(6)
Harmonic mean flow. The flow value corresponding to the number
of daily flow measurements divided by the sum of the reciprocals of the
flows.
(7)
Background
concentration. The concentration of a toxic pollutant at any point in
the Estuary that results from loadings from tributaries, sediments (if
applicable), and any point or non-point sources not subject to control in the
current allocation or reallocation.
(8)
Phase 1 continuous point source
discharge. A discharge of wastewater other than non-contact cooling
water, permitted under the National Pollutant Discharge Elimination System
(NPDES) which occurs without interruption during the operating hours of a
facility except for infrequent shutdowns. and is not primarily dependent on
precipitation-induced flows.
(9)
Long-term average concentration. The mean concentration of a
toxic pollutant in the effluent that represents the desired performance of a
wastewater treatment plant.
(10)
Minimum performance standards. The long-term average
concentration for a parameter for which stream quality objectives have been
established under section
860.3(c) or (d)
of this Title.
(i) For volatile and
non-volatile organic chemicals, the standard is the maximum for a monthly
average specified in the effluent guideline limitations for the Organic
Chemicals, Plastics, and Synthetic Fibers (OCPSF) industrial category, or the
highest reported effluent value for activated sludge treatment specified in the
U.S. EPA's Water Engineering Research Laboratory data base.
(ii) For chlorinated pesticides and
polychlorinated biphenyls, the standard is the practical quantitation limit
(PQL) for the compound.
(iii) For
metals and indicator parameters, the standard is the average concentration of
the parameter in industrial or municipal treatment plant discharges to the
estuary.
(11)
Initial loading. The concentration or mass of a pollutant that
is initially assigned to a discharge that meets the criteria specified in
clause (b)(2)(iii)(c) of this section during the baseline
analysis portion of a wasteload allocation exercise.