[Federal Register Volume 64, Number 33 (Friday, February 19, 1999)]
[Notices]
[Pages 8335-8336]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-4150]
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DELAWARE RIVER BASIN COMMISSION
Notice of Determination Regarding the Assimilative Capacity of
the Tidal Delaware River for Toxic Pollutants; Public Hearings
AGENCY: Delaware River Basin Commission.
ACTION: Notice of Commission determination and public hearings.
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SUMMARY: Notice is hereby given that the Delaware River Basin
Commission will hold public hearings to receive comments on a
determination that the assimilative capacity of the tidal Delaware
River is being exceeded for certain toxic pollutants. This
determination will authorize the Executive Director to establish
wasteload allocations for specific point source discharges of these
pollutants.
DATES: The public hearings are scheduled as follows:
May 3, 1999 beginning at 1:30 p.m. and continuing until 5:00 p.m.,
as long as there are people present wishing to testify.
May 5, 1999 beginning at 1:30 p.m. and continuing until 5:00 p.m.
as long as there are people present wishing to testify; and resuming at
6:30 p.m. and continuing until 9:00 p.m., as long as there are people
present wishing to testify.
May 11, 1999 beginning at 1:30 p.m. and continuing until 5:00 p.m.,
as long as there are people present wishing to testify.
ADDRESSES: The May 3, 1999 hearing will be held in the Second Floor
Auditorium of the Carvel State Building, 820 North French Street,
Wilmington, Delaware.
The May 5, 1999 hearing will be held in the Goddard Conference Room
of the Commission's offices at 25 State Police Drive, West Trenton, New
Jersey.
The May 11, 1999 hearing will be held in the Jefferson Room of the
Holiday Inn at 400 Arch Street, Philadelphia, Pennsylvania.
FOR FURTHER INFORMATION CONTACT: Susan M. Weisman, Commission
Secretary, Delaware River Basin Commission, P.O. Box 7360, West
Trenton, New Jersey 08628. Telephone (609) 883-9500 ext. 203.
SUPPLEMENTARY INFORMATION:
Background and Rationale
On October 23, 1996 the Delaware River Basin Commission amended its
Comprehensive Plan, Water Code and Water Quality Regulations concerning
water quality criteria for toxic pollutants, and policies and
procedures to establish wasteload allocations and effluent limitations
for point source discharges to the tidal Delaware River.
Specifically, water quality criteria for selected toxic pollutants
were incorporated in the Comprehensive Plan and Article 3 of the Water
Code and Water Quality Regulations as stream quality objectives.
Article 4 of the Water Quality Regulations was amended to include
policies and procedures to be used to establish wasteload allocations
for those discharges containing pollutants which exceed the stream
quality objectives and impact the designated uses of the river
following a Commission determination that the assimilative capacity of
a zone of the Delaware River is exceeded. These amendments provided a
mechanism for identifying toxic pollutants which impair aquatic life
and human health, and developing uniform and equitable wasteload
allocations for those NPDES discharges to the tidal Delaware River
which contribute to their impairment. The permitting authorities of the
Basin states will utilize allocations developed by the Commission to
establish effluent limitations for NPDES permittees in their
jurisdiction, as appropriate.
The subject of the hearings is a proposed determination by the
Commission that the assimilative capacity of the tidal Delaware River
(Trenton, NJ to the head of Delaware Bay) is being exceeded for 1,2-
dichloroethane, tetrachloroethene, chronic toxicity and acute toxicity.
These parameters were selected based upon their mass loading to the
estuary, minimal interaction with estuary sediments, and the
availability of calibrated and validated water quality models that
could be used to develop the wasteload allocations. This determination
will authorize the
[[Page 8336]]
Executive Director to establish wasteload allocations for continuous
point source discharges pursuant to Sections 4.30.7A.1. and
4.30.7B.2.c. of the Commission's Water Quality Regulations.
Seventy-six continuous point source discharges were considered in
each of the wasteload allocation exercises, although the number
included in any allocation varied from 10 to 55. The procedure used to
develop the wasteload allocations is called Equal Marginal Percent
Reduction or EMPR. EMPR is a two step process in which a discharge is
first considered independently of all other discharges to the estuary.
In this step called the Baseline Analysis, each discharge must meet
stream quality objectives in and of itself. In the second step called
Multiple Discharge Analysis, the cumulative impact of all discharges,
discharging at the baseline loading established during step one, is
evaluated against the stream quality objectives. If the analysis
indicates that an objective is exceeded, then the baseline loads of all
discharges significantly contributing to the violation are reduced by
an equal percentage until the stream quality objective is met.
For 1,2-dichloroethane, 11 of 51 discharges were adjusted from
their initial loading in order to meet the stream quality objectives.
For tetrachloroethene, seven of 40 discharges were adjusted in order to
meet the stream quality objectives. For chronic toxicity, ten of the 55
discharges were adjusted during the baseline analysis portion of the
wasteload allocation. The multiple discharge analysis portion of the
procedure will not be implemented for chronic toxicity so that
additional data on the relationship between the concentration of
specific chemicals and toxicity of both wastewater and ambient samples
can be obtained. This portion will be deferred until Phase 2 of the
Total Maximum Daily Load (TMDL) is completed.
For acute toxicity, eight of the ten discharges evaluated were
reduced from their initial wasteload allocation concentration during
the baseline analysis portion of the allocation. As with chronic
toxicity, the multiple discharge analysis which will determine the
total surface area of the estuary assigned to mixing areas will be
deferred until Phase 2 of the TMDL is completed.
In accordance with Section 4.30.7B.2.c.5). of the Commission's
Water Quality Regulations, a document entitled Wasteload Allocations
for Volatile Organics and Toxicity: Phase 1 TMDLs for Toxic Pollutants
in the Delaware River Estuary has been prepared which describes the
process used to develop wasteload allocations for continuous point
source discharges as part of Phase 1 of a Total Maximum Daily Load for
selected toxic pollutants for the tidal Delaware River. This document
is available on the Commission's web site at www.state.nj.us/drbc, or
by contacting Christopher Roberts, Public Information Officer, at (609)
883-9500 ext. 205.
The following supporting documents describing the mathematical
models used in the process are also available from the Commission:
Calibration and Validation of a Water Quality Model for Volatile
Organics and Chronic Toxicity in the Delaware River Estuary.
Calibration and Validation of the DYNHYD5 Hydrodynamic Model for
the Delaware River Estuary.
Development of a Tidal Version of the CORMIX Models for Application
to Discharges in the Delaware Estuary.
Copies of these documents may be obtained by contacting Christopher
Roberts, Public Information Officer at (609) 883-9500, extension 205.
Persons wishing to testify are requested to notify the Secretary in
advance. Written comments on the proposed determination should also be
submitted to the Secretary.
Delaware River Basin Compact, 75 Stat. 688.
Dated: February 9, 1999.
Susan M. Weisman,
Secretary.
[FR Doc. 99-4150 Filed 2-18-99; 8:45 am]
BILLING CODE 6369-01-P
