Hawaii Administrative Rules
Title 11 - DEPARTMENT OF HEALTH
Subtitle 1 - GENERAL DEPARTMENTAL PROVISIONS
Chapter 54 - WATER QUALITY STANDARDS
Section 11-54-9 - Zones of mixing
Universal Citation: HI Admin Rules 11-54-9
Current through February, 2024
(a) As used in this section, "zones of mixing" means limited areas around outfalls and other facilities to allow for the initial dilution of waste discharges.
(b) Zones of mixing for the assimilation of domestic, agricultural, and industrial discharges which have received the best degree of treatment or control are recognized as being necessary. It is the objective of these limited zones to provide for a current realistic means of control over the placement and manner of discharges or emissions so as to achieve the highest attainable level of water quality or otherwise to achieve the minimum environmental impact considering initial dilution, dispersion, and reactions from substances which may be considered to be pollutants.
(c) Establishment, renewal, and termination.
(1) Application for establishment of a zone
of mixing shall be made concurrently with any discharge permits whenever
applicable and the conditions of a zone of mixing shall be incorporated as
conditions of the discharge permits. Every application for a zone of mixing
shall be made on forms furnished by the director and shall be accompanied by a
complete and detailed description of present conditions, how present conditions
do not conform to standards, and other information as the director may
prescribe.
(2) Each application for
a zone of mixing shall be reviewed in light of the descriptions, statements,
plans, histories, and other supporting information as may be submitted upon the
request of the director, and in light of the effect or probable effect upon
water quality standards established pursuant to this chapter.
(3) Whenever an application is approved, the
director shall establish the zone of mixing, taking into account the
environmental impact, including but not limited to factors such as the
protected uses of the body of water, existing natural conditions of the
receiving water, character of the effluent, and the adequacy of the design of
the outfall and diffuser system to achieve maximum dispersion and assimilation
of the treated or controlled waste with a minimum of undesirable or noticeable
effect on the receiving water.
(4)
Approval of a zone of mixing shall be made either after a public hearing is
held by the director in the county where the source is situated, in accordance
with chapters
91 and
92, HRS and the rules of practice and
procedures of the department, or after the public notification and comment
process duly established for a discharge permit in the case when the zone of
mixing is being considered concurrently with the discharge permit.
(5) No zone of mixing shall be established by
the director unless the application and the supporting information clearly show
that:
(A) The continuation of the function or
operation involved in the discharge by the granting of the zone of mixing is in
the public interest;
(B) The
discharge occurring or proposed to occur does not substantially endanger human
health or safety;
(C) Compliance
with the existing water quality standards from which a zone of mixing is sought
would produce serious hardships without equal or greater benefits to the
public; and
(D) The discharge
occurring or proposed to occur does not violate the basic standards applicable
to all waters, will not unreasonably interfere with any actual or probable use
of the water areas for which it is classified, and has received (or in the case
of a proposed discharge will receive) the best degree of treatment or
control.
(6) Any zone of
mixing or renewal thereof shall be established within the requirements of this
section and for time periods and under conditions consistent with the reasons
therefore and within the following limitations:
(A) If the zone of mixing is established on
the grounds that there is no reasonable means known or available for the
adequate prevention, control, or abatement of the discharge involved, it shall
be allowed only until the necessary means for prevention, control or abatement
become practicable, and subject to the taking of any substitute or alternative
measures that the director may prescribe. No renewal of a zone of mixing
established under this subsection shall be allowed without a thorough review of
known and available means of preventing, controlling, or abating the discharge
involved;
(B) The director may
issue a zone of mixing for a period not exceeding five years;
(C) Every zone of mixing established under
this section shall include, but not be limited to, conditions requiring the
applicant to perform appropriate effluent and receiving water sampling
including monitoring of bottom biological communities and report the results of
each sampling to the director. A program of research to develop reasonable
alternatives to the methods of treatment or control in use by the applicant may
be required if research is deemed prudent by the director; and
(D) In order to prevent high temperature
discharges from violating section
11-54-04
(a) (4), no new or increased domestic, industrial, or other controllable source
shall discharge at a maximum temperature which will cause temperatures to
exceed three degrees Celsius above ambient, or thirty degrees
Celsius, whichever is less, within one meter of the bottom within a zone of
mixing. For discharges with or without submerged outfalls, the director may
make a limited allowance for higher discharge temperatures if there is
satisfactory demonstration that the elevated temperature will not cause damage
to the local aquatic community.
(7) Any zone of mixing established pursuant
to this section may be renewed from time to time on terms and conditions and
for periods not exceeding five years which would be appropriate on initial
establishment of a zone of mixing, provided that the applicant for renewal had
met all of the conditions specified in the immediately preceding mixing, and
provided further that the renewal and the zone of mixing established in
pursuance thereof shall provide for the discharge not greater in quantity of
mass emissions than that attained pursuant to the terms of the immediately
preceding zone of mixing at its expiration. Any new zones of mixing or requests
for zone of mixing renewals for wastewater treatment plants (WWTP) performing
primary treatment shall comply with section 301(h) of the Federal Water
Pollution Control Act of 1972 (
33 U.S.C.
1251 ). No renewal shall be allowed except
upon application. Any renewal application shall be made at least one hundred
and eighty days prior to the expiration of the zone of mixing.
(8) No zone of mixing established pursuant to
this part shall be construed to prevent or limit the application of any
emergency provisions and procedures provided by law.
(9) The establishment of any zone of mixing
shall be subject to the concurrence of the U.S. Environmental Protection
Agency.
(10) Each mixing zone may
be subject to revocation, suspension, or modification if, after notice and
opportunity for a hearing pursuant to chapter
91, HRS and the rules of practice and
procedures of the department, the director determines that the terms specified
in section
342D-6,
HRS have been violated. In taking any action, the director may consider
operating records, compliance investigations, or other information regarding
discharge quality or impact on receiving waters. The action shall be effected
by giving written notice to the permittee, which shall contain the reasons for
the action.
(11) The director shall
be notified within thirty days of the permanent discontinuance of a discharge.
The zone of mixing shall terminate thirty days after such notification has been
received.
(12) Upon expiration of
the period stated in the designation, the zone of mixing shall automatically
terminate and no rights shall become vested in the designee.
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