Hawaii Administrative Rules
Title 11 - DEPARTMENT OF HEALTH
Subtitle 1 - GENERAL DEPARTMENTAL PROVISIONS
Chapter 55 - WATER POLLUTION CONTROL
Section 11-55-41 - Zones of mixing
Universal Citation: HI Admin Rules 11-55-41
Current through February, 2024
(a) Zones of mixing are defined and authorized for use in discharge permits in section 11-54-1. Zones of mixing allow for dilution of wastes before compliance with the applicable water quality criteria must be met. Zones of initial dilution are a subset of zones of mixing that are applied to toxic pollutants.
(b) 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 chapter
11-54.
(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.
(E) The capacity of the
receiving water to dilute a pollutant or assimilative capacity is available in
the receiving water for the pollutant in which a zone of mixing is being
requested.
(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 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 conditions requiring the applicant to perform
effluent monitoring, at a minimum, for pollutants with effluent limitations
established in the permit, and receiving water quality monitoring, at a
minimum, for pollutants for which a zone of mixing is established. Additional
effluent and receiving water monitoring, including monitoring of bottom
biological communities, may be required as appropriate. The results of all
required monitoring shall be reported 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 meets the requirements in section
11-55-41. The renewal 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, unless such an increase is in
accordance with state and federal anti-degradation and anti-backsliding
regulations as applicable. Any new zones of mixing or requests for zone of
mixing renewals for wastewater treatment plants 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 three hundred
and sixty 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) 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.
(10) 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.
(11) 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.
Disclaimer: These regulations may not be the most recent version. Hawaii may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
