Current through Register Vol. 63, No. 3, March 1, 2024
(1) Purpose. The
purpose of the Antidegradation Policy is to guide decisions that affect water
quality to prevent unnecessary further degradation from new or increased point
and nonpoint sources of pollution, and to protect, maintain, and enhance
existing surface water quality to ensure the full protection of all existing
beneficial uses. The standards and policies set forth in OAR 340-041-0007
through 340-041-0350 supplement the Antidegradation Policy.
(2) Growth Policy. In order to maintain the
quality of waters in the State of Oregon, it is the commission's general policy
to require that more efficient and effective waste treatment and control
accommodate growth and development such that measurable future discharged waste
loads from existing sources do not exceed presently allowed discharged loads
except as provided in section (3) through (9) of this rule.
(3) Nondegradation Discharges. The following
new or increased discharges are subject to this division. However, because they
are not considered degradation of water quality, they are not required to
undergo an antidegradation review under this rule:
(a) Discharges Into Existing Mixing Zones.
Pollutants discharged into the portion of a water body that has been included
in a previous mixing zone for a permitted source, including the zones of
initial dilution, are not considered a reduction in water quality, so long as
the mixing zone is established in accordance with OAR 340-041-0053, there are
no other overlapping mixing zones from other point sources, and the discharger
complies with all effluent limits set out in its National Pollutant Discharge
Elimination System (NPDES) permit.
(b) Water Conservation Activities. An
increase in a pollutant concentration is not considered a reduction in water
quality so long as the increase occurs as the result of a water conservation
activity, the total mass load of the pollutant is not increased, and the
concentration increase has no adverse effect on either beneficial uses or
threatened or endangered species in the water body.
(c) Temperature. Insignificant temperature
increases authorized under OAR 340-041-0028(11) and (12) are not considered a
reduction in water quality.
(d)
Dissolved Oxygen. Up to a 0.1 mg/l decrease in dissolved oxygen from the
upstream end of a stream reach to the downstream end of the reach is not
considered a reduction in water quality so long as it has no adverse effects on
threatened and endangered species.
(4) Recurring Activities. Since the baseline
for applying the antidegradation policy to an individual source is the water
quality resulting from the source's currently authorized discharge, and since
regularly-scheduled, recurring activities remain subject to water quality
standards and the terms and conditions in any applicable federal and state
permits, certifications and licenses, the following activities will not be
considered new or increasing discharges and will therefore not trigger an
antidegradation review under this rule, so long as they do not increase in
frequency, intensity, duration or geographical extent:
(a) Rotating grazing pastures,
(b) Agricultural crop rotations,
and
(c) Maintenance
dredging.
(5) Exemptions
to the Antidegradation Requirement. Some activities may, on a short term basis,
cause temporary water quality degradation. However, these same activities may
also have substantial and desirable environmental benefits. The following
activities and situations fall into this category. Such activities and
situations remain subject to water quality standards and must demonstrate that
they have minimized adverse effects to threatened and endangered species in
order to be exempt from the antidegradation review under this rule:
(a) Riparian Restoration Activities.
Activities that are intended to restore the geomorphology or riparian
vegetation of a water body, or control invasive species need not undergo an
antidegradation review so long as the department determines that there is a net
ecological benefit to the restoration activity. Reasonable measures that are
consistent with the restoration objectives for the water body must be used to
minimize the degradation;
(b)
Emergency Situations. The director or a designee may, for a period of time no
greater than 6 months, allow lower water quality without an antidegradation
review under this rule in order to respond to public health and welfare
emergencies (for example, a significant threat of loss of life, personal injury
or severe property damage); and
(c)
Exceptions. Exceptions authorized by the commission or department under (9) of
this rule.
(6) High
Quality Waters Policy: Where the existing water quality meets or exceeds those
levels necessary to support fish, shellfish, and wildlife propagation,
recreation in and on the water, and other designated beneficial uses, that
level of water quality must be maintained and protected. However, the
commission, after full satisfaction of the intergovernmental coordination and
public participation provisions of the continuing planning process, and with
full consideration of sections (2) and (9) of this rule, and 340-041-0007(4),
may allow a lowering of water quality in these high quality waters if it finds:
(a) No other reasonable alternatives exist
except to lower water quality; and
(b) The action is necessary and benefits of
the lowered water quality outweigh the environmental costs of the reduced water
quality. This evaluation will be conducted in accordance with DEQ's
"Antidegradation Policy Implementation Internal Management Directive for NPDES
Permits and section 401 water quality certifications," pages 27, and 33-39
(March 2001) incorporated herein by reference;
(c) All water quality standards will be met
and beneficial uses protected; and
(d) Federal threatened and endangered aquatic
species will not be adversely affected.
(7) Water Quality Limited Waters Policy:
Water quality limited waters may not be further degraded except in accordance
with paragraphs (9)(a)(B), (C) and (D) of this rule.
(8) Outstanding Resource Waters Policy. Where
existing high quality waters constitute an outstanding State or national
resource such as those waters designated as extraordinary resource waters, or
as critical habitat areas, the existing water quality and water quality values
must be maintained and protected, and classified as "Outstanding Resource
Waters of Oregon."
(a) The commission may
specially designate high quality water bodies to be classified as Outstanding
Resource Waters in order to protect the water quality parameters that affect
ecological integrity of critical habitat or special water quality values that
are vital to the unique character of those water bodies. The department will
develop a screening process and establish a list of nominated water bodies for
Outstanding Resource Waters designation in the Biennial Water Quality Status
Assessment Report (305(b) Report). The priority water bodies for nomination
include:
(A) Those in State and National
Parks;
(B) National Wild and Scenic
Rivers;
(C) State Scenic
Waterways;
(D) Those in State and
National Wildlife Refuges; and
(E)
Those in federally designated wilderness areas.
(b) The department will bring to the
commission a list of water bodies that are proposed for designation as
Outstanding Resource Waters at the time of each triennial Water Quality
Standards Review; and
(c) When
designating Outstanding Resource Waters, the commission may establish the water
quality values to be protected and provide a process for determining what
activities are allowed that would not affect the outstanding resource values.
After the designation, the commission may not allow activities that may lower
water quality below the level established except on a short term basis to
respond to public health and welfare emergencies, or to obtain long-term water
quality improvements.
(d) The
following are Outstanding Resource Waters of Oregon:
(A) The North Fork Smith River and its
tributaries and associated wetlands, South Coast Basin. See OAR
340-041-0305(4).
(B) Waldo Lake and
its associated wetlands, Willamette Basin. See OAR 340-041-0345(7)
(C) Crater Lake, Klamath Basin. See OAR
340-041-0185(6)
(9) Exceptions. The commission or department
may grant exceptions to this rule so long as the following procedures are met:
(a) In allowing new or increased discharged
loads, the commission or department must make the following findings:
(A) The new or increased discharged load will
not cause water quality standards to be violated;
(B) The action is necessary and benefits of
the lowered water quality outweigh the environmental costs of the reduced water
quality. This evaluation will be conducted in accordance with DEQ's
"Antidegradation Policy Implementation Internal Management Directive for NPDES
Permits and section 401 water quality certifications," pages 27, and 33-39
(March 2001) incorporated herein by reference; and
(C) The new or increased discharged load will
not unacceptably threaten or impair any recognized beneficial uses or adversely
affect threatened or endangered species. In making this determination, the
commission or department may rely on the presumption that, if the numeric
criteria established to protect specific uses are met, the beneficial uses they
were designed to protect are protected. In making this determination the
commission or department may also evaluate other state and federal agency data
that would provide information on potential impacts to beneficial uses for
which the numeric criteria have not been set;
(D) The new or increased discharged load may
not be granted if the receiving stream is classified as being water quality
limited under sub-section (a) of the definition of "Water Quality Limited" in
OAR 340-041-0002, unless:
(i) The pollutant
parameters associated with the proposed discharge are unrelated either directly
or indirectly to the parameter(s) causing the receiving stream to violate water
quality standards and being designated water quality limited; or
(ii) Total maximum daily loads (TMDLs), waste
load allocations (WLAs) load allocations (LAs), and the reserve capacity have
been established for the water quality limited receiving stream, compliance
plans under which enforcement action can be taken have been established, and
there will be sufficient reserve capacity to assimilate the increased load
under the established TMDL at the time of discharge; or
(iii) Effective July 1, 1996, in water bodies
designated water-quality limited for dissolved oxygen, when establishing WLAs
under a TMDL for water bodies meeting the conditions defined in this rule, the
department may at its discretion provide an allowance for WLAs calculated to
result in no measurable reduction of dissolved oxygen (DO). For this purpose,
"no measurable reduction" is defined as no more than 0.10 mg/L for a single
source and no more than 0.20 mg/L for all anthropogenic activities that
influence the water quality limited segment. The allowance applies for surface
water DO criteria and for Intergravel dissolved oxygen (IGDO) if a
determination is made that the conditions are natural. The allowance for WLAs
applies only to surface water 30-day and seven-day means; or
(iv) Under extraordinary circumstances to
solve an existing, immediate and critical environmental problem, the commission
or department may, after completing a TMDL but before the water body has
achieved compliance with standards, consider a waste load increase for an
existing source on a receiving stream designated water quality limited under
sub-section (a) of the definition of "Water Quality Limited" in OAR
340-041-0002. This action must be based on the following conditions:
(I) That TMDLs, WLAs and LAs have been set;
and
(II) That a compliance plan
under which enforcement actions can be taken has been established and is being
implemented on schedule; and
(III)
That an evaluation of the requested increased load shows that this increment of
load will not have an unacceptable temporary or permanent adverse effect on
beneficial uses or adversely affect threatened or endangered species;
and
(IV) That any waste load
increase granted under subparagraph (iv) of this paragraph is temporary and
does not extend beyond the TMDL compliance deadline established for the water
body. If this action will result in a permanent load increase, the action must
comply with sub-paragraphs (i) or (ii) of this paragraph.
(b) The activity,
expansion, or growth necessitating a new or increased discharge load is
consistent with the acknowledged local land use plans as a statement of land
use compatibility from the appropriate local planning agency
establishes.
(c) Oregon's water
quality management policies and programs recognize that Oregon's water bodies
have a finite capacity to assimilate waste. Unused assimilative capacity is an
exceedingly valuable resource that enhances in-stream values and environmental
quality in general. Allocation of any unused assimilative capacity should be
based on explicit criteria. In addition to the conditions in subsection (a) of
this section, the commission or department may consider the following:
(A) Environmental Effects Criteria:
(i) Adverse Out-of-Stream Effects. There may
be instances where the non-discharge or limited discharge alternatives may
cause greater adverse environmental effects than the increased discharge
alternative. An example may be the potential degradation of groundwater from
land application of wastes;
(ii)
Instream Effects. Total stream loading may be reduced through elimination or
reduction of other source discharges or through a reduction in seasonal
discharge. A source that replaces other sources, accepts additional waste from
less efficient treatment units or systems, or reduces discharge loadings during
periods of low stream flow may be permitted an increased discharge load
year-round or during seasons of high flow, so long as the loading has no
adverse effect on threatened and endangered species;
(iii) Beneficial Effects. Land application,
upland wetlands application, or other non-discharge alternatives for
appropriately treated wastewater may replenish groundwater levels and increase
streamflow and assimilative capacity during otherwise low streamflow
periods.
(B) Economic
Effects Criteria. When assimilative capacity exists in a stream, and when it is
judged that increased loadings will not have significantly greater adverse
environmental effects than other alternatives to increased discharge, the
economic effect of increased loading will be considered. Economic effects will
be of two general types:
(i) Value of
Assimilative Capacity. The assimilative capacity of Oregon's streams is finite,
but the potential uses of this capacity are virtually unlimited. Thus it is
important that priority be given to those beneficial uses that promise the
greatest return (beneficial use) relative to the unused assimilative capacity
that might be utilized. In-stream uses that will benefit from reserve
assimilative capacity, as well as potential future beneficial use, will be
weighed against the economic benefit associated with increased
loading;
(ii) Cost of Treatment
Technology. The cost of improved treatment technology, non-discharge and
limited discharge alternatives may be evaluated.
Statutory/Other Authority: ORS
468.020,
468B.030,
468B.035
& 468B.048
Statutes/Other Implemented: ORS
468B.030,
468B.035
& 468B.048