Ontario's water quality objective development process /

64 Pages·1991·12.9 MB·English

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ONTARIO'S
1
WATER QUALITY OBJECTIVE
DEVELOPMENT PROCESS
MAY 1991
Environment
TD
3GS
Environnement
Ps 76
058
Ontario
i9()1
ISBN 0-7729-7532-9
ONTARIO'S WATER QUALITY OBJECTIVE
DEVELOPMENT PROCESS
AQUATIC CRITERIA DEVELOPMENT COMMITTEE
WATER RESOURCES BRANCH
ONTARIO MINISTRY OF THE ENVIRONMENT
MAY 1991
RECYCUHEE
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nest disponible qu'en anglais
Copyright: Queen's Printer for Ontario, 1991
This publication may be reproduced for non-commercial purposes
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ABSTRACT
As part of its program to ensure that the surface waters of Ontario are satisfactory for
aquatic life and recreation, the Ontario Ministry of the Environment develops Provincial
Water Quality Objectives (PWQOs) and Guidelines (PWQGs). This report details the
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procedures used to develop PWQOs and PWQGs. PWQOs are developed from the best
available knowledge on the effects of substances on aquatic life. Data are required for
acute and chronic toxicity, bioaccumulation and mutagenicity. Also considered is avail-
able information on environmental fate, physical-chemical properties, taste and odour in
water and tainting of fish tissues. If adequate information is unavailable for setting a
PWQO, a PWQG is developed using uncertainty factors which depend on the quantity
and quality of the toxicological data.
RESUME
En formant parti de la programme pour assurer que la qualite des eaux de surface de la
province de I'Ontario suffise pour supporter la vie aquatique et la recreation, le
Ministere de 1'Environnement de ]'Ontario ddvelope des Objectifs Provinciaux pour la
Qualitd des Eaux (OPQE) et des Normes Provinciaux pour la Qualitd des Eaux
(NPQE). Ce rapport donne les details ndcessaires pour ddvelopper les OPQEs et les
NPQEs. Les Objectifs Provinciaux pour la Qualitd des Eaux sont dtabli par une
connaissance le meilleur possible des effets des agents chimiques sur la vie aquatique.
Des informations sont requises concernant la toxicitd aigue et chronique, la
bioaccumulation, et la mutagdnicitd. Autres renseignements considdres sont le sort
dans 1'environnement, les proprdtds physico-chimique, gout et odeur dans ]'eau, et le
potentiel pour corrompre la chair des poissons. Jusqu'A temps que ]'information ne
suffise pour ddvelopper un OPQE, une NPQE est determinde. Pour ddvelopper une
Norme, on applique plusieurs facteurs d'incertitude qui ddpendent sur la qualitd et la
quantitd de ]'information toxicologique.
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ACKNOWLEDGEMENTS
This document is the product of the Aquatic Criteria Development Committee. What
started out as an attempt to formalize existing procedures for developing PWQOs turned
into a reassessment of the process itself. The following people made significant con-
tributions to the document through discussions within the committee and in writing
drafts:
EditinS
Conrad de Barros
Peter Dennis
John Ralston
Dave Rokosh
Glenn Rutherford
Wolfgang Scheider
Doug Spry
Gary Westlake
Contributors
Scott Abernethy, Roy Angelow, Norm Bazinet, Karen Johnson, Mary Kirby, Eric
t
Leggatt, Archie McLarty, Dwayne Moore, Christine Neville, Ron Pierce, Mike Salamone
and Ian Smith.
The Guideline chapter was produced from an earlier separate version developed by
Scott Abernethy, John Ralston and Conrad de Barros.
The tables and figures were prepared by Tom Dickie, Tim Fletcher and Natalie
Waddell.
The final draft report was widely circulated across Canada and the United States for
scientific peer review. Many comments and suggestions were received, all were carefully
evaluated and appropriate changes were subsequently made to the document. The
Aquatic Criteria Development Committee appreciates the assistance of all those people
who contributed their time and knowledge to the completion of this document.
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Table of Contents
ABSTRACT .....................................................
ii
RESUME ......................................................
ii
..........................................
ACKNOWLEDGEMENTS iii
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...........................................
INTRODUCTION
1 1
1.1 The Basis for Provincial Water Quality Objectives ....................
1
1.2 The Basis for Provincial Water Quality Guidelines ....................
2
1.3 Application of PWQOs and PWQGs ..............................
2
1.4 Other Water Quality Objectives and Guidelines ......................
............... 3
1.5 Water Quality Objective Setting Administrative Structure 4
1.6 What are Object.iv.e.s. a.n.d. .G.u.i.d.e.l.in.e.s.?. -. .A. .D.e.f.in.i.ti.o.n. .o.f .T.e.r.m.s. ................. 4
1.6.1 Objective ........................................... 4
1.6.2 Guideline ..................................... 4
1.6.3 Interim Guideline ........................ 4
1.7 Priority of Candidate Substances for PWQO..s......................... 5
1.8 Summary of PWQO and PWQG Setting ......................... 5
1.8.1 SAelescstioing onf Cmanedindatte .S.u.b.s.t.a.n.c.e.s................................ 6
1.8.2 ..................... 6
1.8.3 Information Acquisition and Assessment .................. 6
1.8.4 Setting a Provincial Water Quality Objective .................. 7
1.8.5 Setting a Provincial Water Quality Guideline 7
...........
2 SETTING PROVINCIAL WATER QUA.L.I.T.Y. .O.B.J.E.C..T.IV..E.S............ 9
2.1 Substance Physical-Chemical. P.r.op.e.r.ti.e.s............................. 9
2.2 Acute and Chronic Toxicity .............................. 9
2.2.1 Acute Versus Chronic Tests ............................. 9
2.2.2 Primary and Secondary Data ............................. 10
2.2.3 Minimum Data Requ.i.r.em..e.n.ts.............................. 10
2.2.4 Modifying Facto.rs....................................... 11
2.2.5 Safety Factors ..................... 12
2.2.6 Selecting a Preliminary Objective Valu..e............................................ 12
2.3 Bioaccumulation ................................ 13
2.3.1 Consumption Guidelines ........................... 13
1 2.3.2 Fish Equivalency Concentration .............. 15
2.3.3 Determining the Acceptable Water Concentration ...... 15
2.3.4 Calculating. .th.e. B..io.a.c.cu.m..u.la.ti.o.n.-B..as.e.d. P.r.e.li.m.i.n.ar.y. O..b.je.c.ti.v.e...... 16
2.3.5 Summa.r.y............................................. 16
2.4 Mutagenicity ...................................... 17
2.4.1 Acceptable Data ...................... 18
1 2.4.2 Minimum Test Protocol Requir.e.m.e.n.ts........................ 19
2.4.3 Primary and Secondary Data 19
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2.4.4 Modifying Factors ............ 19
2.4.5 Process for Setting Objectives Base.d. o.n. M..u.ta.g.e.n.ic.i.ty............. 20
2.4.5.1 Determining Mutagenic Potential........................... 20
2.4.5.2 Setting Mutage.n.ic.it.y. O..bj.e.c.ti.ve.s............................. 20
2.4.6 Safety Factor ..................... 21
2.4.7 Selecting a. P.r.e.li.m.i.n.a.ry. .O.b.je.c.ti.v.e. V.a.l.u.e...................... 22
2.4.8 Summary ....... 22
2.5 Impacts on T.a.s.t.e .a.n.d. O.d.o.u.r. i.n. W..a.te.r. a.n.d. T..ai.n.ti.n.g. o.f. F.i.s.h .T.i.ss.u.e.s........ 23
2.6 Recreation ........................................... 24 I
2.7 Wildlife Protection............................................ 24
2.8 Sediment Quali.ty.............................................. 25
2.9 Other Effects ............................... 25
2.10 Recommending the Final PWQ.O................................. 25
2.11 Objectives of Othe.r. A.g.e.n.c.ie.s.................................... 25
2.12 Research Needs 26
...........
3 SETTING PROVINCIAL WATER QUA.L.I.T.Y. .G.U.I.D.E..L.IN..E.S............ 27
3.1 Substance Physical-Chemical Properties ........................... 27
3.2 Selection Of Baseline Uncertainty .F.a.c.to.r............................ 28
3.3 Evaluation of Toxicological Data .............................. 29
3.3.1 Primary Or Secondary Data .............................. 29 I
3.3.2 Optimal Data Req.u.i.re.m..en.t.s............................... 29
3.3.3 Simulated Data .......................... 30
3.3.4 Applicati.on. .o.f .T.o.x.ic.o.lo.g.i.c.al. D..at.a........................... 30
3.4 Bioaccumulatio.n.............................................. 31
3.5 Mutagenicity ............................ 32
3.5.1 Numeric Mutagenicity Guidelines ...................... 32
3.5.1.1 Optimal Guideline Data Requiremen.t.s....................... 33
3.5.2 Narrative Mutagenicity Guidelines ............... 33
3.6 Impacts on Tas.te. .A.n.d. O..d.o.u.r .o.f .W.a.t.e.r .A.n.d. F.i.s.h. T.i.ss.u.e.s................ 34
3.7 Other Effects ................................ 34
3.8 Recommending the Final PWQG................................... 34
3.9 Objectives of Other. A..ge.n.c.i.es..................................... 34
3.10 Research Needs 34
.............................................
4 REFERENCES 35
...............
APPENDIX A - Bioaccumulation: Theoretical Considerations Al
................
APPENDIX B - Mutagenicity: Acceptable Tests and Species B1
- Worksheets and Tables ...............................
APPENDIX C
C1
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INTRODUCTION
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1.1 The Basis for Provincial setting considers a wide variety of rep-
Water Quality Objectives resentative aquatic organisms, critical life
stages and toxic effects, including muta-
The mandate for water quality manage- genicity. To expand the assessment
ment in Ontario is legislated under beyond direct toxic effects, the PWQO
1 several statutes, most notably, the Water development process also considers bioac-
Resources Act. In addition, the Ministry cumulation and taste and odour in water
of the Environment has specific policies and tainting of fish tissues. The following
(MOE, 1984) with the goal: factors are employed:
Mandatory factors:
"to ensure that the surface waters of the
province are of a quality which is satis-
factory for aquatic life and recreation. " Toxicity to aquatic life (acute, chronic,
lethal, sublethal)
To support this goal, the Ministry's policy
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further states that: Bioaccumulation (Animals consuming
aquatic organisms and humans
'... the Objectives tire set at such values consuming sport fish)
as to protect all forms of aquatic life and
all aspects of the uquatic life cycles. The Mutagenicity to aquatic life
clear intention is to protect all life stages
during indefinite exposure to the water. " Other factors:
In order to achieve these water manage- Fate and physical-chemical factors
ment goals, a comprehensive understan-
ding of, and sound management program Sources and ambient levels
for the control of physical, chemical and
bacteriological pollutants is required. Taste and odour in water and tainting
Since 1978, Ontario has relied on Provin- of fish tissues
cial Water Quality Objectives and Guide-
lines as principal tools for surface water Impacts on wildlife
quality management.
Recreation
Objectives are numerical and narrative
values designed to protect all stages of Sediment quality
aquatic life cycles during indefinite ex-
posure to the water. The purpose of this Objectives of other agencies (for
document is to set forth detailed proced- comparison only).
ures for developing Provincial Water
Quality Objectives (PWQOs). The PWQO setting is not influenced by analy-
PWQO development process closely ad- tical limitations, economics, social factors,
heres to the water management policy of or waste treatment availability. All of
the Ministry by requiring that PWQO these are important in water management,
and are considered in the site-specific
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application of the Objectives. PWQOs tent approach in establishing environmen-
are designed to take into account both tal protection values for substances with
cold-water and warm-water environments limited information, a process for setting
in a single Objective, with the exception Provincial Water Quality Guidelines
of dissolved oxygen. An assessment of (PWQG) was established.
toxicity to both cold and warm-water
species is a requirement of the PWQO The PWQG setting process was developed
setting process. Consequently, Objectives to parallel, as closely as possible, the
will be applied independent of the nature Objective setting process by employing
of the possible resident species (e.g. cold- toxicological data as well as considering
water or warm-water species), the type of bioaccumulation, mutagenicity and other
waterbody (lake or stream) and its trophic factors, yet permitting the development of
status. substance-specific environmental protec-
tion values with even a small amount of
The influence of water temperature and data. The PWQG process sets a margin
other specific physical and chemical fac- of uncertainty whose size is dependent on
tors such as pH and hardness are, how- the quantity and quality of available data.
ever, considered when they affect the The process encourages the publication of
toxicity of the candidate substances for new aquatic toxicity data to further refine
PWQO setting. The PWQO for the PWQG or allow it to become a
ammonia, for example, is related to both PWQO.
pH and water temperature and the Objec-
tives for many of the metals are related to
water hardness. 1.3 Application of PWQGs and
PWQGs
The process of developing PWQGs has
evolved with experience so that it is effec- This document is not intended to describe
tive at taking into account crucial aspects in detail the application of Objectives and 1
of the hazard of substances in aquatic Guidelines in Ontario's water quality
environments. The process is also eff- management programs. Objectives and
icient at developing Objectives and Guidelines are designed for application to
Guidelines with limited resources. The all surface waters (rivers, streams, lakes,
purpose of this document is to describe etc.) in Ontario regardless of their existing
this process. By doing so, the applicability use or condition. With specific respect to
as well as the limitations of the Objectives the use of PWQGs and PWQGs, the
will better be understood by water quality Ministry's surface water quality manage-
managers, by the public, as well as by ment goal is supported by a series of
those who assist in the process. policies and application procedures. Key
policies state:
1.2 The Basis for Provincial
"In areas which have water quality better
Water Quality Guidelines than the Provincial Water Quality Objec-
tive [or Guideline], water quality shall be
It is recognized that, for many substances maintained at or above the Objectives
of concern, there are not sufficient toxi- [or Guidelines] ",
cological or other data to prepare a
PWQG. In an effort to achieve a consis-
and
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icance of the materials that may be found
"Water quality which presently does not in waterbodies as the result of spills and
meet the Provincial Water Quality Objec- uncontrolled sources, and to protect local
tives [or Guidelines] shall not be de- water quality in situations where tech-
graded further and all practical measures nology based requirements may not be
shall be taken to upgrade the water qual- stringent enough to protect aquatic life.
ity to the Objectives [or Guidelines]."
PWQGs are set for individual chemicals
PWQOs and PWQGs are, therefore, used or homologous groups and, for the most
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in combination with water quality monit- part, do not account for joint toxicity (i.e.
oring data to assess ambient conditions in additive, synergistic or antagonistic ef-
Ontario and to identify areas with existing fects) resulting when a mixture of hazar-
or potential water quality problems. dous substances is present in a waterbody.
In application, models addressing com-
The PWQO development process follows bined toxic effects should be employed
the policy of the Ministry to treat all wherever possible. At the very least,
surface waters in the province alike, ex- water quality managers should consider
cept for distinguishing between waters that waters with a quality at or near the
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that are of acceptable quality and those Objectives for several parameters may not
that are degraded. It is essential afford adequate protection to aquatic life.
therefore to set Objectives that are The empirical approach of testing whole
stringent enough to protect the most effluent or receiving water samples dir-
sensitive environments. ectly addresses the joint toxicity of com-
plex mixtures of substances.
Although Objectives and Guidelines are
not legal standards per se, they are emp-
loyed in various types of water quality 1.4 Other Water Quality
models to establish acceptable wastewater Objectives and Guidelines
loading limits on a site-specific basis.
These loading limits, contained in Control PWQO's and PWQG's are designed prim-
Orders or other similar instruments, are arily to meet the Ministry's goal of protec-
legally enforceable. ting aquatic life and recreational uses.
There are other uses and criteria that
1 The Ministry's water management policy should be considered. The Canadian
lists several substances with "zero Water Quality Guidelines (CCREM,
tolerance limits" which "... should be 1987) for agricultural uses (irrigation and
completely eliminated [from discharges]". livestock watering) and industrial water
The Municipal and Industrial Strategy for supply provide protection for these uses
Abatement (MISA) is based on the goal and should be considered where applic-
of the virtual elimination of persistent able.
toxic substances from point source dis-
charges. Both of these policies relate to PWQGs are not Drinking Water Objec-
effluent control and in regulatory instru- tives and thus do not apply to drinking
ments they may supersede waste loading water. The Ministry has set Drinking
limits derived from a PWQO or PWQG.
Water Objectives which apply specifically
Objectives and Guidelines are needed, to to finished drinking water and not raw
assess the aquatic environmental signif- water. These Objectives are developed
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