Water Quality Guidelines Online - Introduction
Environmental Values, the Guideline Lists and the Categories
Environmnental Values - What are They?
Environmental values are the expression of the community's desires and needs in relation to the
value or use of a section of waterway or an area of a waterbody. Usually the need to develop a
water quality management plan is driven by concerns that one or more of the present or future
environmental values in the waterbody is threatened by degrading water quality.
This will generally occur because of problems in the catchment that have been identified by
water quality testing or other concerns. The sources may be point-source or diffuse, or a
combination of both.
Setting the environmental values for all the receing waters and their sections throughout a
catchment through stakeholder consultation is one corner stone for building a water quality
management plan. The other cornser stones are identifying the cause of the specific problems,
how to fix them effectively and how to establish effective monitoring and reporting strategies.
Environmental values are the beneficial uses of the environment and ecological values that
are important and require protection from the effects of pollution, waste discharges,
deposits and degradation of the catchment and its waterbodies.
The environmental values recognised by the water quality guidelines are:
=> Aquatic ecosystems with six types specified (upland rivers, lowland rivers,
lakes and reservoirs, wetlands, estuaries, marine) + sediments.
=> Primary industries (irrigation and general water use, stock drinking water,
aquatic and human consumption of aquatic foods),
=> Recreation and Aesthetics ;
=> Drinking Water;
=> [Industrial and Cultural/Spiritual Values are not currently included in the guidelines]
Several environmental values may be designated for a specific waterbody.
It is assumed that meeting the needs for the most stringent environmental value will satisfy
the requirement for other values specified. This means that only one guideline value (or a small
set of integrated indicators) and water quality objectives need be specified for each attribute.
For example if the waterbody is to be used for Drinking Water and for Irrigation and the
Lead (Pb) concentration is a problem. Then the guideline for Lead in irrigation is used for
management of this problem to protect the values as this has the most stringent requirement.
Guideline Value Lists and Categories for Ecosystem Protection
Protection of Aquatic Ecosystems - Marine & Freshwater Toxicants
Toxicants (Marine & Freshwater) are chemical contaminants such as metals, aromatic hydrocarbons,
pesticides and herbicides that can potentially have toxic effects at concentrations that
might be encountered in the environment. Separate guidelines are specified for four levels of
protection for ecosystems classified into three consition categeories:
=> 1. High conservation/ecological value systems - effectively unmodified or other
highly-valued ecosystems, typically (but not always) occurring in national
parks, conservation reserves or in remote and/or inaccessible locations.
(Guideline trigger values are specified for protection of 99% of species ie effectively no
change in species diversity).
=> 2. Slightly to moderately disturbed systems - ecosystems in which aquatic
biological diversity may have been adversely affected to a relatively small
but measurable degree by human activity. The biological communities remain
in a healthy condition and ecosystem integrity is largely retained.
Typically, freshwater systems would have slightly to moderately cleared catchments
and/or reasonably intact riparian vegetation; marine systems would have largely intact
habitats and associated biological communities.
(Guideline trigger Values specified for protection of 95% of species).
The 99% protection levels can also be used as default values for slightly–moderately
disturbed systems where local data are lacking on bioaccumulation effects or where
it is considered that the 95% protection level failsto protect key species.
=> 3. Highly disturbed systems These are measurably degraded ecosystems of lower
ecological value. Examples of highly disturbed systems would be some
shipping ports and sections of harbours serving coastal cities, urban streams
receiving road and stormwater runoff, or rural streams receiving runoff from
intensive horticulture.
(Two guideline trigger values are specified for the protection of 90% and 80% of species).
Guideline trigger values recommended for slightly to moderately disturbed ecosystems
In addition to the trigger values specified for four levels of protection (99%, 95%, 90% and 80% guideline
triggger values are recommended for slightly to moderately disturbed ecosystems.
These mostly correspond with the 95% level of protection, but for a few chemicals the 99% level
of protection is recommended, mostly because of the toxicity data used to derive the trigger value
is inadequate.
Protection of Aquatic Ecosystems - Physical and Chemical Stressors
Physical and chemical stressors include the natural water quality parameters, nutrients, biodegradable
organic matter, dissolved oxygen, turbidity, suspended particulate matter, temperature, salinity, pH
and changes in flow regime. Physical and chemical stressors are major contributors to changes in aquatic
ecosystems, such as nuisance growth of aquatic plants, smothering of organisms living in aquatic
environments, and stress to or death of native freshwater fish. They may also modify the effects of
toxicants. The Water Quality Guidelines classify physical and chemical stressors into two broad types,
those having direct and those having indirect effects on ecosystems.
Guidelines are provided for four regions throughout Australia and also for New Zealand.
Guidelines are also provided for 7 ecosystem types, lowland and upland rivers, wetlands, lakes &
reservoirs, estuaries, and inshore and offshore marine ecosystems. Generally a single default trigger
guideline is specified for slightly-moderately disturbed ecosystems.
Note that for High Conservation areas the target is 'no detectable change from natural variation'.
In some cases values are specified for particular States and for local areas or regions with States.
For more details see Vol 1 3.3-1., and the notes and codes displayed on the web pages.
Protection of Aquatic Ecosystems - Sediments
The recommended guideline values for sediments are tabulated as interim sediment quality
guideline (ISQG) values.
There are two categories:
=> Low ISQG - This corresponds with the effects range-low in the NOAA listing (Long et al. 1995)
=> High ISQG - This corresponds with the effects range-median in the NOAA listing (Long et al. 1995)
See Volume 1 page 3.5-1 for more details.
Protection of Aquatic Ecosystems - Sediments Quality Guidelines for Disposal of Dredged Materials
These guidelines were derived from the sediment guidelines - shown above.
The Screening and Maximum Guideline categoreis are the same as the Low and High
guidelines for the Sediment Guidelines (see above)
=> Screening Guideline - This corresponds with the effects range-low in the NOAA listing (Long et al. 1995)
=> Maxiumum Guideline - This corresponds with the effects range-median in the NOAA listing (Long et al. 1995)
See the link below for more details