Water Quality Guidelines Online - Introduction
Guideline Lists and the Categories for Primary Industries
Primary Industries - Irrigation
Agricultural practice in Australia and New Zealand is often dependent on irrigation, because of climatic
constraints on crop demand. An important goal of these Water Quality Guidelines is to maintain the
productivity of irrigated agricultural land and associated water resources, in accordance with the
principles of ecologically sustainable development and integrated catchment management.
This should be a key consideration in any irrigation strategy, alongside maximum yield and economic
viability.
In developing the guidelines, emphasis has been placed on sustainability in agricultural practice
(DEST State of the Environment Advisory Council 1996), which aims to ensure that:
o the supply of necessary inputs is sustainable;
o the quality of natural resources is not degraded;
o the environment is not irreversibly harmed;
o the welfare and options of future generations are not jeopardised by the production and consumption
activities of the present generation; and
o yields and produce quality are maintained and improved.
In terms of water quality, the focus for sustainable farming systems is on adopting management
practices that maintain productivity and minimise the off-farm movement or leaching of potential
aquatic contaminants. Key issues include soil erosion, landscape salinity, fertiliser and pesticide
management, livestock access to streams, and safe disposal of effluent from intensive animal industries.
The categories vary depending on the type of stressor (See the footnotes for details).
=> Long Term Trigger Values - The long-term trigger value (LTV) is the maximum concentration
(micro g/L) of contaminant in the irrigation water which can be tolerated assuming 100 years of
irrigation, based on the irrigation loading assumptions described in the water quality guidelines.
=> Short Term Trigger Values - The short-term trigger value (STV) is the maximum concentration
(micro g/L) of contaminant in the irrigation water which can be tolerated for a shorter period of
time (20 years) assuming the same maximum annual irrigation loading to soil as for LTV.
Various sensitivity categories are provided for various indicators from 'sensitive' to 'highly tolerant'
values for the indicators. (see Voulume 1 page 4.1-1 for details.)
Primary Industries - General Water Use - Corrosiveness of Water
Corrosion of pumping, irrigation and stock watering equipment is a common problem in many
agricultural areas of Australia, particularly where groundwater sources are used. It often results in the
deterioration of well and pumping equipment, pipelines, channels, sprinkler devices and storage tanks,
leading to decreased or uneven water distribution. Corrosion can be caused by chemical, physical or
microbiological processes acting on metal surfaces in contact with water.
Plastics and concrete may also deteriorate, through processes similar to corrosion, if elevated levels
of certain constituents are present.
Corrosiveness is classified as Limited, Increasely, Likely and High Corrosion Potential.
Primary Industries - General Water Use - Fouling Potential
Fouling of agricultural water systems can lead to decreased water quality and yield
as a result of clogging, encrustation and scaling. All parts of the system can be
affected including wells, pumping equipment, pipes and sprinklers. The main
causes of fouling in agricultural water systems can be attributed to physical,
chemical and biological properties of the water.
Fouling Potential is classified as Limited, Moderate, and Increased Fouling Potential.
Primary Industries - Livestock Drinking Water
Good water quality is essential for successful livestock production. Poor quality water may reduce
animal production and impair fertility. In extreme cases, stock may die.
Contaminants in drinking water can produce residues in animal products (e.g. meat, milk and eggs),
adversely affecting their saleability and/or creating human health risks.
Animal industries themselves may impair water quality downstream (e.g. through faecal contamination),
highlighting the need for an integrated approach to land and water management in rural catchments.
Daily water intake varies widely among different forms of livestock and is also influenced by factors
such as climate and the type of feed being consumed.
The guidelines are trigger values below which there should be minimal risk to animal health.
If the water quality exceeds a trigger value, it is advisable to investigate further to determine
the level of risk.
The three categories used for these guidelines are identical to those for the Drinking Water
Guidelines because the guidelines for pesticides and other toxicants are derived from the
Drinking Water Guidelines.
* Not Detected - For pesticides, which are not approved for use in water or water catchment areas
the guideline value is set at or about the limit of determination (LOD). This value is the
level at which the pesticide can be reliably detected using practicable readily available
and validated analytical methods. This also applies to some bacteria.
* Health - A health-related guideline value is the concentration or measure of a water quality
characteristic that, based on present knowledge, does not result in any significant risk to
the health of the consumer over a lifetime of consumption.
* Aesthetics - An aesthetic guideline value is the concentration or measure of a water quality
characteristic that is associated with good quality water.
Primary Industries - Aquaculture and Human Consumption of Aquatic Foods
Aquaculture involves the production of food for human consumption, fry for recreational fishing
and natural fisheries, ornamental fish and plants for the aquarium trade, raw materials for energy and
biochemicals, and a number of items for the fashion industry.
Within the growing aquaculture industry, it is well accepted that satisfactory water quality
is needed for maintaining viable aquaculture operations. Poor water quality can result in loss of
production of culture species, and can also reduce the quality of the end product.
Production is reduced when influent water contains enough contaminants to impair development, growth
or reproduction, with the ultimate result being death.
Quality is reduced when low levels of a contaminant cause no obvious adverse effects but gradually
accumulate in the culture species to the point where it poses a potential health risk to human
consumers.
Thus, both these issues needed to be considered if useful and usable guidelines are to be
provided for the aquaculture industry.
Water quality guidelines are provided for influent (i.e. water that is entering the
aquaculture operation) or source water quality, and it also addresses the safety of aquatic foods
for human consumers, whether the foods be produced by aquaculture, or commercial, or recreational
or indigenous fishing.
Guidelines are provided for:
# Freshwaters
# Marine Waters (and sometimes for estuarine waters)