Richmond River
Water Quality Objectives explained

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This section explains each of the eleven Water Quality Objectives (WQOs) developed for NSW rivers and estuaries, and provides guideline levels to assist water quality planning and management. Guideline levels are not provided for industrial water supplies as requirements are industry specific.

See the WQOs that apply to each part of the Richmond River catchment.

Achieving each WQO will mean improving poor water quality or maintaining existing good water quality.

Objectives consist of three parts: environmental values, their indicators and their guideline levels. For example, if the objective is to protect secondary contact recreation (environmental value), we need to keep the faecal coliform levels in the water (the indicator) below a specified number or guideline level.

The objectives comprise community-based environmental values and their associated national criteria drawn from the ANZECC 2000 Guidelines. They provide the statewide context for taking this work forward into catchment action plans, regional strategies and local environmental plans. 

Tailoring Water Quality Objectives to local conditions

Local water quality varies naturally because of various factors, including the type of land the waters are draining (e.g. soils, slope), or rainfall and runoff patterns (e.g. ephemeral or permanent streams). Different land use and land management practices also affect water quality. Local WQOs must take account of these variations, particularly for the environmental value of aquatic ecosystems.

The ANZECC 2000 Guidelines move away from setting fixed single number water quality criteria, and emphasise water quality criteria that can be determined on a case by case basis, according to local environmental conditions. This is done through the use of local reference data and risk based decision frameworks — see section 2.2.1.4 Tailoring guidelines for local conditions (ANZECC 2000 Guidelines). The ANZECC 2000 Guidelines establish default trigger values that are set conservatively and can be used as a benchmark for assessing water quality. Further refinement of the trigger values may be needed to take account of local conditions, especially for aquatic ecosystems and particularly in places, or for issues, requiring priority action. This should be consistent with the approach advocated by the ANZECC 2000 Guidelines of focusing on the actual issue (or threatening process) that is a risk or potential risk to the environmental value(s). The selection of the indicator and derivation of the trigger value should trigger action or investigation before the environmental value is compromised. Trigger levels that have been locally refined must still protect the environmental value and drive local protection or improvement of water quality.

The key indicators and trigger values used here are examples of some of the indicators  listed in the ANZECC 2000 Guidelines. Key indicators for each environmental value are listed below. 

Downstream impacts

Planning and management decisions need to recognise that activities and decisions made upstream affect water quality downstream. Where this involves cumulative impacts for nutrients and sediments, the best approach may be to develop load targets for the catchment (see ANZECC 2000 Guidelines).

Water Quality Objectives

Meeting water quality levels suitable for local ecosystems is generally the basis for protecting the other environmental values, which are the uses people have for water.

Aquatic ecosystems

Maintaining or improving the ecological condition of waterbodies and their riparian zones over the long term

Where the objective applies

Examples of key indicators and their numerical criteria (default trigger values)

The following table includes examples of some of the key water quality indicators and related numerical criteria (default trigger values) selected from the ANZECC 2000 Guidelines, relevant to assessing and monitoring the health of aquatic ecosystems. To use and interpret these guidelines, see supporting information below and the ANZECC 2000 Guidelines. The booklet "Using the ANZECC Guidelines and Water Quality Objectives in NSW" explains key terminology and concepts used in the guidelines, in the context of NSW policy.

Aquatic ecosystems
Indicator Numerical criteria (trigger values)
Total phosphorus
  • Upland rivers: 20 µg/L
  • Lowland rivers: 25 µg/L for rivers flowing to the coast; 50 µg/L for rivers in the Murray-Darling Basin
  • Lakes & reservoirs: 10 µg/L
  • Estuaries: 30 µg/L
Total nitrogen
  • Upland rivers: 250 µg/L
  • Lowland rivers: 350 µg/L for rivers flowing to the coast; 500 µg/L for rivers in the Murray-Darling Basin 
  • Lakes & reservoirs: 350 µg/L
  • Estuaries: 300µg/L
Chlorophyll-a
  • Upland rivers: not applicable
  • Lowland rivers: 5 µg/L
  • Lakes & reservoirs: 5 µg/L.
  • Estuaries: 4 µg/L.
Turbidity
Salinity (electrical conductivity)
  • Upland rivers: 30–350 µS/cm
  • Lowland rivers: 125–2200 µS/cm
Dissolved oxygen
  • Upland rivers: 90–110%
  • Lowland rivers: 85–110%
  • Freshwater lakes & reservoirs: 90–110%
  • Estuaries: 80–110%

Note: Dissolved oxygen values were derived from daytime measurements. Dissolved oxygen concentrations may vary diurnally and with depth. Monitoring programs should assess this potential variability.

 
pH
  • Upland rivers: 6.5–8.0
  • Lowland rivers: 6.5–8.5
  • Freshwater lakes & reservoirs: 6.5–8.0
  • Estuaries: 7.0–8.5

Changes of more than 0.5 pH units from the natural seasonal maximum or minimum should be investigated.

See supporting information

Temperature See ANZECC 2000 Guidelines, table 3.3.1.
Chemical contaminants or toxicants See ANZECC 2000 Guidelines, chapter 3.4 and table 3.4.1.
Biological assessment indicators This form of assessment directly evaluates whether management goals for ecosystem protection are being achieved (e.g. maintenance of a certain level of species diversity, control of nuisance algae below a certain level, protection of key species, etc). Many potential indicators exist and these may relate to single species, multiple species or whole communities. Recognised protocols using diatoms and algae, macrophytes, macroinvertebrates, and fish populations and/or communities may be used in NSW and interstate (e.g. AusRivAS).

Supporting information

Visual amenity

Aesthetic qualities of waters

Where the objective applies

Examples of key indicators and their numerical criteria

Indicators used to assess and monitor visual amenity are summarised in the table.

Visual amenity
Indicator Numerical criteria (trigger values)
Visual clarity and colour Natural visual clarity should not be reduced by more than 20%.

Natural hue of the water should not be changed by more than 10 points on the Munsell Scale.

The natural reflectance of the water should not be changed by more than 50%.

Surface films and debris Oils and petrochemicals should not be noticeable as a visible film on the water, nor should they be detectable by odour.

Waters should be free from floating debris and litter.

Nuisance organisms Macrophytes, phytoplankton scums, filamentous algal mats, blue-green algae, sewage fungus and leeches should not be present in unsightly amounts.

Supporting information

Secondary contact recreation

Maintaining or improving water quality for activities such as boating and wading, where there is a low probability of water being swallowed

Where the objective applies

Examples of key indicators and their numerical criteria

Indicators used to assess and monitor water for secondary contact recreation are summarised in the table.

Secondary contact recreation
Indicator Numerical criteria (trigger values)
Faecal coliforms Median bacterial content in fresh and marine waters of < 1000 faecal coliforms per 100 mL, with 4 out of 5 samples < 4000/100 mL (minimum of 5 samples taken at regular intervals not exceeding one month).
Enterococci Median bacterial content in fresh and marine waters of < 230 enterococci per 100 mL (maximum number in any one sample: 450-700 organisms/100 mL).
Algae & blue-green algae < 15 000 cells/mL
Nuisance organisms Use visual amenity guidelines.

Large numbers of midges and aquatic worms are undesirable.

Chemical contaminants Waters containing chemicals that are either toxic or irritating to the skin or mucous membranes are unsuitable for recreation.

Toxic substances should not exceed values in tables 5.2.3 and 5.2.4 of the ANZECC 2000 Guidelines.

Visual clarity and colour Use visual amenity guidelines.
Surface films Use visual amenity guidelines.

Primary contact recreation

Maintaining or improving water quality for activities such as swimming in which there is a high probability of water being swallowed

Where the objective applies

Examples of key indicators and their numerical criteria

Indicators used to assess and monitor water for primary contact recreation are summarised in the table.

Primary contact recreation
Indicator Numerical criteria (trigger values)
Turbidity A 200 mm diameter black disc should be able to be sighted horizontally from a distance of more than 1.6 m (approximately 6 NTU).
Faecal coliforms Beachwatch considers waters are unsuitable for swimming if:
  • the median faecal coliform density exceeds 150 colony forming units per 100 millilitres (cfu/100mL) for five samples taken at regular intervals not exceeding one month, or
  • the second highest sample contains equal to or greater than 600 cfu/100mL (faecal coliforms) for five samples taken at regular intervals not exceeding one month.

ANZECC 2000 Guidelines recommend:

  • Median over bathing season of < 150 faecal coliforms per 100 mL, with 4 out of 5 samples < 600/100 mL (minimum of 5 samples taken at regular intervals not exceeding one month).
Enterococci Beachwatch considers waters are unsuitable for swimming if:
  • the median enterococci density exceeds 35 cfu/100mL for five samples taken at regular intervals not exceeding one month, or
  • the second highest sample contains equal to or greater than 100 cfu/100mL (enterococci) for five samples taken at regular intervals not exceeding one month.
ANZECC 2000 Guidelines recommend:
  • Median over bathing season of < 35 enterococci per 100 mL (maximum number in any one sample: 60-100 organisms/100 mL).
Protozoans Pathogenic free-living protozoans should be absent from bodies of fresh water. (Note, it is not necessary to analyse water for these pathogens unless temperature is greater than 24 degrees Celsius).
Algae & blue-green algae < 15 000 cells/mL
Nuisance organisms Use visual amenity guidelines.

Large numbers of midges and aquatic worms are undesirable.

pH 5.0-9.0 (see supporting information)
Temperature 15°-35°C for prolonged exposure.
Chemical contaminants Waters containing chemicals that are either toxic or irritating to the skin or mucus membranes are unsuitable for recreation.

Toxic substances should not exceed the concentrations provided in tables 5.2.3 and 5.2.4 of the ANZECC 2000 Guidelines 2000.

Visual clarity and colour Use visual amenity guidelines
Surface films Use visual amenity guidelines

Supporting information

Livestock water supply

Protecting water quality to maximise the production of healthy livestock

Where the objective applies

Examples of key indicators and their numerical criteria

Indicators used to assess and monitor water for livestock water supply are summarised in the table.

Livestock water supply
Indicator Numerical criteria (trigger values)
Algae & blue-green algae An increasing risk to livestock health is likely when cell counts of microcystins exceed 11 500 cells/mL and/or concentrations of microcystins exceed 2.3 µg/L expressed as microcystin-LR toxicity equivalents.
Salinity (electrical conductivity) Recommended concentrations of total dissolved solids in drinking water for livestock are given in table 4.3.1 (ANZECC 2000 Guidelines).
Thermotolerant coliforms (faecal coliforms) Drinking water for livestock should contain less than 100 thermotolerant coliforms per 100 mL (median value).
Chemical contaminants Refer to Table 4.3.2 (ANZECC 2000 Guidelines) for heavy metals and metalloids in livestock drinking water.

Refer to Australian Drinking Water Guidelines (NHMRC and NRMMC 2004) for information regarding pesticides and other organic contaminants, using criteria for raw drinking water.

Supporting information

Irrigation water supply

Protecting the quality of waters applied to crops and pasture

Where the objective applies

Examples of key indicators and their numerical criteria

Indicators used to assess and monitor water for irrigation water supply are summarised in the table.

Irrigation water supply
Indicator Numerical criteria (trigger values)
Algae & blue-green algae Should not be visible. No more than low algal levels are desired to protect irrigation equipment.
Salinity (electrical conductivity) To assess the salinity and sodicity of water for irrigation use, a number of interactive factors must be considered including irrigation water quality, soil properties, plant salt tolerance, climate, landscape and water and soil management. For more information, refer to Chapter 4.2.4 of ANZECC 2000 Guidelines.
Thermotolerant coliforms (faecal coliforms) Trigger values for thermotolerant coliforms in irrigation water used for food and non-food crops are provided in table 4.2.2 of the ANZECC Guidelines
Heavy metals and metalloids Long term trigger values (LTV) and short-term trigger values (STV) for heavy metals and metalloids in irrigation water are presented in table 4.2.10 of the ANZECC 2000 Guidelines.

Supporting information

Homestead water supply

Protecting water quality for domestic use in homesteads, including drinking, cooking and bathing

Where the objective applies

Examples of key indicators and their numerical criteria

Key indicators for drinking water quality at the point of use in the Australian Drinking Water Guidelines (NHMRC & NRMMC 2004) are set out below. Monitoring should also be considered for health-related parameters of local concern. Communities should refer to the Australian Drinking Water Guidelines (and updates) [www.nhmrc.gov.au/publications/synopses/eh19syn.htm] for information on additional parameters.

Homestead water supply
Indicator Numerical criteria (trigger values)
Blue-green algae Recommend twice weekly inspections during danger period for storages with history of algal blooms. No guideline values are set for cyanobacteria in drinking water. In water storages, counts of < 1000 algal cells/mL are of no concern.

>500 algal cells/mL - increase monitoring.

>2000 algal cells/mL - immediate action indicated; seek expert advice.

>6500 algal cells/mL - seek advice from health authority

Turbidity 5 NTU; <1 NTU desirable for effective disinfection; >1 NTU may shield some micro-organisms from disinfection. (see supporting information)
Total dissolved solids < 500 mg/L is regarded as good quality drinking water based on taste.

500-1000 mg/L is acceptable based on taste.

>1000 mg/L may be associated with excessive scaling, corrosion and unsatisfactory taste.

Faecal coliforms 0 faecal coliforms per 100 mL (0/100 mL). If micro-organisms are detected in water, advice should be sought from the relevant health authority.

See also the Guidelines for Microbiological Quality in relation to Monitoring, Monitoring Frequency and Assessing Performance in the Australian Drinking Water Guidelines (NHMRC & ARMCANZ 2004).

pH 6.5-8.5 (see supporting information)
Chemical contaminants See Guidelines for Inorganic Chemicals in the Australian Drinking Water Guidelines (NHMRC & NRMMC 2004).

Supporting information

Drinking water - Disinfection only, or

Drinking water - Clarification and disinfection

Drinking water - Groundwater

Refers to the quality of drinking water drawn from the raw surface and groundwater sources before any treatment

Where the objectives apply

Examples of key indicators and their numerical criteria

Key indicators for raw water for drinking water supply that is to undergo coarse screening only are listed below. These indicators are drawn from the National Health and Medical Research Council Australian Drinking Water Guidelines (NHMRC & NRMMC 2004).

Note that a wide range of treatment technologies are available (e.g. coagulation, flocculation, filtration, ion exchange, reverse osmosis, carbon adsorption columns) that enable the production of acceptable drinking water from almost any raw water. The ANZECC 2000 Guidelines do not specify criteria for the many types of water quality that could be involved.

Refer to the NSW Groundwater Protection Policy, (DLWC 1998b) for information on the management of groundwater quality.

All drinking water should comply with the Australian Drinking Water Guidelines (NHMRC & NRMMC 2004) at the point of use. Refer to the Summary in the Australian Drinking Water Guidelines.

Drinking water
Indicator Numerical criteria (trigger values)
Blue-green algae Recommend twice weekly inspections during danger period for storages with history of algal blooms.

>500 algal cells/mL - increase monitoring.

< 2000 algal cells/mL - water may be used for potable supply.

>2000 algal cells/mL - immediate action indicated; seek expert advice.

>6500 algal cells/mL - seek advice from health authority.

>15 000 algal cells/mL - may not be used for potable supply except with full water treatment, which incorporates filtration and activated carbon.

Source: Australian Drinking Water Guidelines (NHMRC & NRMMC 2004).

Turbidity Site-specific determinant.
Salinity (electrical conductivity) <1500 µS/cm

> 800 µS/cm causes a deterioration in taste.

Faecal coliforms* 0 faecal coliforms per 100 mL (0/100 mL)
Total coliforms* 95% of samples should be 0 coliforms/ 100 mL throughout the year.

Up to 10 coliform organisms may be accepted occasionally in 100 mL.

Coliform organisms should not be detected in 100 mL in any two consecutive samples.

Dissolved oxygen > 6.5 mg/L (> 80% saturation)
pH 6.5-8.5
Chemical contaminants See ANZECC 2000 guidelines, section 6.2.2.

* Values given are NHMRC criteria for raw waters before disinfection or clarification. Raw waters can have concentrations of faecal coliforms above the NHMRC criteria, even in pristine ecosystems. Slightly greater faecal coliform or total coliform contamination, may therefore be acceptable in raw waters that are to be disinfected before delivery to the consumer. (Faecal coliform criteria used in Victoria have suggested that for raw waters requiring only low-level treatment, natural background levels of 95% of samples should have <10 faecal coliforms/100 mL. For high-level treatment, 95% of samples should have <100 faecal coliforms/100 mL.) For a full discussion of drinking water system management and criteria, see the Australian Drinking Water Guidelines (NHMRC & NRMMC 2004).

Supporting information

Aquatic foods (cooked)

Refers to protecting water quality so that it is suitable for the production of aquatic foods for human consumption and aquaculture activities.

(Note: The ANZECC 2000 Guidelines lists this environmental value as Aquaculture and human consumption of aquatic foods)

Where the objective applies

Examples of key indicators and their numerical criteria

Indicators used to assess and monitor water quality so that it is suitable for the production of aquatic foods are summarised in the following table. Other indicators are listed in the ANZECC 2000 Guidelines and Food Standards Code (ANZFA 1996 and updates available at www.anzfa.gov.au).

Aquatic foods
Indicator Numerical criteria (trigger values)
Algae & blue-green algae No guideline is directly applicable, but toxins present in blue-green algae may accumulate in other aquatic organisms.
Faecal coliforms Guideline in water for shellfish: The median faecal coliform concentration should not exceed 14 MPN/100mL; with no more than 10% of the samples  exceeding 43 MPN/100 mL.

Standard in edible tissue: Fish destined for human consumption should not exceed a limit of 2.3 MPN E Coli /g of flesh with a standard plate count of 100,000 organisms /g.

Toxicants (as applied to aquaculture activities) Metals:
  • Copper: less than 5 µgm/L.
  • Mercury: less than 1 µgm/L.
  • Zinc: less than 5 µgm/L.

Organochlorines:

  • Chlordane: less than 0.004 µgm/L (saltwater production)
  • PCBs: less than 2 µgm/L.
Physico-chemical indicators (as applied to aquaculture activities)
  • Suspended solids: less than 40 micrograms per litre (freshwater)
  • Temperature: less than 2 degrees Celsius change over one hour.

 

Supporting information

Industrial water supplies

The high economic value of water taken from rivers and lakes for use by industry needs recognition in water quality planning and management. It has been identified as an important environmental value through community consultation.

As industry water supply needs are diverse, relevant water quality criteria are not summarised here and the ANZECC 2000 Guidelines do not provide guidance on the water quality needed for various industries. Sources of water used for industry invariably have other environmental values, which mostly need water of a higher quality than that needed by industry. Further, individual industries generally have the capacity to monitor and treat the available water resources to meet their own needs.

This page was published 1 May 2006

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