Recycled Water Irrigation in Australia - Environmental Sustainability: Role of Green Technologies - page 40

Table 1 Water quality standards and applications for water classes A-D in South Australia
Class

Applications Microbiological criteria

Chemical/physical criteria

A Primary contact recreation <10 Escherichia coli /100 mL Turbidity ≤ 2 NTU

Residential non-potable Specifi c removal of viruses,

protozoa and Helminths may be
required

BOD <20 mg/L

Unrestricted crop irrigation Chemical content to match use

Dust suppression with
unrestricted access
Municipal use with
public access

B Secondary Contact recreation <100 Escherichia coli /100 mL BOD <20 mg/L

Restricted crop irrigation Specifi c removal of viruses,

protozoa and Helminths may be
required

Suspended Solids <30 mg/L

Irrigation of pasture and fodder
for grazing animals

Chemical content to match use

Dust suppression with
restricted access
Municipal use with restricted
access

C Passive recreation <1000 Escherichia coli /100 mL BOD <20 mg/L

Municipal use with restricted
access

Specifi c removal of viruses, protozoa
and Helminths may be required

Suspended Solids <30 mg/L

Restricted crop irrigation Chemical content to match use

Irrigation of pasture and
fodder for grazing animals

D Restricted crop irrigation <10000 Escherichia coli /100 mL Chemical content to match use

Irrigation for turf production Helminths may need to be

considered for pasture and fodder

Silviculture
Source : DOH and EPA ( 1999 ); NTU Nephelometric Turbidity Units

approved manner varies across the jurisdictions
as do the requirements for ongoing monitoring,
audits and reviews. The extent of the relevant
authorities' ongoing involvement in a scheme
depends on its size, the risk associated with reuse
and sensitivity of the receiving area.
Currently each state authority holds the
responsibility for defi ning the quality of water
that can be used to irrigate fruits/vegetables;
guidelines for reclaimed water use exist in each
state and territory (Power 2010 ). Recycled water
guidelines set targets for removal of pathogens,
nutrients, toxicants and salts. Health-based tar-
gets receive the greatest emphasis, and microbial
contaminants present the greatest risk to human
health; studies have shown that in achieving tar-
gets for pathogen removal, the chemical hazards
which threaten human health are also reduced to
acceptable levels.
Both the National and State guidelines for
recycled water use were until recent times

based around matching defi ned classes of water
(based largely on their pathogen burden, bio-
chemical oxygen demand and turbidity) with
preapproved uses (Table 1 ). The highest qual-
ity A + recycled water could be used in residen-
tial dual reticulation systems, and the lowest
classes, C or D, could only be used for irriga-
tion of nonfood crops, e.g. instant turf, wood-
lots and fl owers.
In 2006, in the face of increasing pressure on
freshwater resources, the National Water Quality
Management Strategy Australian Guidelines for
Water Recycling : Managing Health and
Environmental Risks (AGWR) was released
(NRMMCEP and HCAHMC 2006 ). The AGWR
was produced in an effort to establish consistent
standards for reclaimed water schemes across the
country and to introduce the risk management
framework promoted by the World Health
Organization ' s Guidelines for Drinking - water
Quality (WHO 2008 ).