Fremantle Port Inner Harbour and Channel ... - Fremantle Ports

of the ANZECC/ARMCANZ (2000a) Australian and New Zealand Guidelines for Fresh
and Marine Water Quality (as agreed with the DEC in previous correspondence); and
• for ‘other’ chemicals not listed within the above, Low Reliability Values (LRVs) defined
in Chapter 8 of ANZECC / ARMCANZ (2000a) and Table 2c of EPA (2005a).
4.1.2. Recreational and Aesthetic Values (EQOs 3 to 5: Maintenance of primary
and secondary contact recreation values and aesthetic values)
Toxicants at primary contact areas
Water quality triggers for toxicants including metals, organotins, organochlorine (OC)
pesticides, and polycyclic aromatic hydrocarbons (PAHs), adopted to protect recreational
values within primary contact areas, as shown in Table 4.5, are based on the approach
defined by the NHMRC (2008) Guidelines for Managing Risks in Recreational Waters:
“The quantitative risk assessment should consider the expected exposure in terms
both of dose (i.e. ‘Is there significant ingestion’) and of frequency of exposure. The
Australian Drinking Water Guidelines (NHMRC/NRMMC 2004) provide a point of
reference for exposure through ingestion but with a few exceptions these relate to
significant lifetime exposure.
Mance et al (1984) suggested that environmental quality standards for chemicals in
recreational waters should be based on the assumption that recreational water makes
only a relatively minor contribution to intake. They assumed a contribution for
swimming of an equivalent to 10% of drinking water consumption. Since most
authorities (including WHO) assume consumption of 2 litres of drinking water per day,
this would result in an intake of 200 mL per day from recreational contact with water
(WHO 2003). This provides for a simple screening approach in which a substance
occurring in recreational water at a concentration of 10 times that stipulated in the
drinking water guidelines may merit further consideration.”
Water pH in Primary and Secondary Contact Areas
The water quality guideline trigger for pH has been adopted from Tables 6 and 7 of
Environmental Quality Criteria Reference Document for Cockburn Sound (EPA 2005a), which
state the same Environmental Quality Standard (EQS) for either primary or secondary
contact recreation:
“The median of the sample concentrations from the area of concern (either from one
sampling run or from a single site over an agreed period of time) should not exceed
the range of 5 – 9 pH units.”
Water clarity and aesthetics of Primary Contact Areas
The guideline trigger for water clarity has been adopted from Table 6 of Environmental
Quality Criteria Reference Document for Cockburn Sound (EPA 2005a), which states the
following Environmental Quality Guideline (EQG) for primary contact recreation:
“To protect the visual clarity of waters used for swimming, the horizontal sighting of a
200 mm diameter black (Secchi) disc should exceed 1.6 m.”
This trigger has also been adopted as a surrogate target to manage potential impacts on the
aesthetic values of waters in areas of primary contact. Community perceptions of what
constitutes aesthetic values that should be maintained will also prompt management, e.g.
based on aerial imagery and public complaints.
12 Oceanica: Fremantle Ports: Inner Harbour and Channel Deepening - Water Quality Monitoring Program