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

o
o
The cause of any exceedance shall be investigated, potentially including water
quality monitoring for toxicants at additional sites.
Additional protection barriers shall be implemented, e.g. additional silt curtains,
raising of weir box to reduce flow volume of return water.
Toxicants at Primary Contact Areas
Frequency
• Baseline prior to dredging, and thereafter only if toxicants within the Inner Harbour
dredge plume or return water plume outside of the silt curtain exceed triggers for high
protection of ecosystem health (see Section 5.1.1 - Toxicants within Return Water
Plume).
Location
• Six contingency ‘recreation/aesthetic’ beach sites as detailed in Section 3.5 and
Figure 3.1.
Method
• Collect a single integrated-depth water sample from each site, every week.
• Store chilled and immediately send samples to a NATA-accredited laboratory for
analyses of the concentration of toxicant analytes listed in Table 4.5 (metals,
organotins, OC pesticides, PAH).
• Toxicant concentration data shall be processed (within 10 days from collection of
baseline samples, within 5 days from collection of samples triggered by return water
plume exceedances) and compared against triggers for primary contact recreation
where available and listed in Table 4.5, to determine the appropriate management
response as listed below.
Contingency Management Measures
• Where a toxicant analyte is determined to be above the trigger level, then:
o the CEO of the Office of the EPA and DoH will be informed of the exceedance
and proposed management strategies (see below) as soon as practicable and
no later than within 72 hours of detection of the exceedance (i.e. subsequent
to processing of toxicant data);
o if applicable, any management actions already implemented within 72 hours
shall also be reported; and
o all management strategies will be implemented as soon as practicable.
• The exceedance will also be noted in fortnightly reporting (by the Environmental
Monitoring Contractor) to Fremantle Ports and the Office of the EPA;
• If water quality does not improve and is deemed to be an ongoing risk to primary
contact recreation values, the following hierarchy of management measures shall be
implemented as soon as is practicable:
o Erect signage at beaches to warn public of potential health risk of toxicants.
o The cause of any exceedance shall be investigated, potentially including water
quality monitoring for toxicants at additional sites.
o Additional protection barriers shall be implemented, e.g. additional silt curtains,
raising of weir box to reduce flow volume of return water.
o Return water discharge shall cease until it can be demonstrated that no risk to
primary contact recreation values is posed by toxicants.
Water pH in Primary and Secondary Contact Areas within Proximity of the Return Water
Plume
Frequency
• Baseline prior to discharge of reclamation water, and thereafter only if pH within the
return water plume outside of the silt curtain exceed triggers for high protection of
ecosystem health (see Section 5.1.1 – Water pH within Return Water Plume).
Location
• Six sites including one site within the reclamation pond, one site within the weir box,
three ‘dynamic transect’ sites within the return water plume (at distances 10 m,
200 m and 500 m from silt curtain) and two ‘static reference’ sites within the
Cottesloe Reef Fish Habitat Protection Area, as shown in Figure 3.1 (N.B. ‘mock’ sites
Oceanica: Fremantle Ports: Inner Harbour and Channel Deepening - Water Quality Monitoring Program 27