This week’s water quality monitoring report provides water quality data for the second week of Phase 2 of the dredging.
The report highlights that water clarity at all coastal beach sites met guideline levels, although water clarity was reduced at Preston Point Beach in the Lower Swan River Estuary. However,the water clarity at this site was similar to that determined during the baseline period, which is naturally reduced in comparison to coastal beaches during the winter months. Dissolved oxygen levels during the second week of dredging met relevant ecosystem health protection levels at all monitoring locations.
Also included are the results of baseline (prior to recommencement of dredging) testing of mussels. Baseline concentrations of metals and organotins, pesticides, PAHs and PCBs in mussels did not exceed guideline levels relevant to the protection of fishing and aquaculture values.
Summary of monitoring data report posted 20/8/10
This week’s water quality monitoring report provides remaining data for the baseline (pre-dredging surveys) and water quality data from the first week of ‘Phase 2’ dredging works, which commenced 9 August 2010.
The report highlights that water quality within the Inner Harbour meets public health and ecological protection guideline levels and that amenity and aesthetics criteria have been met in the first week of dredging.
The report also indicates that baseline sediment samples taken at sites surrounding the Inner Harbour largely met guideline levels for moderate ecological protection areas (MEPA’s). Elevated levels of some toxicants were identified at locations of known historical contamination outside of the dredge areas. Further sampling will be undertaken at these locations and the sediments in those areas will not be disturbed by dredging activities.
Summary of monitoring data report posted 13/8/10
This week’s water quality monitoring report covers water quality monitoring results within primary contact areas and in the proximity of the visible plume following the commencement of ‘Phase 2’ dredging activities on 9 August.
Water clarity at all “Recreation and Aesthetic” sites met water clarity guidelines for this monitoring period. Similarly dissolved oxygen levels in bottom waters of the Inner Harbour met relevant ecosystem health protection levels. Data relating to the chemical analysis of water and sediments will be reported following completion of laboratory testing.
Summary of monitoring date report posted 6/8/10
This report contains the results from the baseline water quality monitoring for Phase 2 dredging provided by environmental consulting group Oceanica Pty Ltd.
These results relate to water quality only and include the parameters: dissolved oxygen, pH, secchi depth and total suspended solids. Additional data relating to the baseline chemical analysis of water and sediments will be reported following completion of laboratory testing.
Secchi depth data measured at the river beach at Preston Point was 1.5 m and thus less than the environmental quality guideline for visual clarity of waters used for swimming in Perth’s coastal waters. This exceedance occurred in the absence of dredging activity and is indicative of the baseline water clarity in the Preston Point Region of the Lower Swan River Estuary, which is naturally reduced during the winter months.
The first phase of dredging involved an 11-week program to remove sand from the Inner Harbour, Entrance Channel and Deepwater Channel, with all of the sand placed into reclamation at Rous Head. This initial phase of dredging and reclamation commenced on 6 January 2010 and was completed on 21 March 2010. The final phase of dredging is scheduled to commence on 9 August 2010 and will involve the removal of limestone from the Inner Harbour and the Deepwater Channel and placement of this material into a deep offshore area in Gage Roads.
Summary of monitoring data report posted 11/5/10
This week’s water quality monitoring report provides the final set of data associated with the first phase of the Inner Harbour dredging. The data, collected by the Department of Water as part of the regular fortnightly water quality monitoring, demonstrates that dissolved oxygen levels in waters continue to meet the relevant ecological protection criteria.
Summary of monitoring data report posted 30/4/10
Two reports have been posted this week. The first is a revision of Supplement 1 (originally posted 23 April) in which some processing errors relating to the results for organotins and hydrocarbon in sediments are corrected. The second report is a Data Report Revision which corrects sediment results that were similarly affected from the reports posted on 18 February, 25 February and 18 March.
Our consultant has identified that these errors have arisen due to their use of incorrect figures in a normalisation calculation (for total organic carbon) that is applied to organotin and hydrocarbon data in sediments. This processing error was discovered following further examination when the mean TBT result for a Rous Head Harbour site (70 micrograms per kilogram at site RH2) in the April report was found to have been rounded down by the consultant from 70.47 micrograms per kg. The re-examination subsequently identified that the incorrect data set for total organic carbon was used for the normalisation calculation and consequently when recalculated the correct value for site RH2 was in fact 57.9 micrograms per kg. As the same process was used for hydrocarbon results in sediments samples from January, February and March, these have also been corrected.
It is important to note that the requirement for recalibration of the affected figures related to only a very small part of the monitoring program and that the adjustments have not resulted in any change to the outcomes in respect to comparison with applicable re-sampling triggers.
The remainder, and by far the majority of the monitoring results, are not affected as the toxicity data included in the reports are taken directly from certified laboratory reports.
The revised results in Supplement 1 and the Data Report Revision do not change any of the required management responses in relation to relevant triggers as contained in the original reports.
The Office of the EPA has been advised of the processing error and Fremantle Ports is working closely with the consultant to ensure appropriate procedures and controls are implemented to prevent any further errors occurring.
Summary of monitoring data report posted 23/4/10
This week’s water quality monitoring report contains outstanding results from previous sampling and analysis. It confirms compliance with relevant ecosystem health criteria with the exception of tributyltin in sediments at three locations and hydrocarbons in sediments at one location that exceeded the ‘low’ trigger level but did not require any further action.
Summary of monitoring data report posted 15/4/10
This week’s water quality monitoring report highlights that all relevant public health, amenity and aesthetics and ecosystem health criteria continue to be met.
Summary of monitoring data report posted 9/4/10
This week’s water quality monitoring report highlights that all relevant public health, amenity and aesthetics and ecosystem health criteria are being met.
Summary of monitoring data report posted 1/4/10
This week’s water quality monitoring report highlights that, apart from some increases in light attenuation at some seagrass and coral monitoring sites, all relevant public health, amenity and aesthetics, and ecosystem health criteria are being met.
Stage 1 of the dredging campaign being undertaken by the Cornelis Zanen was completed on 23 March and the dredge has departed for Dampier.
Summary of monitoring data report posted 25/3/10
This week’s water quality monitoring report highlights that: - all relevant public health criteria continue to be met - all ecosystem health criteria relating to potential contaminants, pH and dissolved oxygen are met - some reductions in water clarity were recorded at Port Beach, Fremantle Surf Life Saving Club, Preston Point Beach and offshore.
The material being dredged over this monitoring period was clean sand from the Deepwater Channel (the channel ranges from 5km to 8km offshore), as reflected by the white cloudiness in the water and the measured reductions in water clarity at times.
Summary of monitoring data report posted 18/3/10
This week’s monitoring report shows that all public health, aesthetics and human amenity criteria continue to be met.
Occasional increases in light attenuation measures north of the harbour entrance have been measured and, as highlighted previously, a coral and seagrass health survey will be conducted this month in order to ascertain whether this is causing any adverse impact.
Low levels of tributyltin (TBT) and hydrocarbon in a few sediment samples in Rous Head Harbour and the Inner Harbour have been detected, but no additional management is required in response to the levels detected.
Summary of monitoring data report posted 12/3/10
This week’s monitoring report shows that apart from some increases in light attenuation measures offshore, all relevant health, amenity, recreational and environmental criteria have been met.
Although changes in light attenuation levels are similar to those occurring in the background at reference sites well beyond the dredging activities, a conservative management response will be adopted with a seagrass health survey being scheduled for later this month.
Summary of monitoring data report posted 5/3/10
This week’s monitoring report has been improved to include a simple summary on the front page.
The report shows that public health and ecosystem health are being maintained.
Water clarity at Preston Point Beach was marginally below the applicable standard on one day and there has been some increase in light attenuation at seagrass monitoring sites north of the harbour entrance. In response to the occasional increases in light attenuation and the fact that several light loggers have been lost during the monitoring period, Fremantle Ports will undertake a seagrass health survey during March.
Summary of monitoring data report posted 25/2/10
All results for the current monitoring period are within applicable health and environmental criteria.
Normalised tributyltin (TBT) results for the two sediment samples (at the entrance to the harbour and in Rous Head Harbour) highlighted in the previous report of 17/02/10 have been received and confirmed to be below the re-sampling trigger, hence no further management response is proposed as these sediments will not be disturbed.
Summary of monitoring data report posted 18/2/10
The following points are highlighted from this week’s water quality monitoring report.
In relation to potential contaminants, all relevant environmental and health criteria continue to be met. All results for hydrocarbons, organotins and pesticide levels remain below detection levels in the dredge plume and offshore from Rous Head. All results for metals are either below high ecological protection levels or below laboratory detection levels in the dredge plume and offshore from Rous Head.
All results for hydrocarbons, pesticides and metals are below the relevant ecosystem health levels or below laboratory detection levels for sediments. Levels of tributyltin in sediments in two samples (at the entrance to the harbour and in Rous Head Harbour) triggered the requirement for re-sampling to be undertaken.
Water clarity measures (Secchi depth) at all river and coastal beach monitoring locations meet the relevant recreational criteria. Some light attenuation management triggers were exceeded in the predicted zone of effect or zone of influence (offshore from Rous Head and at Hall Bank). As noted previously, these variations are similar to or less than those observed at the offshore reference sites, hence further monitoring will determine whether any management response is required.
Summary of monitoring data report posted 10/2/10
The current water quality monitoring report shows that all applicable environmental and health-related criteria continue to be met, consistent with the extensive testing that was undertaken as part of the environmental approval process prior to the commencement of dredging. In fact, the majority of potential contaminants are so low as to be below laboratory detection limits.
The water visibility trigger was exceeded in the waters at Preston Point Beach on the afternoons of 1 February and 2 February but not on 3 February. The relevant visibility criterion continues to be met at all coastal beaches.
The above results are consistent with the Health Department’s public advice last week that periods of reduced visibility should be expected during dredging and that this is aesthetic in nature and not an indication of chemical or heavy metal pollution and does not pose a risk to human health.
Summary of monitoring data report posted 2/2/10
The most recent water quality monitoring report confirms that potential contaminants remain well below the applicable environmental and recreational guidelines at all locations. Testing has been undertaken for metals, pesticides, hydrocarbons and TBT and continues to confirm the findings from the extensive sampling and testing undertaken as part of the Environmental Impact Assessment before commencement of dredging which demonstrated that the dredging would not present any harm to river or beach users.
One result (secchi depth of 1.1m) indicates reduced visibility in the waters at Preston Point Beach in the afternoon of 27 January 2010. One component of the management response to this is to trial the use of silt and air curtains at the Fremantle Traffic Bridge and this trial is expected to commence this week.
At three of the seagrass monitoring sites located within the predicted zones of effect and influence north of the harbour entrance, light loggers recorded light attenuation levels requiring further investigation. This investigation showed that similar light attenuation levels were recorded at the reference sites and also during baseline measurement prior to dredging commencing, hence no management response is required at this stage.
Summary of monitoring data report posted 27/1/10
A further report under the Water Quality Monitoring Program has now been received and includes samples taken as recently as 19/1/10 (see attachment on this page posted 27/1/10).
The report includes the results of analyses for hydrocarbons, metals, tributyltin (TBT) and pesticides. All results were well below the applicable environmental and safe swimming levels.
One result (secchi depth of 1.4m) indicates reduced visibility in the waters at Preston Point Beach in the afternoon of 19/1/10.
Summary of monitoring data report posted 21/1/10
The results of the Water Quality Monitoring Program posted on 19/1/10 identified potential exceedances of moderate ecological protection levels for copper at two locations and lead at one location within the Inner Harbour.
The required management response to these results was to undertake further analyses of the samples to determine whether the copper and lead were in a soluble form that could present any harm to the environment.
These analyses have been completed and no soluble copper or lead was detected, hence no exceedances of the applicable criteria have occurred.
The results of this further testing are shown in the attachment report dated 21/1/10.
Summary of water quality monitoring results posted 19/1/10
Further results from the Water Quality Monitoring Program for the Fremantle Ports Inner Harbour and channel deepening project have been provided by consultants Oceanica Pty Ltd and are now accessible on the Fremantle Ports website (see attachment on this page posted 19/1/10).
All of the results were many times below safe levels for swimming. These results cover samples taken in the river, in the harbour, in the vicinity of the dredge, in and around the reclamation area at Rous Head and at Preston Point Beach.
The outcomes confirmed the findings from the extensive sampling and testing undertaken as part of the Environmental Impact Assessment before commencement of dredging which demonstrated that the dredging would not present any harm to river or beach users.
The most recent testing included analysis for heavy metals, hydrocarbons and pesticides. Testing of water samples has been undertaken for an extensive range of chemicals to microgram levels to accurately measure some of the very low levels within the sediments; hence laboratory processing times have been lengthy.
The results show that the water quality measures are many times below safe levels for swimming.
Moderate ecological protection levels for copper were potentially exceeded at two sample locations and for lead at one sample location, both in the Inner Harbour. The criteria applied at these locations relate to longer term water quality targets within the harbour and hence require ongoing monitoring but are not a cause for concern during temporary disturbance of the harbour sediments.
The required management response in this case is to undertake further analysis of these samples and to continue the ongoing detailed water quality monitoring program for the duration of the project.
Summary of water quality monitoring results posted 15/1/10
The first results from the water quality monitoring program for Fremantle Port’s Inner Harbour Deepening Project were provided by the environmental consulting group Oceanica Pty Ltd to the Office of the Environmental Protection Authority and Fremantle Ports on 15/1/10 (see attachment on this page posted 15/1/10).
These results relate mainly to physical water quality parameters. The parameters are temperature, salinity, pH, turbidity, LOI, secchi depth, total suspended solids and dissolved oxygen. Additional data relating to the actual chemical analysis of the water are not yet available but are expected within the next few days.
Of the eight parameters tested at the four locations, only one parameter at one location was shown to exceed the applicable guideline. The Secchi depth trigger level was exceeded at 12.20pm on the 7 January at Preston Point Beach. Secchi depth is a measure of visibility within the water column, and reductions are to be expected when a plume is present. All other water quality measures at the various test locations were within the guidelines.
If Secchi depth triggers are exceeded and do not improve, the Water Quality Monitoring Program requires a management response to be implemented. Further measurement at 15.43pm on the 7 January showed a significant improvement in water clarity and subsequent monitoring undertaken by the Department of Water has shown that Secchi depths returned to normal.
Regular ongoing monitoring is being undertaken at the river sites and further results will be posted on our website when available.
Posted 15/1/10
An independent consultant, Oceanica Consulting, is monitoring water and sediment quality and seagrass, coral, biota (mussel) health for the dredging and Rous Head reclamation in compliance with the environmental approval conditions. Monitoring results are reported to the Environmental Protection Authority (EPA) and Fremantle Ports.
The results are posted on this page as soon as they are available.
Dredging monitoring
