6. Noosa River DMP Ver0 (Combined)

                                      Requesting Endorsement of Sediment Sampling and Analysis Plan
                                            BMT (OFFICIAL)



Field works will be undertaken by appropriately qualified sediment quality scientists and field
technicians experienced in undertaking marine sediment quality studies.

Sediment Sampling Methodology and Equipment
Sediments in the dredge footprint will be sampled with a vibro-core. The choice of core barrel diameter
and coring methodology would be dependent on the volume of material required for analyses, the
texture of the sediment encountered at each sample location and the required length of core. Generally,
vibro-coring would be undertaken in sandy to muddy substrates. Core penetration in muddy and sandy
substrates is likely to be good, whereas poor penetration will be likely in cobble or gravel substrates
(but such sediments are unlikely to be contaminated).

The acceptability of each sediment core will be determined immediately following collection, and the
criteria for acceptance of the core will include:

•   No obvious loss of surficial sediment
•   The core must have entered the profile vertically
•   There must be no gaps in the stratigraphy
•   There must be no disturbance of the sediment stratigraphy
•   The core must reach the depth of dredging, or core refusal in clay, dense sand or rock.
The sampling device will be thoroughly cleaned with De-con 90 solution prior to use and cleaned and
rinsed with seawater between sampling locations to prevent cross contamination between samples.

An appropriate number of samples will be obtained from each sampling location and composited to
collect sufficient volume of sediment for all analyses.

Sample Handling and Chain of Custody
Sample management procedures will include the careful collection of sediment samples from the core
tube or grab, following the recovery of the sediment sample from the seabed.

Photographs of the cores will be taken and field personnel will log each core profile for its physical
characteristics and variations in sediment type and texture. The core length will be measured and the
appropriate sample interval subsampled and collected in a clean bowl for homogenisation prior to the
filling of analytical laboratory-supplied clean sampling jars.

Subsampling of cores will be undertaken in accordance with Section 3.4. Sample identifiers will include
the location and depth interval.

QA/QC samples will be blind-labelled to ensure that the laboratories cannot relate the QA sample back
to the primary sample.

All sample handling and processing will be performed to minimise contamination and sample mix-ups.
All sample equipment will be cleaned prior to sample collection using a scrub with decontamination
solution followed by a rinse with seawater.

The workspace on the vessel will be washed down regularly with ambient seawater to clean all surfaces
and minimize the potential for dust contamination of samples. All sample processing will be undertaken
away from any potential contamination sources such as engine exhausts, fuels, oils, greases, lead
weights, zinc anodes, antifouling paint etc.




A10342 | 002                                        20                                    15 November 2021