WP 4 - In situ environmental monitoring in seabed sediments
Contaminants released to the sea or other water bodies will settle onto the sediment. Thus, the sediment surface becomes a sink for contaminants and subsequently a potential environmental risk hot zone.
Furthermore, biota mixing of the sediment can result in contaminants associated with old discharges staying active for a long period of time, even after terminating the discharge. The residual risk in seabed sediments is therefore an important part of the legacy of former and ongoing contaminant discharges.
NGI has developed and worked with several methods and types of equipment for monitoring environmental risk in situ in the sediment, such as passive samplers for in situ deployment in sediments and a flux chamber for sediment to water flux.
These methods will be further developed and specialized equipment for deployment will be designed, both for offshore and near shore applications, as well as methods related to the measurement and interpretation of the measurements being refined.
Deployment of diffusive flux chambers
Measuring pore water concentrations using passive samplers in situ. The device was deployed in sediments in Hunters Point, California to detect concentrations of PAHs and PCBs (left). Devices used to measure pore water concentrations in situ. The device can be pushed in to sediment and the passive samplers within the construction accumulate organic pollutants (middle). A diffusive flux chamber placed on the sea bed. The chamber measures the flux of contaminats that come up from the sea bed (right).
