Marine, Soil & Ground Water Analysis
Marine Water and Sediments Sampling & Analysis
CORE Laboratory specializes in the testing analysis of Marine, Creek & Freshwater including Marine Sediments. These sampling and Laboratory analysis are required mainly for remedial investigation, dredging, feasibility studies and risk assessment.
CORE Laboratory use various sampling technology to sample the seafloor sediment and water column in a wide variety of marine environments. Our environmental services include water and sediment sampling on site to the in-house analysis of collected samples.
CORE Laboratory undertake a range of sediment sampling activities including grab sampling (Van Veen grab) and Water Sampling Activities including All Level Sampler, Surface Sampler and Niskin Sampler.
These type of samples also requires low-level detection limits and present unique challenges to the laboratory due to analytical interferences caused by the matrixes. CORE Laboratory has developed and implemented procedures and method modifications to specifically deal with these types of matrices. We have also developed the expertise necessary to perform complex ultra-trace analyses. These low-level analyses of sediment, tissue and water use advanced specialized instrumentation. This instrumentation includes Inductively Coupled Plasma Optical Emission Spectroscopy (ICP/OES), Gas Chromatography/Mass Spectroscopy (GC/MS), and Total Organic Carbon (TOC). Seawater presents no particular challenges when determining organic constituents. However, trace metals analysis in the presence of high dissolved solids requires relatively involved techniques to reach the levels of detection typically required to meet project objectives.
CORE Laboratory typical parameters for the analysis of sediment, tissue, seawater and freshwater matrices in support of marine and freshwater studies are provided in the following sub-sections.
- Marine Water
- Marine Sediments
- Soil and Ground Water Sampling
Site investigation and risk assessment have evolved into a major industry over the last two decades. The assessment of potential contamination within a site is of critical importance for the future use of the site, predicting the cost of possible remediation, and the re-sale value. The design of a site investigation involves a great deal of research, and is generally referred to as Phase 1 investigation. This involves gaining information with respect to previous use of the site, locations of buildings (past and present), location of storage depots (particularly fuel tanks), identification of particular chemicals, feedstocks, and final products likely to have been stored on the site, and the possible discharge/spillages/burial of any materials, including waste generated on the site.
The sampling of the soil (natural ground and made ground) need to reflect all of these considerations with respect to location, depth horizons, frequency, sampling grid pattern, etc. The errors associated with sampling on site are much greater than the analytical errors measured within the laboratory.
Core Laboratory can carry out many techniques to collect sample of Soil of which some are as summarised as follows
| Method | Advantages | Disadvantages |
|---|---|---|
| Trial Pits | Applicable to environmental and Geo-environmental Investigation | Potential for cross contamination (extra care to ensure that the surrounding area is not affected by excavated spoil and the resistant does not leave contaminants exposed on the surface) |
| Allows for detailed visual assessment of ground conditions | Depth of excavation limited to the size of the machine | |
| Rapid and inexpensive technique of examination of the upper 0.5 - 2M | Limited to working above the water level | |
| Applicable to a wide range of ground conditions | Installation of monitoring instrumentation not recommended | |
| Auger Samples | Applicable to environmental and Geo-environmental Investigation | Low quality of sample retrieved is not always representative - small disturbed samples only |
| General low sample disturbance | Potential loss of volabilities | |
| Easy re-installation with only limited spoil for disposal | Unsuited for rock, with poor recovery and slow process in coarse, granular materials | |
| Installation of narrow diameter monitoring instrumentation (gas & ground water) | Installation have limited annular filter pack / response zone | |
| Percussion/Rotary Drilling | Applicable to environmental and Geo-environmental Investigation | Use of water flush has potential to change natural ground water condition |
| Allows for the greater depth of drilling (in excess of depths reached by cable percussion drilling) | Not all techniques suitable for solids; core recovery in soft/loose soils is poor or requires more specialist techniques | |
| Permits installation of permanent monitoring instrumentation | Borehole may need to be progressed to rock head by cable percussion techniques |
Volatile organic compounds (VOCs) are common determinants requested on soil samples, which has to be collected under specific conditions. CORE Laboratory has the facility to collect the soil sample in tight jar and avoid minimal gaps or a headspace – volatiles will quickly be lost into these spaces. The samples are then kept cold – a cool box with frozen icepacks and the samples are returned to the laboratory as soon as possible.
Core Laboratory has capability to carry out ground water sampling by installing piezometer after the percussion drilling, or in some cases with auger sampling if the ground water level are low.
Installation of Observation well 8m comprising of 75 mm uPVC solid/slotted pipes plugged at the bottom and with screen wrapped with geo fabric & extending to 0.5 m above water table & at least 1m below water table, backfilling the annular space with 5-10 mm washed and cleaned gravel filter from the bottom up to 1 m above the uppermost perforation, 0.5m thick bentonite seal and cement-bentonite grout for the remaining part. A platform of approx. 1 m dia. Can be prepared to safeguard the borehole in case of permanent bore well.
After a period of 24-48 Hours, the well shall be installed with flush mounted covers and shall be purged which is known as well development. The objectives of well development are to remove sediment that may have accumulated during well installation, to consolidate the filter pack around the well screen, and to enhance the hydraulic connection between the target zone and the well. In most instances, a bailer will be used to remove sediment and turbid water from the bottom of the well.
Once the purging is completed, the sample for ground water can be collected. CORE Laboratory has also the facility to carry out on site analysis on ground water which includes VOCs (from the top of the well through PID sensor) and pH, Turbidity, Conductivity, Dissolved Oxygen, etc.
The typical parameters list which CORE Laboratory can perform the analysis are detailed as below
- Soil
- Ground Water