What Is Seawater?
Seawater analysis determines physical, chemical and microbiological parameters in coastal and open sea waters. The purpose can be bathing water quality, marine discharge monitoring, or marine environment status assessment; the parameter list is built accordingly.
Purpose of Seawater
The purpose is to show the seawater meets the quality requirements of the relevant legislation and to monitor the discharge's impact on the marine environment.
Which Products Is Seawater Applied To?
- Bathing water monitoring points
- Vicinity of a deep-sea discharge
- Fish farming areas
- Port and marina waters
- Marine environment monitoring stations
In Which Sectors Is Seawater Used?
Standards Related to Seawater
- TS ISO 5667-9 (guidance on sampling of sea waters)
- TS EN ISO 7899-1/-2 (intestinal enterococci)
- TS EN ISO 9308-1/-3 (E. coli)
- TS EN ISO 17294-2 (determination of elements by ICP-MS)
- TS EN ISO 5667-3 (preservation of samples)
Seawater Conditions
- Specimen depth
- From the surface or a defined depth, per the monitoring purpose
- Salinity effect
- The high-salt matrix interferes with many analytical methods; the method is chosen accordingly
- Coordinates
- Specimen point coordinates and meteorological conditions are recorded
- Time
- Microbiological specimens must be analysed within the short time defined in the standard
Equipment for Seawater
- Depth samplers (Niskin, etc.)
- Membrane filtration system and incubators
- ICP-MS and matrix separation systems
- GC-MS
- Multi-parameter field probe
Sample Requirements for Seawater
- Sampling is the largest component of total uncertainty in environmental analysis. The specimen container, preservation (acidification, cooling, storage in the dark), fill method and time to reach the laboratory are all defined in the standard; if any one is not met, the result loses its validity. Sampling must be carried out by authorised personnel per a written plan.
- Specimen point coordinates, depth and field conditions must be recorded
- The microbiological specimen must be transported in a sterile container via cold chain
- Additional specimen volume may be needed for some parameters due to the saline matrix
Duration of Seawater
Microbiological parameters depend on the incubation time. Trace element and organic pollutant analyses take longer than freshwater analyses because the salt matrix must be separated.
Seawater Procedure
- 1Monitoring purpose and parameter list are determined.
- 2Specimen points and depths are planned.
- 3Field measurements (temperature, salinity, pH, dissolved oxygen) are performed.
- 4Specimens are taken in suitable containers and preserved.
- 5They are analysed in the laboratory with methods suited to the matrix.
- 6Results are compared against the relevant quality requirements.
Seawater Acceptance Criteria
For bathing water, 2006/7/EC defines quality classes based on intestinal enterococci and E. coli. For marine environment status, the 2008/56/EC framework and national monitoring programmes apply. Applicable values are determined per the monitoring purpose and current legislation.
Evaluation of Results
Seawater results are assessed with a monitoring series, not a single specimen: bathing water classification is based on a dataset spanning multiple seasons. Rainfall and current conditions also markedly affect the result and are recorded in the report.
Seawater Report
- Specimen point coordinates, depth and field conditions
- Monitoring purpose and parameter list
- Field measurements and laboratory results
- Measurement uncertainties
- Quality requirements compared against
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- 2006/7/EC Bathing Water Quality Directive
- 2008/56/EC Marine Strategy Framework Directive
- 2000/60/EC Water Framework Directive
Environmental Analysis — What Does This Testing Field Cover?
The section below describes the field that the Seawater test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Environmental analysis determines the presence and concentration of pollutants in water, soil, waste, air and flue gas samples. The output of this family is usually part of a permit, a declaration or an inspection file; the result has direct legal consequences.
In this family SAMPLING is half the result, and this is the feature that most sets the field apart. A sample taken at the wrong time, in the wrong container, under the wrong preservation or from the wrong point gives an invalid result no matter how well it is analysed in the laboratory. In waste water a grab sample and a composite sample give different information; in soil, surface and depth produce different results. Sampling therefore has its own standards and its own accreditation scope.
On the water side, physico-chemical parameters (pH, conductivity, turbidity, COD, BOD, suspended solids), ions, heavy metals, organic pollutants and microbiological parameters are measured. Drinking water and waste water carry different parameter sets and different limits; the same laboratory method leads to a different decision under the two regimes.
In soil and waste, heavy metals, hydrocarbons, PAH and PCB compounds and LEACHING BEHAVIOUR are determined. The leaching test carries a logic peculiar to this field: it is not the total amount of a pollutant in soil but the fraction that can pass into water that determines the environmental risk. Waste classification and the disposal decision rest largely on this test.
On the emissions side, dust, sulphur dioxide, nitrogen oxides, carbon monoxide, oxygen, moisture and total organic carbon are monitored in flue gas. Measurement is made on site under operating conditions and must represent the plant's actual operating regime; a measurement taken at low load does not show the emissions at full capacity.
Continuous measurement systems are a separate body of work. In large plants emissions are monitored continuously and the accuracy of these systems is verified periodically by comparison with independent measurements; the quality assurance framework governs this.
Noise and vibration measurements complete the environmental impact side of the field: environmental noise mapping, workplace noise exposure and vibration exposure measurements produce evidence for both environmental and occupational health legislation.
Method groups in this field
Sampling
Separate sampling standards for water, waste water, soil, waste, flue gas and ambient air; grab, composite and continuous sampling techniques.
Water physico-chemical
pH, conductivity, turbidity, colour, suspended solids, COD, BOD, TOC, alkalinity, nitrogen and phosphorus species.
Elemental analysis
Determination of heavy metals and trace elements in water, soil and waste by ICP-OES and ICP-MS.
Organic pollutants
Volatile organic compounds, PAH, PCB and organochlorine pesticides by GC-MS; hydrocarbon oil index.
Flue gas
Measurement of dust, SO2, NOx, CO, O2, moisture and total gaseous organic carbon; quality assurance of automated measuring systems.
Leaching and waste characterisation
Leaching tests and waste classification parameters; the basis for the disposal decision.
Commonly confused in this field
- An analytical result cannot be used on its own without the sampling record; the time, point, conditions and chain of custody are part of the report.
- Total content and leachable amount give different information; in waste classification, leaching behaviour is what counts.
- Emission measurement must be made under representative operating conditions of the plant; a result taken at partial load is misleading.
- Drinking water and waste water limits are defined in different legislation; the same parameter carries a different threshold under the two regimes.
- A sample from a single point does not represent the whole area; assessment of a contaminated site requires a grid-based sampling plan.
Which decisions these results support
- Compliance with environmental permits and discharge limits
- Quality assurance of continuous emission measurement systems
- Contaminated site assessment and the remediation decision
- Waste classification and selection of the disposal method
- Workplace exposure measurements and occupational health obligations
Related Tests
Frequently Asked Questions About Seawater
Is a specimen taken after rain valid?
It is valid but its interpretation changes. Heavy rainfall carries land-based pollution into the sea and temporarily raises microbiological results. This condition must be recorded and taken into account in the assessment.