EnviroMail 064 HK - Introduction to vessel discharge analysis
Intaking and discharging marine water across the global regions is often required in vessel operations
To avoid the growing environmental impact to the marine native species and ecosystem, the vessel is required to test the discharge water after treatment and comply with the related regulations, such US EPA VGP 2013, before discharging to the sea.
As an accredited lab, ALSHK have provided sampling and testing service for the different testing schemes. The Four (4) main types of water samples are recognised as Ballast water, Gray water Bilgewater and Gas Scrubber Washwater.
Ballast water
Ballast water is the water held in tanks of ship to increase stability and maneuverability during transit.
Analyte description | Method reference | Limit of reporting |
Heterotrophic Plate Count | APHA 9215: A & B | 1 CFU/mL |
Enterococci | USEPA 1600 | 1 CFU/100mL |
Escherichia coli | APHA 9223B | 2.2 MPN/100mL |
Total Residual Chlorine - Field test | APHA 4500 Cl: G | 0.1 mg/L |
Gray Water
Gray water refers to the wastewater generated from lavatory sinks, laundry, and water fountains. Below parameters is included but not limited for gray water testing.
Analyte description | Method reference | Limit of reporting |
Biochemical oxygen demand | APHA 5210 B | 2 mg/L |
Faecal coliforms |
APHA 9222D / DoE Section 7.8 & 7.9 |
1 CFU/100mL |
Escherichia coli | APHA 9223B | 2.2 MPN/100mL |
Tota suspended solids | APHA 2540D | 2 mg/L |
pH Value - Field test | APHA 4500 H: B | 0.1 pH unit |
Total Residual Chlorine - Field test | APHA 4500 Cl: G | 0.1 mg/L |
Bilge water
Oily bilgewater is the mixture of water, oily fluids, lubricants and grease, cleaning fluids and other wastes that accumulate in a vessel from mechanical and operational machinery.
Analyte description | Method reference | Limit of reporting |
HEM (oil and grease) | APHA 5520B | 5 mg |
Hydrocarbon Oil Index (Total Petroleum Hydrocarbon C10-C36) |
USEPA 8015 | C10-C14: 20 ug/L C15-C28: 50 ug/L C29-C36: 100 ug/L |
Gas scrubber washwater
Vessel with a wet exhaust gas scrubber system is required to collect and analyze exhaust gas scrubber sample. During each sampling event at least each of the inlet and outlet samples is required as compassion. The analysis is listed as below.
Analyte description | Method reference | Limit of reporting |
Dissolved & Total Heavy Metals* | USEPA 6020 | 0.1- 5 Lg/L |
Nitrate as N | UAPHA 4500NO3: I | 0.01 mg/L |
Nitrite as N | UAPHA 4500NO3: I | 0.01 mg/L |
16 PAHs** | USEPA 8270C | 0.5 -1 Lg/L |
References
- United States Environmental Protection Agency
VESSEL DISCHARGE SAMPLE COLLECTION & ANALYTICAL MONITORING - A How-To Reference for EPA’s 2013 Vessel General Permit (VGP) (2014) - International Maritime Organization (IMO)
www.imo.org/en/ourwork/environment/pages/ballastwatermanagement.aspx
Get in touch with us
If you have any questions relating to vessel discharge water analysis, please contact:
Download as a PDF