Biological Oxygen Demand (BOD) of wastewater discharged from Australian Antarctic Stations

Full description

INDICATOR DEFINITION
This indicator is an estimate of the biological oxygen demand (BOD) of effluent discharged into the ocean from the waste treatment plants (WTP) at each continental station. It is tested monthly and reported in the station plumbers' reports to the Building Services Supervisor in Kingston.

TYPE OF INDICATOR
There are three types of indicators used in this report:
1.Describes the CONDITION of important elements of a system;
2.Show the extent of the major PRESSURES exerted on a system;
3.Determine RESPONSES to either condition or changes in the condition of a system.

This indicator is one of: PRESSURE

RATIONALE FOR INDICATOR SELECTION
The stations produce liquid waste, comprising human waste, waste from kitchens and bathrooms, and limited volumes from workshops (contamination of the latter is usually minimal as it is cleaned of oil before discharge into the sewage system). This is treated in the waste treatment plants.

BOD measurements are an indication of the efficiency of the WTP in destroying microorganisms and of the numbers of live microorganisms being released into the ocean as a result of human occupation.

DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM
Spatial scale: Australian Antarctic continental stations and Macquarie Island station.

Frequency: Monthly reports

Measurement technique: Samples are tested using the Oxitop Control method.

Station doctors are trained in the Oxitop control method before departure for Antarctica. The Laboratory Manager, Australian Antarctic Division, Kingston, interprets results. Samples are collected, analysed, interpreted and reported monthly.

Waste at Casey is also UV treated before being discharged into the environment. The data given for Casey station are readings after UV treatment.

RESEARCH ISSUES
The following would increase knowledge of the potential impacts of the discharge of the wastewater:

Winter and summer values will also be compared to detect any effects resulting from smaller winter populations, and higher summer populations.

More accurate microbiological tests.

Chemical analysis of effluent for phosphate and other nutrients. This would indicate the extent of enrichment that may occur in the adjacent oceans, and allow feedback for example on the types of washing detergent supplied at stations.

LINKS TO OTHER INDICATORS
SOE Indicator 48 - Station and ship person days
SOE Indicator 50 - Volume of wastewater discharged from Australian Antarctic Stations
SOE Indicator 52 - Suspended solids (SS) content of wastewater discharged from Australian Antarctic Stations

Lineage

Progress Code: onGoing

Statement: The physical, chemical and biological characteristics of domestic and light industrial wastes may influence the receiving waters. Therefore it is important to monitor these properties in any wastewater being released. BOD measurements are one element of this, as an indicator of the total microbial load. The WPT specifications allow for a BOD range of 0 - 60 mg/l, although figures of 300 mg/l occur at times, particularly in summer. Results exceeding 60 mg/l are seen as indicative of poor efficiency of the WTP and the need for servicing or adjustment.