BIOLOGICAL MONITORING OF SALTERNS

Revised 3 June 2002

RISK ASSESSMENT

Assess Safety, Health, Quality and Environmental aspects of each specific step.

OVERVIEW

These instructions outline the biological monitoring to be undertaken at solar saltfields to determine biological causes of production problems. Monitoring biological parameters allows predictions to be made about the quality of maiden brine and enables operators to put a remedial program in place with the minimum of delay.

Regular monitoring also provides a database of biological factors for future management.

TASK SAFETY REQUIREMENTS

Safety boots are mandatory

SPECIFIC JOB STEPS RISK ASSESSMENT RISK CONTROL
SAMPLE LOCATIONS

The choice of sites is important because they must be representative of changes in brine chemistry and biology. However, a solar saltfield may change over the years and it is important that the sampling locations change too, to provide consistency.

If there is an unusual isolated occurrence, such as a small algae bloom, by all means sample it and add it to the routine sampling sheet but it is important that this non-representative sample is NOT incorporated into the database as representative. Historical databases are often made useless because spurious data distorts longer term trends.

Taking a non-representative sample. It is necessary that the person taking the samples use their discretion when collecting them, so as not to take a non-representative sample. Flowing, well mixed brine is preferable to use for sampling, but this may not always be available. When not available samples taken away from the "normal" sites should be used to give a more accurate representation of the pond as a whole.

Always attempt to conduct sample runs during calm weather.

After reviewing the biology and pond system choose locations representative of:

Input brines (as many as input points), last ponds of separate brines, ponds with mixtures of streams, early gypsum precipitation ponds, Synechococcus ponds, immediately post Synechoccus ponds, crystalliser input.

Seawater intakes may not be pumping.

Seawater SG may be very low.


Maiden brine may not be pumping

If the brine is not being pumped samples should be taken on the seaward side of the pump.

If the brine SG is below 1.020 do not take a sample.

If the brine is not being pumped sample the brine which is closest to saturation. If the brine SG is below 1.180 do not take a sample.

REGULAR SAMPLE COLLECTION AND TESTING

The sample should be taken from running brine and should be typical for that pond. A 500 mL sample should be taken from each location. Samples shall be collected and transported as specified in Test Method: Collecting, Preparing, Storing & Transporting Samples.

Hot weather may affect samples. Always put samples in the biological samples esky. Use ice in warm weather to keep the samples cool.
SG, Temperature, Turbidity and pH shall be measured at the sampling site and the results recorded immediately.    
On return to the laboratory, the following parameters should be measured for each sample:
- Viscosity
- Nutrients
and recorded in the laboratory daybook. Samples shall be prepared for plankton counts as per
Test Method: Plankton Counts and shall be recorded in the daybook
   
     
What When How
SG as collected Hydrometer - Test Method: Specific Gravity
Temperature as collected Thermometer - Test Method: Specific Gravity
pH as collected Calibrated pH meter - Test Method: pH of waters
Plankton treat immediately on return to laboratory with lugols media and leave to sediment overnight Test Method: Plankton Counts
Viscosity within one day Test Method: Viscosity
Nutrients immediately on return to lab As specified in the Merck manual
Turbidity as collected Secchi Disk - Test Method: Turbidity
     
     
 SPECIFIC JOB STEPS RISK ASSESSMENT RISK CONTROL
As the data will form part of a saltfield's baseline data for that saltfields' biology a copy shall be providedto the client as a permanent record.  Delta owns the daybooks A copy shall be made and provided to the client
EQUIPMENT REQUIRED FOR TAKING SAMPLES

10 x 500 mL sample bottles

hydrometers (range 1.000 - 1.250)

thermometer (0 - 50oC)

pH meter

secchi disk

Contaminated bottles Always use the marked bottles in the correct ponds
SAMPLING FREQUENCY

The sampling should be done every fortnight during the peak flow period.

The flow may be reduced in winter in southern saltfields The sampling should be less frequent when the brine is not flowing. During winter for example, a sample every two months would be appropriate.
MONITORING SPECIFIC PARAMETERS

24 hour samples may be collected for measuring SG variation, colour and turbidity. Samples are collected with an EPIC Water Sampler or similar automatic sampler..

The operator does not know how to operate the EPIC. Ensure a manual is provided to the operator

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