Bio-Remediation, May 21 2009

Currency Creek, SA

After heavier trucks got bogged in the soft lakebed mud last week, smaller machines are being used now.

Three machines collecting 350kg each time, traveling from the dumped source in a side street in Nth Goolwa to

about a km or more out to the spreading site on the western edge of the 2-3km wide Currency floodplain.  It is estimated 600 tonnes (overall) is needed in the Currency Creek and Finniss River areas.

The shallow mounds of crushed limestone are only about two meters wide and in some instances 30-50cm high.  It is being placed across depressions in the bed of the system selected by DEH. The depressions are many hundreds of meters apart, again leading to the question of how much water do they expect down the Currency system to spread it out? And how much do they believe these small mounds will cover when spread?

In addition to the limestone dumping, aerial seeding of approximately 5000 hectares around the barrage islands in Lake Alexandrina and exposed areas in Goolwa Channel has started.

(click on any photo for a larger view)

 Locals are referring to the dropping of rye grass seed  as 'planting the lawn'.

The drivers try to select a new path out and in for every trip. Thats because first time over the spongy muds and silt is fair warning that not all is well below.  The ground feels like jelly.

The crushed limestone is coming from Robe in the South East. Its not cheap and the journey has a 6 hour turnaround.

Only a spade width below the surface, sodden acid soil with the hallmarks of pyrites rich soils only a whisker away from oxygen.