07/2023 - Response to Information Request [As Published] · 132007.2023

f. Treatment Pad Design

If lime is incorporated with soil at a specific mixing area then the treatment pad should
be bunded (as specified in section 4.e).

If the pad floor is constructed from untreated acid sulfate soil then the floor must be lime
treated as specified in section 4.a.

Validation testing of lime treated samples will require time for sampling, sample
transport to a laboratory, sample drying and analysis. This process can easily require
5-7 working days. The treatment pad and any storage areas need to be sized to
accommodate treated soil that remains to be validated.

q. Exposed Cut Surfaces

If excavation areas will be left exposed then these should be capped to minimise
oxidation of sulphidic and acid soil. The minimum depth of limed capping should be 800
mm.

i, Vegetated Cover

If the excavated area is to be revegetated then topsoil should be placed at the surface.
The lime treatment rate is conservative and an alkaline soil pH is expected. This may
not suit re-vegetation and could result in nutrient deficiency (eg. Zn, Fe, Mn & P). To
avoid this problem it is recommended the existing 0-200 mm soil layer is stripped from
the site and

ystockpiled. This assumes the 0-200 mm soil layer is currently vegetated, non-saline,
well oxidised and non-sulphidic. Care must be taken to restrict the topsoil removal to this
depth to avoid sulphidic material deeper down.

The final placement over the cut material should be:

0-200 mm __ replaced topsoil, uncompacted for revegetation (existing pH/acidity)

200-400 mm __ limed cut material, low level of compaction to allow for drainage
and root penetration (strongly alkaline, no acidity)

400-1000 mm _limed cut material, high level of compaction to minimise oxidation
and deep drainage (strongly alkaline, no acidity)

ii. Non-Vegetated Cover

lf the excavated area is not to be revegetated then no topsoil is required.

The final placement over the cut material should be:

0-800 mm _ limed cut material, high level of compaction to minimise oxidation
and deep drainage (strongly alkaline, no acidity)

h. Runoff Control

It is recommended a runoff diversion drain be constructed to divert runoff water away

from untreated excavated soil and excavation areas should these lie within a runoff

pathway. The drain should be checked daily to ensure it is servicable.

i, Ponded Water