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

a. Lime Treatment Strategy
IF REQUIRED.

A safety factor of two is recommended for sites regarded as sensitive to acid export.
These include areas:

* within 50 metres of a drainage line, stream or other surface water
* where the watertable is within 2 metres of the surface
* where the site is below the 50 year flood tine.

A safety factor of 1.8 is recommended where more than 5% of samples have a %Spos
or %S¢, greater than 0.03% or TAA greater than 100 moles/ton. A safety factor of 1.6
can be used for samples with lower levels of acidity or potential acidity.

The treatment rate is calculated using the average of all samples with a % S,,, > 0.03%.
The worst case sample must have a minimum safety factor of 1.2.

In the absence of field bulk density measurement the design in-situ bulk density is 1.65
tons/cubic metre and the excavated (loose spread, uncompacted) soil bulk density is 1.2
tons/cubic metre.

b. Lime Application

It is recommended the disturbed soil is spread across fill areas in layers with the
appropriate quantity of lime being spread across the surface. The lime is then cultivated
through the layer to provide uniform mixing. The depth of the fill layer will be affected by
compaction requirements, machinery, the physical condition of the soil and operator
preference. The exact method of mixing is of no consequence provided lime is mixed
uniformly through the placed soil. It is stressed care should be taken with mixing as
validation samples will subsequently be taken for chemical analysis. If the uniformity of
mixing is poor the validation tests are likely to fail.

c. Lime Storage

Agricultural lime and hydrated lime (builders lime, calcium hydroxide) needs to be stored
on-site in a secure manner. It is recommended the hydrated lime (normally supplied in
bags) is held in a locked shipping container or similar site building. It is recommended
the agricultural lime is held in a bunded storage area. If supplied in bulk then the lime
should be covered to prevent dust becoming a nuisance.

d. Placement of Excavated Soil

It is preferred to retain treated soil on the development area. If off-site placement is
required then the following actions must be undertaken:

the land holder must agree in writing to accept the treated material

the land holder must be provided with copies of soil analysis reports and a written
declaration of the volume and placement location

prior to placement local authority must be provided with copies of soil analysis
reports and a written declaration of the volume and placement location. Check
with the local authority to ensure the placement complies with any local
regulations.

transport of treated soil should be performed using covered vehicles and no
drainage water must escape onto public access areas