Reference Document OPW19 0098 Acid Sulphate Investigation · OPW19/0098

August 2003 -1- 03683042(AA)

 

4.0 “INTRODUCTION

This report details the results of an acid sulfate soil (ASS) investigation carried out by Golder
Associates for a proposed commercial development described as “Precinct N” and Socated
north of Eumundi — Noosa Road, Noosaville. The investigation was undertaken for Mintgrove
Pty Ltd at the request of Noosa Town Planning.

The development includes filling more than 500 m’, with an average fill depth of greater than
0.5 m, on land below the RL 5 m AHD contour. The investigation was undertaken in order to

_ assess the extent of acid sulfate soils and acid ground water across the development site in

accordance with the requirements of the State Planning Policy 2/02 “Planning and Managing
Development involving Acid Sulfate Soils” (SPP 2/02). This report details the results of the
fieldwork and laboratory testing together with an assessment of the extent of ASS.

2.0 SITE DESCRIPTION

“Precinct N” (‘the site’) is located in the northern part of an allotment described as Lot 311 on
SP114182 that covers a total area of 4.368 hectares. Access to Lot 311 is via Gateway Drive
off Eumundi — Noosa Road in the south, and via a track that traverses the adjacent Lot 23 on
RP867628 from Venture Drive in the east. A residential development is located to the west of
the site, with vacant land located to the north and an industrial subdivision to the east.

The site covers an area of about 1.33 hectares and is mostly covered by dense regrowth
vegetation including she-oak and melaleuca. Some vegetation had been cleared from the
western part of the site at the time of the investigation. The remainder of Lot 311 had been
recently cleared. The ground surface generally slopes at about 2° to 3° towards the north,
before increasing up to about 10° adjacent to a break-in-slope which defines the southern edge
of a relatively level, low-lying area. The break-in-slope intersects the north-eastern part of the
site and is shown in Figure 1, together with the approximate extent of vegetation. Vegetation
at the southern fringe of the low-lying area is similar to that described across the sloping part
of the site, however changes to short (sedge) grasses together with scattered melaleuca about
20 m to 30 m towards the north. It is inferred that the low-lying area is part of the flood plain
associated with Lake Doonella, which is located about 300 m to the north of the site.

3.0 PROPOSED DEVELOPMENT

A drawing prepared by Herwig Hartl shows the proposed development layout together with
proposed site levels and drainage (ref. Figure 2). The proposed development will comprise
three childcare buildings, a swim school, gymnasium and an indoor entertainment and
education building together with car parking areas. Earthworks will consist of mostly filling
to depths of up to about 2 m, with some cutting up to about 1 m depth in the south-western
corner of the site (above RL 5 m AHD). Given the proposed filling and design invert levels
for the stormwater drains, trench excavations within in situ soils will be minimal.

Golder Associates