1-22276-01 site plan

Project No. 1-22276                                                                                                                               Page | 3
March, 2020
Ref: 1-22276, 2020-03-25, ASSMP VER 2
Wessel Petroleum Pty Ltd – Acid Sulfate Soil Investigation and Management Plan - Proposed Service Station Reconstruction, 52-54 Mary Street and
Weyba Road, Noosaville




            excavation or the following day. Alternatively, untreated material would need to be
            suitably stockpiled at the off site facility.
           Following excavation to design levels, the exposed material surface is to be lime treated
            with a liming rate of 5kg/m3, where the excavated surface is not to be covered/filled over
            within the maximum allowable exposure times.
           Treatment of all potential ASS should be undertaken on a suitably prepared treatment
            pad (refer below).
           Thorough mixing of the aglime is critical. Following excavation of the material, it must
            be dried and ploughed, followed by lime dosing. This is to be followed by further
            ploughing and harrowing to provide a homogeneous mix of the excavated material and
            the lime.
           Each layer of material to be treated must not be greater than 200-300mm in thickness to
            ensure thorough mixing of the lime.

Treatment Pads and Stockpile Areas

The treatment and/or stockpiling of ASS should be located in settings that will ensure minimal
risk of adverse environmental impacts as a result of acid leachate. The following
recommendations are made for the design of treatment pads and/or stockpiling areas:-

           The treatment pad or stockpile area should be surrounded by bunded drains to allow
            collection, containment and treatment of surface runoff and leachate from the stockpile;
            drains should flow to catchponds.
           It is important that agricultural lime be added to the material used in the bund walls.
           At treatment pad or stockpile locations agricultural lime (at the minimum rates of the
            designated rate as outlined in Table E1 for the fill and natural soils per vertical metre of
            stockpiled soil) should be tyned into the underlying soil for a depth of 0.3m below
            surface level. However, the actual guard layer rate should be calculated in accordance
            with Section 8.3.6 of the Queensland Acid Sulfate Soil Technical Manual. As
            construction proceeds, additional lime may be added should any of the leachate
            neutralise the original lime.
           Regular testing of water/discharge should be undertaken (refer below).

Groundwater/Discharge

Groundwater/discharge encountered during on site excavations should be pumped to tanks for
treatment prior to discharge.

Further, it is critical that all discharge, drains and site runoffs (on site and/or at the off-site
treatment facility) be directed towards catchponds. Catchponds can be used to remedy waters
which are below acceptable discharge quality.

Waters must be treated to bring water quality criteria to acceptable levels and in accordance
with ANZECC Water Quality Guidelines for Fresh and Marine Waters (2000). Appropriate
neutralising agents, eg. aglime, slaked lime or magnesium/calcium hydroxide may be used to
treat catchpond water. However, should be the intention to maintain off-site catchpond waters
at pH levels between 6.5 and 8.5 at all times.



                                                                                                                  SOIL SURVEYS