8. Appendix E - Previous Approval

Notice
Advice Agency Response

(a) The prescribed rate of agricultural lime has been incorporated into all AASS soils that
would come into contact with infrastructure and within 0.3 metres of the finished ground
surface. Bulked composite validation tests have conducted at a rate of not less than 1
test per 500 m® and a failure rate of less than 5% confirms that the treatment has been
successful.

(b) AASS and acidic groundwater are absent; or service infrastructure is constructed of
appropriate acid resistant materials.

8.7 All Acid Sulfate Soil excavated during trenching must be appropriately managed. The applicant is to
provide a concise and site specific Acid Sulfate Soil Management Plan. The assessment manager
must be satisfied that management plan is consistent with the eight Management Principles
documented in the Queensland Acid Sulfate Soil Technical Manual - Soil Management Guidelines
before any operational works are permitted on the site.

8.8 Excavations (e.g. trenching works) must be appropriately designed and staged to minimise
dewatering volumes and the time ASS is exposed to oxidation. Where trenches are to be excavated
through ASS materials, the applicant and construction manager must abide by the following
provisions:

(a) Trenches must only be excavated and dewatered in manageable sections such that the
works and backfilling can be completed within 5 days.

(b) Trenches must be dusted with fine agricultural lime prior to backfilling with non-ASS or
properly treated ASS materials. At least 5 kg of fine agricultural lime (98% purity or
equivalent) is to be used for every linear metre of open trench. Application rates should be
increased in larger trenches or where AASS or groundwater will be encountered.

(c) The section of trench being actively dewatered must not exceed 50 metres in length at
any given time.

(d) Suction depths for dewatering sumps and spears must not exceed 1 metre below the
invert depth of the trench.

(e) Sheet piling or similar must be used in sandy environments to prevent excessive
dewatering requirements and associated decline in local groundwater levels.

(f) Wherever practical, trenchless technologies should used when a service is to be installed
through acid sulfate soils.

8.9 Groundwater discharges from the site must not result in adverse impacts upon municipal
infrastructure (e.g. gutters and stormwater pipes) or the environment. The applicant is to detail
where pumped groundwater is to report (i.e. Stormwater) and the location where these discharges
will flow into the environment. The applicant must also provide a concise discharge plan detailing:

(a) Baseline water quality information for the groundwater to be pumped inclusive of at least
pH, EC, and Fe”* and an estimate of the likely volumes to be pumped per day

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