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Reference Document - Site and Soil Evaluation MCU24/0061
NOOSA COUNCIL
REFERENCE DOCUMENT
MCU24/0061 31 JUL 2024
. . . . Site and Soil Evaluation . . . . .
Client: J. Pollari
Location
94 Tablelands Road
Cooran, QLD
(Lot 17 on SP170297)
Report No.: 220004(A)Rev-A
Date: 11/12/2023
Phone: 0428 310 453
Email: [email protected]
Address: 174 Railway Road, Cooran Qld 4569
Australian Soil Investigations Pty Ltd
ABN: 11147854439
Document Set ID: 23014195
Version: 1, Version Date: 13/05/2024
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Page 2
ON-SITE EFFLUENT DISPOSAL REPORT: Lot 17 on SP170297
94 Tablelands Road, Cooran.
Introduction:
Australian Soil Investigations have conducted a Site and Soil Assessment at the above allotment for the purpose of
determining the most suitable means of on-site effluent disposal. On-site testing for this assessment was
performed in accordance with AS 1547-2012-“On-Site Domestic Wastewater Management and the Queensland
Plumbing and Wastewater Code. Field work for this assessment was undertaken, on the 25/01/2022.
ASI has been asked to provide a design for two bedrooms.
Site description:
The allotment is located within the Noosa l Council and is contained within a rural residential area.
The slope within the allotment is generally linear. The slope within the area best suited for effluent disposal is in
the order of 8%.
On-Site Assessment:
During our site evaluation consideration was given to the following:
the available area for the primary siting of absorption areas (Land Application Area) and alternative
sightings.
the risk of prejudicing adjoining property and underground water supplies, by seepage or run off from the
site.
permeability, soil type and soil depth.
drainage, and envisaged seasonal changes in ground water level.
general climate.
slope and the effects of seepage and water run-off from surrounding higher ground.
On-Site Testing:
Three test holes were excavated in the positions shown in the attached site sketch. These holes were 100mm
diameter x 600 mm deep for the purpose of site soil assessment in accordance with the AS 1547-2012. A further
100mm diameter hole was excavated to determine the soil profile. The site was then classified in accordance with
AS 1547–2012 On-Site Wastewater Management for the purposes of effluent disposal.
Results:
Site Observations
Yes No
Suitable Area for siting a Land Application Area
Adequate area for a Reserve area
Setback requirements to waterways
Is there Adequate Soil Depth above rock or the water table
Is the Soil Type Satisfactory
Is the potential of runoff from the proposed area OK
Is there a potential for groundwater seepage
AUSTRALIAN SOIL INVESTIGATIONS
Document Set ID: 23014195 2 ASI Ref: 220004(A)Rev-A
Version: 1, Version Date: 13/05/2024
Page 3
Soil Borehole Results
Depth Soil Description
00-400 Silty Clay CH
Med to heavy clay, brown red
Moist, moderate. (Cat 5)
400-900 Silty Clay CH
Med to heavy clay, red orange
Moist, massive. (Cat 5)
900-2000 Silty Clay CH
Med to heavy clay, pale orange, grey mottled red
Moist, massive. (Cat 5)
2000 Borehole Terminated
Constant Head Method permeability results
The following design criteria is applicable for the following disposal methods:
1 2 3
Fall (m m ) 25 25 25
Time (m ins) 25 36 33
(secs) 24 19 25
Indicative Permeability (Ksat) 0.1575 0.1101 0.1197
Soil Category 5 5 5
Structure Moderate Moderate Moderate
Indicative Permeability
Test Site: 1 2 3
Soil Category 5 5 5
Structure Moderate Moderate Moderate
Indicative Permeability 0.12-0.5 0.06-0.12 0.06-0.12
DIR 3 3 3
Recommendations:
Based upon our Site and Soil Assessments we recommend the following method of On-Site Effluent Disposal
should be used.
For the treatment of the Effluent we recommend;
Advanced Secondary WasteWater Treatment System (AWTS)
(NOTE: The system chosen must satisfy both the Queensland Plumbing and Wastewater Code and AS 1547-2012
On-Site Domestic Waste Water Code and be approved for use by the Local Shire/Council governing the allotment.)
For the disposal of the treated effluent within the Land Application Area we recommend;
A Pressurised Surface Reticulated Irrigation System
AUSTRALIAN SOIL INVESTIGATIONS
Document Set ID: 23014195 3 ASI Ref: 220004(A)Rev-A
Version: 1, Version Date: 13/05/2024
Page 4
The size of the Land Application Area is calculated as follows:
Minimum requirement q 120 litres per person per day AS 1547 –2012 Appendix H1
Water Supply Tank Water
Number of persons = 4 AS 1547 Table J1
Total Volume Q= 3360 L/week
Soil Category 5 AS 1547 Table M1
Indicative permeability 0.06-0.12 AS 1547 Table M1
DIR 21 mm/week AS 1547 Table M1
2
Disposal Area A= 160 m
WE RECOMMEND THAT A MINIMUM LAND APPLICATION AREA OF 160m 2 BE PROVIDED.
A check of Water Balance requirements in accordance with the Code has been undertaken and have
been found to comply.
The Irrigation System should be designed in accordance with AS 1547–2012 and comply with all relevant statutory
requirements.
Construction Guidelines for Land Application Areas:
Surface Irrigation
Consists of a reticulated pressurised irrigation system that uses a series of surface sprinklers to equally distribute
the treated effluent across the Land Application Area. This system allows vegetation within the area to directly
benefit from such watering which also assists in disposal of the effluent via evapo-transpiration. Points to consider
in the construction of the area include the following:
To avoid runoff from the area it should be as level as possible. Any steep sloping areas should be
terraced or retained and filled.
Rainwater shall be diverted around the perimeter of the area by use of open catch drains or bunding.
Similarly a retention bund should be constructed around the low side of the area to retain any effluent
overflow.
Sprinklers with a throw of not more than one meter shall be used and produce coarse droplets
(instead of a fine mist) to minimise the risk of aerosol dispersion and wind drift of effluent. The
plume height shall not be more than 500 mm above the finished surface of the irrigation area.
The treated effluent must not be used for the irrigation of fruit or vegetables.
Siting of surface irrigation shall be in a location away from regular pedestrian traffic and recreational
areas, so there is no risk of direct spray or wind driven spray onto such areas.
The area should not be within vehicle paths or be near children’s play areas. Refer to Queensland
Plumbing and Wastewater Code for all required setback distances.
Treated effluent quality must conform to AS 1547 - 2012 and the Queensland Plumbing and
Wastewater Code.
We have attached a site plan showing the proposed position of the Land Application Area and also some details
highlighting the construction techniques required for surface irrigation.
AUSTRALIAN SOIL INVESTIGATIONS
Document Set ID: 23014195 4 ASI Ref: 220004(A)Rev-A
Version: 1, Version Date: 13/05/2024
Page 5
Preparation of irrigation area:
When a proposed irrigation area has a low permeability, it is particularly important to ensure that the permeability
of the soil in the irrigation area is improved and maintained and that there is an adequate cover of porous and
fertile topsoil to act as immediate storage of effluent applied to it, and to support rapid growth of vegetation on the
area to maximise evapo-transpiration.
It is recommended that topsoil be imported to improve rapid growth of vegetation and improve the evapo-
transpiration process.
Requirements of irrigation system:
All irrigation pipe work and fittings shall comply with all parts of AS 1477 or AS 2698.2. The distribution irrigation
lines should be buried to a minimum depth of 100mm. There shall be no cross connection between any irrigation
pipe work and the potable water supply. Any pipe work used for the transport of effluent included treated effluent
must be lilac in colour.
Along the boundary of the surface irrigation area there shall be at least two warning signs clearly visible to inform
the occupants of the premises that recycled water is used for irrigation. Each sign shall comply with AS 1319 and
have:
(a) lettering visible at 3m and
(b) wording: Recycled Water
Avoid Contact
DO NOT DRINK
Prior to the use of the system, the warning signs and the landscaping and surface preparation must be completed.
Sighting of the Land Application Area:
The current Code of Practice for On-site Sewerage Facilities (Queensland Plumbing and Wastewater Code) provides
minimum horizontal/vertical separation distances for Land Application Areas. They are as follows;
Sub-Surface Land Application Areas (ADVANCED SECONDARY)
Property Boundaries Upslope from the Area - 2.0m
Property Boundaries Downslope from the Area - 4.0m
Dwellings or buildings - 4.0m
In ground swimming Pools - 6.0m
In-ground potable Water Tanks - 6.0m
Dams, Watercourses or Bores - 10.0m
Vertical distance to water table - 0.6m
Driveway - 2.0m (Upslope);
4.0m (Downslope)
Footpath - 1.0m (Upslope);
2.0m (Downslope)
NOTE:- REFER TO QUEENSLAND PLUMBING AND WASTEWATER CODE FOR SITING OF ON
SITE SEWERAGE FACILITY FOR LOCATION OF TREATMENT PLANT. TREATMENT
PLANT MUST BE 150mm ABOVE Q100 FLOOD LEVEL.
In no instance shall Effluent be used for irrigation of fruit or vegetables.
No Vehicle loading or children’s recreational areas to be applied or constructed within the Land
Application Area.
AUSTRALIAN SOIL INVESTIGATIONS
Document Set ID: 23014195 5 ASI Ref: 220004(A)Rev-A
Version: 1, Version Date: 13/05/2024
Page 6
System Maintenance:
The owner of the property shall ensure that all manufacturers maintenance procedures are undertaken in
accordance with the local authority and the manufacturers recommendations for what ever system is installed.
The system must be inspected/tested on a regular basis in accordance with the manufacturers requirements and
all Statutory requirements from relevant local and state government agencies.
NOTE: No Antibacterial products or disinfectant to be used in the system. Refer to manufacturers
guidelines on safe products to be used in the system.
System Installation:
Installation of the system must be undertaken by a qualified plumber in accordance with local authority
requirements and in accordance with the relevant Australian Standards and Australian Building Code.
NOTE: The system is not to be installed or utilized without Plumbing approval from Council.
The building is not to be occupied without Building and Plumbing approval. Permit Numbers are to
be provided to the installer and designer.
Definitions:
Design Loading Rate (DLR)
The long term acceptance rate (LTAR), reduced by a factor of safety, expressed in L/m2/day or mm/day as applied
to the horizontal design area of a land application system.
Design Irrigation Rate (DIR)
The loading rate that applies to the irrigation of a land application area with effluent of a secondary quality. It is
expressed in L/m2/day or mm/week. If a spray irrigation system is used, the secondary effluent is subject to
continuous disinfection.
Durable Aggregate
An aggregate with the grading requirements specified in AS 2758.1 for single-size course aggregate for nominal
sizes from 20mm - 40mm.
Dry Vault
Commonly known as “composting toilets”, a chamber that receives and treats human and domestic organic waste
using a biological degradation or dehydrating process. The only water used is for cleaning or assisting the
biological degradation process.
Geotextile
Any permeable durable synthetic textile material used with foundations, soil, rock, earth or other geotechnical
engineering related material.
Land Application Area
The designated area of land and reticulation system used for the disposal of the treated effluent.
LTAR
The long term average rate an effluent can be adsorbed into the soil of a disposal system, expressed in litres per
square meter per day. LTAR is dependent on effluent quality, permeability and organic loading.
Permeability
The rate clean water is transmitted through a soil, expressed in meters per day.
Terrace
Where the trenches are in an area where the slope exceeds 15% (approximately 1 in 7) they must be terraced.
Water Reduction Fixtures
Fixtures include 11/5.5 litre water closets, shower flow restrictors, aerator taps and water conserving washing
machines.
AUSTRALIAN SOIL INVESTIGATIONS
Document Set ID: 23014195 6 ASI Ref: 220004(A)Rev-A
Version: 1, Version Date: 13/05/2024
Page 7
Report Limitations:
The log sections in this report should be representative of the soil conditions over this site, however, soil conditions
can change dramatically over short distances. The person responsible for installing the system must observe the
soil profile and ensure it matches the soil profiles recorded in this report. If soil conditions differ from those
recorded by us, we must be immediately notified so that further investigation can be carried out and the system
design modified if necessary. This work may involve additional fees and costs. This company will not accept any
responsibility for additional costs to any party as a result of soil variations.
In writing this report, we have also considered all the information supplied to us by our client. Should the client or
his agent have omitted to supply us with relevant information, our report may be irrelevant and/or inappropriate.
We do not take responsibility for the consequences in such cases and we will make an additional charge if as a
result, more testing or rewriting of this report is necessary.
The operation of the disposal system is dependant upon the hydraulic load, the type of the material entering the
system and the maintenance of the system. As these factors are beyond the control of this company we do not
take any responsibility for the long term adequacy of any disposal system constructed on this site or the
consequences of its malfunction.
WADE HOLMES – QBCC 1120066
for and on behalf of:
AUSTRALIAN SOIL INVESTIGATIONS – QBCC 15072110
AUSTRALIAN SOIL INVESTIGATIONS
Document Set ID: 23014195 7 ASI Ref: 220004(A)Rev-A
Version: 1, Version Date: 13/05/2024
Page 8
Revision Description Date
. . .
. . .
. . .
Document Set ID: 23014195
Version: 1, Version Date: 13/05/2024
Surface
Drainage Good.
Vegetation Grasses &
Scattered Trees
BH 2
Borehole location.
ABN11 147 854 439
Slope Title: SITE PLAN - On-Site Effluent Disposal
measured as a percentage gradient from
AUSTRALIAN
high ground to low ground. SOIL INVESTIGATIONS Project J. Pollari, 94 Tablelands Road
Cooran
Rev.
DO NOT DIMENSION OFF THIS DIAGRAM. Date: Dec 2023 Drg No.220004-ABS .
Page 9
Revision Description Date
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. . .
. . .
J. Pollari AUSTRALIAN
94 Tablelands Road SOIL INVESTIGATIONS
Cooran
Document Set ID: 23014195
Version: 1, Version Date: 13/05/2024 STD DETAIL Drg No. 220004-Detail-A