Original source · versioned page text
Site and Soil Evaluation
. . . . Site and Soil Evaluation . . . . .
Client: C & J Blake
Location
111 Lukes Road
Cooroy Mountain, QLD
(Lot 2 on RP214048)
Report No.: 250385 (A)
Date: 19/01/2026
Phone: 0428 310 453
Email: [email protected]
Address: 174 Railway Road, Cooran Qld 4569
Australian Soil Investigations Pty Ltd
ABN: 11147854439
See the original
The page text is free to read. Viewing or downloading an original file needs an account.
Log in to see the originalFull text of the other 9 pages
Page 2
ON-SITE EFFLUENT DISPOSAL REPORT: Lot 2 on RP214048
111 Lukes Road , Cooroy Mountain.
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 29/10/2026.
ASI has been asked to provide a design for a five bedroom dwelling.
Site description:
The allotment is located within the Noosa Regional Council and is contained within a rural area.
The slope within the allotment is generally linear. The slope within the area best suited for effluent disposal is in
the order of 5%.
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 2 ASI Ref: 250385 (A)
Page 3
Soil Borehole Results
Depth Soil Description
00-300 Silty Clay CH
Med to heavy clay, brown
Moist, moderate. (Cat 5)
300-1100 Silty Clay CH
Med to heavy clay, orange brown
Moist, moderate. (Cat 5)
1100-2000 Silty Clay CH
heavy clay, red orange mottled grey
Moist, moderate. (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) 51 43 45
(secs) 21 8 29
Indicative Permeability (Ksat) 0.0779 0.0927 0.0879
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 0.06-0.12 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 Sub-Surface Reticulated Irrigation System
AUSTRALIAN SOIL INVESTIGATIONS 3 ASI Ref: 250385 (A)
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 = 8 AS 1547 Table J1
Total Volume Q= 6720 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= 320 m
WE RECOMMEND THAT A MINIMUM LAND APPLICATION AREA OF 320m 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:
Sub-Surface Drip Irrigation
Consists of a reticulated pressurised irrigation system that uses an arrangement of equally spaced shallow sub-
surface drains 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. The drains can consist of small diameter poly piping that has pre-drilled holes for drainage of
the effluent. These pipe must be contained within another Agg drain with a geofabric wrapping that inhibits root
growth which could block the system. Other types of drains include pressure compensated dripper lines. A
number of different manufactured systems exist. Points to consider in the construction of the area include the
following:
(i) To avoid runoff from the area it should be as level as possible. Any sloping areas should be terraced
or retained and filled.
(ii) The pump and irrigation system must have a separate effluent storage chamber that matches the
electrical starting requirements of the pump. A volume 200 L is recommended as a minimum. The
pump is to have a minimum capacity of 1.5 times the maximum 30 minute flow rate.
(iii) Rainwater shall be diverted around the area by use of open catch drains or similar from the irrigation
area. Similarly a retention bund should be constructed around the low side of the area to retain any
effluent overflow.
(iv) The pipework is to be spaced to ensure an even distribution of the effluent over the application area.
A maximum spacing of 1000mm in clay soils and 600mm in sand should be adopted. Greater rates of
evapo-transpiration is achieved through closer spacing of the dripper lines and or reducing the spacing
between the drip emitters.
(v) The dripper lines should have a stop cock downstream from their connection to the supply line
(manifold) and be brought to the surface at their ends. This will enable flushing of the individual lines
and enable easy identification of blocked lines.
(vi) The treated effluent must not be used for the irrigation of fruit or vegetables.
(vii) Siting of the irrigation area 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.
AUSTRALIAN SOIL INVESTIGATIONS 4 ASI Ref: 250385 (A)
Page 5
(viii) The area should not be within vehicle paths or be near children’s play areas.
(ix) 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 shallow sub-surface or covered surface irrigation.
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.
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 5 ASI Ref: 250385 (A)
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/m 2/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 6 ASI Ref: 250385 (A)
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 7 ASI Ref: 250385 (A)
Page 8
Revision Description Date
. . .
. . .
. . .
119.000 120.000
121.000
122.000
123.000
124.000
125.000
11 12
9.0 0.0
00 00
1 21
12
124.
3.0
.0 00
00
000
122.
000
ABN11 147 854 439
Title: SITE PLAN - On-Site Effluent Disposal
AUSTRALIAN
SOIL INVESTIGATIONS Project C & J Blake, 111 Lukes Road
Cooroy Mountain
Rev.
DO NOT DIMENSION OFF THIS DIAGRAM. Date: Jan 2026 Drg No.250385-ABS .
Page 9
Revision Description Date
. . .
. . .
. . .
119.000
120.000
121.000
122.000
123.000
124.000
125.000
12
1
1
1 2
23
.00
4
.0
0
00
.0 0
0
122
.000
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 C & J Blake, 111 Lukes Road
Cooroy Mountain
Rev.
DO NOT DIMENSION OFF THIS DIAGRAM. Date: Jan 2026 Drg No.250385-ABS .
Page 10
C & J Blake
111 Lukes Road
Cooroy Mountain
AUSTRALIAN
SOIL INVESTIGATIONS
STD DETAIL Drg No. 250385-Detail