Subdivision and Associated On-Site Wastewater Treatment ... · Topographic Map Sheet, reproduced in...

Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems

219 Bells line of Road, North Richmond

Report No. TFA 3318/01

Prepared by: Hi. Fiander, DipTechEng, BE(Hons),

MEngSe, MIEAust, CPEng,

Toby Fiander & Associates,

Suite 2/7 Wilton Close, Castle Hill PO Box 6200,

Baulkham Hills Business Centre

NSW 2153 [email protected]

Date: 29 October, 2010

NSW LPI Historical Search Title: 87/1040092

LAND AND PROPERTY INFORMATION NEW SOUTH WALES - HISTORICAL SEARCH

SEARCH DATE

4/11/2010 8:43A1

POLIO: 87/1040092

First Title(s): OLD SYSTEM Prior Title(s): EX 3192 NO 795 BIC 4301 NO 524

Recorded Number Type of Instrument C.T. Issue

8/4/2002 DP1040092 DEPOSITED PLAN FOLIO CREATED EDITION 1

8/4/2002 CA84119 CONVERSION ACTION

23/3/2004 AA514472 NOTICE OF DEATH EDITION 2

9/11/2005 A8900354 CAVEAT

29/12/2005 AC15486 TRANSFER EDITION 3

*** END OF SEARCH ***

NP/APEX58629900 PRINTED ON 4/11/2010 Espreon hereby certifies that the Information contained In this document has been provided electronically by the Registrar-General in accordance with Section 968(2) of the Real Property Act, 1900. Any entries preceded by an asterisk do not appear on the current edition of the Certificate of Title.

Warning: The Information appearing under notations has not been formally recorded In the register.

Printed by Espreon 04/11/2010 08:43 AM AEST For: NP Ref: APEX58629900 Page 1/1

Toby Fiander & Associates - Subdivision and Associated On-Site Wassewater Treatment & Disposal Systems at 219 Bells Line of Road. North Richmond, NSW

EXECUTIVE SUMMARY This report has been prepared to accompany the Development Application far a proposed

subdivision between Lot 1 and Lot 2 as well as a proposed dwelling on Lot 1 at 219 Bells Line of

Road, North Richmond.

The property is currently split by Redbank Road which is where the proposed subdivision is to be.

Lot 1 docs not currently have any structures on it. while Lot 2 has a shed and a dwelling which is

classified as a heritage item in the HCC LEP. The features can be seen in an aerial photo of the

site on FIGURE 3. - -

The proposed dwelling on Lot I will requite a wastewater treatment system and disposal area This

report relzrs to the adequacy of the existing wastewater treatment and disposal system at Lot 2 and assesses a number of proposed wastewater treatment and disposal system options for Lot I.

Toby Fiander Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

TABLE OF CONTENTS

BACKGROUND

1.1 Site Location 1.2 Site Description

1.3 Site History

1.4 Performance standards for operation of system of sewage management

2. SITE ASSESSMENT

2.1 Climate • - 2.2 Size & Shape

2.3 Topography & Exposure

2.4 Run-on & Upslopc Seepage 2.5 Erosion Potential

2.6 Existing Fill Maierial

2.7 Existing Vegetation 2.8 Proximity to Threatened Species, Populations or Ecological Communities

2.9 Rocks & Rock Outcrops

2.10 Geology/Regolith 2.11 Site Drainage

2.12 Runoff& Flood Potential

/13 Buffering from Watercourses. Roads & Dwellings

3. SOIL ASSESSMENT

3.1 Soil Types 3.2 Depth of Soil

3.3 Depth to Episodic /Seasonal Watertable

3.4 Soil Permeability 3.5 Course Fragments

3.6 Bulk Density

3.7 pH 3.8 Electrical Conductivity

3.9 Sodicity

3.10 Cation Exchange Capacity 3.11 Phosphorus Sorption Capacity

3.12 Dispersiveness

4, WATER MANAGEMENT OBJECTIVES

5. VOLUME OF EFFLUENT 5.1 Sources of Effluent

5.2 Effluent Estimates 5.2.1 Peak Effluent Estimates

5.1.2 Amenities

5.1.3 Total Effluent

6. EXISTING WASTEWATER TREATMENT SYSTEM

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

6.1 Sewage Treatment Equipment

6.2 System Conditions

Toby Fiander & Associates , Subdivision and Associated On-Site W astewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond. NSW

7. STANDARDS FOR WASTEWATER TREATMENT & DISPOSAL 7. 1 Wastewater Aeration

7.2 Land Application Systems Sizing

9. CONCLUSION

8. WORKS-AS-EXECUTED PLANS & DOCUMENTATION

10. REFERENCES

FIGURES Figure 1:

Figure 2:

Figure 3:

Site Location Map

Soil Landscape Map

Aerial Photo of Site Layout

LIST OF APPENDICES

APPENDIX A. Irrigation Area & Storage Requirements APPENDIX B. Land Application Areas

APPENDIX C. Aerated Wastewater Treatment Systems (AWTS)

APPENDIX D. Waterless Composting Toilet APPENDIX E. Ecomax Cells

Toby Plunder de Associates - Subdivision and Associated On-Site Wastewater Treatment .1 Disposal Systems at 219 Bells Line of Road, North Richmond. NSW

1. BACKGROUND

Approval is sought for a subdivision and proposed dwelling for the property 219 Bells Line

of Road, North Richmond. This report estimates the effluent load produced by the

residence, including assessment at maximum capacity and assesses the capacity of both the

proposed treatment system and existing treatment system to receive and dispose of these

estimated loads.

This assessment has been earned out in Accordance with AS/NZS1547:2000 "On-site

domestic-wastewater management", Hawkesbury City Council's requirements and the

"Environment & Health Protection Guidelines - On-site Sewage Management k>r Single

Households".

1.1

Site Location

The site is located North of the confluence between the llawkesbury, Nepean and Grose

Rivers. The site is located at 219 Bells Line of Road, North Richmond and is also known

as Lot 87 DP1040092. The site can be found at map reference 2876283 on the Kurmjong

Topographic Map Sheet, reproduced in FIGURE 1. and also at the same reference on the

Penrith soil conservation service map sheet, reproduced in FIGURE 2.

1.2 Site Description The approximately 19ha site is divided by Rodbank Road, which is also approximately

along a soil boundary.

The site is characterised by grassy woodland areas and scattered trees. The property

includes a large shed and a residential structure classed as heritage. An aerial photo of the

site is available in FIGURE 3.

The site is not connected to either town sewerage service or water supply.

Toby Fiander & Associates- Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

1.3 Site History The area has been used for keeping horses and other equine activities for a number of

years.

1.4 Performance standards for operation of system of sewage management

(1) A system of sewage management must be operated in a manner that achieves the

following periirmance standards:

(a) the prevention of the spread of disease by micro-organisms.

(b) the prevention of the spread offoul odours,

(c) the prevention of contamination of water,

(d) the prevention of degradation of soil and vegetation,

(e) the discouragement of insects and vermin.

(f) ensuring that Persons do not come into contact with untreated sewage or effluent

(whether treated or not) in their ordinary activities on the premises concerned,

(g) the minimisation of any adverse impacts on the amenity of thc premises and

surrounding lands,

(h) if appropriate, provision kir the re-use of resources (including nutrients, organic

matter and water).

(2) Failure to comply with subclause (I) is not a bleach of that performance standard if the

failure was due to circumstances beyond the control of the person operating the system of

sewage management (such as a fire, flood, storm, earthquake, explosion, accident,

epidemic or wari i kc action).

(3) A system of sewage management must be operated:

(a) in accordance with the relevant operating specifications and procedures (if any) for the

sewage management facilities used far the purpose, and

(b) so as to allow the removal of any treated sewage (and any by-product of any sewage) in

a sat and sanitary manner.

The existing system at the house appears to meet these requirements.

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Lineal Road. North Richmond, NSW

2. SITE ASSESSMENT

It is proposed to treat effluent through aerated wastewater treatment systems. The

proposed locations of the disposal area of the mound have been assessed for wastewater

disposal tasibility following criteria outlined in Section 4 of OSWMSSH (1998) and

Section 4 of AS1547:2000. In Figure 4A, a Site Limitations Plan has been presented,

showing arras where wastewater disposal may not occur, as well as a potential layout

demonstrating how a house site and an aerated wastewater treatment system may be

suitably sited, and the fallowing section discusses the various characteristics of the _

proposed disposal area.

2.1 Sin and Shape Proposed subdivision lots. There is sufficient land area available on each proposed for:

• houses & associated structures;

• wastewater treatment & disposal;

• appropriate buffer distances;

Figure 4 shows how the proposed disposal areas can be suitable situated within the

proposed Lots.

2.2 Topography and Exposure The site is located in Grose Wold and contains mainly woodland. The lots are moderately

steep and is suitable for wastewater disposal.

2.3 Run-on and Upslope Seepage There is no evidence of seepage at any of the proposed disposal sites. A catch drain or

diversion bank is to be constructed to divert runoff from up-gradient arms away from the

disposal area.

2.4 Erosion Potential Bannerman & Hazelton (1990) indicate that the Lu soil landscape generally has low

erosion hazard fir non-concentrated flows and a moderate to high erosion hazard for

concentrated flows. It is proposed to manage soil erosion by:

• detention of water on the site in collection areas, where possible, for settling,

• using hay-bales to slow the velocity of water, • using sediment knees below disturbed areas,

• rapid establishment of vegetative cover.

2.5 Existing Fill Material Them is no evidence that additional fill material has been imported to the site.

uantities are depths in millimetres perrronth or millirrrtres per year.

PERIOD Average Rainfall

Median Rainfall

Average Rain days

Average Pan

Evap'n

Average Inig'n

Min. Irrig'n

Max. Irrig'n

January 142 125 9 192 59 0 134

February 140 113 ICI , 149 37 0 105

March 103 89 9 134 35 0 78

April 77 58 7 100 29 0 75 ,

May 64 33 5 , 65 14 0 53

June 74 30 6 51 7 0 34

July 37 15 4 _13 26 0 40

August 49 28 5 97 31 0 46

September 49 33 5 127 46 5 112

October 72 53 7 165 51 0 148

November 88 76 7 179 47 0 98

December 95 76 - 8 226 75 0 147

YEAR 990 953 82 1558 457 279 789


2.6 Climate

The site is located in Richmond and the climate is expected to be typical of the area with

good winter sunlight due to the open aspects of the site in the proposed wastewater

disposal area. The topography is expected to provide little wind protection. Daily rainfall

and evaporation depths for the site were based on nearby meteorological station Richmond

AMO. 067033. An attempt was made to adjust for increased rainfall as described in later

sections, The most important feature of the data was considered to be the conjunctive

probability of rainfall and evaporation rind the method used makes an attempt to preserve

this facture while ai.A..-uunting for higher rainfall. A period of record from 1970 to 1998 was

used fur modelling as described below. No alteration was made to the patterns of rainfall

and evaporation to as.count for site aspect. Annual rainfall is-estimated to be 1000 mm/y

and annual class A pan evaporation is estimated to be 1500 mm/yr. Inspection of the class

A pan site was carried out in 1991 and indicates that data are rwarded competently.

Table 1. Climatic Summary, Richmond AMO 067033, NSW

The table values for the YEAR period are not necessarily the sum of the monthly values kir the same quantity.


2.7 Site Drainage

The site is well drained with suitable soil.

2.8 Runoff and Flood Potential Provided adequate drainage of any future building and driveway area is provided there will

be limited runoff from the site. The site is not subject to the 1%AEP flood.

2.9 Proximity to Watercourses There is an intermittent watercourses running through the Proposed Lot 22, a dam

located on both proposed Lots, and Woods Creek is located downslope to the west of the

Proposed Lots. No runoff from the disposal area will be permitted to enter these

watercourses.

2.10 Buffering from Watercourses, Roads & Dwellings

The proposed disposal area is located at the appropriate buffer distance from the

watercourse, roads and dwellings. Figure 3 is a site constraints map and shows appropriate

buffer distances from property boundaries, dwelling and watercourses.

To minimise any effect on the surrounding land, it is proposed to:

• apply water to the site only when the soils have sufficient water holding capacity

to prevent runoff • to rely principally on evapotranspiration and wastewater storage for disposal,

• permit application of water to the soil beyond the capacity of the plants to

transpire approximately once in 2 years, • to use vegetation to prevent particulate matter leaving the site as far as possible.

The proposed disposal area is located with appropriate buftr distances in accordance with

the requirements in Dept of Health at al (1998). and the following minimum buffer zones

are provided:

• 6 metres if area up-gradient and 3 metres if area down-gradient of driveways and

property boundaries, • 15 to dwellings for surface irrigation andfor 6- metres to dwellings for sub-surface

irrigation,

• 3 mares to paths and walkways, • 6 metres to swimming pools.

• 100 metres to watercourses,

• 40 metres to dams and drainage lines.

The above bufkr distances am used as a guide to the designs shown in Figure 3.

Additional to this it is also recommended that signs indicating the area is irrigated with

treated wastewater, needs to be placed in the vicinity of the irrigated area to warn people

to exercise caution in these areas.

Toby Fiander & Associates - Subdivision and Associated On-Site W astewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

2.11 Existing Vegetation

Vegetable plantations is found on the area proposed to be utilised for wastewater disposal.

2.12 Proximity to Threatened Species, Populations or Ecological Communities There are no threatened species, populations or ecological communities located on or in

the near vicinity of thc site.

2.13 Rocks and Rock Outcrops Rock and rock outcrop do not occur at the site.

2.14 Geology/Regolith

There is no evidence of geological discontinuities or fractured or highly porous regolith at

the site that may provide a short circuit of wastewater to groundwater.

Toby Fiander & Associates - Subdivision and Associated On-Site W as tewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

3. SOIL ASSESSMENT 11 Soil Types

The Soil Conservation Service 1:100,000 soil landscape map for Penriih, shown in

Figure 2, indicates that the site contains the Luddenham (1u) soil landscape although the

Lucas Heights (Ihl) is also shown nearby. This soil landscape is generally described below.

McInnes (1997) describes the soils of the Lucas Heights landscape as moderately deep,

hardscuing yellow podzolic soils and yellow soloths. Dominant Soil materials include

loose, dark brown to yellowish brown sandy loam (Ihl); bleached, stony, hardsetting sandy

clay loam (1h2); earthy, yellowish brown sandy clay loam (1h3); and pedal, yellowish

brown clay (1h4).

McInnes (1997) describes the soils of the Loddenham landscape as shallow to moderately

deep,dark podwlic soils and massive earthy clays. Dominant Soil materials include friable

dark brown loam (WI); hardsetting brown clay loam (1u2); whole coloured, strongly pedal

clay (1u3); mottled grey plastic clay (lu4);and alxxlal brown sandy clay (u5).

3.2 Depth of Soil The soils of the proposed disposal area will be deeper than 0.6 mares and are considered

suitable for wastewater disposal without adverse environmental or health effects.

3.3 Depth to Episodic /Seasonal Watertahle The site is not located in a regional water supply catchment, and groundwater monitoring

is not considered necessary as pan of this application.

3.4 Soil Permeability The soils of the site are silty clays which are heavier with depth. An indicative

permeability of <0.06 in/day is noted in AS1547:2000 and this is adopted for the site.

Wastewater disposal is designed to rely principally on evapotranspiration, thettfore an

Design Loading Rate (DLR) of 6.0mm/day is acceptable based on the information

provided in AS1547:2000. The DLR for the proposed wastewater disposal area is

0.5mm/day as the proposed method of wastewater disposal .relies on evapotranspiration,

rather than infiltration, for disposal.

3.5 Course Fragments Some course fragments were encountered during the soil examination, but are not

considered to pose a limitation to wastewater disposal as an amended soil will be imported

to the site.

3.6 Bulk Density The soil of the site did not show any signs of compaction. Bulk density testing was not

carried out, but the topsoil was assumed to have a bulk density of 1800kg/e.

3.7 pH The soil of the proposed disposal areas typically has a pH of about 5.0 to 6.5 which does

not present any constraints to plant growth and evapotranspiration rates.

3,8 Electrical Conductivity There is no evidence at the site of high electrical conductivity with good plant growth in

the proposed wastewater disposal areas.

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road. North Richmond, NSW

3.9 Sodidty The soil did not appall to be extremely hard or appear to have surface crusts (hat are

characteristic of sodic soils.

3.10 Cation Exchange Capacity The Cation Exchange Capacity (CEC) of the soils at the site is generally low. This is

considered acceptable for wastewater disposal.

3.11 Phosphorus Sorption Capacity

The soils of the site are considered to have moderate phosphorus sorption capacity,

however as it is proposed to import an amended soil to the disposal arca, the phosphorus

sorption capacity of the in-situ soil material is not an important consideration of this

study.

3.12 Dispersiveness The soils of the site did not show obvious signs of dispersiveness. Soils with low

dispersiveness do not pose any limitations to wastewater disposal, however gypsum can be

applied to the site to prevent soil degradation which may occur through the addition of

sodium in detergents.

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond. NSW

4. WATER MANAGEMENT OBJECTIVES

The general objective of site water management is to limit pollution of downstream waters

both during normal operation and rood events. This is particularly common to all sites

where the capacity of the riverine ecosystem to absorb nutrients is under stress from time

to time.

Issues raised by Council during discussions about similar proposals are:

whether the proposal is likely to increase the nutrient loading on the river and to

what extent, and if them is an increase, what steps would be required to minimise its impact.

The general principal objectives for wastewater disposal on the site are considered to be: • minimisation of erosion.

• minimisation of nutrient loads in runoff other than during exceptional weather.

• minimisation of runoff or application of water to the ground during wet periods, • secondary processing of wastewater prior to application to the ground.

These am considered appropriate in this case and a conceptual design is presented dealing

with the above.

5. VOLUME OF EFFLUENT

Each of the volume of wastewater has been determined using the Australian Standard

AS1547-2000, where the minimum wastewater allowance for design purposes for a

household on a reticulated water supply with full water reduction fittings is

I 10L,itres/pemon/day.

Assuming 10 people per household, the daily volume of water requirement for each

household is estimated as l'100Litrestday. Suitable water conservation measures are

outlined in the Manual edited by White (1999).

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells line of Road. North Richmond. NSW

6. OPTIONS FOR WASTEWATER TREATMENT & DISPOSAL

A variety of options have been examined for the disposal of wastewater at the proposed

sub-division. A comparison of these options has been tmdataken to determine the most

appropriate method of treatment and disposal of the wastewater from an environmental

and economic standpoint. Recommendations for wastewater treatment and disposal

systems have the been made taking the above factors into consideration.

The alternative options for wastewater treatment & disposal examined in this report

• - include:

• Treatment in an Aerated Wastewater Treatment System (AWTS), wet weather

storage and disposal via irrigation. • Treatment in a Composting Toilet and Sand Filter/Subsurface Wetland with wet

weather storage and disposal via irrigation. • Primary Treatment in a Septic Tank and secondary treatment and disposal in an

Ecomax System with a wet weather storage capability and downhill buffer zone. ▪ Treatment in a Septic Tank with disposal via an absorption trench.

All options will utilise the land application areas shown in Figure 3 and follow the generic design layout presented in APPENDIX B.

6.1 AERATED WASTEWATER TREATMENT SYSTEM (AWTS), WET WEATHER

STORAGE & IRRIGATION An AWTS in conjunction with a wet weather storage tank and disposal through irrigation can be used at this site for wastewater treatment & disposal. It is considered that the

installation of a system capable oftreiting lkL/day is a feasible option for the treatment

of wastewater generated at the proposed new residence. APPENDIX C shows a systematic

diagram for the processing, storage, control and land application of wastewater from this proposal. Further details of the Aerated Wastewater Treatment System are also included in

APPENDIX C.

6.1.1 Aerated Wastewater Treatment System An AWTS with a minimum capacity of 1.2kL uses aeration of wastewater as part of the

treatment process. The treatment process involves: • settling of solids and flotation of scum in an anaerobic primary chamber (septic

compartment),

• oxidation and consumption of organic matter through aerobic biological processes, • clarification - secondary settling of solids,

• disinfection using chlorination, or other approved means if surface land application

of wastewater is to occur, • regular removal of sludge to maintain the process.

A more detailed description and a list of the advantages & disadvantages of this system can

be found in the Guidelines (1998). When considering this project, the main advantage is

that a high quality standard of effluent is produced by the system and the main

disadvantage is that the system has high installation and maintenance costs. As with any

system, if the system is not maintained correctly the quality of the effluent will be greatly

Toby Fiander & Associates - Subdivision and Associated On-Site Watewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

• raluced.

Toby Fiander & Associates - Subdivision and Associated On-She Wastewater Treatment & Disposal Systems at 2I 9 Bells Line of Road, North Richmond, NSW

6.1.2 Wet Weather Storage Treatment in the AWTS is followed by storage in a wet weather storage tank which

ensures that irrigation is not required during periods of wet weather. Irrigation is controlled through the use of soil moisture sensors fitted in the disposal area. The volume of the wet weather storage tank is dependent on the volume ofeffluent produced and the area available far disposal of treated wastewater and calculations are provided in APPENDIX A. The wet weather storage required far an average daily flow of 1.1k1.1day with an area of 1000m2 available for disposal is 30 days. which is equivalent to a 331t1.. tank.

6.1.3 Irrigation Irrigation of wastewater is carried out to dispose ofeffiuent. There arc two main types of inigation: surface and sub-surface. Sub-surface irrigation of wastewater requires primary treatment as a minimum bebre irrigation. Surface irrigation requires secondary treatment as a minimum because the wastewater may come into human contact.

The advantages of surface irrigation are that it is possible to monitor the system to ensure

the sprinklers are working correctly and also to take samples ofthe wastewater quality. The disadvantages of surface irrigation is that treated wastewater may come into human contact and climatic conditions, e.g. windy weather, affect irrigation.

The advantages of subsurface irrigation is that the wastewater cannot come into human contact and does not require as high a level of disinfection. The disadvantages of sub-surface irrigation is that it is difficult to determine if ancl where a pmbicm has occurred as components of the system arc not visible. This in turn makes it difficult to repair problems if it has been identified that one has occurred.

It is considered that surface or sub-surface can be carried out at this site provided the

appropriate bulk(' distances are in place. A possible area where disposal of effluent can be undertaken is shown in Figure 3 and provides a total area of 1080m2 far disposal.

It is considered that the irrigation of a 1000m2 disposal area on each proposed lot will provide protection of the soil from sodium degradation and far removal ofphosphoms. In this instance, it is argued that environmental constraints would permit application of wastewater to the ground beyond the ability of the plant material to transpire on 5% of all days.

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road. North Richmond, NSW

6.2 COMPOSTING TOILET, SEPTIC TANK, SAND FILTER Or SUBSURFACE WETLAND, WET WEATHER STORAGE and IRRIGATION A second configuration for on-site waste management involves the installation of composting

toilets, accompanied with septic tank and various loons of disposal. APPENDIX D includes

systems diagrams and notes showing typical arrangement for the processing, storage, control

and land application of wastewater from this proposal.

6.2.1 Composting Toilets Composting toilets, capable of handling the waste of up to 10 persons, may be installed in the

proposed residencies. Composting toilets rely on microbiological activity to breakdown

excreta. There _are two types of composting toilets - wet and dry. A wet composting toilet

accepts all the household wastewater and putreseible household organic solid wastes. A dry

composting toilet accepts human excreta and organic household kitchen scraps only and does

not treat all household water.

The advantages of the wet composting toilet system is that it helps to conserve water, handles

some shock loading and recycles nutrients. Disadvantages include the moderate operational

rtquirements, treated wastewater management is required and it may be aesthetically

unappealing to some people. Thc advantages of the dry composting toilet system is that a

water supply is not ncoded for operation and minimal disposal areas arc required.

Disadvantages include that water content is critical for efficient operation, low temperatures

reduce effectiveness of the composting process and grey water is not catered for by this

technique and it can be aesthetically unappealing to some people.

The use of a dry composting toilet at this site would provide a significant advantage by

reducing the area required for disposal of wastewater as a reduction of 30% in the hydraulic

load of the development can be expected. Calculations showing disposal area and wet weather

storage requirements for dry composting toilets are shown in APPENDIX A. Typical systems

layout of both wet and dry composting toilet systems are shown in APPENDIX D. A description of a typical dry composting toilet is also included. The chosen system will need

to have been approved for the treatment of effluent by the .Environment Protection

Authority or the Health Department. It is envisaged that the chosen system will be supplied,

installed and maintained in accordance with the manufacturer's recommendations to meet the

above standards and that annual monitoring shall be undertaken of its performance.

6.2.2 Sepdc Tank - A 3000 litre septic tanks will need to be installed for the treatment of groywater generated at

the proposed residence if a dry composting toilet is installed for the treatment of blackwater.

Grcywater is wastewater from the kitchen sinks, bath, shower and laundry, but may also

include liquid waste draining fium the composting toilet if necessary. A septic tank allows

preliminary treatment of the greywater, effectively acting as a large grease trap. Following

the septic tank, the treated greywater is to be directed to a sandfilter or subsurface wetland

system.


6.2.3 Sand Filter or Subsurface Wetland

A sand filter provides treatment of effluent after it has la the septic tank. There are several

types of sand filters, br example the recirculating aerobic sand filter devices in which effluent

is distributed through a bed of coarse sand in a similar way to that of a trickling filter. The

quality of the effluent following treatment in the sand filters is similar to that from an AWTS.

Advantages of sand filters are that they produce a high quality effluent and are low

maintenance. Disadvantages are that sand may not be available locally and water conservation

is essential.

A 20m2 subsurtice wetland provides treatment of effluent after it has let the septic tank.

The quality of wastewater following treatment in the subsurface wetland is similar to that from

AWTS, although a higher level of nutrient removal can be expected in an effzetively

maintained wetland. Advantages of wetlands are that they arc capable of producing a high

quality effluent and can also act as effmtive sediment traps and sites br the breakdown of

organic material. Disadvantages are that nutrient removal can be unpredictable in the long

term. A more thorough description of a subsurface wetland is included in APPENDIX D.

6.2.4 Wet Weather-Storage

Treatment in the septic lank and sand filter is followed by storage in a wet weather storage

tank which ensures that irrigation is not required during periods of wet weather. Irrigation is

controlled through the use of soil moisture sensors fitted in the disposal area. The volume of

the wet weather storage tank is dependent on the volume of effluent produced and the area

available far disposal of treated wastewater and calculations are provided in APPENDIX A.

The wet weather storage required for a wet composting toilet which has an average daily flow

of 0.725kLiday with an area of 1080m' available for disposal is 20 days which is equivalent

to a 14k1. tank. The wet weather storage required for a dry composting toilet which has an

average daily flow of 0.508kLiday with an area of 1080m2 available for disposal is 15 days

which is equivalent to an 8kL tank.

6.2.5 Irrigation The types of irrigation available and the advantages and disadvantages of cliff-lent irrigation

systems are previously described in Section 6.1.3 of this report, therefore they are nor

discussed brther here. It is considered that surface and subsurfice irrigation can be undertaken

on the lots provided the appropriate buffer distances are in place. Possible areas where disposal

of effluent can be undertaken are shown in Figure 3 and provide a total of 1080 m' for each

Lot.

It is considered that the irrigation of a 1080m2 disposal area on the proposed lots will provide

protection of the soil from sodium degradation and far removal of phosphorus. In this

instance, it is argued that environmental constraints would permit application of wastewater

to the ground beyond the ability of the plant material to transpire on 5919 of all days.


6.3 SEPTIC TANK & ECOMAX SYSTEM fitted with a WET WEATHER STORAGE

FACILITY

The Ecomax system accepts primary treated effluent from a septic tank and then carries out

secondary treatment in the Ecomax cells. The water is disposed of through the roots from the

grass that grows on top of the cells. The collector drain and soakage system is designed to

limit the impact of any runoff or application of water in excess of the cell to absorb.

APPENDIX E shows a typical arrangement for the processing, storage, control and land

application of wastewater from this proposal. A detailed description of the Ecomax System

can also be found in APPENDIX E as well as data on expected quality of wastewater that will

be obtained using the Ecomax system (although these results are not indicative results of long

term performance).

6.3.1 Septic Tank A 4000 litre septic tank allows preliminary treatment of wastewater by allowing solids to

settle to the bottom of the tank and scum to accumulate on the top of the tank. Anaerobic

digestion of solids produces sludge while the partially treated effluent is directed elsewhere far further treatment or disposal to a soil absorption system.

The advantages of a septic system is that low maintenance is required far such a system.

Disadvantages are that the effluent is highly infectious and highly polluting and subsoil

application is n:quired. The Guidelines (1998) provide finther infonnation on the advantages

and disadvantages of septic systems.

6.3.2 Ecomax System fitted with a Wet Weather Storage Facility Ecomax wastewater- treatment and disposal systems use "red mud" (a Bauxite derivative, which

reacts to adsorb phosphorus) as an integral part of the treatment process. The treatment

process involves:

• settling of solids and flotation of scum in an anaerobic septic tank, • diversion of waStewater into a Ecomax cell (leach drain) which is lined with "red mud"

which has the ability to remove phosphorus, nitrogen & heavy metals from the

effluent, • treated wastewater is disposed of via roots from the grass and vegetation growing on

lop of Ecomax cells where it is transpired into the atmosphere or infiltrated into the

surrounding soils.

Advantages of the Ecomax system are that it is designed to produce effluent with low nuthent

levels while not requiring a large area for disposal of the wastewater. Extensive research

conducted by Ecomax Wastewater Technology have shown that Ecomax systems rempve

between 99.5% to 99% of phosphorus from domestic wastewater and produce treated effluent

with an average phosphorus concentratcion of less than 0.05mg/L (Ecomax, 2001). Another

advantage is that the system requires limited maintenance, involving regular mowing of the

grass on top of the cells to ensure maximum uptake of effluent and nutsients, and directional

valve changes every 6 months so that flow is periodically diverted between the active and

resting cells.

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road. North Riclunond, NSW

Disadvantages of the Ecomax system include that the quality of the final effluent is difficult

to monitor and the small area of disposal can be overcome by shock loads of wastewater and

heavy prolonged rainfall. Longer term effects are also not well known, although there seems

adequate experience to say that in the medium term the periodic localised waterlogging, which

must accompany the process, has little measurable effect. The Ecomax treatment & disposal

area should be designed so that it is located within a bufir area which provides for the

protection of the surrounding areas in the event of overflow from the treatment beds.

Testing of the waste slag from steel smelters in NSW is yet to be undertaken, therefore, the "red mud" shall be sourced from Western Australia until results are available for the alternative

product.

It is proposed that effluent from the dwelling could be treated in the Ecomax system which

comprises Conventional Septic Tanks, two Ecomax Cells, Amended Soil 'Red Mud', Sand

Veneer and a grass cover. This system will have the capacity to treat 1.2 kLiday in an

approved manner while providing approximately 20 days wet weather storage within the

system. An area of approximately 120m2 plus buffers will be required for the red mud

treatment/disposal system which protects against overflows causing pollution.

The process shall have been approved for the treatment of effluent by the Environment

Protection Authority or the Health Department. It is envisaged that the Ecomax system will

be supplied, installed and maintained in accordance with the manufacturer's recommendations

to meet the above standards and that annual monitoring shall be undertaken of its

performance.

The section of the Ecomax system shown in APPENDIX E is similar to that which has been

tested for about 15 years in the Greater Sydney Area. It is recommended that this

arrangement, which can be supplied bu the present agent at Narellan, be installed rather than the reduced volume arrangement promoted by the agent.

6.4 SEPTIC TANK and ABSORPTION TRENCHES This configuration will rely upon primary or secondary treatment in a conventional septic

tank, followed by disposal in an absorption trench designed to treat water though infiltration

and evapotranspiration.

6.4.1 Septic Tank The advantages and disadvantages of septic tanks have been previously described in Section

6.2.2.

6.4.2 Absorption Trenches Absorption trenches accept wastewater that has already undertaken primary or secondary

treatment. Absorption trenches rely on infiltration into the subsoil and plants for

evapotranspiration of wastewater and removal of nutrients. They are recommended to be planted out with water tolerant species which are native to the local area.

The advantages of absorption trenches are that it requires less surfize area than surface

irrigation and it will not come into human . contact. The disadvantages arc that it is difficult

to monitor the removal of nutrients and to know whether the wastewater is being removed

by evapotranspiration or infiltration into the soil.

A septic tank and absorption trench system is NOT recommended for wastewater

i


trratrnent & disposal at this site due to the low permeability of the soil and the high

record of failure of these systems.

Table 2. Assumed Effluent Quality - before and alter treatment

Quantity Raw Effluent 1Yeated Effluent

BOD, 450.mg/L <20.mg/L

Suspended Solids 45Q.mg/L <30.inA/L

Faecal Conforms 3 x I 0'.perlOOrri. up to 10' cfii/ I 00mL

, Oil It grease 7.ntg/L 4 S.7 migiL)

Nitrogen 45.roz/L <50.mg/L.

Phosphorus I 4.rng/L <15.mg/L

Residual Chlorine - 0,5mg/L

Conductivity 60.11S/em O00.1.1S/cin

Toby Fiander & Associates - Subdivision end Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

7. PROPOSED STANDARDS FOR WASTEWATER TREATMENT & DISPOSAL

The options for wastewater treatment and disposal listed in Section 6 have been examined

regarding the site conditions at the proposed lot. The site preparation for cach is different and

generalised preparation prior to subdivision would be difficult. The effmtive operation of the

above options requires the implementation of the fallowing standards and practices.

7.1 Effluent Quality It is proposed that effluent from the dwelling could be treated in a AWTS, Ecomax or

composting toilet arrangement. Input to & output from these systems are expected to have

the following characteristics: ' . _

The process shall have been approved for the treatment of effluent by the Environment

Protection Authority or the Health Department. It is envisaged that the chosen system will

be supplied, installed and maintained in accordance with the manufacturer's recommendations

to meet the above standards _ and that annual monitoring shall be undertaken of its

perfonnanee.

7.2 Hydrological Standards For the purpose of this feasibility study, it is expected that runoff from the site will occur with

rainfall but that effluent will be retained in a vented, dark, destratified storage tank and applied

to the soil only when the soil has sufficient water holding capacity to d.cept it without causing

ponding or runoff except that about every second year on average water in excess of plant

requirements will be permitted to be applied to the ground.

Application beyond the normal plant water use is considered reasonable on some relatively

rare occasions because the soil is considered to have relatively high phosphorus sorption

capacity. Any surf= flow of water that may result from occasional applications of water

beyond the transpiration and storage capacity assumed will have maximum opportunity to be

adsorbed onto the clay of the soil.

If the soil water deficit at which irrigation may commence is controlled so that it is 20%

of field capacity, then there will be maximum opportunity kir wastewater to enter the soil

while rainfall is rejected as runoff Sensing ofdepletions less than 20% is not considered


feasible with cheap equipment. The deficit is considered to correspond to a soil suction of

approximately -0.3hPa.


7.3 Wastewater Application Wastewater can be disposed of at the locations shown in Figure 3.

Sub-surface irrigation of the wastewater would not require disinketion of the wastewater as the

effluent would not come into human contact. Spray irrigation requires further treatment of

thc wastewater through disinfection. Suitable methods of disinfection include: Chlorination,

Ozonisation and Ultra Violet light treatment with Ultra Violet light being the preferred option

due to the minimal use of chemicals involved in this process.

7.4 -Hydraulic Design of Irrigation System Pressure relief or control shall be provided in the pumping mains system so that no emitter

may receive a pressure which is more than 30% above its normal operating pressure under any

circumstances.

Hydraulic design shall be undertaken in accordance with Water Resources Commission (1979)

or any other competent manual of practice provided that the design incorporates the

killowing principles:

• water shall be pumped to the highest point on each setting where a pressure

adjustment mechanism shall be provided,

water shall be gravitated in subrnains from the highest point in the block to each

lateral in submains, and have a maximum difference from the pressure at the highest

point of the block of 20%,

• friction in polythene emitter laterals shall be designed to be balanced by the pressure

provided by the position of the emitters so that there is a 10% pressure variation

fi-om the mean or less.

7.5 Soil Moisture Control of Pumping A soil moisture sensor is required to be inserted in the irrigation pump controls so that

application of wastewater to the ground is not possible when soil has 80% of field capacity or

0.3hPa suction whichever corresponds to the greater soil moisture content.

7.6 Spray-Drift Protection Spray drift protectiOn is only necessary if spray irrigation of wastewater is installed in parts

of the disposal area. With spray irrigation, buffer areas should be planted out with species

recommended in Section 7.8. A more comprehensive list of suitable shrub species is shown

in the Guidelines (1998).

7.7 Filling & Terracing Filling will not be required in the proposed disposal area as the soil is considered suitable for

wastewater disposal in it's present kmm.

Toby Fiander & Associates • Subdivision and Associated On-Site Wastewater Treatment A Disposal Systems at 219 Bells Line of Road,North Richmond, NSW

7.8 Vegetative Cover The disposal area shall have a thick vegetative cover so thai a complete canopy of vegetation

is presented to the sun. As moisturc content of the area will often be high, some native species will not perfonn well in a Phosphorus-rich environment. Tnx and shrub species native to the

Hawk esbury-Nepean area and frost resistant could be considered. Thc area may also be kept as a grassed area which is maintained in the same way as a regular lawn. Example of shrubs

possibly suited to the site are shown below and a more comprehensive list is available in the

Guidelines (1998).

Plants suitable for very wet arras of Irrigation • • - Cares appresso Eleocarpus reticulatus - Blueberry Ash Carex inverse Eucalyptus sparsifolia

Cressida pumila Grevillea Iinearifolia - White Spider Power Melaleuca ericifolia -Swoop Paperbark

Grevillea Seneca - Pink Spider Flower

Acacia data - Cedar Wattle

Melaleuca Bracelet HoneyMyrtle Acacia fimbriata -Fringed Wattle

Melaleuca erubescests - Pink Honcymynle

Acacia tenninatis - Sunshine Wattle

Melaleucu hypericifolia

Acacia rnyrtifolia - Myrtle Wattle

Melaleucu linearifolia - Sno w-in-Sunrxr Rackhousia myrtifolia • Grey Myrtle

Melaleuca nodosa -Ball Honcyrnynle

Callistemon citrinus 'Burgundy'

Mdaleuca quinquinervia - Broad-leaved Paperbark Callistenton 'H ark n es s '

Melaleuca sieberi -Sieber s Paperbark

Collistenon pallidus

Melaleuca squamea - Swamp Honeymyrtle Cullistemon rigidus

Melaleuca squarrasa - Scented Paperbark Callistemon salignus

Melaleuca thymifolia

Callistemon

Leptospermunr grandifolium -Woolly Tea-tree

Callistemon "Vio (rictus'

Restio fasrigiams -Tassel Rush Ceratoperalum gumnriferunt Christmas Bush Tristaniopsis !czarina - Water Gum

Plant species suitable for drier areas of irrigation Acacia elongata

Eucalyptus scias - Large Fruited Red Mahogany Acacia floribunda - White Sallow Wattle

Grevillea conferlifolia prostrate

A Cri cia linifolia -Flax-leafed Wattle

Grevillea gaudichaudii

Acacia longifolia - Sydney Golden Wattle

Grevillea juniperina prostrate red

Eucalyptus haemastoma - Scribbly Gum

Grevillea lannfolia

Eucalyptus piperita - Sydney peppermint

Grevillea rivularis

7.9 Wastewater Quality The raw water is expected to have a total conductivity of about 501./S/cm or less and the

wastewater a total conductivity of about 5001.1S/cm (see Report of the Task Force on the Use

of Reclaimed Water, 1982). The soils of the proposed disposal area will contain some day and. consequently, it is considered that there is the potential for them to be subject to

degradation by sodium adsorption. Experience with similar soils in the Ilawkesbury Valley

indicates that there is unlikely to be any problems with soil adsorption therefore the Sodium

Adsorption Ratio of the anticipated wastewater was not calculated as it is likely to be

relatively low, in any case. It is recommended that gypsum is added to the disposal area annually to protect the soil from sodium degradation.

Toby Fiander & Associates -Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

7J0 Area required for Phosphorus Sorption From experience with similar soils in the Hawkesbury River valley, a sorption rate of 0.3 6g/kg

was adopted far analysis as the soil has a moderate to high phosphorus sorption rate.

In its present compaction state the soil has an estimated water holding capacity of 170mm/m

using textural methods presented in Water Conservation & Irrigation Commission (1978).

The phosphorus balance of the site is desai bed by:

C, = V it P/A - P, - P,

where:

C„. is thc weight of phosphorus in the soil per unit area (g/m3).

V is thc volume of inigation (Ur?), is the concentration in the effluent (g/L),

A is the area irrigated with effluent (m3),

Pr is the weight of phosphorus removed by runoff per unit area (typically 0.5kg/ha= 0.05g/m3),

P, is the weight of phosphorus removed from the site by cropping

or other means (nil for non-agricultural development).

The concentration of phosphorus in the treated effluent is assumed to be 15mg/L. This means

that some nutrient removal in the sludge of thc treatment process will be required.

It is assumed that the effluent will be applied to the soil in such a way that it comes into

intimate contact with the soil matrix to a depth of 0.4 metres (ie. the estimated plant root

depth). It is proposal to have the site viable fix 50 years, based on the requirement in Dept.

of Health at al (1998). This means that annually in the topsoil (assumed to have a density of

I 800kg/m3):

(0.36/50) x 0.4 x 1800 = 365 x 1100 x 0.015/A - 0.05 - 0

The minimum disposal area required for phosphorus removal is estimated to be 1000e.

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 219 Bells Line of Road, North Richmond. NSW

7.11 Nitrogen Nitrogen is assumed to be removed by nitrification and denitrification of the soil is

therefore transient.

Modelling of the nitrogen cycle is feasible At its simplest the nitrogen cycle consists of a

single input, wastewater, as oxidised nitrogen. Nitrogen is removed by three pmcesses:

• deaitrification when wetting and drying occurs,

• mineralisation into the soil, • plant nutrient uptake.

. _

The third process is ignored as it is assumed that plants are returned to the soil and there is

no net plant material leaving the site.

Thus, C, = ki x C;., - k2 - N + N,

where:

is the weight of nitrogen in the soil store on day 9'.

k, is the concentration dependent rate at which nitrogen is removed,

principally by denitrification, k2 is the constant rate at which nitrogen is removed, principally by

mineralisation. N„., is the weight of nitrogen leaving the soil as a result of runoE1

N, is the weight of nitrogen entering on day,

Based on guidance shown in Bacon & Thompson (1982) the likely loss from

denitrification on The -hist day from surfice application is in excess of 30%. However.

15% per day was assumed. The rate mineralisation is much lower and is assumed to be

3g/ha/day. so that as a rate per hectare:

C, = 0.85 x C1.1 -3.0 -0 + (15mg/L x 11001Jday x 10 3)/0.1ha • 0.85 x C.., + 500 (g/ha)

By a series-summing process (and by spreadsheet approximation), it can be seen that this

means that the ratio of effluent nitrogen to concentration in the soil would be about 10

(with identical weight units).

Assuming the top 300mm is involved in the process and that there is a bulk density of

1800kg/m2:

Soil concentration 10 x 1000 x 1000 x 15mg/U(0.3m x 10000 x 1800kg/m3)

30mg/kg

The highest recommended nitrogen concentrations frw plant growth are generally about this

level (see Department of Agriculture, 1982) However, it is likely based on experience that

high nitrogen content in the soil is unlikely to present a constraint to. plant growth. In other

words, the proposed disposal area of 1080m2 is considered adequate with respect to .disposal

• of nitrogen in the long term.

Toby Fiander & Associates -Subdivision and Associated On-Site Wastewater Treatment & Disposal S)werns at 219 Line of Road, North Richmond, NSW

7,12 Water Balance Method A water balance method of calculation was developed in which a daily evaluation of the

following equation was made:

SM, = SW, + R - E, + D

where:

SM, is the soil moisture content on day 'I', R is thc rainfall (mm/day),

• is the evapotranspiration (ie. total evaporation) calculated from class A pan evaporation allowing for the type of

vegetation and the moist= retained on it from rainftll &

irrigation, is the inigation depth required to bring the soil moisture

content to field capacity,

• is the depth that ground water would atx:ept.

The above water balance equation was evaluated for a period of historical record from

1970 to 1998. No attempt was made to extend the record or its probability relationships.

Soil moisture was permitted to range between field rapacity (a root depth of 400mm was

assumed) to wilting point with adjustments for plant water stress bclow 50% of field

capacity. The volume of water applied was dependent on water being available. Irrigation

was not commenced unless soil moisture at the beginning of the day was below 80% field

capacity, under some circumstances, 0.5mm/day was assumed to pass to the ground water.

A separate storage kr effluent was also modelled using the conventional water balance

equation for a closed water storage:

V,,, +T - x

where:

V; is the volume of water in storage on day 'I', is the wastewater inflow to the storage, assumed constant,

• is the irrigated area

Days on which overflows occurred were recorded and the effluent storage size adjusted until

overflows occurred during the period of modelling at the percentage of days shown in

APPENDIX A. The graph of 5% of all days corresponds to application beyond

evapotranspiration requirements with about an average interval of about 2 years.

APPENDIX A shows the relationship between required storage and the average depth of

irrigation. The area required for effluent disposal calculated using the daily water balance is

more than twice the area required by phosphorus sorption of the site. Hence, the daily

water balance is the governing actor in the sizing of the disposal area.

More detailed discussion of the above method can be provided, ifirquined. However, the

methods used are generally those described in Irrigation Association of Australia (1990).

Toby Fiander & Associates - Subdivision and Associated On-Site Wastewater Treatment & Disposal Systems at 2/9 Bells Line of Road, North Richmond, NSW

8. WORKS-AS-EXECUTED PLANS & DOCUMENTATION

A works-as-executed (WAS) plan shall be prepared by marking up in a Ted pen on a copy

of the approved plan, the location of the house, disposal area and system installed at the

site. The final survey shall be carried out by a registered surveyor or a suitably skilled

person capable of locating the exact position of the installed wastewater treatment and

disposal systems. The WAS plan shall be signed by the surveyor and presented to Council

upon completion of the works in conjunction with an application br an "approval to

operate- an on-site sewage treatment and disposal facility.

9. CONCLUSION It is considered that with respect to on-site waste water management issues this site is

capable of being sub-divided under the current proposal. It will be feasible to dispose of

wastewater produced on each block efficiently and without damage to the adjoining land,

nearby watemounes and existing dams. The waste water management systems discussed

above are regarded as appropriate for the site conditions provided that the following

recommendations are taken into consideration.

• The sewage treatment and disposal system shall be as described above and shall take

account of discussion and constraints outlined above and in the Figures and

Appendices. Soil conservation measures should include establishment of sediment fences during

construction and at the conclusion of construction work establishment of a good

vegetative cover of soil exposed during construction with approved plant species. • The system has been approved fir the treatment of effluent by the Environment

Protection Authority or the Health Department. • The system is supplied, installed and maintained in line with manufacturer's

nxotnmendations. • The proposed disposal area shall be filled and laid out in accordance with the notes

provided in Figure 3 and the recommendations of the report. • The EPA Guidelines (1998) for maintenance of the system are undertaken to

ensure the system is functioning correctly. • Maintenance of the wastewater treatment & disposal. beility is to occur at on a

regular basis and an annual report of the condition, perfonnance & maintenance of

the chosen system must be completed and submitted to the Council or any other

,relevant management authority as required. .

• A Works-As-Executed Plan is submitted to Council showing the layout and other

relevant technical information relating to the wastewater treatment & disposal

system installed at the site.

Toby Fiander ct Associates - Subdivision and Associated On-Site W asiewater Treatment de Disposal Systems at 219 Bells Line of Road, North Richmond, NSW

10. REFERENCES

Bannerman & Hazelton (1990) Soil Landscapes of the Pesirith 1:100 000 Sheet. Soil

Conservation Service of NSW. Sydney.

Barnes, D., Bliss, P., Gould, B. & Vallentine, H. (1981) Water and Wastewater

Engineering Systems. Pitman, London

Ecomax Waste Water Technology (2001) Ecomax Information Manual. Sydney

OSWMSSH(1998) Environment arid Health Protection Guidelines - On-Site Sewage

Management for Single Households. Dept. of Health, Dept. of Land & Water

Conservation, Dept. of Local Govt & NSW EPA

Penrith City Council (2001) On-Site Sewage Management Strategy. Penrith City Council

Standards Australia (2000) AS1547:2000 On-site Domestic-Wastewater Management.

Sydney.

Water Resources Commission (1979) Design of Jet Spray Irrigation. Interim Design

Manual. North Sydney.

White, S. (2000) Wise Water Management - A Demand Management Manual. Water

Services Association of Australia

A bibliography of on-site disposal hydrology and environmental engineering is available

to Council. if roquircd.

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