TUENA HALL & RECREATION AREA COMMITTEE BATHURST STREET … · 2018-07-10 · tuena hall &...

TUENA HALL & RECREATION

AREA COMMITTEE

BATHURST STREET

TUENA. NSW. 2583

WASTEWATER MANAGEMENT

REPORT

Prepared by SOWDES 30 June 2018

A: PO BOX 619, GOULBURN. NSW. 2580 | M: 0428 863 401 | E: [email protected]

Wastewater Management Report – Ref: 0031218 Tuena Hall & Recreation Area Committee Bathurst Street, Tuena. NSW. 2583 30 June 2018

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Table of Contents

Wastewater Management Report

· Introduction & Disclaimer

· Wastewater Management Assessment – Site Assessment, Existing Conditions, Development Proposal, Wastewater Management System Details

· Design Producer's Statement

· Site & Soils Information Summary Tables

· Disposal Area Calculations

· Wastewater Management System Treatment and Disposal Recommendations

Design and Installation Requirements


· Materials and Installation Requirements Summary

· Site Plan

· Conventional Absorption Bed Design

· Installation Checklist for Septic Tanks

· Installation Checklist for Absorption Beds

· Installer's Declaration

Technical Specifications · 'NSW Health Department Advisory Note 3 - May 2006'

· Highland Concrete Tanks – 4.500 Litre Concrete Septic Tank

· Everhard Sullage Trench

· Everhard Distribution Box

· Everhard Xtra-treat Grey Water Filter

· Plant Species Suitable for Use in Evapotranspiration & Absorption Beds and Irrigation Disposal Systems

· Aquatec ‘Sewertec 1’ Low Pressure Sewer Pump Station

· ‘Dump Ezy’ Information and Installation Information

· Campervan & Mobile Home Club of Australia ‘Dump Station Subsidy Program’ Information

· Standard Drawings from Clause 3.17.3 (pages 29 and 30) of AS3500:2003, Part 2 Sanitary Plumbing and Drainage – ‘Sullage Dump Points for Caravans’

· Indicative Rates of Toilet Facilities for Large Events


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Wastewater Management Report. SOWDES has been commissioned to undertake a site and soil assessment of the existing wastewater management systems at the Tuena Public Camping Grounds, Bathurst Street at Tuena. NSW. 2583. The purpose of the assessment is to determine the suitability of the existing wastewater management system to adequately handle current and anticipated future effluent loadings and if need be to recommend any remedial actions or upgrades to ensure that the system complies with relevant health and local government requirements. These recommendations are based on the details contained in the attached site information sheets and photographs, and are referenced by AS/NZS 1547:2012 “On-site Domestic Wastewater Management”, “On-site Sewage Management for Single Households (1998)”, Local Council regulations, "Designing and Installing On-Site Wastewater Systems (A Sydney Catchment Authority Current Recommended Best Practice - 2012)" and “Sustaining the Catchments – Neutral or Beneficial Effect on Water Quality Assessment Guidelines” as published by the Sydney Catchment Authority (State Environmental Planning Policy, Sydney Drinking Water Catchment 2011). Within the attached documentation amongst other site specific information is a site plan that includes the major landform features and approximate locations of proprietory infrastructure items. These are placed within the site plan for indication purposes and will need to be amended on site to accommodate the final design concepts, suffice to say that the final design concepts do not reduce the need to include such facilities. The above-mentioned information, details and recommendations are based on site specific parameters obtained from the initial requesting brief and instructions provided by the clients (or their representatives) and the site specific conditions that were applicable at the time of the site inspection. Any subsequent alterations to the nominated location of the proposed infrastructure items or referenced guidelines after the date of this report may therefore render this report and its recommendations invalid.

Paul Johnson Paul Johnson (JP) Bachelor Science Agriculture/Irrigation (CSU) Graduate Diploma Bushfire Protection (UWS) Graduate Certificate Engineering – Water (UTS) 30 June 2018


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Exiting Land Use and Site Conditions. The Tuena Public Camping Ground lies in the centre of the village of Tuena and is comprised of several recreational and community-based facilities along with short term camping sites and public toilet provisions that services the passing tourist, caravan, and recreational vehicle groups. Use of the facility is intermittent and fluctuates from week to week and year to year with a small number of private functions held in the community hall, the occasional sporting event held on the oval in the lower portion of the site, and a varying number of the available camping sites being occupied at any given time. There are some periods of the year when the site is particularly busier than others – most noticeably around long weekend holiday periods in April and October. The Grounds are made up of many portions of land that cover an area of approximately 6 hectares, the most of which are managed by the Upper Lachlan Shire Council with a few smaller portions being privately owned. The site is bordered by the Tuena Creek on the eastern and northern aspects and houses the following facilities; a community hall with recently renovated kitchen and toilet facilities, a small public toilet block near to the entrance driveway and public carpark area adjacent to Bathurst Street, a shower block in the centre of the site, a sports oval with cricket pitch and covered spectator stand / canteen that is located adjacent to the creek in the eastern half of the site, a second toilet block in the lower eastern quarter of the site for use by some of the camping sites and people using the sports oval, approximately 30 camping sites of which 12 are powered, and access to the Tuena Creek for fishing and recreational activities. Management of the site is undertaken by the ‘Tuena Hall and Recreation Area Committee’ (the Committee) with day to day cleaning and maintenance being performed by community volunteers. All persons and travellers wishing to stay at the Grounds are directed to the local Tuena General Store to pay any associated fees with the money raised through the payment of fees being the primary source of annual income for the Committee. Water supply throughout the Grounds is a combination of rainwater harvesting and river water. Rainwater storage tanks are installed adjacent to the larger buildings whilst a pump that is located near to the creek on the northern aspect of the Grounds draws water to storage tanks located near the local Rural Fire Shed that can gravity feed back to the site if required. Potable water for the kitchen in the Community Hall is drawn directly from rainwater tanks located just outside the building. The Grounds are serviced by three separate wastewater management systems, all of which are displaying signs of ‘collapse’ with effluent breaching the surface and with the unmistakable presence of effluent odours permeating throughout. The shower block in the centre of the site is presently not connected to any wastewater management system with the grey water effluent discharging through an open-ended pipe to the grounds below. The following Table summarises the existing wastewater management system arrangements.


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Table 1. Summary of the existing wastewater management systems Description Amenities Wastewater System Location Condition 1 Public toilet

block at the Community Hall

· Female toilet x 2 and hand basin

· Male toilet x 1, urinal and hand basin

Concrete septic tank, nominally 2000 litres with small absorption trench of approximately 6 metres in length

Just below the toilet block on the northern aspect

Failed with effluent breaching the surface and strong odours

2 Community Hall and Kitchen

· Kitchen · Female toile x 3

and basin · Male toilet x 1,

urinal and hand basin

· Shower · Disabled toilet

Fibreglass septic tank, nominally 2500 litres with small absorption trench approximately 6 metres in length

Approximately 3 metres to the northeast of the septic tank, hard against and parallel to the common boundary with the private land to the east

Tank is displaying signs of fatigue with cracks in the lid.

3 Shower Block · Female shower x 2 and hand basin

· Male shower x 2 and hand basin

Open 100Ø discharge pipe

Flowing down the face of the hill on the northern aspect

Does not satisfy NSW Health or Local Government guidelines

4 Public toilet block at the Sports Oval

· Female toilet x 2 and hand basin

· Male toilet x 1, urinal and hand basin

Concrete septic tank, nominally 2000 litres with small absorption trench of approximately 6 metres in length

Just below the toilet block on the northern aspect, draining into a stormwater drainage depression that flows to the Tuena Creek

Failed with effluent breaching the surface and strong odours

It is acknowledged that the existing wastewater management and drainage systems are quite old and were most likely installed under a different set of design standards and guidelines being significantly different from present day recommended best practice principles. The installation of the various wastewater management systems is also probably a victim of the resources that were available at the time with the septic tank at the two public toilet blocks in particular sitting quite proud of the surface and with very little excavation - presumably due to encountered rock and consolidated materials and constraints of available land area in the immediate vicinity. It is speculated that much of the drainage and wastewater infrastructure that is evident today was also probably undertaken on a limited budget, with limited access to resources and with volunteer labour in a majority of instances. It is also possible that the individual wastewater systems were installed at different times as each of the facilities were constructed and bought ‘online’ hence the distributed nature of the infrastructure as opposed to a centralised wastewater management system.


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There is essentially no land area available for remedial work to any of the existing wastewater management systems in their current locations. The position of the respective systems, in particular the effluent disposal systems and their proximity to formed gravel carriageways and publicly accessed areas basically suggests that any attempt to extend, move or remediate the disposal areas will only result in continued and additional failure of the system. The associated effluent smells being experienced around the different toilet facilities and effluent disposal areas is an indication that the underlying and surrounding soils are completely saturated and beyond their capacity to effectively absorb and dispose of the effluent loads. It is the recommendation of this report that all of the existing wastewater management systems be decommissioned in accordance with the guidelines issued by the ‘NSW Health Department Advisory Note 3 – (May 2006), Item 1’ (a copy is attached in the ‘Design and Installation’ section of this report for reference) and that a new centralised wastewater management system be installed in the lower elevations of the site. Whilst there is normally only a low volume of effluent generated within the Grounds on a daily basis the combination of site slope and topography, proximity to the Tuena Creek, and the potential for large volume surge loading at different times of the year suggests that the best option for upgrading the wastewater management system would be for the installation of a larger and predominantly [1] passive energy system that could handle the majority of predictable large effluent loadings. [1] The location of the shower block precludes the possibility of gravity sewer drainage to the proposed new effluent management and disposal system therefore a low-pressure sewer pump station will be required. Further details are provided within the report. It is acknowledged that undertaking the upgrade of all existing wastewater management systems at the one time may be both resource and cost prohibitive, therefore the scope of works may need to be staged to meet funding availability and prioritising of the most significant parts of the Grounds that require the greatest remedial works. The proposed staging of the works will be as follows: Stage 1 – decommission the existing public toilets and wastewater management system adjacent to the Community Hall and the wastewater management system servicing the Community Hall (locations 1 and 2 from Table 1), construct a new public toilet block in place of the old, install a new wastewater management system in the lower western portion of the site including new drainage lines linking drainage services from the public toilet and Community Hall to the new wastewater management system. The new wastewater management system will have an effective treatment and disposal capacity of 1,000 litres per day. Stage 2 – using a low -pressure sewer pump station connect the shower block to the new wastewater management system and drainage services created in Stage 1, and possibly increase the overall size of the effluent disposal area by two-fold to handle a daily volume of 2,000 litres per day


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Stage 3 – investigate alternate wastewater treatment measures for the public toilet block at the sports oval, including the option to decommission the toilet block and add a new toilet block to the existing shower block. The proposed Stage 1 works will be undertaken as soon as practical and subject to available funding with the possibility of including Stage 2 works at the same time if costs are within the initial budget allowance and available funding. The installation of a new wastewater system can utilise the natural falls of the site to locate the wastewater system further away from the various amenities buildings, and at the same time further away from potential vehicle damage associated with the main traffic corridors and camping sites. The opportunity also exists in the future stages to attract more of the passing recreational vehicle traffic to stop at the village, many of which are self-contained units that have their own toilet and sink facilities. By installing an approved ‘Dump Station’ for their waste products at the grounds adjacent to the shower block there may be an additional incentive for these travellers to stop and support the local General Store and bolster the income of the ‘Tuena Hall and Recreation Area Committee’. The following sections within this ‘Wastewater Management Report’, the ‘Design and Installation Requirements’ and the ‘Technical Specifications’ provide a detailed summary of the site conditions and wastewater management system recommendations.

View from the western edge of the internal carriageway showing the location of the BBQ area, the new wastewater management area, and the existing upslope stormwater diversion berm. Final locations subject to confirmation on site during set-out of the works.

Stormwater diversion berm

BBQ area

4,500 litre septic tank

Effluent disposal area

Drainage line from toilets & Community Hall Pressure sewer line from

shower block


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Soils Two soil samples were undertaken within the area nominated for the new effluent disposal system, and both samples were able to attain depths of 1000mm with relative ease using a 75Ø hand operated augur. The soil profile is comprised of a sandy loam topsoil to 300m that rapidly transitions into a sandy clay loam to clay loam at the termination depths. The sandy clay soils are derived of a ferrous based parent material that overlay a compact and consolidated clay loam material with noticeable bleaching, and the clay content is approximately 20 to 25% of the sample. As a sandy clay loam texture the soil is consider have an effective absorption capacity of 10mm per day for primary treated effluent.

Site and Design Constraints The Tuena Public Camping Grounds are located adjacent to the Tuena Creek which is named catchment system. NSW Health Department and NSW Local Government guidelines recommend that the minimum separation distance between any named river, creek or drainage system and an effluent disposal area should be 100 metres. The identified location for the effluent disposal area for the upgraded wastewater management system will be a minimum of 120 metres from the margins of the creek which satisfies the separation distance requirements. The location of the wastewater management system is part way down the face of a sloping terrain that has surface water runoff from both the Bathurst Street traffic corridor and runoff generated from within the higher elevations of the grounds directed toward it by swales and mitre drains. A stormwater diversion berm has been constructed on the upslope side of the nominated effluent disposal area, however the eastern end of the berm will need to be slightly realigned and straightened to facilitate the installation of the new wastewater system, and to ensure effective upslope diversions. The mound is already quite high, being approximately 1 metre above the natural ground level, however it will need to be de-silted along the base and reshaped to ensure an effective and consistent grade toward the northwest to allow water to runoff rapidly and not pond or dam up and potentially seep into the effluent disposal beds. To ensure the protection and longevity of the wastewater management system it is recommended that appropriate fencing, barriers and signage be installed around the effluent management area to prevent heavy vehicles including caravans, motor homes and grass cutting equipment along with general passenger vehicles from causing damage to the components and the system.


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Daily Loading and Disposal Area Calculation

The soil is assessed to have a design loading rate (DLR) for absorption purposes of primary treated effluent of 10mm per day, set at a conservative rate for moderately structured sandy clay loams (AS/NZS 1547:2012 On-site Domestic Wastewater Management, (page 145) Table L1 "Recommended Design Loading Rates for Trenches and Beds"). To determine the land area requirement for a soil based disposal system, the formula of L = Q/ (DLR x W) where; L is the length of the absorption system Q is the quantity of inflows per day DLR is the conservative design loading rate (10mm per day as detailed above), and W is the width of the absorption system. The value for ‘Q’ in this equation is the potential daily loading allowance for the entire site which has referenced two different sources to determine the values: the NSW Health Department publication titled “Septic Tank and Collection Well Accreditation Guideline”, December 2001 and AS/NZS 1547:2012 ‘Onsite Domestic Wastewater Management’. The calculations to determine a potential daily loading for the site has combined information provided by the Committee representatives based on previous years and average numbers, a definition of the different user groups, and the various loading values for each category of user group published in the two aforementioned referenced sources. Table 2 provides a summary of the types of facilities, the usage definition, anticipated numbers and daily loading values. Table 2. Summary of the different wastewater generating facilities, loading values and potential daily totals.

Item Description User Definition Facilities Loading values (litres/person/day)

Numbers Potential loading/day

1 Community Hall and kitchen (i)

Community halls - meetings

WC, urinal, basin, kitchen

10 10 100

2 Community halls - banquet

WC, urinal, basin, kitchen

15 100 1500

3 Camping sites (ii)

Recreation grounds (normal periods)

WC, urinal, basin, shower

23 10 230

4 Recreation grounds (busy periods)


23 50 1150

5 Recreation grounds (exceptional periods)


23 80 1840

6 Public toilets (ii)

Recreation grounds (normal periods)

WC, urinal, basin

3 20 60

7 Recreation grounds (busy periods)

WC, urinal, basin

3 50 150

(i) AS/NZS 1547:2012 ‘Onsite Domestic Wastewater Management’ (ii) NSW Health Department publication titled “Septic Tank and Collection Well Accreditation Guideline”, December 2001


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It is emphasised that the numbers and values are derived from best available sources and are estimates only – they are not intended to be exact and Council may determine that alternate values should be used. In the absence of exact data, it is believed that the numbers and values presented in the Table will adequately cover 80% to 90% of all occurrences in which case it is a sound basis for determining a system recommendation and design. With reference to Table 2 the following scenarios can be used to determine the highest potential daily loading for the site:

Table 3. Possible combinations of events and associated daily loading values.

Scenario Frequency of potential loading

‘Items’ from Table 1 Total potential daily loading (litres/day)

A Normal periods 1 + 3 + 6 390 B Busy periods 4 + 7 1300 C Special event 2 + 3 + 6 1790 D Exceptional periods 5 + 7 1990

The value for ‘W’ in the disposal area calculation is determined by a combination of factors but is mostly dependent upon the available land area and the overall layout of the site - therefore being largely a measurement of convenience. By convention the width of the absorption disposal bed should not exceed 4 metres, and land availability within this site is not a constraint therefore it is proposed that the width of the disposal bed for the wastewater treatment system will be 4 metres.


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Progression of Works and Staging The Stage 1 works will be constructed to treat a potential inflow of 1,000 litres per day, therefore using a conservative effluent loading rate for the soils of 10mm per day and a design width for the disposal bed of 4 metres, the length of the absorption disposal bed will be 25 metres. There are several things to be note with regard to the scenarios presented above:

· The likelihood of conducting meetings or gatherings in the Community Hall during a so called ‘Busy ‘, ‘Special’ or ‘Exceptional’ period can be avoided with scheduling and therefore not considered

· ‘Busy’ periods most often occur three or four times per year whilst ‘Exceptional’ periods would occur at most once per year

· The likelihood of having an ‘Exceptional’ period at the same time as a ‘Banquet’ at the Community Hall, the two largest potential generators of effluent is very low and the site may have to be conditioned that if such a combination of events was to arise that additional portable toilets be hired for the anticipated extra loading.

· If a self-contained recreational vehicle stayed at the site and used a ‘dump station’ (if installed in Stage 3) then the numbers and volumes assumed in Table 2 under the category of ‘Camping Sites’ would still be valid as the effluent would still be considered to have been generated and discharged on the site

· It can be reasonably concluded that the largest potential volume of daily effluent generated across the entire site would be 2,000 litres and therefore it would not be unreasonable for design purposes to assume a maximum daily effluent volume of 2,000 litres for the majority of instances.

· It is noted that until Stages 2 and possibly 3 are undertaken that the volume of effluent reaching the new wastewater management system will be limited to the volumes generated in the Community Hall and adjoining toilet block, and therefore the combination of event scenarios defined as ‘Special Events’ – 1,790 litres per day. In these cases where the anticipated daily effluent volume will exceed the capacity of the wastewater treatment system then portable toilets should be supplied in accordance with the guidelines ‘Safe and Healthy Mass Gatherings’ from the Australian Institute for Disaster Resilience (Manual 12 – 1999) in the absence of any other information or requirements, a copy of which is included in the Technical Specifications section of this report.


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Wastewater Management Proposal

With consideration of the site conditions, potential daily loading, and identified constraints it is determined that wastewater management within the Tuena Public Camping Grounds will be upgraded as follows: Stage 1:

· Decommission the two existing wastewater management systems servicing the Community Hall and the public toilets adjacent to the Community Hall in accordance with the guidelines published by the 'NSW Health Department Advisory Note 3 - May 2006', Item 1 (copy included within the Technical Specifications section of this report)

· Install a 4,500-litre concrete septic tank approximately 80 metres downslope and to the northwest of the Community Hall, on the western aspect of the internal carriageway – refer to the accompanying Wastewater Management Systems Upgrade Site Plan; 0031218-01A.

· Install a gravity sewer line (Line 1) commencing from the old septic tank servicing the Community Hall, past and including the new public toilet block adjacent to the Community Hall and down to the location of the new septic tank

· Install a service junction in the gravity sewer line in a suitable location to facilitate the connection of the drainage associated with the ‘Shower Block’ and possible new toilet block in proposed future works.

· Construct an absorption disposal bed that is 25 metres in length and 4 metres wide approximately 6 metres downslope of the septic tank, on the low side of the existing diversion berm, and 12 metres upslope of the BBQ area.

· If the Stage 2 scope of works is to be undertaken separately of Stage 1 then install the necessary drainage pipework and distribution mechanisms downslope of the septic tank and Stage 1 absorption disposal bed for the proposed Stage 2 undertakings to minimise/eliminate disturbance of the Stage 1 installation

· The absorption disposal bed will be constructed such that the base of the bed is a minimum of 600mm below existing ground level. The finished bed design should have a tapered finish aligned with the natural slope of the site to ensure that surface water does not pond or accumulate around the base of the bed

· The distribution of effluent within the bed shall be achieved by installing two parallel rows of preformed arches similar to the 'Everhard 350mm Sullage Trench' with end caps fitted to each end.

· At each end of the absorption disposal bed two 50Ø uPVC inspection/air induction pipes (four in total per bed) shall be installed to finish approximately 200mm above the finished level of the bed. The bottom of the pipes should be drilled or slotted to allow water entry into the pipe which will allow simple monitoring of the standing water level within the bed. The top of each pipe shall be fitted with an insect proof vent cowl that is pushed onto the pipe – not glued on. The vent cowl will permit air entry into the bed to aid with drying and to also enhance evaporative influences that are created by the passing air currents


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· Excess spoil associated with the excavation process shall be used to continue stormwater diversion measures on the upslope side of the effluent disposal bed to divert surface water run-on away from the effluent management system, and on the low side of the absorption disposal bed to divert surface water away from the downslope BBQ area.

Stage 2:

· Install a low-pressure sewer pump station equal to the Aquatec ‘Sewertec 1’ unit (technical data sheets included in the Technical Specifications Section of this report) on the eastern aspect of the existing shower block

· Install approximately 120 metres of 40Ø PN16 PE100 low-pressure sewer rising main with cream coloured striping (Line 2) approximately 600mm below natural surface level between the service junction in Line 1 created during the Stage 1 works and the low-pressure sewer pump station located at the shower block and decommission all non-conforming drainage external of the building

· To facilitate the additional effluent loading install a second absorption disposal bed that is 25 metres in length and 4 metres wide approximately 4 metres to the northwest of the original absorption disposal bed constructed in the Stage 1 works.

· Construct the second absorption disposal bed in the same manner as the original bed system in Stage 1

· Provide a suitable connection point for a ‘Dump Station’ on the western aspect of the shower block during the Stage 2 (or future) works – refer to the discussion below.

Dump Station The installation of a ‘dump station’ for the safe and responsible disposal of human waste for use by caravans, mobile home and other forms of recreational vehicle travellers is an opportunity to attract visitors to the village who in turn may stop and spend some money and thereby support the local store and Camping Grounds. There is an increasing number of mobile homes and other forms of fully contained recreational vehicles travelling through the less published and popularised tourist areas and opting to explore some of the more regional and rural areas of the state. If there is an opportunity at the time of undertaking future upgrades to the wastewater management system at the Grounds to contemplate installing a dump station, then there are several different formats that the dump station could take. The Australian standard for plumbing ‘AS3500:2003 Part 2, Sanitary Plumbing and Drainage’ list a few connection style options, in particular Clause 3.17.3 (pages 29 and 30) shows two different dump point arrangements. Both arrangements involve the use of a hardstand collection point with a water seal trap underneath that in turn drains to the sewer system. Water for flushing and hosing should be made available at the dump point. The ideal location for the dump station would be on the western side of the ‘Showers’ block where there is ample land area available for long vehicles to be able to approach the site from both directions.


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An alternate option would be to install a prefabricated dump station that connects to the sewer system as normal, however the prefabricated system is visually much tidier, more user friendly and hygienic, can facilitate a wider range of vehicles and is less prone to possible damages. The ‘Dump Ezy’ dump station system is produced by Gough Industries (Queensland) and comes as a pre-packaged system simply needing to be installed on site in accordance with the manufacturer’s installation guidelines. To make the consideration of installing one of these prefabricated dump stations more feasible there is a program run by the ‘Campervan & Motorhome Club of Australia’ (CMCA) that will heavily subsidise the normal cost of purchasing one of these units subject to satisfying a few basic criteria. The criteria surrounds maintenance of the unit, ‘free of charge’ access, general hours of access, vehicle accessibility and the placement of a small sign acknowledging the contribution of the CMCA in the supplying the unit. At a cost of approximately $315.00 Council in turn would receive the ‘Dump Ezy’ dump station unit plus three signs to be used on the approach roads to the village and at the site of the dump station to direct travellers to the facility. As a guide and at the time of preparing this report the advertised cost of the dump station unit as a single purchase is approximately $1336.00 excluding GST and freight from Queensland.

The technical specifications for the Gough Plastics ‘Dump Ezy’ dump station plus the details of the ‘Dump Point Subsidy Program offer by CMCA are included at the end of the ‘Technical Specifications’ sections of this report. The standard drawings from ‘AS3500:2003 Part 2, Sanitary Plumbing and Drainage’ Clause 3.17.3 (pages 29 and 30) are also included in the ‘Technical Specifications’ section for visual comparison purposes.


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Construction and Maintenance

The 'bed' design for the individual absorption disposal systems has been adopted because of the compact nature of the configuration as distinct from a convention trench system which, at 600mm wide would require the equivalent of approximately 160 lineal metres to obtain the same base area requirement. The long trenches are generally ineffective due to the problems associated with maintaining an even distribution of effluent over such lengths, and the fact that they occupy such a large land area that invariably the trenches succumb to vehicle traffic and other damages. The construction of an absorption bed minimises the footprint of the effluent disposal area whilst still achieving the desired results, and therefore maintains much of the available land area to practical uses. The additional benefit of the compact absorption bed is that there is greater likelihood of encountering homogenous soil conditions within the smaller area, whereas the longer trenches tend to cross many heterogeneous soil conditions which influence the efficacy of the absorption system. The 4 metre width of each bed is selected as a suitable width for the disposal system assuming that construction and earthworks are undertaken from one side which allows for the reach of the machinery to excavate the bed and spread the filter and backfill material without the need to operate from within the bed space. Each absorption disposal bed will be 25 metres in length and the distribution of effluent within the bed shall be achieved by installing two runs of preformed arches similar to the 'Everhard 350mm Sullage Trench' with end caps fitted to each end. The distribution of the effluent within each bed shall be set-up through a distribution box or similar device to ensure an even application of the effluent between the two runs of sullage trench, and the base area of the bed needs to be installed level in the ground such that the shallowest point of the bed is a minimum of 600mm below finished surface level, in accordance with AS/NZS 1547:2012 'Onsite Domestic Wastewater Management' Figure L5 Conventional Bed (page 153). Refer to the 'Wastewater Management Site Plan' and the drawing titled 'Conventional Absorption Bed' in the "Design and Installation Requirements" section of this report for the proposed layout of the absorption bed and the approximate location of the wastewater management items as discussed. In each corner of the absorption bed (four in total) a 50Ø uPVC inspection/air induction pipes shall be installed to finish approximately 150mm to 200mm above the finished level of the bed and the bottom of the pipes should be drilled or slotted to allow water entry into the pipe which will allow simple monitoring of the standing water level within the bed. The top of each pipe shall be fitted with an insect proof vent cowl that is pushed onto the pipe – not glued on which will permit air entry into the bed to aid with drying and to also enhance evaporative influences that are created by the passing air currents.


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The clay loam soil texture at the base of the effluent disposal beds may tend to be slightly dispersive therefore it is recommended that gypsum be spread over the entire base area at the rate of 1kg/m² to help bind the soil particles and prevent the clays from dispersing. To help prevent the possibility of back-venting through the septic from the venting tubes in the absorption bed it is recommended that a 100Ø disconnector trap with junction and inspection/rodding point finished at ground level be installed between the outlet of the septic tank and the first distribution point to create a water seal. The outlet junction within the septic tank should be fitted with a filter device similar to the Everhard Xtra-treat filter unit to remove the coarser fraction material from the discharging effluent. Filtering of the effluent will help prevent clogging of the pore spaces in the soil profile and the openings between the individual aggregate materials in the absorption bed. This filter will need to be checked periodically and flushed to remove the entrapped material. Flushing of the filter should be undertaken wearing protective hand and eye apparel and performed over the inlet port of the septic tank such that the filtered material is disposed of safely in an appropriate repository and without potential harm to the environment. To maintain the long-term integrity of the absorption beds it will be necessary to divert any surface water away from the bed area by creating diversion contours or earthen mounds around the bed area at the time of construction. As a general comment, the overflow from rainwater tanks or run-off from impervious surfaces such as driveway and paths should also be diverted away from the effluent management areas to ensure that unnecessary hydraulic inundation does not occur. The surface of the beds should be sown with a turf lawn or a blend of grasses and sedges to help transpire water vapour from the void created within the beds and to provide an element of control as to the type of vegetation allowed to grow over the absorption beds - which in turn will help to reduce the need to mow or slash long grasses and thereby mitigate any need for heavy machinery to be on the surface area of the beds. A list of grasses and sedges suitable to the geographical area for this purpose has been included in the ‘Technical Specifications’ section that supports this report however this list is not a comprehensive list and other planting options should be investigated. It is important to maintain a 'good cover' of vegetation over the surface aea to ensure adequate function of the disposal system, and therefore it may be necessary to monitor the survivability of the plantings in the early establishment phase with any dead plants or turf sections removed and replaced immediately. An indicative sowing rate for potted plants is 6 to 8 plants per m². The surface area of the absorption beds should not be sown with any consumable plant species such as fruits or vegetables as the quality of effluent water can alter with time, usage and inputs, and the ability for plants to screen out viruses and harmful pathogens is not a matter of certainty. This practice is also prohibited under NSW State Health Department guidelines.


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As a general comment, all vehicle and large animal traffic should be avoided over the disposal bed area to ensure that the long-term integrity of the system is maintained by mitigating the opportunity of creating depressions within the bed’s surface which eventually become sinks for rainwater. Whilst there is an element of conservatism within the design parameters, the ingress of rainwater into the absorptive voids will be exacerbated if deep trenches and depressions are formed in the surface of the beds. Stagnant bodies of water lying on the surface of the absorption bed will eventually percolate into the void of the bed system which will ultimately contribute to a premature failure of the design as a result of hydraulic saturation - particularly in 'above average' rainfall years. It is therefore recommended that the effluent disposal area be fenced off and protected by a suitable form of barrier or fencing to prevent visitors to the site from driving or walking over the disposal area. The area should also be sign-posted advising visitors not to enter the effluent disposal area.

Summary and Conclusion For the wastewater management system associated with the Stage 1 works to treat and dispose of a potential load of 1,000 litres per day of effluent within a moderately structured sandy clay loam soil environment a 4,500 litre septic tank discharging to a soil based absorption disposal system having a base area configuration of 25 metres long and 4 metres wide will need to be constructed on the western aspect of the Camping Grounds site – no closer than 100 metres to any part of the Tuena Creek. The final location of the septic tank and the disposal bed will need to be confirmed such that it is protected from possible damaged caused by vehicles, people and possible animal traffic whilst also being protected from surface water run-on. Progression of the Stage 2 scope of works will be determined prior to commencement of the Stage 1 works, and if it is deemed necessary to perform the Stage 2 works separately then sufficient works will still need to be undertaken in Stage 1 to ensure that any future works do not adversely impact on the already Stage 1 completed works. The Stage 2 works will include a duplication of the absorption disposal bed approximately 4 metres downslope of the Stage 1 absorption disposal bed and will therefore care will need to be exercised when working around existing infrastructure. Completion of Stage 2 works will need to ensure that all upslope and downslope stormwater diversion measures are not compromised or damaged. All drainage pipework associated with the wastewater management system and disposal area will need to be installed deep enough below finished surface level and any internal carriageways to protect them from mechanical and/or compaction damage. The absorption beds shall be constructed such that they are level in the ground, no less than 600mm below surface level and the surface area of the absorption beds should be planted with a blend of plants or turf grass to help utilise the water within the bed voids.


17

All plumbing and drainage works will need to be undertaken in accordance with the relevant industry standards (AS/NZS 3500.2:2015 “Plumbing and Drainage – Sanitary Plumbing and Drainage”) and Council’s engineering standards and guidelines. In particular; all traps, inspection openings, junctions and risers will need to be installed in accordance with the relevant guidelines and practices, and where the grade of the sewer pipe exceeds 3% consideration should be given to installing trench stop and/or thrust blocks. If trench stops are installed the calculation D=30/G should be used where D is the distance space between trench stops, and G is the grade of the pipe as a percentage. In possible instances where the anticipated daily effluent volume will or is likely to exceed the design capacity of the wastewater treatment system then portable toilets should be supplied in accordance with the guidelines ‘Safe and Healthy Mass Gatherings’ from the Australian Institute for Disaster Resilience (Manual 12 – 1999), a copy of which is included in the Technical Specifications section of this report. Within the next section titled "Design and Installation Requirements" is a list of the main components and materials required to undertake the installation of the proposed wastewater management system, along with a simple construction / installation procedure that is specific to the development site. These lists are designed to assist the installer understand the design concept and refine the location of the various components. At the conclusion of that section are two separate checklists and an installation declaration to be completed by the installers of the wastewater management system which are to be presented to the Council and the Tuena Hall and Recreation Area Committee after practical completion of the installation. One checklist covers the installation of the septic tank whilst the second checklist covers the installation of the absorption bed system. Both checklist plus the Installer's Declaration are to be completed with as much detail as applicable to the particular development and then submitted as part of the overall certification process to ensure compliance with the recommendations of this report.


18

ON-SITE SEWAGE (WASTEWATER) MANAGEMENT

GENERAL NOTES TO BE APPLIED AS APPROPRIATE FOR THE DEVELOPMENT

1. All proposed wastewater management collection, treatment and discharge measures are to

be installed and commissioned in accordance with the recommendations of the Wastewater Management Assessment that accompanies this development, all relevant NSW Health Department guidelines, Council’s engineering standards, and any conditions of development consent.

2. If the site soil conditions encountered within the area nominated for effluent disposal during the construction process vary from those described in the Wastewater Management Assessment seek additional information and design options from the designer of the system before progressing to completion.

3. All wastewater management collection, treatment and discharge components such as tanks, transfer pipework, disposal areas, and any associated infrastructure used in the construction of the wastewater management system are to be protected from potential physical damage by the installation of appropriate mechanisms such as bollards, fencing or barricades to the satisfaction of the consent authority and/or certifying engineer.

4. All plants, grasses and ground covers sown as part of wastewater treatment measures are to be maintained and/or replaced until a satisfactory strike rate of at least 90%, or until such time as plants have established rigour and survivability. Particular attention is required for sowing plants during the hotter summer months, and when there will be no monitoring of the survivability of the plant material for extended periods of time due to the likes of holidays or contractors moving on due to project completion.

5. Ensure that all civil works such as stormwater diversion berms, mounds and/or trenches are installed prior to completion of the job, and that all excess spoil is removed from around the effluent management area

6. All construction checklists are to be completed with as much detail as appropriate for the development with a copy of the checklist to be presented to the property owner, Council (certifier), and a copy retained by the installer.

7. At the completion of the project complete the ‘Certification Statement’, add additional information to the statement as necessary, and then present a copy of the Certification Statement to the property owner, Council (certifier), and retain a copy for future reference

8. Where possible and appropriate, take photos of the earthworks and installation process at various milestone points and present a copy of the images to the property owner and Council (certifier) to help with identification of the installed products and materials, and for future reference as to the location and physical characteristics of the system.


19

DESIGN PRODUCER STATEMENT

On-site Wastewater Management and/or Effluent Disposal System Design

Issued By:

SOWDES

To:

Upper Lachlan Shire Council

SOWDES Reference No:

0031218

Issued To:

Tuena Hall & Recreation Area Committee

In Respect Of:

On-site wastewater management system upgrades

For Development At:

Bathurst Street Tuena. NSW. 2583

SOWDES has been engaged by Tuena Hall & Recreation Area Committee (the proponents) to provide the technical design details for an onsite wastewater management system. The design has been carried out in accordance with the following Standards and Best Practice Guidelines: · 'Developments in Sydney’s Drinking Water Catchments – Water Quality Information

Requirements'. Sydney Catchment Authority (2010) · 'Environment and Health Protection Guidelines On-site Sewage Management for Single

Households'. Department of Local Government. (1998) · AS/NZS 1547:2012 'On-site domestic wastewater management' · 'Designing and Installing On-site Wastewater Systems'. Sydney Catchment Authority (2012) For details of the site assessment and design particulars, refer to the Wastewater Management Report prepared by SOWDES dated 30 June 2018. DECLARATION: I believe on reasonable grounds that this design has been carried out in accordance with agency and council requirements, and best practice in on-site wastewater design principles and procedures. NOTE: This statement does not approve the installed system.

M: 0428 863 401

E: [email protected]

A: P.O Box 619

Goulburn. NSW. 2580

ABN: 63 326 094 249


20

This is an independent design, covered by a current policy of Professional Indemnity Insurance. Under certain conditions, SOWDES is available to certify the installed system. These conditions include: · the technology supplier(s) take(s) full responsibility for the stated quality and performance of

technologies and other equipment supplied · the installer(s) take full responsibility for installing the system as specified by SOWDES design

reports and the appropriate Conditions of Consent unless departure from the stated specification(s) is subsequently agreed between the installer, SOWDES and the relevant consent authority

· prior to the installation of the wastewater management system as specified in the wastewater management report dated 30 June 2018 SOWDES is to be engaged under separate contract to supervise the installation of all the specified system components.

DISCLAIMER: The Client is to make full disclosure of relevant information on existing and/or proposed activities on the site that will influence the estimation of the likely daily wastewater quantity (potential number of bedrooms and other wastewater producing activities) and quality (in particular any chemicals in the water supply and/or wastewater stream potentially toxic to biological wastewater processes). This design is based on the site assessment carried out by SOWDES and the conditions applicable at the time of the site assessment. Subsequent changes to the site that might affect the topography and soil profiles are to be notified by the client. Failure, by the Client, to provide this information will invalidate this 'Design Producer Statement'. Approval is to be sought from SOWDES should variations to the specification and layout in this report/drawing be considered necessary by the installer prior to or at the time of installation. Failure to do so will invalidate the 'Design Producer Statement' and SOWDES will no longer take responsibility for the design. For and on behalf of SOWDES

Paul Johnson Paul Johnson (JP) Bachelor Science Agriculture/Irrigation (CSU) Graduate Diploma Bushfire Protection (UWS) Graduate Certificate Engineering – Water (UTS) 30 June 2018


21

SITE INFORMATION SHEET Applicant & Location Details:

Reference No:

0031218

Owner:

Tuena Hall & Recreation Area Committee

Mailing Address:

The Secretary, Tuena Hall & Recreation Area Committee

Site Address:

Bathurst Street, Tuena. NSW. 2583

Property Details:

[Category]

Phone:

4835 3020

Latitude S:

-34.01577 Longitude E:

149.32807 Elevation:

490 metres (± 5m) Council & Catchment Details:

Local Government Area: Upper Lachlan Shire Council Date of Inspection: 15 July 2015

Development site


22

SITE INFORMATION SHEET

Topography from the Effluent Disposal Area (dominant features):

Grade Direction Upslope 5° to 15° West Upslope 5° to 15° South Downslope <2° North Downslope <2° East

General Drainage Pattern from the Effluent Disposal Area: Proximity from the Effluent Management Area to Property or Paddock Boundaries (metres):

Distance from the Proposed Effluent Management / Disposal Area to (metres):

North: 100+ South: 100+ East: 100+ West: 25

River, creek, stream, major waterway or storage: 100+ Watercourse (permanent or intermittent): n/a Well / Bore: n/a Dam: n/a

The entire site has a fall toward the north-northeast and to the Tuena Creek catchment area. There are several drainage depressions throughout the site that direct surface water runoff to the creek area


23

SITE INFORMATION SHEET Type of Proposed Development:

Rural Subdivision Number of Lots New Dwelling (unsewered) Number of Bedrooms (including Study) Extension / Renovation Number of Bedrooms (including Study) Rural Structure / Provision Upgrade Existing Wastewater Management System

Water supply:

Rainwater Harvesting (tanks) Dam Bore/Well Reticulated/metered town water supply River

Land area:

Approximate Development Area: 6.2 hectares

Is the Proposed Development Area a Portion of a Larger Lot: Yes No Aspect:

From the proposed development area: Northerly From the wastewater disposal area: Northerly

Land Usage:

Grazing Cropping Rural Residential Recreational Commercial Urban Residential Undisturbed Fields Undisturbed Forest Other


24

SOIL SAMPLE 1

Site Details: Tuena Hall & Recreation Area Bathurst Street, Tuena. NSW. 2583

Date of Inspection: 20th June 2018

Landform: Simple slope

Topography: Slopes south → north

Sample 1 EMA Area

Vegetation: Managed lands

Land Use: Recreational

GPS Coordinates Latitude: -34.01549 Longitude: 149.32735

Elevation: 485m

Aspect: Northerly

Slope: 5° - 10°

Microrelief: Elongated depression

The soil is assessed to have a design loading rate (DLR) for absorption purposes of 10mm per day, set at a conservative rate for primary treated effluent discharging within a moderately structured sandy loam soil environment (AS/NZS 1547:2012 On-site Domestic Wastewater Management, (page 145) Table L1 "Recommended Design Loading Rates for Trenches and Beds").

Dep

th m

m

Text

ure

Coar

se F

ract

ion

Cond

ition

of

Surf

ace

Soil

Peda

lity

/ St

ruct

ure

Fabr

ic

Cons

iste

nce EC

pH

Wat

er R

egim

e

Boun

darie

s

Hor

izon

s

0-100

sandy loam

<40mm firm polyhedral, weak

earthy dry weak

mod

erat

ely

perm

eabl

e, w

ell d

rain

ed

A1

100-200

sandy loam

<40mm polyhedral, weak

earthy dry weak

200-300

sandy loam


earthy dry weak

0.00

5.0

gradual A2

300-400

sandy clay

loam

<20mm

polyhedral, moderate

rough ped

dry, firm gradual B1

400-500

sandy clay

loam

<20mm polyhedral, moderate

rough ped

dry, firm

500-600

sandy clay

loam


rough ped

dry, firm 0.03

4.9

gradual B2

600-700

sandy clay

loam


rough ped

dry, firm

700-800

sandy clay

loam


rough ped

dry, firm

800-900

sandy clay

loam


rough ped

dry, firm 0.03

4.8

gradual B2a

900-1000 sandy clay

loam


rough ped

dry, firm


25

SOIL SAMPLE 2

Site Details: Tuena Hall & Recreation Area Bathurst Street, Tuena. NSW. 2583

Date of Inspection: 20th June 2018

Landform: Simple slope

Topography: Slopes south → north

Sample 2 EMA Area

Vegetation: Managed lands

Land Use: Recreational

GPS Coordinates Latitude: -34.01533 Longitude: 149.32700

Elevation: 485m

Aspect: Northerly

Slope: 5° - 10°

Microrelief: Elongated depression

The soil is assessed to have a design loading rate (DLR) for absorption purposes of 10mm per day, set at a conservative rate for primary treated effluent discharging within a moderately structured sandy loam soil environment (AS/NZS 1547:2012 On-site Domestic Wastewater Management, (page 145) Table L1 "Recommended Design Loading Rates for Trenches and Beds").

Dep

th m

m

Text

ure

Coar

se F

ract

ion

Cond

ition

of

Surf

ace

Soil

Peda

lity

/ St

ruct

ure

Fabr

ic

Cons

iste

nce EC

pH

Wat

er R

egim

e

Boun

darie

s

Hor

izon

s

0-100

sandy loam

<40mm firm polyhedral, weak

earthy dry weak

mod

erat

ely

perm

eabl

e, w

ell d

rain

ed

A1

100-200

sandy loam


earthy dry weak

200-300

sandy loam


earthy dry weak

0.01

5.2

gradual A2

300-400

sandy clay

loam

<20mm

polyhedral, moderate

rough ped

dry, firm gradual B1

400-500

sandy clay

loam


rough ped

dry, firm

500-600

sandy clay

loam


rough ped

dry, firm 0.02

5.2

gradual B2

600-700

sandy clay

loam


rough ped

dry, firm

700-800

sandy clay

loam


rough ped

dry, firm

800-900

sandy clay

loam


rough ped

dry, firm 0.02

4.8

gradual B2a

900-1000 sandy clay

loam


rough ped

dry, firm


26

SELECTED SITE IMAGES

View of the septic tank servicing the public toilets adjacent to the Community

Hall to be decommissioned

Partial view downslope and toward the northwest of the alignment of the new gravity sewer pipeline taken from the location of the septic tank servicing

the public toilet block to be decommissioned


27

WASTEWATER MANAGEMENT SYSTEM RECOMMENDATION Collection and Treatment:

System Type Septic tank Treatment Level Primary Brand Equal to Highland Concrete Tanks Model Tank Capacity Nominally 4,500 litres – Treatment of 2,000 litres per

day Location (approximate)

Approximately 80 metres downslope and to the northwest of the Community Hall (refer to the Wastewater Management System Upgrades Site Plan)

Disposal Method:

Method Absorption Bed with two parallel rows of 350mm sullage trench arches

Dimensions / Area Stage 1 - Single bed 25 x 4 metres – 100m² Stage 2 - Single bed 25 x 4 metres – 100m²

Description / Location (approximate)

The first absorption bed will be located approximately 6 metres to the northwest of the septic tank, the second bed will be no closer than 4 metres to the first bed (refer to the Wastewater Management System Upgrades Site Plan)

Proprietary Products Highland Concrete Tanks 4,500 litre septic tank, 350mm sullage trench, end caps, distribution box, blue metal aggregate or crushed and cycled concrete / brick, geotextile, turf grass or selected plants from list of proprietary species

Site Specific Requirements:

Treatment and Disposal Area to Have Protective Fencing Around Stormwater Diversion Mounds on High Side and/or Around Disposal Area Specific Species of Plants to be Included in Design (refer to covering report)


28

Disposal Land Area Calculations for an Absorption Disposal System

Design Area Sizing for Trenches and Beds - Recommended Design Load Ratings Soil Category Soil Texture Structure Primary Treated

(conservative rate mm/day)

1 Gravels & sands a Structureless 20

2 Sandy loams a Weakly structured 20 b Massive 15

3 Loams a High/moderate structure 15 b Weakly structured or

massive 10

4 Clay loams a High/moderate structure 10 b Weakly structured 6 c Massive 4

5 Light Clays a Strongly structured 8 b Moderately structured 5 c Weakly structured or

massive Site specific

6 Medium to

heavy clays a Strongly structured

Site specific b Moderately structured c Weakly structured or

massive

Sizing of Trenches or Beds The trench or bed length is determined using the formula: L = Q/(DLR x W)

Where: L = Length of trench or bed in metres Q1 = Stage 1 upgrade works design capacity 1,000

Q2 = Stage 2 upgrade works design capacity 1,000

Total Q = Potential daily loading volume - litres/day 2,000 DLR = Design Load Rating (in mm - from above) 10 W = Width of each trench or bed in metres 4 Therefore: L = Length per bed per Stage 25 metres

= The soil type and 'Design Loading Rate' identified for this Development Proposal


29

Recommended Buffer Distance for On-site Wastewater Management Systems.

System Recommended Buffer Distance

All land

application

systems

o 100 metres to permanent surface waters (e.g. rivers, streams, lakes,

etc)

o 250 metres to domestic groundwater well

o 40 metres to other waters (e.g. farm dams, intermittent waterways

and drainage channels, etc)

Surface spray

irrigation

o 6 metres if area up-gradient and 3 metres if area down-gradient of

driveways and property boundaries

o 15 metres to dwellings

o 3 metres to paths and walkways

o 6 metres to swimming pools

Surface drip and

trickle irrigation


swimming pools, property boundaries, driveways and buildings

Subsurface

irrigation


swimming pools, property boundaries, driveways and buildings

Absorption

system


property boundary


swimming pools, driveways and buildings ‘On-site Sewage Management for Single Households’, Table 5 (page 66)


30

Design and Installation Requirements

Table of Contents


· Materials and Installation Requirements Summary

· Site Plan

· Conventional Absorption Bed Design

· Installation Checklist for Septic Tanks

· Installation Checklist for Absorption Beds

· Installer's Declaration


31

WASTEWATER MANAGEMENT SYSTEM RECOMMENDATION Collection and Treatment:

System Type Septic tank Treatment Level Primary Brand Equal to Highland Concrete Tanks Model Tank Capacity Nominally 4,500 litres – Treatment of 2,000 litres per

day Location (approximate)

Approximately 80 metres downslope and to the northwest of the Community Hall (refer to the Wastewater Management System Upgrades Site Plan)

Disposal Method:

Method Absorption Bed with two parallel rows of 350mm sullage trench arches

Dimensions / Area Stage 1 - Single bed 25 x 4 metres – 100m² Stage 2 - Single bed 25 x 4 metres – 100m²

Description / Location (approximate)

The first absorption bed will be located approximately 6 metres to the northwest of the septic tank, the second bed will be no closer than 4 metres to the first bed (refer to the Wastewater Management System Upgrades Site Plan)

Proprietary Products Highland Concrete Tanks 4,500 litre septic tank, 350mm sullage trench, end caps, distribution box, blue metal aggregate or crushed and cycled concrete / brick, geotextile, turf grass or selected plants from list of proprietary species

Site Specific Requirements:

Treatment and Disposal Area to Have Protective Fencing Around Stormwater Diversion Mounds on High Side and/or Around Disposal Area Specific Species of Plants to be Included in Design (refer to covering report)


32

Materials and Installation Requirement Summary

The following Tables represent the primary material, location, construction, installation, commissioning and operational components of the wastewater management system and are to be undertaken to ensure compliance with the design concepts. The respective lists may not be in any particular order of undertaking, and some of the lesser requirements may be omitted or not specifically mentioned, however this does not preclude the need to undertake or supply such items. Construction Materials / Proprietary Products

Component Product Description Septic tank Equal to Highland Concrete Tanks 4,500 litre tank. Sullage trench Equal to Everhard 350mm 'Evertrench' sullage trench Distribution box Equal to Everhard 300mm box Product #: 84910 Sullage trench end cap Equal to Everhard 'Evertrench' end caps Blue metal aggregate or crushed and recycled concrete / brick

Nominally 20 to 40mm

Geotextile material Similar to Geofabric A14 Plants Selected plants from the list provided (refer to the attached

plant species list), or other similar plant species – or turf Outlet filter Equal to Everhard Xtra-treat filter

Location: (refer to the site plan for the proposed locations of main items)

Description Completed Install the 4,500 litre septic tank approximately 80 metres downslope and to the northwest of the Community Hall building Yes No

Install a single absorption bed that is 25 metres long and 4 metres approximately 6 metres downslope and northwest of the septic tank Yes No

Create/modify the stormwater diversion mounds on the upslope aspect of the wastewater management system formed from the excess spoil associate with the installation process

Yes No

Construction / Installation: Septic Tank

Description Completed Install the 4,500 litre septic tank unit as per the manufacturer's specifications Yes No

Connect the drainage pipes from the Community Hall and Public Toilet Block to the inlet side of the septic tank, with the outlet pipe of the septic tank connected to the inlet side of a distribution box at the head of the absorption disposal bed.

Yes No

Install a 100Ø disconnector trap and junction with inspection – rodding point finished at ground level between the outlet of the septic tank and the inlet to the first distribution box at the head of the absorption disposal bed to help prevent possible beck-venting through the septic tank from the absorption bed. Install all necessary pipework and measures for the Stage 2 works

Yes No

Install an outlet filter to the outlet junction within the septic tank Yes No


33

Construction / Installation: Absorption bed (Complete One Checklist for Each Stage of Works)

Description Completed Peg out the perimeter of the absorption bed (25 x 4 metres) and excavate down such that the minimum depth below existing ground level is 600mm - or deeper if necessary to achieve an overall pipe grade of at least 1% between the septic tank and the absorption bed

Yes No

Ensure that the base of the absorption bed is level in the ground and spread gypsum over the entire base area at the rate of 1kg/m² to help prevent the clay soils from dispersing

Yes No

Lay a small bed of 20 to 40mm aggregate material at the inlet end of each row of sullage trench as an anti-scouring pad for the incoming flows

Yes No

Lay two parallel rows of 350mm sullage trench, each spaced 1 metre off the side walls and 2 metres centre to centre and fit end caps at each end (4 in total)

Yes No

Install the distribution box or similar device between the outlet of the septic tank and the inlet side of the absorption bed and ensure that each outlet going to each row of sullage trench is at the same invert level

Yes No

Cut an appropriate sized hole into the sullage trench end caps nearest to the distribution box to fit the 100mm uPVC drainage pipe approximately 300mm above finished bed level

Yes No

Lay 100mm uPVC pipe between the outlet of the distribution box and the two rows of sullage trench with a 45° bend fitted to the end of each outlet of the pipe immediately over the bed of aggregate material laid as an anti-scour pad referenced in Item 2

Yes No

Install a 50mm uPVC pipe inspection / vent tube in each corner of the absorption disposal bed (four in total per bed) to allow monitoring of the standing water level within the bed and to permit the entry of air to aid drying and promote evaporative influences. Each pipe shall be drilled or slotted at the bottom end to allow water entry into the pipe. The top of the pipe should be finished approximately 200mm above the finished level of the bed and fitted with a push-on insect proof vent cowl to allow easy removal for inspection but prohibit the entry of vermin.

Yes No

Install a layer of geotextile fabric over the top and sides of each run of sullage trench Yes No

Install 20 to 40mm aggregate material evenly around the runs of sullage trench and fill to approximately 150mm below finished surface level

Yes No

Install a layer of geotextile fabric across the entire absorption bed area to stop fine particulate matter from the topsoil migrating down into the blue metal layers

Yes No

Backfill the absorption bed area with clean loamy topsoil material from the excavated material, or if the excavated material is of insufficient grade and quality, backfill with imported material. Lightly compact the topsoil material to form a 'mound' with the high point along the centreline of the bed shedding surface water run-off to the sides

Yes No


34

Plant the surface area of the absorption bed with a turf grass or selected plant species. If using selected grasses and/or sedges, sow at a rate of 6 to 8 plants per m².

Yes No

Irrigate the surface area of the absorption bed to promote plant establishment. Implement an irrigation/watering program for the owners to maintain until the planting has successfully established.

Yes No

Create stormwater diversion mounds on any upslope aspect of the wastewater management system formed from the excess spoil associate with the installation process

Yes No

Commission / Operation:

Description Completed Organise appropriate 'hold' and 'witness' inspections as required in the Council's conditions of consent. Yes No

Commission the septic tank unit as per the manufacturer's specifications and requirements Yes No

Complete certification and installation declaration requirements and submit a copy to both the Council and the client. Provide the client with all necessary operating instructions, warranty information and emergency contact information, and site photos that clearly identify the locations of pipes and any other new or identified infrastructure

Yes No

As necessary install bollards or exclusionary fencing around the wastewater management system to prevent the intrusion of vehicles or large animals over the septic tank and the absorption disposal area

Yes No

Decommission the existing septic tank and absorption disposal system in accordance with the guidelines from the 'NSW Health Department Advisory Note 3 - May 2006'

Yes No


35

FOR ELECTRONIC VERSIONS OF THE

REPORT PLEASE REFER TO A1

WASTEWATER MANAGEMENT SYSTEM

UPGRADES SITE PLAN DRAWINGs

REF: 0031218-01B & 0031218-01C


36

FOR ELECTRONIC VERSIONS OF THE

REPORT PLEASE REFER TO A3

CONVENTIONAL ABSORPTION BED DESIGN

DRAWING

REF: 0031218DISP-01


37

Checklist. Septic Tank Installation Inspection for Plumbers / Installers

and Council Inspectors

Owners name:

Address:

Installation date:

Type of tank (tick all applicable e.g. Septic tank plus Pumpwell. NB: where the system involves a septic tank AND a pumpwell, the minimum NSW Health requirement is for the pumpwell to have a capacity of 2000 litres. Dimensions requested in the checklist are for the Septic tank or Collection/holding wells.)

Septic tank Pumpwell Collection / Other holding well Manufacturer: Model #:

Material

Plastic/poly Concrete Fibreglass Other

Comment:

Multiple tanks Yes No

Specified or calculated tank capacity of each tank

(1) L (2) L

Tank dimensions (as provided on manufacturer’s design specification sheet) Tank (1) Tank (2)

Exterior dimensions (diameter & height) mm mm

Interior dimensions mm mm

Exterior height of inlet invert mm mm

Exterior height of outlet invert mm mm

Effective depth mm mm

Tank seam Location

N/A Mid Top Sections joined

Pre-delivery by supplier On-site by supplier On-site by installer

Has the tank been appropriately sealed? Butylmastic Butyl tape Two-part Two-part epoxy Other wrap epoxy and stainless fasteners

Tank structural integrity verified prior to setting: Yes No N/A


38



Excavation / setting tank

Location of tanks:

Verify required inlet / outlet elevations Yes No N/A Groundwater present in excavation Yes No N/A Dewatering performed Yes No N/A Bottom of excavation

Level Yes No N/A Free of rock and debris Yes No N/A Bedding material

Description:

Depth cm Free of large rocks, debris Yes No N/A Compacted Yes No N/A Structural integrity of tank verified

Tank installed level Yes No N/A Tank oriented correctly Yes No N/A Free standing above ground

Flatbed Yes No N/A Compacted Yes No N/A Verify required inlet and outlet elevations Yes No N/A Flotation prevention

Buoyancy calculation provided on design Yes No N/A Anti-flotation implemented

Tank collar Yes No N/A Anchor weight Yes No N/A

Other

Backfill

Backfill material: Compacted Yes No N/A

Free of debris and large rocks Yes

No

N/A


39



Piping

Piping in appropriate sequence (inlet/outlet) Yes No N/A

Inlet mm Outlet / supply line mm

Pipe specifications (material and nominal diameter)

Return line mm Electrical conduit mm Joints in excavated area Yes No N/A Pipe sealing

Pipes appropriately sealed (including electrical conduit) Yes No N/A

Type of sealant Inlet

Outlet / supply line

Return line

Electrical conduit Recirculation device Yes No N/A

Type of device

Baffles / compartments

Inlet baffle type

Outlet baffle type

Effluent screen model and manufacturer

Types of baffles: Poly Plastic Concrete Fibreglass Installation by: Manufacturer Contractor Verify air passage Yes No N/A

Tank access & venting Access location and size Inlet mm

Outlet mm

Centre mm Access risers required Yes No N/A

Sealant used in tank / riser connections Yes No N/A Type of sealant (pipes)

Venting Yes No N/A Through plumbing stack Yes No N/A

Tank vent (describe):


40



Proprietary filter Yes No N/A

Filter manufacturer:

Model #:

Tank water tightness testing Yes No N/A

Manufacturer testing Yes No N/A

Comments, actions or repairs required: (Where a response has been selected in the above Checklist requiring additional information please specify the action plan and corrective process undertaken or proposed to be undertaken to remediate the problem, or the alternative that is being offered).

Service provider: Contact number:

Date:

Signature:


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Checklist. Installation for Trenches and Beds for Plumbers / Installers

and Council Inspectors (Complete One Checklist for Each Stage of Works)

Type of system:

Method of application Gravity Pump Siphon Configuration Trench Absorption bed

Pre-construction considerations

Is the soil moisture too wet for construction? Yes No

Site preparation

Trench / bed area marked out according to site plan /

conditions of consent including buffer distances? Yes No

Is the trench positioned in accordance with design

requirements for contours? Yes No N/A

Trench or bed dimensions

Width: mm Length: mm Depth: mm

Trench / bed dimensions consistent with council’s consent Yes No N/A

Confirm all setbacks Yes No Confirm all system elevations Yes No Stake trench / bed boundaries with elevations Yes No

Method of excavation:

Trench / bed bottom graded to specifications Yes No

Inspection ports

Specification: Type: Diameter: mm

Perforations Slots Holes

Grade from tank to trench/bed Above grade (pump required?) Below grade Secured: Yes No

Media type: Gravel Sand Other (specify)

Media size: Media source:

Total media depth: Total amount of media used: m³

Grade: Cleaned: Yes No

Distribution system

Gravity distribution device: Yes No

Type: Splitter box Sequencing valve Drop box Other (specify)

Distribution device description:


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and Council Inspectors (Complete One Checklist for Each Stage of Works) Distribution system access None Riser Other (give details):

Valve type (where applicable):

Alternating / sequencing valve, type: Field sequencing Globe Gate ball Other

Installation access In valve box in the field In bedding material In dosing tank

Pressure manifold Specification:

Manifold/laterals feed configuration

End Top Centre Bottom Other (give details):

Type

Diameter: mm Length: mm

Access / protection Yes No Describe:

Laterals

Specification: Type:

Diameter: mm Spacing: mm Length: mm

Installation

Geotextile/fabric cover placed over media Yes No

Final topsoil cover

Depth of cover: mm

Imported material required Yes No

Description of texture of imported material:

Stormwater diversion berm / drain where required Yes No Vegetation cover established over disposal area: Yes No

Description of final landscaping:


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and Council Inspectors (Complete One Checklist for Each Stage of Works)

Comments, actions or repairs required: (Where a response has been selected in the above Checklist requiring additional information please specify the action plan and corrective process undertaken or proposed to be undertaken to remediate the problem, or the alternative that is being offered).

Service provider:

Contact number:

Date:

Signature:


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COMPLETION OF WORKS INSTALLATION CERTIFICATE – STAGE 1 On-site Wastewater Management and/or Effluent Disposal System

Issued By (Installer's Details):

To: Upper Lachlan Shire Council

Development Application No:

Property Owners:

Tuena Hall & Recreation Area Committee For Development Located at:


Description of the Project:

1/. Install a 4,500-litre septic tank with outlet filter approximately 80 metres downslope and to the northwest of the Community Hall 2/. Install an absorption disposal bed 25 x 4 metres in dimension approximately 6 metres downslope and to the northwest of the septic tank. 3/. Install a grey water distribution box or similar device between the septic tank and the two rows of sullage trench within the absorption bed 4/. Create stormwater diversion mounds on the upslope and downslope aspect of the effluent management system

INSTALLED IN ACCORDANCE WITH: · SOWDES Wastewater Management Report dated 30 June 2018,

Reference No: 0031218

DATE OF SITE INSTALLATION INSPECTION: _______________________

INSTALLATION REPORT SUMMARY (includes any variations to the original design, etc): · Variations: · Report:

DECLARATION: I believe on reasonable grounds that all of the wastewater works have been completed in accordance with SOWDES Wastewater Management Report dated 30 June 2018, Reference No. 0031218 and Council Consent Number ___________________

For and on behalf of (Installer's Details):

Name:

Signature:

Title:

Date: cc: Tuena Hall & Recreation Area Committee


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COMPLETION OF WORKS INSTALLATION CERTIFICATE – STAGE 2 On-site Wastewater Management and/or Effluent Disposal System

Issued By (Installer's Details):

To: Upper Lachlan Shire Council

Development Application No:

Property Owners:

Tuena Hall & Recreation Area Committee For Development Located at:


Description of the Project:

1/. Install a low-pressure sewer line from the shower block to the inlet junction provided at the septic tank in Stage 1 2/. Install an absorption disposal bed 25 x 4 metres in dimension approximately 4 metres downslope and to the northwest of the absorption disposal bed created in the Stage 1 works. 3/. Install a grey water distribution box or similar device between the inlet line from the septic tank and the two rows of sullage trench within the absorption bed 4/. Create / modify / repair stormwater diversion mounds on the upslope and downslope aspect of the effluent management system

INSTALLED IN ACCORDANCE WITH: · SOWDES Wastewater Management Report dated 30 June 2018,

Reference No: 0031218

DATE OF SITE INSTALLATION INSPECTION: _______________________

INSTALLATION REPORT SUMMARY (includes any variations to the original design, etc): · Variations: · Report:

DECLARATION: I believe on reasonable grounds that all of the wastewater works have been completed in accordance with SOWDES Wastewater Management Report dated 30 June 2018, Reference No. 0031218 and Council Consent Number ___________________

For and on behalf of (Installer's Details):

Name:

Signature:

Title:

Date: cc: Tuena Hall & Recreation Area Committee


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Technical Specifications

Table of Contents

· 'NSW Health Department Advisory Note 3 - May 2006'

· Highland Concrete Tanks – 4.500 Litre Concrete Septic Tank

· Everhard Sullage Trench

· Everhard Distribution Box

· Everhard Xtra-treat Grey Water Filter

· Plant Species Suitable for Use in Evapotranspiration & Absorption Beds and Irrigation Disposal Systems

· Aquatec ‘Sewertec 1’ Low Pressure Sewer Pump Station

· ‘Dump Ezy’ Information and Installation Information

· Campervan & Mobile Home Club of Australia ‘Dump Station Subsidy Program’ Information

· Standard Drawings from Clause 3.17.3 (pages 29 and 30) of AS3500:2003, Part 2 Sanitary Plumbing and Drainage – ‘Sullage Dump Points for Caravans’

· Indicative Rates of Toilet Facilities for Large Events


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Plant Species Suitable for Use in Evapotranspiration & Absorption Beds and Irrigation Disposal Systems

Botanical name Common name

Form Height (m) Description Planting density (plants /

m²) Carex appressa Tall sedge M 0.5 - 1.2 Dense, robust and tough,

hairy and sticky 4 - 8

Carex fasicularis Tassel sedge M 0.5 - 1.0 Coarse, tufted plant 6 - 8 Carex inversa Knob sedge M 0.5 - 1.0 Small tufted or spreading

clump 10

Ficinia nodosa Knobby club-rush

M 0.6 - 1.5 Tall, coarse, wiry and densely tufted perennial rush with creeping rhizomes

6 - 8

Juncus amabilis - M 0.2 - 1.2 Rhizomatous tufted perennial rush

8 - 10

Juncus flavidus Yellow rush M 0.4 - 1.2 Rhizomatous tufted perennial rush, yellow-green

8 - 10

Juncus gregiflorus - M 0.5 - 1.4 Rhizomatous tufted perennial rush

8 - 10

Juncus procerus - M 1.0 - 2.0 Rhizomatous tufted perennial rush

8 - 10

Lepidosperma gladiatum

Coastal sword sedge

M 1.0 - 1.5 Leaves wide and flat with dark green blades

6

Lepidosperma laterale

Variable sword sedge

M 0.5 - 1.0 Leaves wide and flat with dark green blades

6

Lepidosperma longitudinale

Common sword sedge

M 0.6 - 1.7 Sedge with long, flat dark green blades

6

Lomandra filiformis ssp. filiformis

Wattle mat rush

M 0.15 - 0.5 Small tussock with fine blades

6 - 8

Lomandra longifolia var. exilis

- M 0.5 - 1.0 Large tussock with broad flat leaves

4 - 6

Lomandra longifolia var. longifolia

Spiny-headed mat rush

M 0.5 - 1.0 Large tussock 4 - 6

Patersonia occidentalis

Long purple flag

M 0.2 - 0.5 Compact clumping perennial herb

6 - 8

Poa labillardieri Common tussock grass

M 0.3 - 0.8, stems 1.2

Large, coarse densely tufted tussock

6 - 8

Poa morrisii Velvet tussock grass

M Prostrate - 0.3

Soft, dense 6 - 8

Schoenus melanostachys

- M 0.5 - 1.0 Perennial with short stout rhizome, often forms big weeping tussocks

6 - 8

Key to plant species Form: M Emergent macrophyte


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INDICATIVE RATE OF TOILETS FOR EVENTS OR OCCASIONS WHERE THE NUMBER OF PEOPLE WILL EXCEED THE CAPACITY OF THE WASTEWATER MANAGEMENT SYSTEMS

TUENA HALL & RECREATION AREA COMMITTEE BATHURST STREET … · 2018-07-10 · tuena hall &...

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