HEALTH SERVICES. Guidelines for the Installation/Construction of Wastewater System. Design and Construction

Transcription

1 HEALTH SERVICES Guidelines fr the Installatin/Cnstructin f Wastewater System Design and Cnstructin August

2 1.0 Intrductin Legislatin and Guidelines Definitins Applying fr Apprval Fees Applicatin and Inspectin Requirements Plans and Specificatins 6.2 Cmmercial Installatins f Wastewater Systems 6.3 Cnditins when Getech Reprt Required 6.4 Apprval f Plans 6.5 Final Inspectin and Apprval Requirements 6.6 Permit t Use 7.0 Design and Cnstructin General Requirements Septic Tanks and Leach Drain Installatin 7.2 Additinal Requirements Dependent n Applicatin 7.3 Aerbic Treatment Units 7.4 Alternative Treatment Systems and Greywater Systems 8.0 Example Site Plan and As Cnstructed Diagram Shire Cntact Details Related Cntact Details

3 1.0 INTRODUCTION This infrmatin is prvided as a general guide fr wners, architects and/r builders that intend t design, cnstruct/fit-ut and perate an apparatus fr the treatment f sewage. This guide als details the prcess fr apprval an effluent dispsal system within the Shire f Mundaring. Due t variatins in cnditins n each prperty it is advised that yu cntact the Shire s Health Service t discuss yur prpsal and yu may require an n-site inspectin with a Shire Envirnmental Health Officer prir t submitting yur applicatin 2.0 LEGISLATION AND GUIDELINES Wastewater systems are currently gverned by the fllwing legislatin and guidelines: Health Act 1911 Health (Treatment f Sewage and Dispsal f Effluent and Liquid Waste) Regulatins 1974 Health (Temprary Sanitary Cnveniences) Regulatins 1997 Cde f Practice fr the Reuse f Greywater in Western Australia Cde f Practice fr the Design, Manufacture, Installatin and Operatin f Aerbic Treatment Units Guidelines n applying fr apprval f installatin f a cmmercial n-site wastewater system Western Australian Guidelines fr Direct Land Applicatin f Bislids and Bislids Prducts Gvernment Sewerage Plicy Perth Metrplitan Regin Nt all legislatin listed abve is referred t in this dcument. Cpies f the legislatin can be dwnladed at the State Law Publisher website Other useful link: 3

4 3.0 DEFINITIONS Terms used in this dcument aerbic treatment unit means an apparatus fr treating sewage either whlly r partially by aerbic means and includes any assciated effluent dispsal system; alternating system means any apparatus cntaining a flw alternatin device that is cnnected t 2 receptacles fr drainage t allw infiltratin f effluent int the sil; apparatus fr the treatment f sewage means any apparatus fr the bacterilytic r aerbic treatment f sewage r any ther apparatus fr the treatment f sewage apprved by the Executive Directr, Public Health and includes any buildings, fittings, wrks, r appliances used r required in cnnectin with the bacterilytic r aerbic treatment f sewage, and the dispsal f effluent r any residue f such treatment; apprved means (a) (b) in the case f an apparatus t which Regulatin 4 applies, apprved by the relevant lcal gvernment; and in the case f an apparatus t which Regulatin 4A applies, apprved by the Executive Directr, Public Health; AS means Standards Australia standard; authrised persn, in relatin t an aerbic treatment unit, means a persn wh is authrised under Regulatin 42C t carry ut maintenance n that type f unit; blackwater means water cntaining faeces r urine; certificate f cmpliance has the meaning given t that term in the Water Services Licensing (Plumbers Licensing and Plumbing Standards) Regulatins 2000; drainage plumbing wrk has the meaning given t that term in the Water Services Licensing (Plumbers Licensing and Plumbing Standards) Regulatins 2000; dwelling means a building r part f a building that is ccupied r intended t be ccupied fr the purpse f human habitatin; effluent means the liquid discharge frm the treatment tank; fittings means all pipes, meters, r ther apparatus used fr r in cnnectin with the supply f water, and all pipes, cisterns, traps, syphns, manhles, ventilatrs and all ther apparatus cnnected with and requisite t secure the safe and prper wrking f any sewer, drain r water supply fixtures; fixtures means all necessary appurtenances, that may be attached t the plumbing r drainage system f premises and are intended fr the cllectin r retentin f any wastes r waste waters fr ultimate discharge int a drain r sewer; greywater means water cntaining kitchen, laundry r bathrm waste ther than faeces r urine; greywater system means an apparatus fr treating greywater and enabling it t be used fr garden irrigatin; wner, in relatin t an apparatus, means the wner f the premises n which the apparatus is cnstructed r installed; plumbing standards has the meaning given t that term in Regulatin 3(1) f the Water Services Licensing (Plumbers Licensing and Plumbing Standards) Regulatins 2000; receptacle fr drainage means 4

5 (a) (b) an evapratin drain, a sak well, French drain, leach drain r impervius sump; r any ther device r system fr the dispsal r re-use f effluent apprved by the Executive Directr, Public Health; sedimentatin tank means that part f an apparatus designed t retain liquid waste fr sedimentatin, fltatin and treatment; septic tank means the part f an apparatus fr the treatment f sewage designed t retain sewage fr bacterilytic treatment; single dwelling means a dwelling (a) (b) (c) that is ccupied r intended t be ccupied fr the purpse f human habitatin by nt mre than 8 persns; and standing n a lt within the meaning f the Twn Planning and Develpment Act ; and that is the nly dwelling standing n that lt; Standard wastewater system means tw septic tanks, ne primary tank (1520mm Diameter) and ne secndary tank (1220mm) wastewater means greywater and blackwater. Fr full definitins refer t Health (Treatment f Sewage and Dispsal f Effluent and Liquid Waste) Regulatins 1974 and Health Act

6 4.0 APPLYING FOR APPROVAL In areas where reticulated sewerage is nt available, n-site dispsal f wastewater is required. All applicatins fr cnstructin r installatin f an n-site wastewater system must be submitted t the Shire f Mundaring. If the prpsed apparatus is intended t handle less than 540L/ f wastewater r the building t be serviced is a single dwelling the Shire will prcess yur applicatin. If the wastewater vlume generated is mre than 540L/day r the building being serviced is nt a single dwelling the Shire will assess yur applicatin, prepare a lcal gvernment reprt and frward the applicatin t the Department f Health (DH) fr prcessing. Applicatins can be btained frm the fllwing website r by cntacting the Shire s Health Administrative Officer by calling : al.aspx It is an ffence t cmmence cnstructin r installatin f any wastewater system withut apprval frm the Shire f Mundaring r Department f Health. The system must be installed in accrdance with the apprved applicatin and a Permit t Use must be issued prir t the system being used. 5.0 FEES An applicatin fee and inspectin fee f $ is required t be submitted with the applicatin t cnstruct r install an apparatus fr the treatment f sewage. This fee includes: Preliminary site inspectin by the Shire s Envirnmental Health Officer. Applicatin prcessing and apprval. Final inspectin f the installed system by the Shire s Envirnmental Health Officer. Applicatins that require Department f Health apprval will need t include an additinal cpy f the site plan and $35.00 fee made payable t the Executive Directr f Public Health. 6

7 6.0 APPLICATION AND INSPECTION REQUIREMENTS 6.1 Plans and Specificatins A detailed plan f the n-site wastewater system, site plan and a building plan must be submitted. All plans are t be drawn t a scale f 1:100, 1:200 r 1:500. An example f a gd site plan is included with these guidelines. Details t be included: Lcatin f wastewater system and all drains and pipewrk including materials t be used. Distance f the apparatus frm all buildings, bundaries, bres, waterways (including seasnal) and water bdies. Distance f all receptacles fr drainage frm trafficable areas. Site plans are t have all cntur lines marked and numbered. Any wastewater system ther than a standard cncrete system (see terms) must include their cpy f the DH apprval and specific system cnditins. Getech reprt (may be required under certain circumstances), cntact the Shire Health Service in relatin t this requirement. Refer t Applicatin t Cnstruct r Install an Apparatus fr the Treatment f Sewage fr further details required. 6.2 Cmmercial Installatins f Wastewater Systems Infrmatin t accmpany an applicatin fr the installatin f a cmmercial n-site wastewater system: Type f Develpment Descriptin f staged develpment, if planned Size f served facility and calculatins used t determine the prpsed size f the system. Intended use f the building and the intended use f rms within the building; and Prpsed installatin and methds f dispsal/reuse f the final effluent. Site and Sil assessment. The site and sil assessment shuld be carried ut in accrdance with AS/NZS 1547:2000 On-site dmestic-wastewater management Calculatins t be prvided t determine cmpliance with the Gvernment Sewerage Plicy -= Perth Metr Regin. Als refer t DH Guidelines n applying fr apprval f installatin f a cmmercial n-site wastewater system, available at: 7

8 6.3 Cnditins when Getech Reprt required Getech reprts prvide assessment f n-site wastewater dispsal. Getech reprts are t be in accrdance with AS/NZS 1547:2000 On-site dmestic wastewater management. There are a variety f circumstances where a getech reprt will be required t supprt an applicatin. These include but are nt limited t; Land nminated as unsuitable fr effluent dispsal Where the prpsal cannt achieve the fllwing criteria: A minimum 2m vertical separatin between the base f a leach drain and the highest knwn grund water level r impervius layer Areas nminated by the Shire s Health Service such as; Unsuitable sils (Clay, Rck, etc) Excessive surface water runff Sites in (r in clse prximity t) knwn prly drained land (such as flat valley flrs) r where ther site (and ff site) cnditins may nt be cnducive t lng term effectiveness f n-site wastewater system. 6.4 Apprval f Plans A cpy f the apprved plan will be frwarded t the applicant. It is the respnsibility f the applicant t ensure the installer f the system has a cpy f the apprval. All cnstructin must cmply with these plans including any additinal cnditins. Any changes t these plans must be apprved by the Health Service prir t cnstructin. Nte: Depending n changes t the applicatin, amended plans may be required t be submitted t the Shire s Health Service fr apprval. 6.5 Final Inspectin and Apprval Requirements The fllwing must be cmpleted prir t the n-site wastewater dispsal system being cmmissined: The Septic tanks are required t be filled/tested and the dispsal field inspected by a Shire Envirnmental Health Officer. This invlves the septic tank being filled with at least 30cm f water 24 hurs prir t the inspectin time. Als, the septic tank lids must be in a psitin s the level f water and plumbing can be sighted easily. Fr the effluent dispsal field, this must be expsed s the lcatin and details f the system can be checked against the apprved plan. Fr example; leach drain lids are t be expsed t bserve the sealing f lids and pipewrk. The applicant r persn respnsible fr presenting the system fr apprval must be present at the site inspectin unless therwise apprved by the Shire Envirnmental Health Officer All new plumbing wrk must cmply with AS/NZS /2 Plumbing and drainage. A cpy f the certificate f cmpletin/cmpliance and an as cnstructed diagram is t be frwarded t the Shire s Health Service befre any permit t use the system will be issued. 8

9 It is an ffence under sectin 107(4) f the Health Act 1911 t use an apparatus befre it has been inspected and a permit t use the apparatus issued by the Shire f Mundaring (Penalty $1000). 6.6 Permit t Use After the wastewater system has been inspected and apprved by the Shire Envirnmental Health Officer a Permit t Use the system will be issued. The issuing f rubbish and recycling bins will nly be dne nce a Permit t use the Apparatus has been issued. 7.0 DESIGN AND CONSTRUCTION 7.1 General Requirements Septic Tank and Leach Drain installatin Septic tanks are t be a minimum f 1.2m frm any bundary, the edge f the huse pad, r any ther buildings, retaining wall r ftings; unless therwise apprved (will generally require structural engineering details t be cnsidered and certificatin frm a suitably qualified structural engineer). nt t have any structure erected abve it that bstructs free access t the apparatus r has walls n mre than 3 sides. Leach drains are t be a minimum f 1.8m frm any bundary, septic tank, edge f a huse pad r any ther buildings, ftings r retaining walls. nt t be lcated at a distance f less than 30m frm any well, stream, undergrund surce f water intended fr human cnsumptin nt be cnstructed within 6m f any subsil r pen drainage channel t be a minimum f 1.2m frm any trafficable r paved area. t be cvered with a minimum f 150mm and maximum f 300mm f clean sand fill free f clay. Leach drains sides are required t be surrunded with 300mm width x 600mm depth, f 20mm aggregate (blue metal r ther apprved material). If leach drains are t be installed parallel, minimum 3m apart. If leach drains are t be installed end t end, then minimum 1m apart. Fr further infrmatin n Understanding Septic Tank Systems fllw the link t the DH website: 9

10 7.2 Additinal Requirements Dependent n Applicatin Where adequate fall frm the secnd septic tank t the leach drains cannt be achieved a pump pit which is a third septic tank, will need t be installed. An apprpriate pump is required t be installed in the pit t pump effluent t the leach drains. An apprved visual and audible alarm is als required t be fitted within the huse in a prminent psitin t indicate pump failure, if it ccurs. Where a spa bath in excess f 350 litres in capacity is t be installed a separate wastewater dispsal system is required. The dispsal system will need t incrprate an external grated verflw relief gully at least 150mm belw the spa utlet and a sedimentatin tank, which is t be cnnected t a baffled leach drain. The size f the leach drain will be determined by the ttal vlume f the spa, plus an additinal 10% f vlume. 7.3 Aerbic Treatment Units Aerbic Treatment Units are t cmply with the requirements f the Cde f Practice fr the Design, Manufacture, Installatin and Operatin f Aerbic Treatment Units. A list f apprved systems and apprved service prviders is available frm the DH website: Alternative Wastewater Systems and Greywater Systems Any alternative waste water system must be apprved by Department f Health. A list f apprved systems and apprved service prviders is prvided n the DH website: Any installatin f a greywater system requires apprval by the Shire f Mundaring. The DH has infrmatin n greywater systems. Refer t the Cde f Practice fr the Reuse f Greywater in Western Australia. Als check the system yu chse is apprved by the DH. A list f apprved systems is available at the site mentined belw. Fllw the link t the DH website fr infrmatin n greywater: 10

11 8.0 EXAMPLE SITE PLAN AND AS CONSTRUCTED DIAGRAM 11

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13 9.0 SHIRE CONTACT DETAILS Health Services Shire f Mundaring 7000 Great Eastern Highway Mundaring WA 6073 Phne: (08) Fax: (08) shire@mundaring.wa.gv.au Website: RELATED CONTACT INFORMATION 11.1 Department f Health (DH) Envirnmental Health Directrate Water Unit Phne: ehinf@health.wa.gv.au Website: Water Crpratin Plumbing is t be carried ut by a licensed plumber in accrdance with the Metrplitan Water Supply, Sewerage and Drainage Bard by-laws. Phne: Website: Western Pwer and Alinta Gas All electrical and gas fittings shuld be apprved by Western Pwer and Alinta Gas and installed in accrdance with the relevant regulatins. Western Pwer Phne: Website: Alinta Gas Phne: Website: Envirnment and Cnservatin (DEC) Phne: Website: 13