ADDITIONAL INFORMATION FOR WORKING AROUND GAS INFRASTRUCTURE GAS DIVISION

Transcription

1 ADDITIONAL INFORMATION FOR WORKING AROUND GAS INFRASTRUCTURE GAS DIVISION Issue Date: 26/09/2018

2 Cntents 1. INTRODUCTION GLOSSARY FURTHER INFORMATION SAFETY INFORMATION EMERGENCY CONTACT DETAILS: * DUTY OF CARE FOR WORKING AROUND GAS ASSETS OUR NETWORK ABOUT US GAS DISTRIBUTION NETWORK INFORMATION Gas Distributin Netwrk Standards Gas Distributin Netwrk Assets Pipeline Depth f Cver Abandned Assets ATCO CONTACT DETAILS General Enquiries Fr Faults and Emergencies HP Officer Engineering Services WORKING NEAR GAS INFRASTRUCTURE PLANNING WORKS WORKING NEAR ATCO S ASSETS DBYD PLANS DESIGN OF WORKS AROUND GAS INFRASTRUCTURE Separatin Distances TENDERING FOR CONSTRUCTION ENGINEERING SERVICES ENQUIRY Required Lead Times Making an Enquiry t Engineering Services WORKING NEAR GAS INFRASTRUCTURE CONDUCTING WORKS CURRENT DBYD PLANS LOCATING GAS ASSETS Lcating Buried Assets (Pthling) Lcating Assets under Slabbing Lcating Assets Bred within Rck SERVICE CROSSING UNDER, OR OVER, ANY GAS PIPELINE Issue Date: 26/09/2018 Page 2 f 30

3 5.4 SERVICE PARALLELING A GAS PIPELINE HOT WORKS CHANGES TO GROUND LEVELS OR SURFACE CONDITIONS OPERATING OVER GAS INFRASTRUCTURE WITH VEHICLES OR HEAVY EQUIPMENT VIBRATION AND COMPACTION OPERATIONS Vibratin Cmpactin Piling Blasting / Seismic Survey / Explsives DEWATERING ADDITIONAL REQUIREMENTS NEAR METALLIC PIPELINES Pipeline Cating Surveys Electrical Equipment EXPOSURE OF GAS ASSETS HIGH PRESSURE GAS INFRASTRUCTURE MANDATORY REQUIREMENTS ASSETS SUBJECT TO THESE MANDATORY REQUIREMENTS WORKS WITHIN 15 METRES OF HP GAS INFRASTRUCTURE HP Ntificatin Required Lead Times What Infrmatin Will Yu Need t Prvide the HP Officer WORKS WITHIN 5 METRES OF HP GAS INFRASTRUCTURE Attendance by an Apprved Lcatr Wrk Requirements near HP Gas Infrastructure RELATED DOCUMENTS DISCLAIMER APPENDIX A. FEEDBACK FORM LIST OF TABLES Table 1: Terms used within this dcument... 5 Table 2: Rt mitigatin fr planting f vegetatin near gas pipelines Table 3: Minimum time frames when requesting wrks Table 4: Where an Apprved Lcatr is required Table 5: Allwable cmpactin near gas pipelines Table 6: Maximum unsupprted length fr gas pipelines Table 7: Applicatin f Mandatry Requirements t varius types f the Netwrk Table 8: Minimum time frames fr requesting HP Ntificatins Table 9: Standards and legislatin applicable t wrking arund gas infrastructure Issue Date: 26/09/2018 Page 3 f 30

4 LIST OF FIGURES Figure 1: Observing and maintaining safe clearances when bring Figure 2 Mandatry Lcatin Requirements Issue Date: 26/09/2018 Page 4 f 30

5 1. INTRODUCTION This dcument describes the requirements f ATCO fr planning and cnducting wrks near the gas distributin netwrk (Netwrk) which is wned and perated by ATCO within Western Australia. The term near is defined in mre detail thrughut this dcument. The mst imprtant first step is t request Dial Befre Yu Dig (DBYD) plans which cver the area in the vicinity f the relevant wrk site. ATCO will then prvide yu with detailed requirements fr wrking arund the gas infrastructure. This dcument is intended t help prpnents t understand the cntrls expected by ATCO, fr planning wrk, and perating safely arund ATCO s infrastructure. Cautin: Yu are slely respnsible fr ensuring that all safety precautins and measures n site are met, and must endeavur t ensure that n damage ccurs t the gas pipeline. This dcument is live and therefre subject t change. Yu must always use the latest versin, which is available by cntacting ATCO, r visiting ATCO aims t cntinuusly imprve the advice it prvides t help avid delays, r rewrk, r additinal wrk and assciated extra csts being incurred. The Feedback Frm, which is lcated at the end f this dcument, can be used t prvide imprvement suggestins t ATCO. 1.1 Glssary Table 1: Terms used within this dcument Term Apprved Lcatr ATCO DBYD Engineering Services HP Netwrk Prpnent Reference ATCO apprved HP gas pipeline lcatin fficers. ATCO, Gas Divisin Australia Dial Befre Yu Dig, call 1100 r 1100.cm.au The department f ATCO respnsible fr prviding engineering advice relating t the safety f the Netwrk. High Pressure, refer t Table 4 fr where requirements apply. The gas distributin netwrk which is wned and perated by ATCO. This includes high pressure gas pipelines, alng with ther gas mains, services and facilities. Develper, Builder, Owner, Cntractr r Custmer planning r cnducting wrks near the Netwrk. Issue Date: 26/09/2018 Page 5 f 30

6 1.2 Further Infrmatin 2. SAFETY INFORMATION Refer t the Related Dcuments (sectin 7) fr a list f standards and legislatin. Refer t the Feedback Frm (at the end f this dcument). 2.1 Emergency Cntact Details: * In the event that yu becme aware f any gas leak r damage t a gas pipe, act immediately: Leave the area; Keep peple clear f the area; Allw gas t vent int the air; Eliminate ignitin surces (i.e., n smking, d nt light a match / lighter, extinguish any naked flames); D nt use any devices which may be an ignitin surce (this includes vehicle engines, mbile phnes, pwer tls r appliances, electrical r light switches and trches); Where safe t d s, shut ff all machinery, vehicles, tls and equipment in the area; Once clear f the area, immediately cntact: ATCO Faults and Emergencies n * (24 hurs). D nt attempt t stp the flw f gas r repair the gas infrastructure. * Lcal call fee frm anywhere in the state excluding mbiles. 2.2 Duty f Care fr Wrking arund Gas Assets Wrking near any gas pipeline, especially a High Pressure (HP) gas pipeline, can be extremely dangerus. Yu shuld always exercise due care and cautin when wrking near any gas infrastructure. Refer t Table 1 and Table 4 fr the ATCO definitin f HP. In additin t yur general duty f care, there may be ther bligatins under the Occupatinal Safety and Health Act 1984 (and ther relevant legislatin) which require yu t maintain safe practices. In additin t any legal bligatins that yu may have under the Occupatinal Safety and Health Act 1984 (and ther relevant legislatin), ATCO may prescribe specific requirements fr wrking n and arund its gas infrastructure. These requirements are designed t prtect the Netwrk and ther infrastructure, peple wh may be wrking n and arund the gas infrastructure, and the general public. Issue Date: 26/09/2018 Page 6 f 30

7 Due care must be taken at all times nt t damage the gas pipelines r the prtective cating cvering the gas pipelines. Any damage t gas pipelines, their prtective cating, r ther assets must be reprted t ATCO Faults and Emergencies immediately. Cautin: Unreprted damage has the ptential t endanger public safety and any wilful r negligent damage t ATCO pipelines r ther infrastructure may be a prsecutable ffence. 3. OUR NETWORK 3.1 Abut Us ATCO is a private cmpany delivering safe, reliable, cst-effective natural gas t West Australians. As a gas distributin cmpany, ATCO builds, wns and maintains an undergrund netwrk f pipelines that bring natural gas t apprximately 750,000 West Australians. Alng with building and maintaining the netwrk, we als perfrm the wrk t cnnect yur gas and read yur meter. ATCO s assets are lcated acrss the Perth greater metrplitan area, Albany, Brunswick Junctin, Bunbury, Busseltn, Capel, Geraldtn, Harvey, Kalgrlie, and Pinjarra. Thrughut this dcument we refer t ur netwrks f gas infrastructure within Western Australia as the Netwrk. ATCO Gas Australia Pty Ltd, ACN is part f the ATCO Grup f Cmpanies. 3.2 Gas Distributin Netwrk Infrmatin Gas Distributin Netwrk Standards ATCO pipelines are designed, cnstructed, tested and perated in accrdance with the fllwing relevant Australian Standards (AS): Gas Distributin Netwrk Assets AS2885 Pipelines Gas and Liquid Petrleum AS/NZS 4645 Gas Distributin Netwrks AS4799 Installatin f Undergrund Utility Services and Pipelines within Railway Bundaries AS/NZS 4853 Electrical Hazards n Buried Metallic Pipelines The Netwrk cmprises bth belw grund and abve grund assets including gas services, cabling, ande beds, cncrete slabbing, vent ples, pits, test psts, signage and cabinets which may nt be marked n the DBYD plans. Cautin must be used at all times. Gas services (and/r gas pipeline rad crssings) t individual premises will ften nt be shwn n the DYBD plan r gas asset drawings. As a matter f cautin, yu shuld assume that there are gas services present in the grund and take care t lcate them prir t and during excavatin and backfilling wrks. Issue Date: 26/09/2018 Page 7 f 30

8 With the exceptin f Albany, ur Netwrk reticulates Natural Gas frm transmissin pipelines t custmers. The Albany netwrk reticulates Liquefied Petrleum Gas (LPG) vapur frm a strage facility. While Natural Gas is lighter than air, LPG is heavier than air and can pl in lw lying areas like trenches r pthles. Additinal cautin shuld be used when wrking arund the LPG netwrk in Albany Pipeline Depth f Cver Over time the grund prfile, site cnditins and ther aspects f a lcatin may change. Accrdingly, it shuld nt be assumed that any wrks will be safe based n the typical minimum depth f cver, the actual lcatin f gas assets must first be prven as per Sectin 5.2. Furthermre, fittings are ften installed n the pipes which may prtrude abve the general elevatin f, r alngside, the pipeline. Any alteratins t the grund cnditins must cmply with the fllwing, unless therwise apprved by Engineering Services: HP gas pipelines, including bth steel and plyethylene pipelines, require a minimum 1200mm depth f cver, particularly under radways, traffic area r ptential traffic areas. The maximum depth f cver ver a HP gas pipeline must nt exceed 1.8m unless therwise apprved. Refer t Sectin 5.2 fr clarificatin f hw ATCO defines assets as being HP. Other gas mains require a minimum 750mm depth f cver. Increased depth f cver may be required under radways, traffic area r ptential traffic areas. The maximum depth f cver ver these gas mains must nt exceed 1.5m unless therwise apprved. Refer t Table 7 fr further details. Where the existing depth f cver des nt cmply with the minimum levels indicated abve, there is an increased risk f damage t gas infrastructure. Reduced depth f cver can impact n the safety f a wide variety f activities, including cmmn wrks near grund level and vehicle crssings. In these instances, further advice shuld be sught by cntacting Engineering Services Abandned Assets Engineering Services must apprve remval f any abandned (AB) (r retired) assets in writing and in accrdance with the fllwing cnditins: 1. Prir t the remval f any abandned pipelines, the pipes must be tested by ATCO t cnfirm the absence f gas. 2. Gas testing can be arranged by Engineering Services nce the request fr remval has been received. 3. The requesting party will be liable fr all csts invlved in cnducting the gas testing. Where apprval has been prvided the requestr must supply an As Remved drawing (r gas map sketch) within 24 hurs, which will enable ATCO t update the Netwrk mapping system. Issue Date: 26/09/2018 Page 8 f 30

9 Assets anntated as ABS (Abandned Sld) n DBYD plans are assets that have been sld t a third party. These pipes may cntain third party utility assets and shuld be treated with care. These are indicated n the DBYD fr reference nly, ATCO makes n assurances abut their cntents, cnditin, remval r therwise. 3.3 ATCO Cntact Details General Enquiries Fr mre infrmatin abut ATCO and all general enquiries, cntact us n (Mnday t Friday, 7am t 6pm), r visit Fr Faults and Emergencies Call ATCO Faults and Emergencies n * (24 hurs) HP Officer T btain r mdify a HP Ntificatin (see Sectin 6.2 belw), frward all relevant details and cntact the ATCO HP Officer between 8am 4pm weekdays: Phne: HPenquiries@atcgas.cm.au Engineering Services Fr wrks that may require alteratin t the Netwrk r fr an Engineering Assessment f yur prpsed wrks, please send all relevant infrmatin t Engineering Services: ATCO Engineering Services Lcked Bag 2, Bibra Lake DC, Engineering.Services@atcgas.cm.au ATCO shuld be cntacted at the abve address at the earliest stage f the design, in rder fr assessment and (if necessary) relcatin wrk t be planned and cmpleted t ATCO s requirements, well in advance f yur wrks. 4. WORKING NEAR GAS INFRASTRUCTURE PLANNING WORKS 4.1 Wrking near ATCO s Assets Any activities ccurring near gas infrastructure require due cnsideratin f the risks and cntrls t ensure they can be cnducted safely. At clser prximity the risk and extent f cntrls will increase accrdingly, as indicated thrughut this dcument. Unless stated t relate t depth r radial distance frm the infrastructure, the distances in this dcument relate t the hrizntal distance frm the pipeline alignment, nt including any vertical separatin. Certain types f assets have additinal risks that necessitate particular cntrls being impsed, such as HP gas infrastructure and metallic pipewrk. These cntrls will typically apply fr wrks that are within 15m f the gas infrastructure. Issue Date: 26/09/2018 Page 9 f 30

10 Activities likely t result in high vibratin levels have increased ranges f influence where they may impact the safety f the gas pipeline, particularly piling (30m) and blasting (100m). High Vltage assets may als influence the safety f metallic assets ver large distances. Please refer t the relevant parts f Sectin 5 regarding these types f activities. 4.2 DBYD Plans DBYD plans shuld be btained and reviewed at the earliest stage f planning yur wrks. These plans will help identify the presence f gas infrastructure and their apprximate lcatin. The gas pipeline anntatin identified n the DBYD plans will help yu t identify the type f gas pipeline and sme key prperties. Sme examples: 300 ST 4.2 HP 1920kPa 160 PE 1.5 HP 700kPa 110 PE 1.5 PEHP 350kPa 100 PVC 1.5 MP 70kPa Where 300 = Nminal Diameter f the pipe in mm (i.e., DN300mm) ST = Material f pipe (Steel, Plyethylene, Plyvinyl Chlride, etc.) 4.2 = Apprximate distance frm prperty bundary in metres (as recrded) HP = Netwrk descriptr (a full list is detailed in Sectin 6.1) 1920 = Maximum Allwable Operating Pressure (i.e., MAOP = 1920 kpa) Guidance n the interpretatin f the DBYD plans is prvided within the DBYD cver sheet. Where the wrks will be in clse prximity t the undergrund assets, a mre accurate psitin will be required t facilitate further detailed design and cnstructin wrks. In this instance, lcating f the pipeline must be cnducted in accrdance with Sectin Design f Wrks arund Gas Infrastructure The mst effective means f reducing the risks f wrking arund gas infrastructure is t plan wrks in lcatins where the gas infrastructure is nt lcated, r lcatins where the impact can be minimised. Where this is nt pssible, risk can be minimised thrugh accurate lcating and maximising clearances during the design phase. Safety in design shuld be paramunt, with due cnsideratin f safe methds fr the cnstructin f the wrks and the ability t apply adequate cntrls fr these activities. The design dcuments must take int accunt the requirements utlined within this dcument, alng with any ther cntrls that may be required by ATCO Separatin Distances Guidance n separatin distances are utlined in the fllwing sectins. Yu must cnsult with Engineering Services t cnfirm the separatin and/r parallel distance (buffer zne) frm the gas pipeline where these cannt be achieved. Issue Date: 26/09/2018 Page 10 f 30

11 Yu must receive apprval frm ATCO where new infrastructure will result in exclusin znes r ther restrictins n access t ATCO s assets, including any restrictins n excavatins within the vicinity f gas assets Undergrund Infrastructure The installatin f undergrund assets must nt restrict access t ATCO s assets, including the preventin f r restrictin n excavatin withut shring r ther means f trench supprt. Infrastructure must nt be installed in clse prximity t gas assets where access restrictins are required unless cntrls are installed t maintain access as apprved by Engineering Services. The installatin f any undergrund infrastructure must be cnducted in accrdance with Sectins 5.3 and Psts and Ples Psts r ples (including pst/sleeves fr water mnitring pints) must have suitable clearance t gas assets with apprpriate shring r restraints t prtect and maintain access t gas assets. This generally requires a minimum clearance f 1.5m t HP Gas Pipelines, r 1m t ther gas mains. Fr clearances less than these distances, apprval frm Engineering Services is required fr each specific site. Exceptins may be cnsidered fr the replacement f existing ples. Psts and ples lcated within rad reserve, such as thse used fr signage and lighting, must have adequate clearance t gas assets t prevent damage in the event f vehicle impact. Where apprval fr installatin with reduced clearances has been requested, the party cnducting the wrks must demnstrate that the pst r ple will nt damage gas assets in event f a vehicle impact, thrugh frangible pst design r therwise Structures and Ftings Separatin distances t structures / walls / ftings / retaining walls / gantry r hardings must be maintained, typically 1.5m depending n alignment. In general, n structure can be installed ver any pipeline. N pening t an enclsed structure is allwable within 3m f any HP asset, r within 1m f any ther gas asset. Any installatin must cnsider safe access t the gas pipe in case f emergency access, i.e., that adequate separatin be maintained s that when excavating the gas pipe r ther asset, that there is n risk f the installed structure tppling / cllapsing r therwise effecting the gas asset r the persnnel wrking n that gas asset Planting f Vegetatin In general, planting f vegetatin arund the gas assets is acceptable prvided that the rts f the plant are nt capable f causing damage t the Netwrk and free passage is maintained alng the pipeline rute. Separatin distances shuld be planned, and the expected height f the fully grwn plant shuld be taken int accunt s that the plant cannt fall nt any cmpund fence r abve grund asset, nr the rts interfere with the gas pipes r belw grund assets. Damage and increased fire risk are issues fr abve grund assets, whilst breakages, restrictin f flws and damage t pipeline cating are issues fr belw grund assets. Issue Date: 26/09/2018 Page 11 f 30

12 Table 2 cntains guidelines fr the apprpriate mitigatin f rts t be fllwed when planting trees near gas pipelines. If further guidance is required, please cntact Engineering Services. Issue Date: 26/09/2018 Page 12 f 30

13 Table 2: Rt mitigatin fr planting f vegetatin near gas pipelines Distance frm Gas Asset Greater than 3m Required Rt Mitigatin Methds A minimum buffer f 3 metres is required between trees and gas mains fr deep-rted trees if rt arrestrs r ther mitigatin methds are nt used. 1 3 metres Inside the 3-metre buffer zne, specific tree types may be accmmdated after further cnsultatin with Engineering Services and the use f special rt barriers that wuld mitigate any damage t gas pipelines and ther services in the vicinity. Rt arrestrs nrmally cnsisting f prperly wrapped and secured rbust plyethylene / nyln sheeting r slid cncrete cylinders must be emplyed t a minimum depth f 1m; r 250mm deeper than the gas pipeline, whichever is greater metres With less than a 1-metre buffer t pipeline, additinal rbust physical rt barriers are required. These must extend 250mm deeper than the gas pipe as a minimum and allw fr a minimum 300mm lateral clearance between the rt barrier wall and the gas pipe wall, after cnsultatin with Engineering Services. In this case, heavy prefrmed cncrete r plyethylene pipe / liners used as rt barrier are mandatry (e.g., Rcla r similar type cncrete pipe r PE strmwater / sewer pipe). Cncrete sakwells used as a rt barrier arund the tree next t a gas main are anther apprved ptin subject t blcking all hles n the full half side facing the gas main metres Planting directly ver gas mains is nt permitted in any lcatin, as it prevents emergency and maintenance access. Lcal tree rts may eventually break the gas pipe and leaking Natural Gas will likely kill any vegetatin in cntact. 4.4 Tendering fr Cnstructin D nt issue any tenders r cmmence any site-wrks, withut first cntacting ATCO t assess whether any ATCO assets may be affected by prpsed wrks. Yu shuld btain advice in writing frm ATCO regarding the separatin distance required and any relevant cnditins that may be impsed prir t calling fr tenders. Yu shuld specify in the tender / cnstructin dcumentatin that the successful site-cntractr will need t cmply with the requirements f this dcument (as a minimum). Fr wrks near High Pressure Gas Infrastructure, the requirements f Sectin 6 will als apply. These include the use f an Apprved Lcatr t search fr, and visually identify, the existing gas pipelines n site immediately prir t cmmencing any site-cnstructin r any site-wrks, t cnfirm and visually verify the accuracy and relevance f any prving results that were btained during the design stage. Issue Date: 26/09/2018 Page 13 f 30

14 4.5 Engineering Services Enquiry Where acceptable cnditins fr prpsed wrks are nt detailed within this dcument, please enquire with Engineering Services t establish a suitable apprach fr prceeding with the wrks. Sme scenaris requiring assessment by Engineering Services are listed thrughut this dcument. In mst cases the wrks will be allwed t prceed with suitable cntrls in place. Hwever sme cases require certain limitatins r restrictins t be enfrced t maintain the safety f the Netwrk. Where adequate clearances r cntrls cannt be applied, relcatin f either the prpsed wrks r the gas infrastructure may be required t facilitate the prpsed wrks. In each case, yu must make a written request regarding the prpsed wrks t, and btain written apprval frm, Engineering Services prir t prceeding Required Lead Times ATCO shuld be cntacted at the earliest stage f the design, in rder fr any assessment and necessary relcatin wrk t be planned and cmpleted t ATCO s requirements, well in advance f yur wrks (refer t Table 3 fr typical requirements). Yu shuld allw fur weeks fr an initial Engineering Assessment f the wrks, with further time required if the wrks are cmplex and/r further infrmatin is required t prperly assess the wrks. Where yu require any wrks (including alteratins / relcatins) t be cnducted n the Netwrk t facilitate r therwise allw yur wrks t prceed, the minimum time frames fr cnducting the wrks shuld be allwed within yur prject frm the time f the initial assessment. Table 3: Minimum time frames when requesting wrks Wrk Requested Altering / relcating HP gas pipelines Altering / relcating ther gas mains Gas check n abandned assets (Sectin 3.2.4) DCVG survey t inspect fr pipeline cating damage (Sectin ) Making an Enquiry t Engineering Services Time Frame mnths 6 mnths 4 weeks 4 weeks Please ensure that all relevant infrmatin relating t prjects that may impact upn the Netwrk are prvided t: ATCO Engineering Services Lcked Bag 2, Bibra Lake DC, t: engineering.services@atcgas.cm.au When submitting prpsed wrks t Engineering Services fr assessment, the fllwing items may be requested depending n the nature f the wrk. Please have this infrmatin readily available fr review by the Engineering Services team: scpe f wrks, including all activities whether temprary r permanent; lcatin f wrks / extent f site; Issue Date: 26/09/2018 Page 14 f 30

15 plans / drawings shwing the prpsed wrks, including: lcatin f wrks / extent f site; changes t the surface types / surface levels; lcatin f the gas infrastructure relative t the wrks; depth f cver f the gas infrastructure and any prpsed changes; safe wrk methd statements, including the type and size f equipment t be utilised and the prpsed clearances fr the equipment; risk assessments relevant t the wrks / gas infrastructure, including cntrls in place t prevent damage t the gas infrastructure; relevant calculatins fr the wrks, such as surface lading frm heavy vehicles; and prpsed timing f the wrks / requested respnse time. Pipeline alteratins / relcatins that are required are typically cmpleted at the prpnent s cst. ATCO will nt be respnsible fr delays r liable fr any csts assciated with any ptential delay due t issues with cmpliance t any requirements. 5. WORKING NEAR GAS INFRASTRUCTURE CONDUCTING WORKS Yu must nt cnduct any wrks / activities n-site within 15 m f HP gas infrastructure prir t btaining a HP Ntificatin relevant t the wrks, as detailed in Sectin Current DBYD Plans All cnstructin persnnel must be made aware f the presence f gas infrastructure at the daily pre-start meetings and the weekly tlbx meetings, with due cnsideratin given t the gas infrastructure within the relevant Jb Safety Assessment / Take 5. Gas warning signs / sign psts must nt be disturbed, relcated, remved, r altered withut the prir written apprval f Engineering Services. Surces f electrical energy such as generatrs r ther machinery must nt impart any current r vltage t the gas assets. Current DBYD plans must be btained immediately prir t any cnstructin cmmencing within a prject area. Current plans must be kept n site thrughut the duratin f the wrks (current means 30 days frm the date f request). DBYD plans must be available n site in clur and f a clearly legible size (either in hard cpy r in electrnic frm). 5.2 Lcating Gas Assets Prir t wrks cmmencing, it is the respnsibility f the manager f the wrks, the nsite supervisr and the machine peratr t arrange lcatin f all assets that might be affected by the wrks t prtect these assets during the wrk activities, and t cnduct the wrks safely. Issue Date: 26/09/2018 Page 15 f 30

16 The presence f gas infrastructure can be readily determined by cnducting a DBYD enquiry (Sectin 4.2). After receiving the DBYD plans, buried gas assets can be lcated thrugh safe excavatin methds (pthling) as detailed in the fllwing sectins. A small percentage f the gas pipelines (apprximately 10% f the Netwrk) will require lcatin by an Apprved Lcatr (refer t Table 4 and Sectin 6.1). Fr the rest f the Netwrk, it is acceptable fr the prpnent t hand dig t identify the lcatin f the gas pipelines. Where the peratr is nt familiar r cnfident wrking arund gas assets, the use f an Apprved Lcatr is recmmended. Table 4: Where an Apprved Lcatr is required Pressure Acrnym Netwrk Descriptr 350kPa PEHP Plyethylene High Pressure, sizes DN160mm and abve CHP City High Pressure kPa HP High Pressure NOTE: ATCO refers t the assets identified in Table 4 as HP. When wrking near r abve gas pipelines r services, the lcatin f the gas assets must always be pegged r suitably visually indicated Lcating Buried Assets (Pthling) Pthling is the practice f hand digging r vacuuming a test hle t expse undergrund assets t ascertain their exact psitin and depth. Pthling must be carried ut prir t any drilling r excavatin that may impact these undergrund assets. Pthling can be carried ut with a hand shvel r by vacuum extractin. If using vacuum extractin, please nte that water jetting at high pressures has the ptential t damage buried assets. Care shuld be taken if water jetting and water pressures shuld be limited t 1500 psi (100bar) t avid damage. Pthling shuld never be carried ut with a mechanical excavatr. Prir t any pthling being carried ut yu must read the DBYD plans t fully understand what utilities are in the vicinity and identify any assciated street furniture (access pits, test psts, etc.). Yu are nt permitted t cnduct any wrks (including pthling) within 15 metres f HP gas assets withut a valid HP Ntificatin being issued by ATCO, ther utilities may have similar cnditins fr wrks arund their assets. It is cmmn practice t utilise sectins f PVC r ther material t lcate and mark the pipeline. Once the measurements have been made, the marker ples must be repsitined vertically t ensure there is a minimum f 300mm clearance frm the gas pipeline t the bttm f the marker. Nte: An end cap must be attached t the bttm f the marking pipe t prevent damage t the undergrund asset. Clean fill must be replaced arund the pipe and under the pst t return the sil t grund level. This will assist in preventing damage t the pipeline frm vertical impacts t the marker psts, frcing the psts dwn nt the pipeline. Issue Date: 26/09/2018 Page 16 f 30

17 Cnsideratin shuld be given t utilise qualified lcatrs fr all asset lcatins. Fr HP gas assets, an Apprved Lcatr must be used in all cases, after a valid HP Ntificatin has been issued (refer t Sectin 6). In additin t pthling t lcate the asset, strategic slip trenching shuld be cnsidered fr all drilling r excavatin wrks. Slip trenching prvides a visual separatin t undergrund assets and is useful, and may be required, when drilling near gas assets r ther high risk utilities. If unable t lcate the service, cntact the utility prvider and yur supervisr and d NOT prceed with any drilling r mechanical excavatin Lcating Assets under Slabbing In sme lcatins cncrete (r ther apprpriate material) slabbing has been installed t prtect the gas assets frm damage. Prtective slabs can ften be identified thrugh writing n the tp f the slab (i.e., HP Gas Pipeline ) r thrugh the presence f yellw gas warning tape acrss the tp f the slab. Where these slabs are required t be remved t psitively identify the gas pipeline, an Apprved Lcatr must always be used. DBYD infrmatin may indicate the start and end pints f the slabs. Slabs are generally 1.2m x 1.2m f cncrete with lifting lugs t assist with remval, hwever ther materials (and cnfiguratins) are becming mre cmmnly available. Gas pipes are generally 300mm belw the bttm f the slab. Where required, excavate t allw remval f the slab ensuring that ther assets are lcated and prtected. Using an Apprved Lcatr, remve the slab and stre it in a safe lcatin t prevent damage t the slab r frm the slab falling int r causing cllapse f the trench. Cntinue hand excavatin under the slab until the pipeline is lcated in accrdance with the requirements f sectins and 6.3. Fr any wrks arund HP Gas Pipelines, the pipe itself must be visually sighted. On cmpletin f the wrks the prtectin slabs must be reinstated using an Apprved Lcatr. A minimum f 300mm clean fill must surrund the gas assets and the gap between slabs must be n greater than 200mm and n less than 25mm. Cautin: Cncrete (r ther apprpriate material) slabbing is ften used t prtect the pipe in instances f reduced depth f cver r in areas f high cnsequence. Due cautin shuld be exercised fr wrks t prceed safely Lcating Assets Bred within Rck Fr lcatin f bred sectins f pipe within rck where the pipe cannt be visually checked, cntact with Engineering Services is required t determine clearances and crssing requirements. In these situatins, DBYD infrmatin may indicate the start and end pints f the bres, but where drawings d nt shw this infrmatin please cntact Engineering Services. At the bre entry r exit pint the pipeline shuld be lcated and expsed utilising the lcatin requirements f this sectin. The pipe within a bre shuld either be steel r PE, and if PE have tracer wire attached t the PE pipe. This tracer wire r the steel pipe can be used by an Apprved Lcatr t attach a lcating signal fr psitining the pipe within the bre fr depth and alignment. In sme cases, additinal bre infrmatin (bre lgs) is available. Issue Date: 26/09/2018 Page 17 f 30

18 5.3 Service Crssing under, r ver, any Gas Pipeline At the prpsed crssing, yu must lcate the gas pipeline and verify its psitin and depth visually at the prpsed crssing pint. Any service crssing must be perpendicular t the gas pipeline, unless written apprval frm Engineering Services is btained prir t the installatin f the service. Yu will need t visually sight the gas pipeline again, using a suitable nn-mechanically excavated bservatin pit, t ensure that the drill / header / auger / jacking-pipe / crssing being used is able t be clearly seen by eye. This is t ensure that yu are able t bserve where the lcatin f the gas pipeline is at all times and t prevent any pssible damage t the gas pipeline frm the installatin f the crssing (refer Figure 1). Unseen jack / drilling / header advancing, r blind bring, pse high risks t the gas pipeline and shuld nt be attempted under any circumstances. Cautin: N machinery is t be used within 1m f a HP main expsure is by nn-mechanical excavatin nly. Directinal drilling inset belw Figure 1: Observing and maintaining safe clearances when bring A minimum clearance f 300mm is required between the gas pipelines and any third party pipe r service crssing. Fr cncrete mains passing abve gas pipelines a minimum clearance f 500mm is required. Plunking is nt an accepted hand excavatin technique, when wrking in the vicinity f gas assets, and requires equivalent cntrls and supervisin as mechanical excavatin. Issue Date: 26/09/2018 Page 18 f 30

19 5.4 Service Paralleling a Gas Pipeline T determine the psitin f the pipe, yu will need t lcate the gas pipeline at 10m intervals alng the parallel straight sectins and physically lcate all bends, junctins / laterals service fftakes and tappings / prtrusins and at entry and exit lcatins. Sme site cnditins may require intervals f 5m r less fr accurate lcatin f services. With the exceptin f pthling t lcate the pipe, installatin wrks must nt disturb the grund 500mm all arund the gas assets. This includes the cllapsible area arund the excavatin due t the angle f repse r natural angle f the lay f the sil during the wrks. On cmpletin f pthling, the grund arund the pipe shuld be reinstated t existing grund levels as described in sectin and sectin 6.3 (as relevant t the specific circumstances). The services must nt be installed such that the gas pipeline cannt be safely accessed withut wrking in the cllapsible zne f the service. Fr any installatin less than 1-metre frm a gas pipeline, pthle spacing must be n greater than every 5 metres. Cautin: Yu are slely respnsible fr ensuring that all safety precautins and measures n site are met, and must endeavur t ensure that n damage ccurs t the gas pipeline. 5.5 Ht Wrks All ht wrks cnducted within 15m f any gas infrastructure must be in cmpliance with applicable laws and Australian Standard Typical ht wrks include grinding, welding, thermal cutting, cncrete cutting (wet r dry) r heating, and ther related heat-prducing r spark-prducing peratins including nn-mechanical cable jinting. The presence f gas infrastructure must be specifically identified as a hazard, with the requirements f Sectin 3 Hazardus Areas within AS applied accrdingly. These requirements include a ht wrks permit authrised by a respnsible fficer, mnitring fr flammable gases, and respnse prcedures in the event f fire r flammable gas detectin. D nt let heat surces r ht wrks impact n gas infrastructure and take int cnsideratin that the grund r adjacent structures may als be capable f transmitting heat s as t circumvent prtectin affrded by a heat shield r barrier. ATCO requires a review by Engineering Services prir t ht wrks where there is excavatin resulting in less than 600mm grund cver t buried gas infrastructure, r within 5m f any gas infrastructure lcated abve-grund (including any pits r valve cvers). 5.6 Changes t Grund Levels r Surface Cnditins Material must nt be placed n r near the pipeline, nr can grund levels be altered withut written permissin frm ATCO. Any prpsed alteratins t the finished surface level, width r surfacing f any street, rad reserve r crssver must be submitted t Engineering Services fr assessment in-line with this dcument. Issue Date: 26/09/2018 Page 19 f 30

20 If up t 100mm depth f cver is t be temprarily remved ver a HP pipeline fr the installatin f a dmestic driveway, the driveway has a width f less than 10m and a hand held cmpactr r bbcat f less than 1.7T is prpsed, then wrks may prceed with a HP Ntificatin. Driveway cnstructin nt in accrdance with these parameters will require assessment by Engineering Services prir t cmmencement f site wrks, and may require a Pipeline Cating Survey t be undertaken as detailed in Sectin Rutine rad maintenance cnsisting f resurfacing existing rad surfaces withut excavatin deeper than 100mm can prceed with a HP Ntificatin. Changes t rad levels, widths r maintenance with deeper excavatin requirements will require assessment by Engineering Services prir t cmmencement f site wrks. 5.7 Operating ver Gas Infrastructure with Vehicles r Heavy Equipment Vehicles crssing ver the pipeline are limited t light vehicles (grss vehicle mass nt greater than 4.5 tnnes) r heavy vehicles n established sealed crssvers (cmpliant general access (as f right) vehicles). Any crssings with reduced cver r exceeding the abve limits must be assessed by Engineering Services. 5.8 Vibratin and Cmpactin Operatins Vibratin T avid pipeline damage, vibratins frm any site-wrks r activities must nt exceed 5 mm/sec Peak Particle Velcity (PPV) as measured at the gas pipeline, by an ISO 9000 quality-accredited vibratin mnitring cmpany. If requested, yu must prvide ATCO with the results f the vibratin readings by the next wrking day. Issue Date: 26/09/2018 Page 20 f 30

21 5.8.2 Cmpactin Piling Methds f cmpactin within the prximity f gas pipelines must be restricted t prevent damage t gas pipelines and their catings. Cmpactin requirements are subject t site review, with Table 5 prviding a guide t acceptable cmpactin methds arund gas infrastructure, including t pipelines with reduced depth f cver. Any cmpactin nt in cmpliance with these guidelines must have written agreement frm Engineering Services prir t cnducting any wrks. Table 5: Allwable cmpactin near gas pipelines Hrizntal distance t gas pipeline Minimum undisturbed depth-f-cver prvided Size f Cmpacter / Rller 0 5 metres 300mm Small hand-held plate cmpacter nly 500mm 900mm All HP 750mm PVC & PE Hand-held larger plate cmpacter Maximum (ttal) 8- tnne tandem-drum Maximum (ttal) 8- tnne tandem-drum Maximum (ttal) 10- tnne vibratry rller 5 10 metres N/A Maximum (ttal) 8- tnne tandem-drum Maximum (ttal) 10- tnne vibratry rller metres N/A Maximum (ttal) 10- tnne vibratry rller > 15 metres N/A N restrictins Vibratin mde Any vibratin setting Any vibratin setting Static rller nly (n vibratin) lw-amplitude vibratin setting nly Static rller nly (n vibratin) Any vibratin setting lw-amplitude vibratin setting nly Any vibratin setting Any cmpactin in rcky areas must be submitted t Engineering Services fr assessment prir t wrks cmmencing. Cnsideratin shuld be given t using scillating rllers rather than vibrating rllers. N pile-driving, sheet-piling, vibr-piling, hammer-piling is permitted within 30m f a gas main, except with specific prir written cnsent frm Engineering Services. It shuld be nted that cntiguus piling is a preferred methd f retaining, subject t assessment by Engineering Services Blasting / Seismic Survey / Explsives N blasting, seismic survey r any use f explsives is permitted within 100m f a gas main, except with specific prir written cnsent frm Engineering Services. Calculatins demnstrating the predicted maximum particle velcity will be required fr assessment by Engineering Services. Issue Date: 26/09/2018 Page 21 f 30

22 5.9 Dewatering The site cntractr must make sure that any dewatering n-site des nt result in gas pipeline subsidence. Yu are respnsible fr engaging specialist dewatering firms t submit relevant dewatering calculatins and figures t ATCO fr acceptance, shwing that yur dewatering peratins will have n detrimental impact t ur pipeline. We will review yur submissin and, depending n the prpsed impact, yu may be required t install a mnitring bre(s) Additinal Requirements near Metallic Pipelines Pipeline Cating Surveys Prir t any rad wrks r grund surface treatments ccurring, Pipeline Cating Surveys may be required in rder t check the cnditin f the gas pipeline s prtective cating. Yu will be respnsible fr the csts f any testing required. Generally, if 10m r mre f steel HP gas pipeline will subsequently be lcated within 500mm measured hrizntally, r under, the finished surface f the rad / driveway r shulder yu must first pre-rganise with Engineering Services t perfrm a Direct Current Vltage Gradient (DCVG) Survey t determine the cnditin f the pipeline cating. If the survey indicates that additinal cating prtectin r cating repairs will be required, please ensure that yu allw fr additinal time in yur prject in rder t arrange these wrks. Yu shuld nt call fr tenders r cmmence site-wrks, befre a DCVG Survey and/r pipeline cating repair is cmpleted. If any catings are fund t have been damaged by yur wrks r activities, r by the lack f preventative actins, then yu will be charged fr the csts assciated with the damage and repair f the cating, including any indirect damage that has ccurred during yur wrks such as cating damage frm excessive vibratin Electrical Equipment Surces f electrical current (such as abve and belw grund electrical cables, earth rds, substatins, transfrmers, r impressed current systems f nn- ATCO pipelines) must nt interfere with the crrsin prtectin and induced vltage mitigatin equipment f existing ATCO assets. ATCO requires any new electrical infrastructure near gas assets t cmply with AS/NZS 4853 Electrical Hazards n Metallic Pipelines. Apprval by ATCO f any prpsed mitigatin requirements must be btained prir t installatin f the infrastructure. During the design stage the prpnent must verify the lcatin f metallic pipelines, including any appurtenance affected by the Earth Ptential cntur hazard. Please nte that DYBD plans may nt shw all gas assets nr may it distinguish frm abve r belw grund assets. Earthing rds, substatins, transfrmers, earthing-stakes, nn- ATCO pipeline impressed current systems, cables perating abve 22kV, r banks f cables perating at 22kV, will ften adversely affect the safety f the gas pipelines unless mitigatin is emplyed in accrdance with AS/NZS Engineering Services must be pre-ntified in all cases, and where mitigatin cntrls are required an Earth Ptential reprt may be required. Issue Date: 26/09/2018 Page 22 f 30

23 5.11 Expsure f Gas Assets Where gas pipelines are required t be temprarily expsed, measures must be put in place t prtect the pipelines frm damage. Measures must be taken t prtect the pipe frm accidental (cnstructin r vehicle impact) and deliberate damage (vandalism). Where any expsed gas pipe will be left unattended fr any perid f time, prir apprval must be btained frm Engineering Services. Damage by sagging must als be prevented, with safe wrking prcedures develped fr expsing any gas pipelines. Fr any unsupprted span f pipe, Engineering Services can be cntacted fr advice n safe wrking prcedures. Table 6 can be used as a guide fr maximum lengths f pipe that can be left unsupprted fr any perid f time, subject t n-site review f the pipeline cnditin and safe wrking methds being utilised. Table 6: Maximum unsupprted length fr gas pipelines Pipe Size (Diameter, mm) Pipe Material (Maximum Unsupprted Length, m) Steel (ST) Plyethylene (PE) Plyvinyl Chlride (PVC) Prir t backfilling, a minimum f 150mm all arund the pipe must be filled and packed with suitable backfilling material. The padding must be fine, lse material, equivalent t washed beach r river sand. The sand must be clean, free frm all sharp bjects, clay material, vegetable matter, building debris and disused rad paving material. The crwn (tp), f the asset must be cvered with a minimum f 300mm f clean backfill material prir t mechanical cmpactin. The remainder f the excavatin must be backfilled at 300mm increments and cmpacted t the density level in the surrunding sub-grade material and cmpactin requirements f the relevant rad authrity. All mechanical cmpactin must cmply with Sectin 0. Issue Date: 26/09/2018 Page 23 f 30

24 6. HIGH PRESSURE GAS INFRASTRUCTURE MANDATORY REQUIREMENTS 6.1 Assets Subject t these Mandatry Requirements Additinal requirements are impsed n any activities ccurring in clse prximity t HP gas infrastructure. These requirements are in additin t the bligatins set ut in the planning and cnducting wrk sectins in this dcument. These mandatry requirements apply t all wrks within 15m f HP gas infrastructure, as shwn in Table 7. Table 7: Applicatin f Mandatry Requirements t varius types f the Netwrk Pressure Acrnym Netwrk Descriptr Mandatry Requirements 20kPa AMP Albany Medium Pressure N LPG Netwrk 7kPa MLP Medium-Lw Pressure N 70kPa MP Medium Pressure N 350kPa PEHP Plyethylene High Pressure N, sizes DN110mm & belw CHP City High Pressure Yes kPa HP High Pressure Yes Yes, sizes DN160mm & abve The mandatry cnditins arund this infrastructure apply t all wrks including service lcatin and all abve grund activities that culd impact n the infrastructure. The mandatry requirements are shwn schematically in Figure 2 and detailed in this sectin, summarised as fllws: Wrks within 15m f HP Gas Infrastructure: All wrks must have a current ATCO HP Ntificatin (Sectin 6.2.1). Wrks within 5m f HP Gas Infrastructure: All wrks must have a current ATCO HP Ntificatin (Sectin 6.2.1). Attendance is required by an Apprved Lcatr fr all activities / wrks (Sectin 6.3.1). The lcatin f gas assets must be prven immediately prir t wrk (Sectin 6.3.2). Issue Date: 26/09/2018 Page 24 f 30

25 Figure 2 Mandatry Lcatin Requirements Limitatins n activities and use f mechanical equipment apply (Sectin 6.3.2). 6.2 Wrks within 15 Metres f HP Gas Infrastructure Due t the risk assciated with wrking arund HP gas pipelines, all wrks that are prpsed within 15m f HP gas infrastructure must be evaluated by ATCO. Once cnsent is prvided by ATCO as the asset wner, a HP Ntificatin will be prvided that will list the permitted activities and any cnditins that must be fllwed. A cpy f the current HP Ntificatin must always be n site and presented t any authrised fficer f ATCO upn request. Relevant wrks are any actin r activity r the missin f any act r activity that culd affect the gas pipeline including, but nt limited t: Weight lading nt the pipeline heavy vehicle crssings, crane psitining, equipment strage, cmpactin, additinal grund cver. Vibratin lading cmpactin, drilling, piling, vibratry rlling. Impact digging, drilling, tie-back bars, ple installatin, fencing, bring, new service installatin, grund anchrs, tree remval r stump grinding, etc. Alteratin f grund cnditins rad wrks, land develpments, ftpaths, crssvers, cycle paths, water curses (including swales r pen drains), planting f vegetatin, etc., including any activities that may limit access r cause the grund t shift r subside. Ht wrks grinding, welding, thermal cutting r heating, and ther related heatprducing r spark-prducing peratins per Sectin 5.5. The lcatin / psitin and bvert level (i.e., tp ) f all gas pipelines shuld be prven using direct visual identificatin during the planning / design stage f the prject. In sme instances, prving f the gas pipeline is necessary t btain a HP Ntificatin fr subsequent activities. Issue Date: 26/09/2018 Page 25 f 30

26 6.2.1 HP Ntificatin The HP Ntificatin is prvided by the ATCO HP Officer nce all requested infrmatin has been prvided, and ATCO is satisfied that the wrks can prceed withut damaging the Netwrk. Where deemed necessary, the wrks may have t be reviewed by Engineering Services. The ATCO HP Officer at their sle discretin will decide whether t issue a site specific HP Ntificatin with accmpanying cnditins / requirements impsed and the prpnent must cmply with such cnditins / requirements. Yu must nt cnduct any wrks / activities n site, prir t btaining the relevant HP Ntificatin frm the ATCO HP Officer. Cautin: The HP Ntificatin must be kept n site with the wrks supervisr. All f the activities within 15m f HP Gas Infrastructure must be cvered under the HP Ntificatin. ATCO regularly patrls its gas pipelines, and this HP Ntificatin must be presented upn request by an fficer f ATCO. Failure t prvide the HP Ntificatin r failure t demnstrate the wrks are in cmpliance with the apprved activities may result in halting f the jb until cmpliance with ATCO requirements is prven by the peratr. ATCO reserves the right t ntify WrkSafe and EnergySafety in cases f nn-cmpliance and initiate prsecutin as necessary Required Lead Times The minimum times that shuld be allwed fr requesting and receiving a HP Ntificatin t allw wrks within 15m f HP Gas Assets are as shwn in Table 8. Table 8: Minimum time frames fr requesting HP Ntificatins Type f Request HP Ntificatin withut Engineering Assessment HP Ntificatin with Engineering Assessment Time Frame 2 business days 4 weeks Where the prpsed wrks are altered r added t, additinal time shuld be allwed fr reassessment. Where wrks may require alteratins t the Netwrk, additinal time will be required per Sectin What Infrmatin Will Yu Need t Prvide the HP Officer Yu must frward all relevant prject details and drawings f any prpsed wrks (including any temprary wrks / activities) and prpsed machinery deplyment, t the ATCO HP Officer. A current ATCO DBYD Sequence Number must als be prvided when calling. Issue Date: 26/09/2018 Page 26 f 30