Gully Trap

Everything you need to know about gully traps Waste Pipes Ground Level Concrete Surface Grating 25mm above paved and 100mm above unpaved What is a gully trap? Agullytrapisabasininthegroundwhichreceivespiped wastewaterfromyourkitchen,bathroomandlaundrybeforeitis emptiedintothesewer. Thebasinhasawatersealtopreventfoul odoursofthesewerreachingthesurface. Thetoporsurroundis raisedabovegroundleveltopreventstormwaterandotherforeign matterenteringthesewer. What should my gully trap look like? Thediagramshowstheacceptedconfigurationofagullytrapasset outintheNewZealandBuildingCode.Gullytraparrangementswhich TheBuildingCodesaysyourgullytrapsurroundsmustbe25mm aboveapavedsurfaceor100mmaboveunpavedsurfaces. Compacted granular bedding material Separation from building material Gully traps are not meant for stormwater Inperiodsofheavyrain,asuddenincreaseinwater flowingintothesewerthroughgullytrapscanresult inwastewateroverflowselsewhereinthesewerage system. Thiscanresultinrawsewageentering ourharb our. Theseexcessiveflowscanalsocause problemsatthewastewatertreatmentplantdueto systemoverloading. Approved gully trap keeping rain water out of the wastewater system.Illegal gully trap allowing rain into the wastewater system. Common reasons why rain water flows into a gully trap inClude: †¢ Incorrectheightofthegullytrapsurrounds †¢ Downpipesplumbedintothegullytrapinsteadofthestormwatersystem A TAURANGA CITY COUNCIL SERVICE †¢ Landscapingthatdirectswaterintothegullytrap Water seal 65mm (min) donotcomplywiththisconfigurationareconsideredillegal. 600mm (max) Preventing sewer overflows to keep our harbour clean TheSouthernPipelineisa$106Mwastewaterpipeline thatwillredirectmostofthecity’swastewateroverto TeMaunga.However,it’sstillafewyearsaway. InthemeantimeCouncilhasstartedinspectinggully trapsthroughoutthecitytohelpcustomersknowif theirsisOK,andtoofferadviceonhowtofixthemif they’renot. Ifeverypropertyownerwithanincorrectlydesigned gullytrapfixedit, theamountofstormwatersneaking intothewastewatersystemwouldbegreatlyreduced. Not all problems will be solved by these options . . . Ifyouhavelandscapingthatdirectsstormwater intoyourgullytrap,youmayneedtospeaktoyour drainlayeraboutoptionstofixthis. Somegully trapsmayalsoneedadditionalworktomakethem compliant.Tofurtherminimiseanywatergettingintothe wastewatersystemallpropertyownersmust ensurethat: †¢ anypavingsurroundingthegullytrapisgraded todirectallstormwaterawayfromit †¢ allwastepipeconnectionstothegullytrap remainwatertight †¢ anydownpipesthatcurrentlydischargeinto thegullytrapareredirectedtoastormwater system(e. g. soakholeorreticulationsystem). How can I fix my gully trap? Toraiseyourgullytraptotherequiredheight, suitable. hereareacoupleoflowcostoptionsthatmaybe 1. Installaplasticriser. Thisisfittedoverthe gullytrapwithsealantaroundtheedgesand walltokeepstormwateroutofthegullytrap.Theseareavailablefromhardwareoutlets likeMitre10,PlacemakersorCarters. 2. Installac oncretehalfring(alsoknownasa nibwall). Thisiscementedintoplacewith sealantaroundtheedgesandwalltokeep stormwateroutofthegullytrap. These areavailablefromaconcretesupplierlike Humes. For more information or advice, please contact Tauranga City Council on (07) 577 7000 or go to www. tauranga. govt. nz and type in key words ‘gully trap’. A TAURANGA CITY COUNCIL SERVICE If you need more help contact Waterline Ph: 577 7000 Web: www. tauranga. govt. nz MVM50675F