techiaith/bydtermcymru-tm-en-cy huggingface dataset:
English: A land-bank is a stock of planning permissions which usually relates to the extraction of non-energy minerals and provides for continuity of production in spite of fluctuations in demand.
Welsh: Yr hyn yw banc tir yw stoc o fwy nag un caniatâd cynllunio sydd, fel arfer, yn gysylltiedig â chloddio am fwynau nad ydynt yn cynhyrchu ynni. Mae'n darparu ar gyfer parhad cynhyrchiant er gwaethaf amrywiadau yn y galw.
English: For the purposes of commercial stability, the aggregates industry requires a proven and viable landbank.
Welsh: At ddibenion sefydlogrwydd masnachol, mae'r diwydiant agregau angen banc tir hyfyw sydd wedi hen ennill ei blwyf.
English: Planning authorities should include policies in their development plans for the maintenance throughout the plan period of land-banks for non-energy minerals which are currently in demand.
Welsh: Dylai awdurdodau cynllunio gynnwys polisïau yn eu cynlluniau datblygu ar gyfer cynnal, trwy gydol cyfnod y cynllun, fanciau tir ar gyfer mwynau nad ydynt yn cynhyrchu ynni ac y mae galw amdanynt ar hyn o bryd.
English: This must be adequate but not excessive
Welsh: Rhaid i'r rhain fod yn ddigonol, ond nid yn ormodol
English: A minimum ten year landbank of crushed rock and minimum seven year landbank for sand and gravel should therefore be maintained during the entire plan period of each development plan unless agreement is reached for other authorities to make a compensating increase in their provision.
Welsh: Felly, dylid cynnal banc tir deng mlynedd o leiaf ar gyfer craig wedi malu a banc tir saith mlynedd o leiaf ar gyfer tywod a graean trwy gydol cyfnod pob cynllun datblygu, oni bai y cytunir i awdurdodau eraill gynyddu eu darpariaeth i wneud iawn am hynny.
English: There is no requirement for a landbank to be maintained within National Parks and AONBs.
Welsh: Nid oes gofyn cadw banc tir mewn Parciau Cenedlaethol ac AHNE.
English: See Ministerial letter of 25 July 2014
Welsh: Gweler llythyr y Gweinidog 25 Gorffennaf 2014
English: In these circumstances, authorities must agree a joint approach with neighbouring authorities in line with current regional arrangements and may require liaison with relevant mineral planning authorities in England.
Welsh: O dan yr amgylchiadau hynny, rhaid i awdurdodau gytuno i gydweithio ag awdurdodau cyfagos yn unol â'r trefniadau rhanbarthol presennol, ac mae'n bosibl y bydd angen iddynt drafod ag awdurdodau cynllunio mwynau perthnasol yn Lloegr.
English: This could reasonably include:
Welsh: Byddai'n rhesymol i'r polisïau hynny gynnwys:
English: using prohibition orders to ensure that no further extraction takes place without a further planning consent so as to provide certainty about future workings;
Welsh: defnyddio gorchmynion gwahardd er mwyn sicrhau na fydd unrhyw gloddio pellach heb ganiatâd cynllunio newydd er mwyn rhoi sicrwydd ynghylch gweithio'r safleoedd hynny yn y dyfodol;
English: restoration and after care proposals, which could include natural re-vegetation for nature conservation/ ecological interests in accordance with local Biodiversity Action Plans, green infrastructure assessments or the conservation of historic assets for tourism;
Welsh: cynigion adfer ac ôl-ofal (a allai gynnwys aildyfiant naturiol at ddibenion cadwraeth natur/ buddiannau ecolegol yn unol â Chynlluniau Gweithredu Bioamrywiaeth lleol, asesiadau seilwaith gwyrdd neu warchod asedau hanesyddol ar gyfer twristiaeth);
English: a suitable proposed after-use.
Welsh: ôl-ddefnydd arfaethedig addas.
English: It is important that the future of these sites should be finally determined to provide certainty to the local community and secure the restoration of old workings at the earliest opportunity, including capturing any potential for improving the resilience of ecological networks.
Welsh: Mae'n bwysig penderfynu'n derfynol ar ddyfodol y safleoedd hynny er mwyn rhoi sicrwydd i'r gymuned leol a sicrhau bod hen weithfeydd yn cael eu hadfer cyn gynted ag y bo modd, yn cynnwys manteisio ar unrhyw botensial i wella cydnerthedd rhwydweithiau ecolegol.
English: It is in the interests of the minerals industry that landbanks reflect real possibilities for future mineral working.
Welsh: Mae er budd i'r diwydiant mwynau bod banciau tir yn adlewyrchu posibiliadau gwirioneddol ar gyfer cloddio am fwynau yn y dyfodol.
English: In some circumstances, it may be necessary to maintain an adequate landbank by approval of new permissions in more acceptable locations.
Welsh: O dan rai amgylchiadau, mae'n bosibl y bydd angen cadw banc tir digonol trwy roi caniatadau newydd mewn lleoliadau mwy derbyniol.
English: Mineral operators should discuss with authorities inactive permissions which will not be reactivated.
Welsh: Dylai gweithredwyr mwynau drafod gyda'r awdurdodau unrhyw ganiatâd sydd heb ei weithredu ac na fydd yn cael ei ddefnyddio eto.
English: Where these sites have been inactive and there is no prospect of future working, authorities should consider the use of prohibition orders.
Welsh: Os bu'r safleoedd hynny'n anweithredol, ac nad oes unrhyw olwg y byddant yn cael eu gweithio yn y dyfodol, dylai awdurdodau ystyried defnyddio gorchmynion gwahardd.
English: Areas of Future Working
Welsh: Ardaloedd Gwaith ar gyfer y Dyfodol
English: This approach brings a high degree of certainty to all.
Welsh: Mae'r ymagwedd hon yn darparu lefel uchel o sicrwydd i bawb.
English: Policies and proposals should relate to identifiable areas of land unless there is a good reason why this is not possible and should cover mineral resources which are currently used or which may need to be used in the foreseeable future.
Welsh: Dylid cysylltu polisïau a chynigion ag ardaloedd penodol o dir oni bai bod rheswm da pam nad oes modd gwneud hynny, a dylent gwmpasu adnoddau mwynau sy'n cael eu defnyddio ar hyn o bryd neu y gall fod angen eu defnyddio hyd y gellir rhagweld.
English: These should be clearly identified on a proposals map and should, in the following order of preference, take the form of:
Welsh: Dylid nodi'r lleoedd hynny'n glir ar fap cynigion, a dylent fod ar ffurf:
English: Specific Sites where mineral resources of commercial significance exist and where any planning applications which come forward for those sites are likely to be acceptable in planning terms;
Welsh: Safleoedd Penodol lle mae adnoddau mwynau o bwys masnachol i'w cael, a lle bo unrhyw geisiadau cynllunio a gyflwynir ar gyfer y safleoedd hynny yn debygol o fod yn dderbyniol o safbwynt cynllunio;
English: Preferred Areas which will be areas of known resources with some commercial potential and where planning permission might reasonably be anticipated;
Welsh: Ardaloedd a Ffefrir sef ardaloedd lle gwyddys bod adnoddau ac iddynt rywfaint o botensial masnachol, a lle byddai'n rhesymol disgwyl i ganiatâd cynllunio gael ei roi;
English: Areas of Search where it is likely that some sites will be appropriate for mineral extraction, depending on economic and/or environmental circumstances.
Welsh: Ardaloedd Chwilio lle byddai cloddio am fwynau yn debygol o fod yn briodol ar rai safleoedd, gan ddibynnu ar amgylchiadau economaidd a/ neu amgylcheddol.
English: Areas of search will define broad areas that are believed to contain mineral resources of commercial significance but whose extent is uncertain.
Welsh: Bydd ardaloedd chwilio yn diffinio ardaloedd bras y credir bod ynddynt adnoddau mwynau o bwys masnachol ond nad oes sicrwydd ynghylch union faint o'r adnoddau hynny sydd i'w cael yno.
English: Within these areas it is likely that appropriate mitigation measures can overcome all environmental effects.
Welsh: Mewn ardaloedd o'r fath, mae'n debyg y byddai mesurau lliniaru priodol yn gallu goresgyn yr holl effeithiau amgylcheddol.
English: Within areas of search, planning permissions could be granted to meet a shortfall in supply should specific sites, preferred areas, or extensions to existing sites identified in the plan, not come forward.
Welsh: Mewn ardaloedd chwilio, byddai modd rhoi caniatâd cynllunio er mwyn mynd i'r afael â diffygion yn y cyflenwad pe na bai ardaloedd penodol neu ardaloedd a ffefrir ar gael, neu pe na bai modd estyn safleoedd sy'n bodoli eisoes.
English: It will not usually be appropriate for an authority to identify only areas of search in a plan; full justification for adopting such an approach would be needed;
Welsh: Fel rheol, ni fyddai'n briodol i awdurdod nodi ardaloedd chwilio, a'r rheini'n unig, mewn cynllun, a byddai angen rhoi cyfiawnhad llawn dros wneud hynny;
English: Other Areas:
Welsh: Ardaloedd Eraill:
English: Planning permission should not be granted in areas outside those identified in the plan except where the mineral is needed to make good a proven shortfall in supply, and where the proposal is demonstrably proven to be environmentally acceptable and to have no adverse impact on the amenity of nearby residents or communities
Welsh: Ni ddylid rhoi caniatâd cynllunio mewn ardaloedd y tu allan i'r rheini a nodir yn y cynllun oni bai bod angen y mwynau dan sylw oherwydd diffyg amlwg yn y cyflenwad, ac oni bai y profwyd bod y cynllun yn amgylcheddol dderbyniol ac na fydd yn effeithio'n andwyol ar amwynder trigolion na chymunedau cyfagos
English: They may do this individually or in collaboration with adjoining authorities
Welsh: Gallant wneud hynny'n unigol neu ar y cyd ag awdurdodau cyfagos
English: For aggregates via RAWP annual surveys and the preparation of five yearly regional technical statements
Welsh: Ar gyfer agregau trwy arolygon blynyddol RAWP a thrwy baratoi datganiadau technegol rhanbarthol bob pum mlynedd
English: National, Regional and Local needs for Non-Energy Minerals
Welsh: Anghenion Cenedlaethol, Rhanbarthol a Lleol ar gyfer Mwynau Nad Ydynt yn Cynhyrchu Ynni
English: The recovery of high purity or high quality minerals to meet a particular specification may necessitate the removal of lower grade material.
Welsh: Gall cloddio am fwynau pur neu fwynau o safon uchel i fodloni manyleb benodol olygu bod angen cael gwared ar ddeunydd o radd is.
English: Wherever possible, scarce resources of high grade material should be reserved for the most appropriate high-end use.
Welsh: Lle bynnag y bo modd, dylai'r adnoddau prin sydd ar gael o ddeunydd gradd uchel gael eu cadw at y defnydd mwyaf priodol.
English: The main sources of aggregates are crushed rock and sand and gravel - both land-won and marine-dredged.
Welsh: Prif ffynonellau agregau yw tywod a graean a chreigiau wedi'u malu - sy'n cael eu casglu oddi ar y tir ac o'r môr.
English: A number of secondary materials are used for construction purposes.
Welsh: Defnyddir nifer o ddeunyddiau eilaidd at ddibenion adeiladu.
English: These materials are often by-products of industrial processes and include slag from steel manufacture, ash from power stations, colliery spoil, slate waste and recycled material such as demolition arisings and road planings.
Welsh: Yn aml, mae'r deunyddiau hyn yn sgil-gynhyrchion prosesau diwydiannol, ac maent yn cynnwys slag o waith dur, lludw o orsafoedd pŵer, gwastraff pyllau glo, gwastraff llechi a deunyddiau wedi'u hailgylchu sy'n dod o waith dymchwel a gwastraff ffyrdd.
English: The importance to the UK of aggregates should be taken into account when planning applications are being considered together with other policies in this guidance and relevant Minerals Technical Advice Notes (MTANs) and Technical Advice Notes (TANs).
Welsh: Wrth ystyried ceisiadau cynllunio, dylid cofio pa mor bwysig yw agregau i'r DU, a dylid hefyd ystyried polisïau eraill yn y canllawiau hyn ac yn y Nodiadau Cyngor Technegol Mwynau (MTANs) a'r Nodiadau Cyngor Technegol (TANs) perthnasol.
English: In order to conserve natural resources, particular emphasis should be given to increasing the use of alternative products to primary materials where appropriate
Welsh: Er mwyn gwarchod adnoddau naturiol, dylid rhoi pwyslais arbennig, lle bo hynny'n briodol, ar ddefnyddio mwy o gynhyrchion amgen yn hytrach na deunyddiau sylfaenol
English: The UK and regional need for such minerals should be accorded significant weight provided environmental impacts can be limited to acceptable levels.
Welsh: Dylid rhoi pwyslais sylweddol ar angen y DU ac angen rhanbarthol am fwynau o'r fath cyn belled bod modd cyfyngu effeithiau amgylcheddol i lefelau derbyniol.
English: The fundamental characteristics of these materials, which distinguish them from more general-purpose aggregates, are their ability to meet the stringent specifications required for road construction and repair and wherever possible high specification aggregates should be used for these purposes.
Welsh: Nodweddion sylfaenol y deunyddiau hyn, sy'n eu gwahaniaethu oddi wrth agregau â diben mwy cyffredinol, yw eu gallu i fodloni'r manylebau caeth sy'n ofynnol ar gyfer adeiladu a thrwsio ffyrdd, a lle bo'n bosibl dylid defnyddio agregau manyleb uchel ar gyfer y dibenion hyn.
English: Planning authorities should identify potential high specification aggregate resources and consider whether there is a need to protect these resources and potential rail connections to the resources from sterilisation.
Welsh: Dylai awdurdodau cynllunio nodi adnoddau agregau gradd uchel ac ystyried a oes angen gwarchod yr adnoddau hyn a chysylltiadau rheilffordd posibl i'r adnoddau rhag sterileiddio.
English: The slates of North-West Wales are of high quality and are available in extensive quantities.
Welsh: Mae llechi Gogledd-orllewin Cymru yn rhai o safon uchel, ac mae llawer ohonynt ar gael.
English: The total area of land affected by slate extraction is relatively small, but vast quantities of waste materials have been generated and at the present time there are only limited potential uses.
Welsh: Mae cyfanswm yr arwynebedd tir yr effeithir arno gan waith cloddio llechi yn gymharol fach, ond mae llawer iawn o ddeunydd gwastraff wedi'i gynhyrchu, ac ar hyn o bryd, nid oes llawer o botensial i ddefnyddio'r deunydd hwnnw.
English: In South Wales, slate is more restricted in distribution and the resource has not been worked on any scale for many years although some slate waste has been used as aggregate material.
Welsh: Yn Ne Cymru, mae dosbarthiad llechi yn fwy cyfyngedig ac ni fu gwaith mawr ar yr adnodd hwn ers blynyddoedd lawer, er bod rhywfaint o wastraff llechi wedi'i ddefnyddio fel deunydd agregau.
English: In North Wales the increased use of slate waste should be encouraged, as for all potential sources of secondary material and where this option is not commercially viable, areas should be identified for restoration.
Welsh: Yn y Gogledd, dylid annog y defnydd cynyddol o wastraff llechi, yr un fath â phob ffynhonnell deunydd eilaidd a lle nad yw'r opsiwn hwn yn fasnachol hyfyw, dylai ardaloedd gael eu nodi i'w hadfer.
English: Active slate quarries play an important part in maintaining local building character where the use of slate of a specific appearance is a strict planning policy.
Welsh: Mae chwareli llechi yn gwneud cyfraniad pwysig at gynnal cymeriad adeiladau lleol, lle mae defnyddio llechi o fath penodol yn bolisi cynllunio caeth.
English: It is important that the supply of slate is maintained but balanced against the need to protect important landscapes.
Welsh: Mae'n bwysig bod y cyflenwad llechi'n cael ei gynnal, ond wedi'i gydbwyso yn erbyn yr angen i warchod tirweddau pwysig.
English: Dimension stone is used in new buildings where it is important to maintain local building character.
Welsh: Defnyddir cerrig dimensiwn mewn adeiladau newydd pan fo'n bwysig cadw cymeriad adeilad lleol.
English: It may be necessary to obtain dimension stone from geological formations which are restricted in occurrence in order to obtain a particular colour, texture or homogeneity.
Welsh: Efallai y bydd angen cael cerrig dimensiwn o ffurfiannau geolegol nad ydynt i'w gweld yn aml iawn, a hynny er mwyn cael math arbennig o liw, ansawdd neu unffurfedd.
English: There is often a large proportion of waste produced that may be utilised as general construction aggregate.
Welsh: Yn aml, mae modd i gyfran fawr o'r gwastraff a gynhyrchir gael ei ddefnyddio fel agreg adeiladu cyffredinol.
English: Market demand will usually result in low rates of output from relatively small sites which may be temporary or intermittent and a flexible approach may be necessary to deal with the long duration of planning permissions which result from such a working pattern.
Welsh: Fel rheol, bydd y galw yn y farchnad yn arwain at gyfraddau cynhyrchu isel o nifer cymharol fach o safleoedd a all fod yn rhai dros dro neu'n rhai ysbeidiol ac efallai y bydd angen dull hyblyg i ymdrin â hyd hir caniatadau cynllunio sy'n deillio
English: The cumulative impact of a number of small sites operating in close proximity should be taken into account.
Welsh: Dylid ystyried yr effaith gronnol a gaiff nifer o safleoedd bach yn gweithredu'n agos at ei gilydd.
English: Limestone for Industrial Uses
Welsh: Calchfaen at Ddibenion Diwydiannol
English: There may be a need to maintain a longer landbank of reserves at such sites than required for general aggregates to justify the considerable investment in plant.
Welsh: Efallai y bydd angen cynnal banc tir hirach o gronfeydd mewn safleoedd o'r fath nag sy'n ofynnol ar gyfer agregau cyffredinol i gyfiawnhau'r buddsoddiad mawr mewn ffatrïoedd.
English: Mineral planning authorities are encouraged to discuss these matters with the industry with a view to reaching agreement on the extent of resources likely to be required during the life of a development plan.
Welsh: Anogir awdurdodau cynllunio mwynau i drafod y materion hyn gyda'r diwydiant gyda'r nod o ddod i gytundeb ynghylch faint o adnoddau sy'n debygol o fod eu hangen yn ystod oes cynllun datblygu.
English: High purity limestone
Welsh: Ceir calchfaen pur iawn
English: In north Wales, the thickest deposits of high purity limestone occur near the Flintshire/Denbighshire border, which supply stone for cement manufacture at Buckley.
Welsh: Yng Ngogledd Cymru, ger y ffin rhwng Sir y Fflint a Sir Ddinbych, y mae'r haenau mwyaf trwchus o galchfaen pur iawn ac maent yn cyflenwi cerrig ar gyfer gwaith sment Bwcle.
English: The environmental impact of quarrying for high purity materials is similar to that for aggregates, except that processing plant may be on a larger scale and transportation of output may involve longer distances to industrial markets.
Welsh: Mae'r effaith amgylcheddol a gaiff cloddio am ddeunyddiau pur iawn yn debyg i effaith amgylcheddol cloddio am agregau, ac eithrio y gallai'r offer prosesu fod yn fwy, ac y gallai bod angen teithio ymhellach er mwyn cludo'r cynnyrch i farchnadoedd diwydiannol.
English: Where quarries produce limestone for both aggregate and non-aggregate use, the reserve will normally be split and each category determined by the predicted reserve for each type.
Welsh: Lle mae chwareli'n cynhyrchu calchfaen at ddefnydd agregau ac at ddefnydd arall, fel arfer bydd y gronfa'n cael ei rhannu a phob categori'n cael ei bennu gan y gronfa a ragwelir ar gyfer pob math.
English: Operators should ensure such reserves are calculated using up to date information and using recognised trade formulae (for example PERC).
Welsh: Dylai gweithredwyr sicrhau bod cronfeydd o'r fath yn cael eu cyfrifo gan ddefnyddio'r wybodaeth ddiweddaraf a fformiwlâu masnach cydnabyddedig (er enghraifft, PERC).
English: Future peat extraction should not be granted permission unless it is limited to wholly exceptional circumstances in areas which have already been damaged significantly by recent human activity where restoration towards wetland habitats could improve the nature conservation importance of a worked out bog.
Welsh: Ni ddylid rhoi caniatâd i gloddio mawn yn y dyfodol oni bai ei fod wedi'i gyfyngu i amgylchiadau gwbl eithriadol mewn ardaloedd sydd eisoes wedi'u difrodi'n sylweddol gan weithgareddau dynol diweddar lle gallai adfer y tir er mwyn creu cynefinoedd gwlyptir wella, o ran ei phwysigrwydd cadwraeth natur, cors sydd wedi'i dihysbyddu.
English: NRW and the planning authority's ecologist and archaeological advisor should be consulted on proposals for peat extraction.
Welsh: Dylid ymgynghori â CNC ac ag ecolegwyr a chyngorydd archaeolegol yr awdurdod cynllunio am unrhyw gynlluniau i gloddio mawn.
English: Over time these activities have declined and some are unlikely to be reactivated.
Welsh: Dros amser, mae'r gweithgareddau hyn wedi dirywio ac mae rhai yn annhebygol o gael eu hailfywiogi.
English: If applications for development do come forward the criteria based policy applicable for the extraction of aggregates should be applied.
Welsh: Os gwneir ceisiadau am ddatblygiad, dylid defnyddio'r polisi seiliedig ar feini prawf ar gyfer cloddio am agregau.
English: It may be appropriate to consider other policies, determined on a case by case basis, including an assessment of the need for the mineral.
Welsh: Efallai y bydd hi'n briodol ystyried polisïau eraill, a bennir fesul achos, gan gynnwys asesiad o'r angen am y mwynau.
English: These include use for industrial purposes in the steel industry, in speciality carbon markets, in the making of concrete and for domestic use.
Welsh: Fe'i defnyddir at ddibenion diwydiannol yn y diwydiant dur, mewn marchnadoedd carbon arbenigol, i wneud concrit ac at ddibenion domestig.
English: Coking coal, for example, which is largely imported is used in coke manufacture for the steel industry and directly in blast furnaces.
Welsh: Defnyddir glo golosg er enghraifft, y caiff y rhan fwyaf ohono ei fewnforio, i weithgynhyrchu golosg ar gyfer y diwydiant dur ac yn uniongyrchol mewn ffwrneisi chwyth.
English: Whilst the use of coal for energy generation should not be permitted if, exceptionally, planning applications come forward for industrial uses for coal then each case would need to be considered individually and the policies contained in MTAN 2:
Welsh: Er na ddylid caniatáu defnyddio glo i gynhyrchu ynni, os daw cais cynllunio eithriadol ar gyfer defnydd diwydiannol i lo, yna rhaid ystyried pob achos yn unigol a defnyddio'r polisïau sydd wedi'u cynnwys yn MTAN 2:
English: Coal applied, including the test outlined in paragraph 45 of MTAN 2.
Welsh: Glo, yn cynnwys y prawf a amlinellir ym mharagraff 45 o MTAN 2.
English: Such contracts may require the supply of large quantities of minerals as engineering fill over a short timescale which may cause significant environmental impact and disturbance to local communities.
Welsh: Maent yn gysylltiedig â chontractau priffyrdd, neu safleoedd llenwi siâl bach fel arfer. Gall fod angen llawer iawn o fwynau mewn amser byr ar gyfer contractau mawr, a hynny fel llenwad peirianyddol.
English: Planning authorities must ensure that there are clear environmental benefits from meeting supply from a proposed borrow pit as opposed to supply from secondary or recycled aggregates, or from established mineral working sites or areas identified in the development plan.
Welsh: Dylai awdurdodau cynllunio sicrhau bod manteision amgylcheddol clir o ddefnyddio pyllau benthyg arfaethedig yn hytrach na chyflenwad o agregau eilaidd neu agregau wedi'u hailgylchu, neu o safleoedd mwynau sefydledig neu ardaloedd a nodwyd yn y cynllun datblygu.
English: Borrow pits have potential for impacting adversely on buried archaeological evidence and early consultation should be undertaken with the planning authority's archaeological advisor so that all known sensitive archaeological features can be identified.
Welsh: Mae gan byllau benthyg y potensial i gael effaith andwyol ar dystiolaeth archaeolegol claddedig, a dylid cynnal ymgynghoriad cynnar â chynghorydd archaeolegol yr awdurdod cynllunio fel bod modd nodi'r holl nodweddion archaeolegol sensitif hysbys.
English: Borrow pits must be restored to the high standard expected of other forms of mineral development. The potential cumulative impact of a number of closely sited borrow pits must be carefully considered and it is likely that the impact will not be acceptable in particularly sensitive locations.
Welsh: Mae'n bwysig bod pyllau benthyg yn cael eu hadfer i'r un safon uchel ag a ddisgwylir ar gyfer mathau eraill o ddatblygiadau mwynau. Bydd angen rhoi ystyriaeth ofalus i effaith gronnol bosibl nifer o byllau benthyg sy'n agos at ei gilydd, ac efallai na fyddai hynny'n briodol mewn lleoliadau sy'n arbennig o sensitif.