The group stated that there needs to be greater clarity over what waste materials can be used as infill and what needs to be sent to a waste site.
Dywedodd y grŵp fod angen mwy o eglurder ynghylch pa ddeunyddiau gwastraff y gellir eu defnyddio i fewnlenwi a beth sydd angen cael ei anfon i safle gwastraff.