Biogas can be simply collected using cost-effective surface covers. These are
secured around the pond perimeter either by burying in a trench or by
anchoring to a concrete perimeter curb. Covers can be manufactured from
high density polyethylene (HDPE) or preferably polypropylene (PP) or
polyester scrim reinforced polypropylene (XR-5 or similar). These materials
have a life-span of more than 20 years and are easily repaired.