No. The three primary reasons: Plastics like polyesters and PETs (the two most commonly used plastics in water bottles) do not biodegrade very easily. The processes required to make the plastics break down to their constituent molecules require high temperature and pressure, which is not available in a landfill or composter environment. Once these products are discarded into dumpsites, they contaminate potential sources of dirt recycling such as agricultural soil and living plants by imposing an ever-present toxic contaminant that will exist for perpetuity or at least until it reaches critical concentrated levels.