Ecological Burial (updated)

In 2004, my dad passed away at the age of 96. In his Last Will and Testament, he designated cremation for his body but did not specify what to do with the ashes. After the cremation and memorial service, I asked my mother what she thought we should do with them and she suggested perhaps spreading them somewhere in nature, since he liked nature walks. However, I was concerned that spreading them in nature was like littering. My chief concern was that the ashes may contain toxic chemicals and therefore it would be irresponsible to spread them in nature. Since no one else in the family was interested, I...