Water Burial Urns are biodegradable urns meant to float for a short time before gently submerging. This allows time for a farewell ceremony, before the urn gently sinks. The rate of submersion will vary by urn type and other factors such as ash volume and water conditions. A water burial ceremony is sometimes referred to as a scattering ceremony even if there is no scattering of ashes. A water burial with a biodegradable cremation urn can take place in the ocean, lake or even a river. Water burial urns are often chosen by those concerned with the environmental impact of the urn. Cremation ash is sterile and does not present any health hazard.