The Kapiti Coast District Council Biosolids Strategy - Investigating Viable Resource Recovery Options
Annual Conference
❄
Globally there has been a paradigm shift from disposal to resource recovery of biosolids. The K?piti Coast District Council is in a favourable position to be a leader with municipal biosolids beneficial use in New Zealand. This is due to high quality Grade ‘A’ equivalent biosolids being produced from its sludge treatment systems which allow various beneficial use options to be a possibility.
Cardno BTO updated Kāpiti Coast District Council’s existing district-wide biosolids strategy to identify any alternative biosolids disposal options superior to the current method (disposal of dried sludge at the Otaihanga Landfill). The biosolids strategy methodology followed to determine and justify the preferred biosolids disposal/reuse option involved comparison by 1) a financial analysis, 2) a multi-criteria analysis and 3) consideration of best engineering practice.
The biosolids reuse/disposal options considered for evaluation included disposal at the Otaihanga Landfill (the current option), an alternative landfill where any potential environmental effects are minimised, monofilling, application to expressway land, and to forestry land. Emerging treatment options were discussed in detail and it was recommended to investigate these options further once findings from pilot plant trials and any scaled up processes are known.