The Value of Biosolids in New Zealand - an Industry Assessment

New Zealand’s municipal water industry spends an estimated $40M per year to dispose of or beneficially reuse biosolids. New narratives of zero‐waste, circular economy, nutrient cycle, and resource recovery are changing the way politicians, the public, and us as an industry think about waste and resources. This paper assesses the biosolids sector to identify ways of reducing cost, and capturing the value of biosolids in terms of: 

 nutrient cycle including chemical fertiliser vs organic nutrients;

 carbon footprint;

 soil enhancement by returning moisture and organic carbon;

 land, quarry or mine rehabilitation; and

 zero‐waste.

The paper characterises biosolids production, disposal and reuse across New Zealand and discusses the drivers and frameworks that result in different regional end‐use or disposal solutions. Critical success factors of successful beneficial reuse initiatives are identified. The challenges of pathogens, metals and emerging contaminants are discussed. The strengths and weaknesses of the industry are presented and  recommendations are made. The regulatory framework, end markets, cultural and social aspects are also discussed. Nutrient markets and economics, and the role our industry can play in this are assessed.

A discussion on industry challenges and opportunities with some recommendations is presented with the goal to find more sustainable and resilient outcomes that capture the value of biosolids and reframes the problem to one that sees product and value.