Stockholm International Water Institute / Robert B. Daugherty Water for Food Global Institute at the University of Nebraska / International Water Management Institute / Stockholm Environment Institute

Harnessing opportunities for the safe reuse of wastewater in agriculture

Tuesday 29 August | 13.45-18.00
Photo: Kim Andersson

Reuse in practice (excursion)

This session takes you out to the field for a full-afternoon excursion to a decentralized wastewater reuse project in the Södertälje Municipality. This visit gives you an opportunity to meet experts and researchers and also discuss the case of blackwater reuse with farmers and politicians.  

Achieving food security (SDG 2) is of high priority, increasingly threatened by water scarcity and climate change impacts. The safe reuse of wastewater could play an important role towards increasing agricultural production. A key motivation for increasing wastewater reuse in agriculture is reduced costs, since this waste contains nutrients useful as agricultural fertilizer, along with enough water to irrigate part of all the irrigated farmland in the world. Wastewater reuse also reduces nutrient leaching to lakes, rivers, and groundwater. But how do we harness these opportunities and tap into this largely unused resource from a planning, policy, livelihoods and financial point of view? And what are the pitfalls that should be avoided to ensure safe and sustainable wastewater reuse?

The objective of the seminar is to discuss opportunities and limits for the safe reuse of wastewater and in agriculture.


Reuse in practice (excursion)

Chair: Dr Kim Andersson, SEI

13:45 Meeting time outside the venue for the bus to Hölö, Södertälje 

15:00 Welcome by local project leader

15:10 Eco Municipality: Planning and steering towards reuse
Karl-Axel Reimer, Södertälje Municipality

 15:20 Cross-sectoral collaboration for sustainable agriculture
(TBC), Federation of Swedish Farmers

 15:30 From waste to fork: Building consumer acceptance
(TBC), Food industry/retailer representative

 15:40 Reuse-oriented water and sanitation development for sensitive areas
(TBC), Telge Nät

15:50 Q&A

16:10 Visit to the decentralized resource recovery plant

17:00 Bus leaves from Hölö, Södertälje

18:00 Bus arrives at the World Water Week venue


Wastewater availability is likely to increase in quantity over the coming decades due to population growth and urbanization. In order to combat water scarcity and to improve crop productivity, recent findings show that wastewater is playing an increasingly important role. Current agricultural wastewater use is already a multitude larger than previously estimated; around 10-15% of irrigated croplands indirectly use untreated wastewater globally. This figure is likely to increase markedly over the next few decades in response to rising levels of water stress in inhabited catchments. This raises health concerns and contributes to the negative perception of its use, as treated wastewater is only applied on 0.3% of irrigated croplands.

Different case studies presented during the seminar showed the successes linking the sanitation chain with irrigated agriculture and the advantages of doing so with regards to access to water, nutrients and the improved quality of life through economic gains. Although success stories are present, and can be learned from, there are still major challenges in terms of health security, economic viability, government support and public acceptance. Especially with the increase of anthropogenic pollutants, such as pharmaceuticals, strong regulatory frameworks are needed to secure health safety and promote public acceptance, while identifying solutions that are acceptable and economically feasible for farmers and agricultural workers. In low density rural areas, evidence shows that low cost interventions at the household and community level is an opportunity to increase agricultural wastewater re use.

A limiting factor for further increases of wastewater reuse in agriculture is consumer’s acceptance and risk perceptions. Harnessing the opportunities for agricultural wastewater reuse, however, requires closing the gap between public perception and actual knowledge, which in turn needs taking into consideration the different ways people learn. Consequently, a portfolio of transfer approaches, such as information sharing mechanisms and applications, field visits, and traceability applications, among others, should be considered. Achieving agricultural reuse of wastewater in practice requires long-term cross-sectoral dialogue and engagement processes. Long-term financial viability of wastewater reuse projects requires that externalities, in this case negative impacts on humans and the environment, need to be accounted for in the financial model of the systems.

We advocate for a change of mentality - making resource recovery and reuse central to treatment, while also protecting health. This requires increasing social acceptability and trust along the entire value chain - from waste to food – as we need to be responsive to the diverging interests and needs among the different sector stakeholders. By doing so, wastewater reuse in agriculture can contribute to achieving several 2030 SDG’s, among which are 1 (poverty), 2 (food security) and 6 (water and sanitation).