In recent years, McCarthy’s work on biosolids has received support from the Canadian Water Network, the Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA), and the Ontario Ministry of the Environment and Climate Change (MOECC). Under controlled laboratory conditions, the impact of soil amended with different types of biosolids from municipalities across Canada on the growth, behaviour, and/or reproduction of a multi-species array of terrestrial and aquatic organisms has been assessed and the results disseminated (Canadian Water Network publication below).
On August 12, 2016, Dr. McCarthy and fellow scientists Drs. Paul Sibley, Chris Metcalf, and J.E. Loyo released a rebuttal to the Open Letter stating that biosolids are treated through sophisticated, engineered processes to meet strict government regulations that assure health and environmental safety before they can be applied to agricultural lands. They cite the disposal of biosolids through land application as a sustainable, cost-effective solution that adds nutrients to the soil, benefiting crop production and reducing the need for chemical fertilizers.
What is agreed on, is the growing pressure that municipalities face about biosolids management, from increasing volume and costs for landfill disposal, to public distrust of land application methods. Dr. McCarthy cites that public discourse and education is a critical component of the discussion.
To support public discourse and education, Dr. McCarthy has been an invited speaker at several events in the US and in Canada in the last year. Dr. McCarthy has spoken about her own biosolids research, in addition to, her extensive knowledge of the scientific literature to date.
Next Research Steps:
- Evaluating use of engineered wetlands to reduce eutrophication effects caused by agricultural runoff
- Macrophyte selection criteria: non-invasive native species in Ontario
- Indigenous species: Zizania aquatica (wild rice) and Carex sp. (fox sedge) will evaluate for nutrient sequestration efficiency