ARSENIC RISK MAPPING AND COMMUNITY KNOWLEDGE TRANSLATION: IMPROVING WELL WATER PROTECTION AND HEALTH IN NOVA SCOTIA

A multi-barrier approach, encompassing the need for community awareness and information exchange through to well water monitoring and treatment, is an integral part of ensuring safe drinking water. Source water monitoring and protection for Canada’s four million private well users is largely uncoordinated, with individual homeowners responsible for ensuring the safety of their well water. In Nova Scotia 45% of households receive their drinking water from a private well and naturally occurring arsenic, a known carcinogen, is widespread in groundwater. Analysis of over 3000 well water samples from across the province show 9% to be above World Health Organization’s provisional arsenic guideline level (10ug/L), with large spatial variation in risk.

This paper discusses the challenges of communicating complex information on a risk that is both health-related and hydrogeological in nature. We present maps, developed from geospatial analysis, showing the spatial variation in arsenic risk across Nova Scotia and its clear association with local geological features. We discuss the challenges of communicating this risk information to the public and ensuring well users in high risk areas regularly test and treat their drinking water. Results from our well water survey (420 households) and interviews show that even in areas of known high arsenic occurrence many people underestimate their well water risk and do not test their well water regularly, and those that do experience difficulties in interpreting results and accessing reliable treatment advice. We identify the need for locally based information on both arsenic risk and health awareness education. We consider the role of utilizing community knowledge translation and the provision of local geospatial risk mapping, in conjunction with Province-wide programs, to support improved well water protection practices.