The District of Sechelt, B.C. is pursuing a unique pilot project that will use recovered sewage solids to remove traces of pharmaceutical drugs, recreational drugs and hormones from post-treatment wastewater.
Such a system could be used to treat the province’s wastewater before it is discharged into surface water systems used for drinking water by downstream communities. Many municipalities outside the Lower Mainland discharge treated wastewater into rivers and a handful — such as Vernon and Oliver — already use it for irrigation on golf courses and hay fields.
The U.S. Geological Survey recently reported that pharmaceuticals persist for several months in irrigated soils, which Sechelt Mayor John Henderson fears could hinder consumer acceptance of foods grown with reclaimed water. Plus, trace chemicals from treated municipal wastewater are known to disrupt the reproductive systems of fish.
Sechelt is hoping to divert its wastewater for use in agriculture and Henderson hopes the pilot will help answer the “last objection” from people concerned about the introduction of trace amounts of drugs and other contaminants into the food system.
The Sunshine Coast community plans to make charcoal for filtration from wood waste, paper and solids recovered from sewage by heating it to at least 500 C, which destroys pathogens and contaminants and leaves behind a powerful filtration medium not unlike activated charcoal, according to Sechelt’s water treatment project coordinator Paul Nash.
The product — called biochar — will then be used to remove drugs, hormones and other contaminants dangerous to humans and other living creatures from treated wastewater.
A treatment facility that uses biochar made from sewage solids to filter drugs and hormones from water would the first of its kind in the world, said Henderson.
“If we succeed, we will have a way to remove pharmaceuticals from both effluent and biosolids using waste as a resource,” said Henderson.