Levels of lead in drinking water city-wide should begin dropping in early 2023 when orthophosphate is added at Edmonton’s water treatment plant, two years later than initially promised. Epcor announced Thursday the odourless, colourless chemical will be added to city water by early 2023. Orthophosphate creates a protective barrier inside a pipe to prevent lead from leaching into the water. Around 4,200 Edmonton homes are currently serviced by lead pipes owned by Epcor, the utility said. Adding this treatment by the end of 2020 was promised as part of broader lead-reducing plans approved by city council in March 2019 around the time Health Canada reduced the concentration of lead in water allowed to five micrograms per litre from 10 micrograms per litre.