Hastings District Council says all parts for the new Brookvale water treatment station are in Hawke's Bay, and the UV treatment system is in place.
In the last update from council a fortnight ago, some parts were still on their way. Council's asset manager Craig Thew said the last of the parts had arrived last week.
From Monday the filtration plant was being assembled on site and working started on connecting the electricity and the pipes that carry the water to the residential areas. That work will carry on into next week.
After that work is completed, the water will be flushed and tested.
"It is part of ensuring that all the parts of the treatment system are working and the water is safe to drink. People may notice water going into the storm drain in the rural Brookvale area. This is unavoidable as we work to comply with drinking water standards."