Donegal County Council has power-hosed Buncrana Pier and treated it with special chemicals ahead of the busy summer season.
The overhaul took place just a day before the Buncrana-Rathmullan ferry recommenced on Friday, June 17.
Sean McGrotty, his sons Evan and Mark, mother-in-law Ruth Daniels, and sister-in-law Jodie Lee Daniels all perished when their 4x4 slipped into Lough Swilly on March 20.
Heroic passer-by Davitt Walsh managed to swim to the sinking jeep and rescue Mr McGrotty’s baby daughter Rioghnac-Ann.
Two days after the tragedy, gates locking the pier were still open and drivers were allowed to freely travel up and down the dangerous slipway.
A spokesman for Donegal County Council has confirmed the pier has now been treated and will be monitored in the coming weeks and months.
Dangerous algae on which the family’s vehicle is believed to have slipped has been removed and the pier will be treated on a continuous basis during the busy summer season.
A spokesman said “Donegal County Council treated and removed algae on Thursday, June 16, in advance of the ferry commencing. It was treated by applying the sodium hypochlorite on Thursday and by pressure washing on Friday to remove the dead algae.
“Some further algae was removed on June 20 from lower down the slipway that couldn’t be removed on Friday due to the neap tide.
“It is not possible to remove the algae that is under water.”
It also confirmed that new signs have been erected at the slipway and that a gateway to the slipway will remain locked when the ferry is not operating.
“The situation will continue to be monitored over the next three months while the ferry is in operation.”