The cost of the new Belleville Ferry Terminal in Victoria Harbour is now up to 416 million dollars.
The province issued an update on the project Tuesday.
The original estimate was $331 million dollars.
The news release attributes the hike to complex geotechnical and seismic conditions, site constraints and significant soil contamination that will require extensive remediation.
Other factors in the $85 million dollar increase include inflation and safeguarding against economic uncertainty related to tariffs on steel and other products.
The federal government has confirmed it will increase its contribution to more than $45 million for the project.
Pomerleau will begin work within the next few days with the major construction getting on track later this summer with completion in 2028.