I have a 1099S form from selling a property in 2018 . Can I deduct the cost of the sewer line and property taxes. Inherited in 98 for the cost of 10k sold for 40K.

[HelenaC]

You may add the cost of the sewer line to your basis. Generally, when property or other assets are inherited, the cost basis is usually equal to the fair market value of the property or asset at the time of the decedent's death or time of actual transfer.

• See Where do I enter the sale of a second home, an inherited home, or land?

You can’t add the property taxes for the year's since 1998 to your property’s basis. You may have been able to deduct them each year on your personal income tax return. You may be able to deduct the real estate taxes that you paid in 2018, on your personal income tax return. 

See Can I deduct property (real estate) taxes? and Where do I enter my real estate (property) taxes in TurboTax Online?