.net - Web service reference location? -

I have a Visual Studio 2008 solution that is currently included in three projects:

1. Project for a datafactory commercial logic / data access.
2. A web project consisting of real user interfaces, pages, controls, etc.
3. One web Core project which includes utility classes.

The application needs to use the web service I will usually add a service reference for the web project, but I'm not sure whether this is the best practice or not.

The following options are open to me:

1. Add a reference to the web project.
2. Web. Add a reference to the core project, and create a cover method that calls to consume the web web service.
3. Add a new project called Web Survers, and copy Step 2.

The size of this project is expected to increase so I am open to any suggestions. 3. The option of the web service is not wrapped with any existing project.

option 3. If the web service function is not wrapped with any existing project.