How to use LINQ in traditional n layer code pattern

LINQ to SQLis the Data Access Layer in my opinion, so the LINQ data context should be part of the business layer. In effect you can dump the DAL entirely, other than for things that aren't possible with LINQ to SQL.

There are three problems with putting LINQ to SQL in your DAL:

1. Ratio of plumbing code to real code starts to get a bit high.
2. Incorporating business logic within your projections breaks the abstraction.
3. Objects returned by the DAL support lazy fetching, making mockery of your division.

Joe