No, these are two separate documents.
The North London Waste Plan is about the use of land and it will identify suitable sites for new waste facilities. The North London Waste Plan is being prepared by the same London Boroughs as those involved with preparing the North London Joint Waste Strategy, but in their separate capacity as planning authorities. The North London Waste Plan will set the land use planning framework for siting waste facilities in north London up until 2020, i.e. it will identify 'where' facilities will be located. Moreover, it will do this for all waste arising in north London, whether household, commercial, industrial, construction, demolition, clinical etc.
The website for North London Waste Plan is www.nlwp.net.
The North London Joint Waste Strategy sets out 'how' waste will be managed in the same period and it relates only to the waste collected by the seven London Borough Councils, which will be about a quarter of the total amount of waste considered within the North London Waste Plan.
Whilst the North London Joint Waste Strategy provides a key input into the North London Waste Plan, the two documents and processes are separate. Sustainability appraisal, which is being undertaken on the North London Waste Plan is also a slightly different process to SEA.