The Province of BC now has regulations governing grey water and composting toilets.
BC Sewerage System Regulations page (scroll to the bottom)
The Manual of Composting Toilets & Grey Water Practice document.
This manual is detailed, it is technical, and designed mostly for those folks doing design and install and the other regulatory professionals that oversee public health. The regulations apply to the whole of BC, a tough task when addressing such drastically varying climates especially winterized systems. As time progresses we are likely to see modifications. Thanks to all those that provided input during public review.