New Septic Tank and plumbing

[MB1]

Hi.

I am installing a new septic tank and associated pipe work from scratch in a bungalow. I would appreciate answers to the following questions.

1) What gradient should I use for Foul water pipes and Grey water pipes?
2) I intend to have the Foul and Grey water falling into their own individual short vertical stacks that are vented to above the roof line. Do I need any other vents in the pipe/tank system?
3) The house is built on a terrace with about 10 meters between the front of the house to the edge of the terrace. The septic tank needs a 'soakaway' pit for the runoff water. Using British regs how close to the house can I build the foul water soakaway?

Thanks in advance.

 

[powell30]

If you are using british regs is this being done in England/wales? if so it's notifiable work so speak to local building controls officer. If abroad check local regs requirements......for info regs here are - gradient should be 1 in 40, 2 stacks venting the lines should be sufficient. Can't answer your final question.