The outlet from the second chamber (the 'liquids' chamber) of my septic tank takes an age to empty into my soakaway, causing obvious problems further upstream if a large quantity of water is suddenly dumped into the system (from an emptied bath for example). It's been like this for years but is getting noticeably worse.
Who/what industry 'body' would I call in to evaluate what needs to be done and, only if absolutely necessary, re-build or install a new soakaway?
Thanks