We have a Victorian 5” diameter interceptor (please see the photo), serving our 7 bedroom house with 6 WCs. During the last 20 years we have had up to 12 people staying overnight with no problems. However, next August, we will have 24 people staying overnight (including 8 camping) and I’m worrying whether the interceptor and drains will cope during the morning. Any comments or suggestions please. I am considering periodically flushing all six loos (with water only) at the same time during the morning and, perhaps, also flushing the interceptor directly with a number of large buckets or containers of water. Your thoughts please.