On 28/07/2020 14:16, Dave Liquorice wrote:
On Tue, 28 Jul 2020 12:12:49 +0100, NY wrote:

It's about the same noise at 100 yards as standing right next to a noisy
fridge. Maybe his sewage works is an early model and more noisy that
modern ones.

The latter. The active systems I've encountered have had noise levels
about that of a fridge when right next to them not 100 yds away.

They are more than just a motorised stirrer, there is a compressor to
bubble air through the contents as well.

Not in mine there isn't

Nor most similar in the neighbourhood.

They just carry air pockets under the surface and let them bubble up

--
Religion is regarded by the common people as true, by the wise as
foolish, and by the rulers as useful.

(Seneca the Younger, 65 AD)