Sorry, should have been clearer .... these were in place in 1960
"Upton Storm Water Tanks (S.W. overflow and pumping station)"
which was under the control of (Birkenhead) Borough Engineer and Surveyor and Planning Officer's Department.
I am guessing where the sewage works are now - in fact just looked at a modern map and the sewage area is marked TANKS and OUTFALL. There were two sewage spreader/filter tanks there in the 70s and three now, but I wouldn't have called these STORMWATER TANKS.
In a time of universal deceit - telling the truth is a revolutionary act. George Orwell
When the debate is lost, slander becomes the tool of the loser. Socrates