Technical sewerage

In this isolation
There are suprising bonds
Isomers, my friends
Of technical sewerage
Are ever on my mind.
My planning permission
Building regs approval
Are all pent up and pending
Hanging on their sanction
Technical discretion
Sewerage, I have filled their forms
Name, Address, scale plans
Descriptions of inclines
And are they fans
Of the pipe thickness, flow design?
Technical sewerage is flooding my mind.