The Seafield Waste Water Treatment Works
There’s no MV Gardyloo now, gently relieving herself
of Edinburgh’s sewage in the Firth of Forth, that day trip
for hardy birders. She’s more than been replaced:
six digesters which, from the sea, blend into Arthur’s Seat.
Seagulls are winging in from the firth, taking a dip
in the settlement tanks. From the metal stairs above
you can see beyond the catchment, across Inchkeith
to the Lomonds, beyond Almond and Esk. It’s said
sunrise is stunning if you’re on summer night-shift.
Never locked up and left, yet hardly a soul to be seen.
What seems like a space-station of engines, pipework,
pumps gets on with the daily business. Seven screens
in the control-room keep up a stream of information:
that outlet, this sluice, that consistency, this flow rate,
that temperature, this sewer, that wind direction;
it’s all monitored, someone always on the bridge.
It’s hard to believe that the waste from almost a million
of us flows as sweetly as it does up the massive
Archimedes screw, passes through ever finer screens,
makes something clean and degradable from all the
paper clutter, removes the occasional shopping trolley.
Then it rests as grit to be pumped out settles in the sump.
Seagulls relax, make a long pearl necklace of a pipe, keep
a cold eye on pigeons that flap about the skips, nicking
pickings from that sifted grit waiting to be recycled.
Then on it hurtles at thousands of litres per second
to settle and separate: sludge ever thickening, ever
purifying; and the captured methane, a virtuous cycle
powering the process with energy to spare; lorries snatch
the digested residue that will nourish next year’s crops.
And all this time the effluent has streamed on, aerated
so those bugs can get to work to clean it up. In summer
the biggest set of UV lights in Europe zaps the nasties
that might still lurk, the salmonella. Listen, it has
the speed and sparkle of a Highland burn in spate.
SEPA checks we could fill a kettle, dilute a dram at the
rushing outlet piped far into the shining Forth. But still
we turn on taps, endlessly shower. Design, maintenance,
monitoring, improving process: they’re never done.
For that we should be grateful each time we flush.