Derby Sewage Works
Description of Derby Sewage Works 1915
The Sewage dispoasal works situated at Spondon Derby, OCR:
The Disposal Works at Spondon, designed by Messrs. Jas. Mansergh & Sons, of Westminster,
1 consist of a Pumping Station with main and storm pumps, boiler-house, sludge pumps,
Three horizontal cross-compound condensing steam engines, by Yates & Thom, of
Three sets of three-throw single-acting vertical plunger pumps, including air and
vacuum vessels, suction and delivery pipes and valves.
Three " lnvincible '' vertical tandem compound direct acting condensing centrifugal
pumping engines, including all necessary steelwork for supporting same, suction
and delivery pipes and valves, gallery, packing stages, staircases and columns, etc.
Capacity of Pumps. Each of the three sets of '' main '' pumps are capable of raising
6oo cubic feet of sewage per minute to a height, including friction, of 26 feet.
Each of the three " storm '' pumps are, when running at a speed of 288 revolutions per
rninute, capable of raising 9oo cubic feet of storm water per minute to a height, including friction,
of 14 feet.
The Purification Works consist of 6 open septic tanks, each with three divisions, 25' and
60' and 22.5' long respectively, 37 feet wide, and about 10 feet deep ; 30 continuous filters, each
100 feet diameter, with revolving distributors of Adam's '' Cressit '' and " Adamic '' pattern, the
filtering material of the first I8 built is hard selected clinker of various sizes and not graded in
any way, except that all dust and small pieces (say less than a walnut in size) were kept out.
The second instalment of filters, 12 in number, are filled with clean, broken granite, the top Iayer
I' 3'' in depth being broken to 1" to 1/2'' gauge, and the bottom layer 5' 3" in depth, 2" to I"
gauge, making a total depth of 6' 6".
Six Separator tanks each 28 feet square and I8 feet deep, on the upward flow or Dortmund
principle ; 6 storm water beds, having a total area of about 5~ acres filled with clinker for a depth
of 3' 3'', together with a laboratory, and four cottages for the engineman and firemen. The sludge
is disposed of on several acres of land trenched out for its reception , being pumped on to the
land fron) the septic tanks by a Tangye's Horizo,~l ~' Special '' Sludge Pump with io'' diameter
buckets and a 36" stroke, and by a motor driven centrifugal pump from the separator tanks.
The old sewers were picked up and the sewage first delivered at the new works in April. 1907.
The total area of land acquired by the Corporation for sewage purposes at Spondon is
about 2I8 acres, of which about I47 acres is let to tenants and the remaining 71 acres is taken
up by the Pumping Station Buildings, Cottages, tanks, filters, and sludge trenches. The total
cost of the works, including land, easements, sewers, disposal works, Engineer's commission, etc.,
has been about £325,000, and the disposal works themselves having cost about £150,000.
The average dry weather flow of sewage is about 4 3/4 million gallons per 24 hours.