|Title ID||7946||Collection ID||920|
|Title||Getting Your Own Back|
|Date||[ca. mid 1980s]|
|Collection||Woking Film Makers|
|Theme||Cine Club Film-making Public Services|
|Keywords||Industry Workers Houses Food Family|
|Duration||16 min. 45 sec.|
|Copyright & Access||Copyright restrictions apply, contact Screen Archive South East for details|
From a domestic kitchen to the local sewage treatment works and back again; the story of water treatment produced by John Boice and the Woking Film Makers. The voiceover explains the technical process of removing the solid waste and large debris from waste water, as it passes through the water plant. Scenes also show the main pumping station machinery, the sedimentation tanks, aerators and quality testing process before the water is returned to the river.
The film opens with a woman washing lettuce leaves in a kitchen, calling up to her husband, who flushes the toilet in the bathroom. The shot dissolves into a view of waste water being pumped at a water treatment works explaining the multistage process used to recycle water. [Opening section is mute for online clip].
The voice-over explains that rags, wood and other large objects, which could damage pumps and other machinery, must be removed from the waste water and sewage. Sewage is passed through screens to trap the objects, where the material is conveyed to a bagging machine. The bagging machine is seen, turning and changing the bags automatically. The sewage is passed through hydrofoils into a large tank which allows a reduced flow rate. Sand and grit, called detritus', which would cause wear to machinery is guided to the side of the tank. A dredger removes the girt, used in road repairs.
The sewage flows along concrete channels, passing between a flume to maintain the works' records. Oils, fats and detergents are collected, an automatic system controls the pumps. The main lift pumping station is seen. A plaque reads "Pumping Machinery manufactured and installed by Sigmund-Pulsometer Pumps LTD (plant division), Oxford Road, Reading." The electric motors and control gears are housed on the floor, from which automatic drive shafts descend from the pumps themselves. The drive shafts are heard at work as the camera pans down from the floor above. the sewage is fed to the primary sedimentation tanks, where suspended solids and grease is removed. The sludge settles on the bottom of the tank, where a rotating scraper moves it to the centre. The weight of the water pushes the sludge out of the tank.
Primary effluent overflows into the secondary treatment plant, where it is processed by percolating filters, made of clinker or blast furnace slag, where micro bacteria digestion takes place. The bacteria feed on the waste matter, leaving only gasses and water. The filtered water moves onto the next process. The aeration method is shown, an alternative to the sedimentation tank method. The sewage is fed by several Archimedes screw pumps (that push the water uphill) to the first of the aerators. Humus tanks allows any remaining substances to settle before being returned to the sedimentation tanks or aerators for reprocessing. Clean water is fed into a river outlet, controlled by government regulations, the water is more pure and higher in oxygen than many rivers. River views with small fish follow. The Laboratories are seen, where standards are quality checked and maintained.
An atomic absorption spectrometer is used for finding and measuring metals. An experiment assesses the ammonia content, measured in a collecting glass. The camera follows a system of coils and glasses. The heavy crude sludge is disposed by a giant compressor, to be sold as fertiliser once compressed into blocks. Digestion tanks reduce the volume and produce gasses, which are burnt to heat the tanks to make the microbes more active, taking 35 days. Secondary digestion tanks are seen, where remaining gas is given off, separated into water and digested sludge. The liquor is drawn off for recycling.
The digested sludge is disposed of during evaporation in drying out beds, slow evaporation or pumping into tanks, taken directly to farms. A Thames Water truck is seen, driving to a raised tank, where the driver opens a pipe, letting the digested sludge pass into the truck. The sludge is sprayed onto the land by tanker, free to the farmer at this time. The white truck arrives at a farm, where the sludge is sprayed from the back, across a field. The land takes on a "dark look" but reverts to its colour after rain. The farmer is rewarded by crops. A lettuce is seen growing over time. At the home of the couple, seen at the beginning of the film, the woman has prepared a meal. "Looks delicious," exclaims her husband. "I got most of the vegetables from that new farm shop down the road," she says. Her husband clears his plate; "that was really splendid, we must go to that farm shop again. They must have a magic formula for producing vegetables like that!" 'Bon Appetit'.