A COUPLE of weeks ago we ran a series of cracking photographs showing construction work at the Acomb Landing water treatments works.

The photographs all came from the collection of the Yorkshire architectural and York Archaeological Society (YAYAS). But while we knew what they showed, we weren't exactly sure of the dates. A series of construction projects were carried out to extend the treatment works between 1878 and the early 1900s: and the photographs could have been taken at any time during that period.

We asked if any readers knew more about the photographs. Step forward Graham Wilford. Graham worked for York Waterworks between 1972 and 1999, first as chief engineer and subsequently as managing director. And he was able to provide us with some expert commentary on exactly what the photographs showed.

We have taken the unusual step in Yesterday Once More this week, therefore, of reproducing no fewer than five of the photographs we carried two weeks ago, along with two that we didn't have room for last time. Graham's expert commentary explains exactly what is going on in each photograph...

1, 2 and 3: These three photographs show the 15inch diameter cast iron water main being laid under the River Ouse in 1904 to supply water from York Waterworks’ Treatment Works at Acomb Landing, to the Clifton area of York – and the diver who was involved with the work. "The water main is still in use today, located immediately adjacent to the downstream side of Clifton Bridge," Graham says. "The photos show the unusual ‘ball’ joints, connecting the individual lengths of pipe to provide the flexibility for the main to settle onto the uneven bottom of the trench dug across the river, whilst still remaining watertight.

"They were obviously effective as there is no record of there being problems with that length of main in its 113 year life to date."

4: This photo shows the original Treatment Works at Acomb Landing which was constructed and commissioned in 1850 to provide York for the first time with a supply of ‘treated’ water . "Previously the water went virtually straight out of the river and into supply, via Lendal Tower!"Graham says. "In the foreground of the photograph are the three original slow sand filters – the second to be constructed in the UK, the first were at Chelsea Waterworks in London. These remained in use until the 1970s when other slow sand filters were uprated to replace them. Undoubtedly, the introduction of slow sand filtration provided the greatest single improvement in the quality of the public water supply that York has ever seen. In the background are the associated pumping station and primary settlement tank.

5. The first of the ‘horizontal’ steam engines installed in 1895 to increase the pumping capacity of the Treatment Works. "These were only superseded in the 1920s by the introduction of oil engines to drive the pumping plant," Graham says.

6. The construction in 1902 of the first set of ‘rapid gravity’ filters at the Treatment Works – amongst the first to be constructed anywhere in the UK. "These provided an additional stage of treatment between the initial settlement and the slow sand filters," Graham says. "Rapid gravity filters were ‘mechanical’ filters – trapping the solids between the sand particles, whereas the slow sand filters were ‘biological’ filters, removing bacteria and organic matter from the water."

7: The ‘standpipe’ which was located alongside the former Severus storage reservoir located on Severus Hill near Manor Drive, Acomb. "As the water from the treatment works was pumped up one leg of the standpipe, over the top and down the other, it ensured that there was sufficient pressure in the main to provide the water supply to the higher parts of Acomb," Graham explains. "The photo shows the work in progress in 1901 to increase the height of the standpipe, to further increase the pressure available to supply Acomb - but the work shows scant regard for health and safety! The standpipe still exists today - the legs of the standpipe forming the inlet and outlet pipes to Severus water tower.

"The tower, holding 300,000 gallons of treated water, was constructed in 1914 around the standpipe (and) remained in use until a few years ago when it was taken out of service.

8: Another set of rapid gravity filters constructed in 1904, to build on the success of those constructed in 1902.

Long after these photographs were taken, York Waterworks remained at the forefront of the latest techniques in water treatment, Graham says. "Although Acomb Landing treatment works has been further developed in recent years, it remains the principle source of the public water supply for York. That is a tribute to our forbears - most significant amongst them, the eminent Victorian Civil Engineer Thomas Hawksley - who in 1837 identified Acomb Landing as the most suitable point to abstract and treat the water for York’s public water supply.

"It was an ideal site, as it was upstream of the city and hence clear of the pollution caused within the city; close enough to the city to avoid long and expensive lengths of delivery main; adjacent to the river itself for the source of water; and next to the railway, enabling coal to be brought in by rail for the steam driven plant."

Many thanks for the information, Graham.

Stephen Lewis