Editing Heathrow (hamlet) (section)

==Industry==
A brickearth and gravel quarry and brick works was opened in the 1930s. At a survey in 1934 the quarry was {{convert|15.9|acre}}, of which {{convert|5.3|acre}} was lake. Later it expanded to the northeast and finally the lake was about {{convert|1/4|mi|spell=in}} long.<ref name="ps2009"/>{{rp|84}} The Heathrow Brick Company went into liquidation in 1943<ref>{{Cite news|url = https://www.thegazette.co.uk/London/issue/36119/page/3506|title = Heathrow Brick Company Limited (In Voluntary Liquidation)|work = The London Gazette|access-date = 23 July 2015|date=August 1943|page = 3506}}</ref> and was wound up in 1944.<ref>{{Cite journal|url = https://www.thegazette.co.uk/London/issue/36626/page/3481|title =Heathrow Brick Company Limited (In Voluntary Liquidation) |date = 25 July 1944|journal = The London Gazette|access-date = 23 July 2015|page = 32481}}</ref>

{{anchor|Perry Oaks sewage sludge works}}
A sewage sludge works was built in the Perry Oaks part of Heathrow in 1934, and a {{convert|2|foot|mm|adj=on}} gauge railway installed three years later.<ref name=":0">{{cite web|url=http://www.framearch.co.uk/t5/2007/04/24/the-perry-oaks-water-treatment-works/|title=1934 – 2002 The Perry Oaks Sludge Works|date = 24 April 2007|website=Framearch.co.uk|access-date=18 August 2017}}</ref> Improvements were made in the 1950s and 1960s, and the works were eventually demolished in 2002 to make way for Terminal 5.<ref name=":0" />

The settled sludge of the large [[Mogden Sewage Treatment Works]] (West Middlesex Sewage Treatment Works) in [[Isleworth]]/[[Twickenham]] was pumped west to Perry Oaks for further settling and conversion for use in agriculture in pelleted or powder form as [[biosolids]]. Sales were eventually stopped because of the possibility of contamination with toxic
metals.<ref>{{cite book |last1=Crocker |first1=Glenys |title=Surrey's industrial past |date=1999 |publisher=Surrey Industrial History Group |location=[Guildford] |isbn=0952391880}}</ref>

;Timeline of the sludge works<ref name="ps2009"/>{{rp|32-41}}
* 12 June 1931: [[Middlesex County Council]] bought the site for £33,000 from W.Whittington & Son, the owners of Perry Oaks farm; it was [[orchard]] then.
* 1934: It occupied {{convert|220|acre}}; later enlarged.
* 1937: A portable {{convert|2|foot|mm|adj=on}} gauge railway was in use on the beds to transport sewage sludge. 
* 1944: The Air Ministry, when taking over Heathrow, tried to take over the sludge works, but for obvious basic hygiene the sludge needed somewhere to be treated, which forced Middlesex County Council to resist; after a volcanic official row the Air Ministry admitted defeat and had to change its plans.
* 1952: The early circular concrete tanks were supplemented with large rectangular tanks, and later by a series of lagoons. 
* 1960s: A large dried sludge storage/collection area was built.
* 1965: This was augmented by installing a conveyor system.
** Both were replaced by centrifuges able to discharge directly into parked trailer units.
* 2002: The second-stage works forming the whole site was replaced by Terminal 5, preceded by a detailed archaeological dig over the area.

It has been inferred that the route of the under-pressure sludge sewer, which needed access points to prevent blockages, could have stopped the building of the airport.<ref name="ps2009"/>{{rp|38}} He states if it had gone across the Heathrow fields area, e.g. straight from Harlington Corner to Perry Oaks, the amount of work and time in wartime needed to divert it would have stopped the airport from being developed.<ref name="heathrowoldmaps">Old 1:2500 scale Ordnance Survey maps, reproduced at about 15 inches = 1 mile, publ. Alan Godfrey Maps:-
* Heathrow, 1934, Middlesex sheet 19.08, {{ISBN|978-1-84784-112-4}}
* Hatton, 1935, Middlesex sheet 20.05, {{ISBN|978-1-84784-279-4}}
* [[Sipson]], 1935, Middlesex sheet 19.04, {{ISBN|978-1-84784-120-9}}</ref><ref>{{cite web|url=http://www.framearch.co.uk/t5/2007/04/24/the-perry-oaks-water-treatment-works/|title=1934 – 2002 The Perry Oaks Sludge Works - Archaeology at Heathrow Terminal 5|website=Framearch.co.uk|access-date=18 August 2017}}</ref>