Is it an Arched trench or a very smelly wet church. Blame the Aussies

[Marc Berger]

Has anybody come across a septic system called Trench Arch

Its specifications, if that's what you can call them seem to originate from this document http://ew.ecocongregation.org/downloads/TrenchArch.pdf they seem to treat archaeology as a problem.

and this Cumbrian trust seem to want to advertise its use in Gloucester which is a bit odd

http://www.ctfc.org.uk/trench-arch.html

I rang some of these people up, unfortunately a few have passed away but some said that they did not have trench arch and others seem to have been piped into the mains. I got through to one which was put into a Victorian chapel and was told it was alright as nobody had used it.


and then there is this obscure mob who have written this

The provision of toilets or kitchen facilities will require water, drainage and ventilation. A prior archaeological assessment will usually be required in order to establish the impact of such installations. Subject to archaeological advice, these should be routed underground rather than directly through walls. The use of composting or macerating lavatories can remove or reduce the need for drainage trenches. In rural buildings where use is not heavy and where space allows, the Trench Arch system can avoid deep excavation and complex drainage.

which they proudly produced in this document. http://www.english-heritage.org.uk/publi...p-2012.pdf I did try finding out who the particular author was but got bounced around until I felt a bit uninvited. I could not find anybody who would call themselves an archaeologist who had looked at this system.


I think that it is a basic soak away except its full of shit that they imagine will never need emptying as it will disappear by biological activity, and they will put it right by the tower if not in front of the entrance and put the bog in the tower. The premise is that it will not get used very much-much less even than a family house, but its nice to have a toilet that is disable friendly and be part of a facility that is designed to facilitate over a hundred or two people at a single sitting. Apart from a certain anxiety that putting mains water into an unheated, prone to vandalism, isolated building is asking for serious water damage, my concern is that no work what so ever should be done by/through a church tower with just a watching brief as the mitigation, or that putting any type of hole through ancient foundations which all show evidence of movement is very clever, but I particularly think that no archaeologist could seriously say that the change in the hydrology around the soak away will not have serious consequences for the preservation of your average dark age cemetery although they are rather two a penny I suppose just by church entrances. I also would not want any future job of digging near one.


The ecumenical powers seem to be able to get these things put in because the environment agency/defra have thrown the rules away on registering septic tanks or even what a septic tank/pool is and since the new single government web portal its almost impossible to work out who is in charge but there is this https://www.gov.uk/government/uploads/sy...T_5666.pdf which seems to fit the bill.


What I have found most intriguing is trying to work out who devised the beloved English Heritage term Trench Arch (I presume that they will have an official glossary and thesaurus in which it will be data based). The answer seems to be that its was cleverly coined from the generic "Arched trench". http://www.centcoast.tas.gov.au/webdata/...rocess.pdf

[barkingdigger]

Funny how we don't like this re-invention of the traditional waste-disposal method that predated sewers, but just let us find a medieval vaulted cesspit and we're as happy as a pig in... well, YOU know! :o)

Having read the EH guide, it DOES have a boat-load of pointers about seeking suitably qualified archaeological, architectural, and structural advice from professionals. So I assume its mention of Trench Arch (the Emperor's new cesspit?) is simply a suggestion that they don't always need to deep-trench all the way out to the main sewer in the street? All other common-sense caveats would still apply, and any Curator who failed to take the archaeology (both below & above ground) into account would need a serious slapping! I see the waters calming in this particular teacup...

[Marc Berger]

Barking, have you come across any examples of arched trench put in a church?

[barkingdigger]

Nope - not yet. But I've had the pleasure of dealing with the medieval predecessors...

[Marc Berger]

Were these predecessors of vaulted cesspits in Anglo Saxon parish churches?,... I have found records of old crones wetting themselves waiting for the sermon to end and for the consumption of church ales but I have found no evidence of mains water or of the general populace sitting in the tower merrily evacuating the preceding nights vindaloo whilst performing a bit of campanology as the bride was accompanied down the aisle to odious embellishments to the wedding march. Please what traditional waste-disposal method that predated sewers are you talking about related to churches. I would say they are conspicuous by their absence. These are places of burial grounds and graveyard soils. There is the possibility that they were selected for their grave capabilities and that the absence of water table and the eternal collection of cess may have been a criteria -only a personal theory.

[barkingdigger]

No - mine were in domestic settings - obviously. As for the other reasons for choosing a location for a church, who'da thunk? But in truth, good drainage and capacity were probably much lower on the list than say availability of donated land, so there are some churches on dry high ground, and others standing in puddles of rising damp. And some don't even have room for a graveyard! (And in the pre-modern period Church officials were far less prissy about preserving the integrity of burials, often slapping foundations for new aisles through the graves...)

But the basic issue remains that EH does not actively encourage ignorance of heritage or structural safety - only that these Trench-Arch thingies MIGHT be a viable lower-impact alternative to the full-on sewer connection. Only a moron would approve one in close proximity to the foundations, or on top of ancient burials! But then, not all churches were ENTIRELY cut off by crowded burials on all sides, coming right up to the walls, so there is often room for a short pipe-run to a nearby bit of uninteresting ground. Common sense is still a general requirement, and the various powers that be should be looking at all proposals with a critical eye.

Have you had to dig up the after-effects of one of these modern demon cesspits? You certainly seem passionate about the issue!

[Marc Berger]

Never thought that you would ask. I did one a couple of months ago and walked of the job in high dungeon. I don't think that there is any problem with "deep" drain runs to mains sewer if there is a mains drain nearby and there was one in the road next to the church. The same road from which the mains water was fed. The faculty plan I was shown showed two 1 meter by 15m long drains about 15 metres from the church but after it was pointed out that they couldn't get any slop from the church "they" decided that the two runs could be joined together into a 2 metre wide 15 metre long hole and that regs allowed them to bring soakaways to within 3 metres of the church. So as it was a soakaway 3 metres from the church then that was alright then. I was told that the architect was on the diocesan faculty committee and everything was alight as "trench arch" was designed for churchyards. I told them to get stuffed and they got another archaeologist in to sign it off. I put my bill into the builder and he doesn't talk to me anymore.

[barkingdigger]

So, this was mitigation for a new build, rather than digging features around an existing "used" one, then? It definitely sounds like a poorly-assessed design (esp with the ad-hoc change)... But if it was for a new build, were you at least offered the chance to mitigate the full footprint? I certainly wouldn't work around a used one - at least until it had a few centuries of biodegrading under its belt!

[Marc Berger]

Yes this is mitigation for new build. It was mitigated as a watching brief although i dont know that any archaeologist was involved pre-faculty.

As the archetectural person pointed out English heritage says in a paragraph about archaeology.

In rural buildings where use is not heavy and where space allows, the Trench Arch system can avoid deep excavation and complex drainage.

I would have thought that it should have said that a septic soak away close to the church will introduce complex chemical drainage that will require deep excavation in mitigation well beyond the footprint of the arched trench. As I said I could find no author of the document at English Heritage who would claim to be an archaeologist. I think that English Heritage have fallen for a green technology con.

[barkingdigger]

Well, in EH's defence, their statement that a Trench Arch can reduce complex drainage is true, but it definitely doesn't rule out the need for the architect to also consider the effects of the "waste" run-off or the impact on pre-existing foundations or burials. What surprises me is that nobody else picked him up on it before it got to fieldwork - that suggests a definite gap in the curatorial system. If you felt the need to educate the architect on the finer points of his job, then it sounds like he had a fool for a client and you're better off out of it!

PS: The whole "no name" thing on EH Missives is fairly common. It goes in & out of favour, and I suspect it depends on how big a "name" the author is...