Wed 4 Sep 2019

Bulk water provision?

Dean Public Seen by 284

Given the issues with water provision in recent years, I wondered if it would be worthwhile having some central provision instead? E.g. a giant tanker at the top of the site, possibly with some piping leading down the site and taps at lower locations (powered by gravity, no pumps required). There are companies that do bulk water delivery for events, e.g. https://www.watermills.net/events-and-festivals.html

Alternatively, given the existence of one mains water tap on site this year, is there prospect of getting any more of those? :)


Case Thu 5 Sep 2019

I looked into bulk water provision a couple of years ago. A 2000 l tank with a refill during the week was quoted at £4,400 from water-direct. This was 7 days provision, and is expensive because it is drinking water. At 5 l/person/day, this is 114 people's water for the week, £38 each. Probably more expensive given the inaccessibility of the Cornwall site.

Increasing the number of tanks would probably reduce the cost, as the refill is the expensive bit. I don't know how big a road tanker is, but probably big enough to fill a couple of bowsers. Without the refill we would either have to sign a waiver saying it being non-potable is fine, or the hire company would simply not deliver it. (I found this varied between suppliers). I think we are simply too small to make commercial water hire feasible.

Adding piping that we create removes the guaranteed potable bit, so might mean some people don't want to partake, and for others this might be cost prohibitive.

I'm all for communal water, but we should think carefully about it. I don't know the flow rate of the tap on site, but it's possible we could build a suitable pump (looking at @adriangodwin here). I believe there was talk of metering this connection and possibly charging us for it.


Paul Phare Thu 5 Sep 2019

While these are all great ideas, you need to consider that the landlord has put in a tap for us down by the water treatment plant. I assume this is water that comes from the land, treated locally and pumped to the main house and gardens. It might therefore be worth considering running a pipe up the hill to save people having to go down to the tap


Adrian Godwin Fri 6 Sep 2019

Perhaps, but don't make too many assumptions.

  1. There may not be enough pressure to go up the hill. The main house is quite low and we don't know if the plant also supplies the gatehouse.

  2. We don't know the capacity of the filtration plant. While a single tap that's a long walk (and long carry!) for many visitors was not heavily used, making it easily available for 500 people might be neither polite nor practical.


Paul Phare Fri 6 Sep 2019

How about building a water tower somewhere up the hill and supplying it from the tap. Pressure should be enough to fill the tank (even if slowly) to supply 500 people


Adrian Godwin Fri 6 Sep 2019

It's true that, at the limits of a pump's pressure, it will often still operate at reduced flow. But that isn't true forever : there is a hard limit in height beyond which it won't pump. That limit depends on the design of the pump.

It's possible to get around this problem by adding a further pump to provide the extra head of pressure needed to get to the top of a water tower, but that would need electric power etc.

The more important question though, is whether the owners would want that. If we exceed the capacity of the filtration system we might affect the house supplies, be offering inadequately filtered water, or cause additional maintenance costs.


Paul Phare Fri 6 Sep 2019

Sure, I wouldn’t doubt there are issues with this idea, but I think it’s worth investigating along with the others. In terms of the height; I’d imagine the pumps have to push water to the top floor of Alex’s house which will be higher than we need so I very much doubt we will be at the limit of what the pump can deliver. Also if we have a header tank with capacity enough for one day, it could be refilled during the night when the house doesn’t need it. All this would have to be discussed with Alex


Adrian Godwin Fri 6 Sep 2019

Yes, absolutely fine if it's with Alex's support. I just wanted to point out that there are both physical and financial issues to consider. Also, I think the top floor of the house is probably similar to the theme camp hill, but not as high as the free camping field.


Paul Phare Sat 7 Sep 2019

Ah okay, I was only thinking of theme camps. There is a water trough up by free camping though I'm not sure where that water comes from.


Adrian Godwin Thu 5 Sep 2019

As Case says, I am interested in the possibilities of building a ram pump (water powered water pump) to take water from the ford to the theme camps. It would be quite a low flow rate, transferring non-potable water to Case's filter set and then my ice machine.

However, I discovered there's already two pumps on site - a ram pump and a slightly younger engine-powered pump. These are in a small wooden shed at the bottom of the waterfall, not the brick building where the tap was placed (which I assume also has filtering equipment).

This could be used to provide a shower (as could the waterfall alone ..) or a washing source but it would be a struggle to get it as far as the free camping site.

I see water direct have 1000l 'aqube' palletised drinking water at £389 - this seems a lot cheaper than the 2000l tank but maybe there are hidden costs such as delivery. https://www.water-direct.co.uk/product/aqube/


Adrian Godwin Thu 5 Sep 2019

I think this is the same company that provided the toilets : if they're local and we're using them for other services they might be more economical. https://tardishire.co.uk/site-water-services/water-bowser-hire/


Ax Mon 18 Nov 2019

Hiya, I organised the community water delivery last year and looked into the alternatives such as AquaCube. I believe that they were a similar price but local water provider Pure Dartmoor were preferred since they collect and re-use the empty water bottles, so it meshed well with Leave No Trace.

I'd be curious what other options are being considered. I've attached the final costs for water in 2019 below. I thought it would be useful as a comparison to the new infrastructure you are considering,


Stephen Brannigan Thu 26 Dec 2019

My new boss is an ex plumber, so I asked for his advice on this.

The TL;DR: We can easily get a tap for each theme camp running from the mains connected tap to past where Crumpet was to have a tap for free camping for not that much money or effort.

All we need to do is buy a bunch of garden hose:


Then a bunch of three way splitters (one for each camp that wants a tap plus free camping):


Then a tap for each one of those:


I’d suggest putting the free camping tap as far from Crumpet as possible without crossing the road, as vehicles need access to the road.

Jobs a good un’. 

Now, the issue of pressure. I don’t think this will be a significant issue for a number of reasons. The main ones are that camps could be asked to fill water containers from the tap creating a buffer, so slower filling wouldn’t be a big deal. We could even have radios for every tap and a dedicated water radio channel, so we could easily take it in turns to fill up. Maybe even designated times that each of the camps can use the tap. If, somehow, even this wasn’t enough to resolve the issue, then we could invest in a pump:


But frankly, judging by the power of that tap, I think just hose and taps would be enough to get this sorted out.

As Organisational Lead for The Whisper, and Dangerous Arts Lead, I might be stretching myself a bit to take on Water Lead as well, but if nobody else steps up then I can do.


Martin Evans Sat 4 Jan

I ran the Water Project with Ax last year, but won't be doing it again this year.
I've run QGIS on the location and the figures look like this (see attached):
Height between tap and junction of roads at top of hill c 40m (the reservoir will probably be at a similar height)
Distance between both points: c.410m

Garden hose isn't potable, and leaks like buggery at joins
Alex might have something to say about taking his water
x, Martin


Stephen Brannigan Sun 12 Jan

Thanks for the feedback Martin, we need to know what can and cannot work. Let's get this right.

I think I should be clear, the reason that I’m suggesting a basic plumbing system, is that surely this HAS to be cheaper, and better for the environment than buying plural thousands of liters of mineral water. Let alone when you include the costs to ship that to site.

So, in response to your post Martin, firstly, it seems that you are right about the height being an issue, I gather I didn't communicate this well to my plumber friend. To counter this, he suggested upgrading to a 3 bar pump like this:


Garden hose can leak at its joints, but that depends on what joints we use. However, considering the logistics and additional pressure the system would be under, I think plan B is in order.

For joints that absolutely will not leak we could use Hep20 pipe:


With joints that are extremely quick to use, and take off:


Plus tap connectors for these:


So numbers time.

That would be £260 for the pump.

Assuming we need to go 305m across (I measured that distance on Google Maps), and 410 - 65 = 345m up (based on Martins diagram) that means we need 460m of pipe minimum (a2+b2=c2).

I’d allow at least 600m of pipe so £85 x 12 = £1020

Plus £27 for a connecter, £8 for a tap connecter and £8 for a tap for each theme camp makes £43 per theme camp.

This is still vastly cheaper than buying mineral water. 

Granted, I would certainly request extra budget for this project. Among other things, this plan notably neglects Desanka,  Welfare and The Point among others (assuming they are in the same places as last year), but including them would be very doable. 

Does anyone have any corrections or feedback regarding my suggestion as it stands now?


Case Thu 23 Jan

I would get someone experienced in large scale supplies to check your maths. To get water up 40 metres you need a 4 bar pump. You also need to account for pipe losses and pressure needed at the outlet, so add at least another bar. With multiple taps there's the possibility that there may be multiple people using the system at the same time so whoever's closest to the tap would get the water at any given time. Bear in mind that this is getting above pressure limits for municipal supplies as high pressure water can be dangerous, so you'd need some mitigation at the bottom of the hill.

You would also want to sterilise the system before each use/year which would be a largish job.

As well as pressure you need to consider flow rate. My back of the envelope calculations show that 60 l/hour would be sufficient to supply everyone with drinking water, but that the tap would almost constantly be in use at this (or at least half the time). However it would take 30 seconds to fill a standard water bottle. 100 l/hour would give enough water to supply all needs (at 5 l/person), but would be drawn constantly and would still take 18 seconds to fill a water bottle. You would also need to factor in leaks. There will be leaks in a system like this, unless you have a team of volunteers monitoring it, much like the electricity team. What is the flow rate of the tap itself? (simple test - time how long it takes to fill a 2 l bottle)


Adrian Godwin Mon 13 Jan

I think you'd need to add an estimate for how much water would be used (600m of 15mm pipe will severely limit the flow rate) before going to Alex with the request.

The tap isn't mains water : it's from a small purification plant intended to serve the main house and near-continuous use may be well beyond its capacity.


Stephen Brannigan Thu 23 Jan

So, I just had a very productive discussion with Alex, the land owner, about this idea. He raised two issues which I'd like to feed back to the hive mind here.

Firstly, with pipes being directly exposed to the sun, and the water potentially remaining stagnant there, what, if any, is the probability of legionnaires disease?

Secondly, the only information I have regarding the total amount we are likely to use is 5L per person per day, x500 people, doubled (because it's a fun event). Can anyone contribute a more accurate estimate?


Ax Thu 13 Feb

Did you see the costs of the community water delivery that I posted here: https://www.loomio.org/d/W9CHFL4a/bulk-water-provision-/11


Martin Evans Mon 17 Feb

As Ax points out, we supplied 5,345L bottled water last year - not all drunk by the end of the festival and split between theme camps and free-campers.


Adrian Godwin Fri 24 Jan

How does the gatehouse get it's water ?

Being near the road, it might be on mains. Or it might be from the pumphouse, in which case we can assume the pumphouse has enough pressure to at least reach that height with enough flow to fill a storage tank.

So an alternative system might be to constantly fill a tank from a tap at the gatehouse and pipe that along the roadway adjacent to the free camping field with perhaps a tap as low as Crumpet. At worst, just take it to the nearest edge of the camping field : it's still a much shorter trip, has no hill and is a huge improvement over shipping bottles.

That requires no pump since it's gravity fed, has less worst-case pressure, and provides water for those with the longest journey, the free campers. The theme camps aren't so far from the pumphouse tap and carrying water is less of a problem - they can more easily share the cost and effort of a rolling container.


Kay Holford Wed 19 Feb

I would like to add, on an Access note, that the single tap down by the lake is great, but completely inaccessible to folks with mobility issues. Therefore, any idea involving taps needs to take this into consideration and have a tap on the trackway, or where someone in a wheelchair can access it. Ty!