Discharges in Groundwater Source Protection Zone 1

[Drellingore]

This isn't quite building regs, but I couldn't find a subforum for the Environment Agency  Mods, please feel free to relocate the thread if I chose the wrong place.

 

Does anyone have experience of getting a permit for anything that's not a cesspool in Groundwater Source Protection Zone 1? Is it possible? Or am I on a hiding to nothing?

 

Without an EA permit, our only option is a cesspool. We're trying to build something environmentally-friendly and sustainable, and a cesspool definitely isn't! It looks like we need a whacking-great 84m³ cesspool too, which is massive. Ideally we'd like a reedbed, but I'm not sure if there'll be space, and I can imagine the EA finding it easier to permit a packaged treatment plant. The only problem is that I've got not idea what kind of discharge metrics they'll find acceptable. The advice from one treatment plant vendor was that the EA will only tell you what quality you need to achieve after applying for a permit!

 

Any help or anecdotes would be most gratefully received. 

[saveasteading]

A properly selected treatment plant into a proper soakaway will more than perform  (the drainage beds are very conservative, ie oversized ) and should be signed off easily enough.

Metrics are based on building use, presumably domestic, number of bedrooms and ground permeability.

What is the ground/ water table level?

[Drellingore]

Wow, thanks for the very quick response  I'm mostly working solo on this at the moment, and so the kindness of strangers is appreciated.

 

8 minutes ago, saveasteading said:

A properly selected treatment plant into a proper soakaway will more than perform  (the drainage beds are very conservative, ie oversized ) and should be signed off easily enough.

Metrics are based on building use, presumably domestic, number of bedrooms and ground permeability.

 

That's encouraging to read! There's a small matter of the land having belonged to the water board, and there being some restriction in the title, but I'll save that for another day!

 

6 minutes ago, saveasteading said:

What is the ground/ water table level?

 

I'm slightly embarrassed to say that I don't know. Any ideas how to find out? We are about 200m from the local water supply pumping plant though 

[saveasteading]

44 minutes ago, Drellingore said:

how to find out

Ask neighbours. Dig a hole. 

Simply, for now,  what do you find 300 down?

[ProDave]

What I found (SEPA in Scotland, so slightly different) is you choose your treatment plant, apply for a permit stating the manufacturers quoted figures, and that is what is put on your permit.

[saveasteading]

For ours, I did the drainage investigation, the report and the design. It is something I do.

Whether sepa even looked at it we can't tell.

 

It is quite a complex process. The treatment plant manufacturers will specify appropriately, but you need to be, or make yourself, fairly expert to do the disposal assessment, esp as you are looking at soakaway. Otherwise you will need professional help. 

For now, let us know the ground and we can help with the initial feasibility.

Also...do you have much land available for a drainage system.

Reed beds are great in principle. Depends on circumstances.

[Gone West]

1 hour ago, Drellingore said:

I'm slightly embarrassed to say that I don't know. Any ideas how to find out?

A starting point might be local borehole details.

 

https://www.bgs.ac.uk/information-hub/borehole-records/

 

[Gone West]

1 hour ago, Drellingore said:

Ideally we'd like a reedbed

We used reedbeds with our treatment plant at our last house and found them quite high maintenance.

[Drellingore]

Wow, you folks are super-responsive and helpful. 

 

1 hour ago, saveasteading said:

Ask neighbours. Dig a hole. 

Simply, for now,  what do you find 300 down?

 

lol - in that case I'm fairly sure the water table is well below the ground level. I've dug 50cm trial pits for structural surveys, and there was no sign of any water. The site is at the bottom of a 'dry valley', which is made of chalk so all the water seeps quite deep down. The area used to flood once every seven years or so, forming a temporary river locally known as the "nailbourne". Since the started abstracting the local water supply from the bottom of the valley, it's never been known to flood.

 

57 minutes ago, Gone West said:

A starting point might be local borehole details.

 

https://www.bgs.ac.uk/information-hub/borehole-records/

 

Thanks! There is a result just south of our site (at the same altitude above sea level) but I'm snozzwangled if I can make any sense of it! One of the neighbours used to work for the water board, so I might ask him.

 

1 hour ago, saveasteading said:

For ours, I did the drainage investigation, the report and the design. It is something I do.

Whether sepa even looked at it we can't tell.

 

It is quite a complex process. The treatment plant manufacturers will specify appropriately, but you need to be, or make yourself, fairly expert to do the disposal assessment, esp as you are looking at soakaway.

 

Ah, I gather you're in Scotland. Sensibly (it seems many Scottish government decisions are more sensible than ours!) it seems that cesspools aren't even allowed in Scotland, so presumably up there y'all must've figured out a sensible solution in these sorts of areas. I think the permit application we have to make in England is Part B6.5, and because there's two buildings we'll apparently have to provide a "Flows and Loads - 4" calculation. There's mention of a risk assessment in the form that needs to be done, but because we'll be < 2m³ a day, the EA will do that for us.

[Gone West]

2 minutes ago, Drellingore said:

forming a temporary river locally known as the "nailbourne".

So you must be in the Barham area. I used to live near Westmarsh so know the area.

[Gone West]

7 minutes ago, Drellingore said:

The site is at the bottom of a 'dry valley', which is made of chalk so all the water seeps quite deep down.

The water table where I used to live could vary by 2.5m over a year from ground level downwards. I had a borehole drilled and it was water bearing all the way down to the chalk which was also water bearing at 47m down.

[Drellingore]

1 minute ago, Gone West said:

So you must be in the Barham area. I used to live near Westmarsh so know the area.

 

Ha! Small world! The site is that of an old farm called "Drellingore", a bit further south than Barham. I think I might actually have gotten the name wrong, and it's a different winterbourne, as the AONB management guide says:

 

Quote

The larger dry valleys such as Elham and Alkham have the sporadic winterbournes such as the Nailbourne in Elham, flowing occasionally during the very wettest winters.

 

That or it's a common term, rather than a name.

 

...And now I'm down a local history rabbit hole  There's a local history site that references the "Drellingore Nailbourne", and even some antique photo on eBay!

[saveasteading]

Our project is Scotland. I have done far more work in Kent.

 

The rules are much the same.

 

So you have the land, have dug a hole, know that there is chalk below. All looking good.

 

There is an unusual concern on the chalk, that water will disperse down a crack and cause a sink-hole. Spreading it wide resolves that.

 

Unless you can do it yourself I would get some professional help on this. Seeing the site is crucial.

 

Doing test holes and permeability tests are easy and you can do them before engaging help.

 

But for free.... how many bedrooms? Do you think it is clay? Is there a stream or ditch adjacent?

[Jilly]

Mad suggestion perhaps, but my pet subject: there are compost loos which will pass Building Control, some with a small incinerator. That will just leave you with grey water to get rid of. 

[Gone West]

50 minutes ago, Drellingore said:

I think I might actually have gotten the name wrong,

I lived in the area for a long time and only saw the Elham Nailbourne flowing in a few winters.

 

http://www.barham-kent.org.uk/modern_nailbourne.htm

 

 

[Drellingore]

13 hours ago, saveasteading said:

But for free.... how many bedrooms? Do you think it is clay? Is there a stream or ditch adjacent?

 

One building that'll be permanently occupied is 4 bedrooms, and the annexe (which might be a holiday let, depending on planning) 2 bedrooms. I don't think there's clay, and no streams or ditches. That said, there might be one on the other side of the road that adjoins the property, so I could check that out. 

 

13 hours ago, Jilly said:

Mad suggestion perhaps, but my pet subject: there are compost loos which will pass Building Control, some with a small incinerator. That will just leave you with grey water to get rid of. 

 

Nice idea! We built an outdoor composting loo (basically a shed around a wheelie bin!) so we could camp there. I'd be up for this, but I'd have to get it past the family. I like your thinking, and I'm interested in greywater recycling generally, and would welcome any thoughts you have on that.

 

12 hours ago, Gone West said:

I lived in the area for a long time and only saw the Elham Nailbourne flowing in a few winters.

 

http://www.barham-kent.org.uk/modern_nailbourne.htm

 

 

 

The "Gone West" username makes sense now

[Gone West]

14 hours ago, Drellingore said:

Thanks! There is a result just south of our site (at the same altitude above sea level) but I'm snozzwangled if I can make any sense of it! One of the neighbours used to work for the water board, so I might ask him.

Rather than the specific details of a particular borehole it's whether there are several historical shallow wells in the area, less than ten feet deep, that could indicate a high water table. Where I used to live was, hundreds of years ago, the old coastline salt marshes and the geology changed significantly over short distances. Most of the pre 20thC properties in the area had shallow wells.

 

PS It looks like the borehole details you linked to showed that they drilled 180 feet but never finished the well and that it is capped off.

Edited November 4, 2022 by Gone West

[saveasteading]

The cleanest of the grey water (bath, shower) could feasibly go to smaller soakaways. That might be a 'good thing to do', but won't reduce the digester and drainage bed size which is based on number of bedrooms.

 

You will see discussions on here of tanks being held down to avoid floating in high water tables. The drainage must struggle but it seems to be permitted. 

 

I suggest you now do a percolation test or 2 or 3, in the likely location for your soakaway (which i should warn will be about 60m2! This is easy and is in the building regs. It is well explained in jdp (a drainage supplier) website .   Search " percolation test jdp".

This won't be definitive but will show tbe feasibilty. 

 

 

[Drellingore]

2 hours ago, Gone West said:

they drilled 180 feet but never finished the well

 

I assume as they never got to the water (it'd be a bit weird to keep drilling after hitting the water table).

 

44 minutes ago, saveasteading said:

your soakaway (which i should warn will be about 60m2!

Cripes, that's a big area.

 

Thanks for your thoughts all, I'll continue to look into this and let you know how I get on.

[saveasteading]

Just now, Drellingore said:

that's a big area.

I'm convinced the rules are misguided. There is a formula for semi-treated outflow, which needs a big gravel area for bacteria to finish thd job, and they knock off 20% for fully treated.

Hence a handy ditch can save lots of money and hassle.

[Drellingore]

Thanks for all the help in both this and the other thread.

The approach I'm taking now is pursuing intended restriction breach insurance, and then going to the Environment Agency for a discharge permit. Because we're in Source Protection Zone 1, I'm going to need to spec something really clean in order for it to get approved (that, or wait months longer making multiple applications). 

 

Something like a Vortex, a Gem-APS and a UV filter should make the water as clean as it can be. If that's the case then hopefully the EA will approve it, which will give insurers more confidence, and then we just hope that the water company see sense eventually. If not, we've got the cesspool as a fallback, but it could cost £5k/year to empty, which is a bit rubbish.

 

I'm going to do a percolation test, and also dig a water-table trial hole (2m deep, 1m square) to check that the water table isn't high. I was thinking of doing the latter by hand, as I like a bit of exercise. Am I mad? I reckon it'll take a good few hours, if the ground isn't full of stones.

[Kelvin]

If there’s anything I’ve learned about digging big deep holes use a machine. Done in minutes as opposed to hours. I dug a 21m trench for the electricity ducting to go in. I did have someone coming with a digger to do it for me but it was only a few days before SSEN came to lay the cable so I didn’t want to risk any delays. Took me days to dig it by hand largely because of big stones under the beautiful top soil. 
 

Do you know anyone with a digger that could come along for a few quid? 
 

When I had a percolation test done they dug multiple biggish holes all around the plot where a soakaway might go (so away from the house) It was surprising how different the results were between the trial pits. 

Edited November 22, 2022 by Kelvin

[saveasteading]

50 minutes ago, Drellingore said:

reckon it'll take a good few hours, if the ground isn't full of stones

Doing this will give you a unique undertstanding of your ground.

I suggest that as you progress, you do more percolation tests, just in case it is much better at lower levels.

Machines are a good invention though.

 

Also ground  strength tests while you are at it.  I can explain the easy low-tech way if you are interested.

 

I wonder if you are overworrying about the quality. Have you discussed with a digester manufacturer?  I have had lots of good advice from Marsh Industries over the years. Email first with the background,  then poss phone. Others may be good too.

[Drellingore]

3 hours ago, saveasteading said:

I can explain the easy low-tech way if you are interested.

 

Thanks! If it's not too much effort, I'd be interested to read that just in case it comes in handy. There are barns already existing, but turning them into dwellings is presumably going to put more load on the ground, so maybe it'll be useful to know. Don't put yourself out though, you've been helpful enough already!

 

3 hours ago, saveasteading said:

I wonder if you are overworrying about the quality. Have you discussed with a digester manufacturer?  I have had lots of good advice from Marsh Industries over the years.

 

EDIT 2: Forgot to write that I'm waiting for a callback from Marsh, so I'm glad to hear a recommendation for them

 

It's quite possible that I am. The issue(s) I have are that:

• It's source protection zone 1
• There are title restrictions explicitly banning anything that discharges to ground
• The local aquifer is 300m away
• It's arguably in a flood risk zone
• The Environment Agency will not tell me what water quality I need to achieve before applying for a permit, and I don't want to lose time with multiple rounds of application

 

The last one is a bureaucratic pain in the backside. It reminds me of when the MOD needed to approve Crossrail routes, but of course can't say where to avoid digging tunnels. So the developers had to just keep submitting plans until they managed to not 'hit' any secret facilities. Kinda like inverse Battleship! EDIT: If I had a vague idea of what they'd find acceptable, it would be a different ballgame.

 

Because of this I think the compromise of risk/progress is to go to the EA with the best solution I can afford (which at the moment is cheaper than the cesspool that would be required), get a permit, then either get insurance on the title restriction or convince the beneficiary to change them. If I go to the EA with anything other than the best I can reasonably afford and it gets rejected, then I won't learn if a solution is possible at all, or whether I just didn't spec high enough.

 

Edited November 22, 2022 by Drellingore

[Drellingore]

3 hours ago, Kelvin said:

Do you know anyone with a digger that could come along for a few quid? 

 

Kinda. There's one really helpful local farmer, bloke in his 70s who is an absolute legend. I feel a bit bad asking for favours though, as we don't have anything to give him in return (he doesn't drink, so it's not like I can just bung him a bottle of wine or something).

 

How hard is it to operate a small digger? Tempted to rent one. In fact, we'd been looking at buying an electric one (eco-hippy who has only ever driven electric cars) and then either trying to monetise it through rental or flogging it on, but I don't know enough about the market to know if that's a silly idea or not.