Treatment Plant discharge into watercourse

[Lincolnshire Ian]

Hi all

We have bought a plot in rural fenland Lincolnshire. We will need a foul water treatment plant, and previously, we have been able to get permission to discharge the treated wastewater into an adjacent water course.
This time, we don't have a directly adjacent watercourse, but we do have one just across the very narrow, infrequently used road that our house sits on.

The road also has storm drains that run alongside our plot and into the watercourse.

If possible, we would like to avoid installing a drainage field. It would work well for us to discharge either into the storm drain, which then flows into the watercourse, or even dig up the road and install a pipe and discharge directly into the watercourse.

Both options will require lots of permissions, engineering work, large costs, etc, but I was wondering if anyone had done something similar to avoid the need for a drainage field.

Thanks

Edited June 16 by Lincolnshire Ian
Clarity of description

[Kelvin]

I’m in Scotland so didn’t get a choice and had to put in a drainage field. You’re only allowed to discharge to a watercourse if there are no other options. If you have the space and ground is suitable what’s the big deal? Modern treatment plants output mostly clear water and a drainage field isn’t terribly expensive to put in. 

Edited June 16 by Kelvin

[Redoctober]

Hi @Lincolnshire Ian - If I am reading this correctly, you are looking to discharge your "foul" water into a storm drain. My understanding is that storm drains cater for "surface" water - rain fall - not sewage, albeit treated foul water. 

 

What have the Local Authortity said about dealing with such discharge?

[nod]

We’ve done exactly what you are proposing (Twice) While we have plenty of space to instal a soak away 

Both occasions we where on Boulder clay 

[joe90]

My discharge was to a ditch (dry in summer months but with a rumble drain) but this then went into a surface water drain in the road then to a water course and this was allowed (England).

[scottishjohn]

44 minutes ago, Kelvin said:

I’m in Scotland so didn’t get a choice and had to put in a drainage field. You’re only allowed to discharge to a watercourse if there are no other options. If you have the space and ground is suitable what’s the big deal? Modern treatment plants output mostly clear water and a drainage field isn’t terribly expensive to put in. 

took alot of talking to get sepa to agree to NO soakaway field 

even with treatment plant they still wanted some sort of drainge field before it went to water course

,only the lack of space and rock ground made them agree to discharge into  water source  and that only because it never drys up

[crispy_wafer]

how close are the storm drains to your plot, if they are like less than a meter, id be tempted to dig an 18" trench right up to the storm drain, fill it with stone and your outlet pipe, either 4" soil pipe or 4" leaky land drain pipe.  However that said, I'm down the road from you in lincoln, and have my pumped mdpe pipe running straight into a fieldside drain, all the neighbours are doing similar...  BCO just said crack on, dont think he was interested tbh, more focus on the pipework around the build and distance to the wtp 

[saveasteading]

Do it properly say I.

Although the water is nearly clean, you wouldn't drink it or use it in any way, so it should not go into a water course. 

My only issue with drainage fields is that the reg's vastly oversize them. So I designed ours to be made in phases. Phase A was accepted on its own at inspection.. as hoped.

[Kelvin]

Also worth keeping in mind that a soakaway and a drainage field aren’t the same even if the terms get used interchangeably. We have an engineered drainage filed even though it’s described as a soakaway in the plans. 

[Roundtuit]

It's fairly standard to discharge to a dyke around here, so shouldn't be a problem.  I'd guess that you may have to go directly to the dyke rather than via a storm drain, so the roadworks sounds like the challenging part of the proposal.  I believe you can mole 110mm pipe, so that might be cost-effective way of negating red tape perhaps?

[IanR]

Assuming you are in England, you need to follow the General Binding Rules 

 

https://www.gov.uk/guidance/general-binding-rules-small-sewage-discharge-to-a-surface-water

 

The above section is specific to discharging to surface water. It's not a last resort in England, perfectly OK to do, if you fit within the rules. If you do fit within the rules then no further permissions or permits are required, although you are criminally responsible for meeting the rules.

 

Read all the caveats, but as long as you meet them then the storm drain will be fine if, for most of the year, it has water running in it. If it doesn't then there's an option to discharge to ground, within the storm drain, with a partial drainage field (length of perforated pipe) as described by @crispy_wafer

Edited June 16 by IanR

[saveasteading]

Lecture follows.

In any area where flooding is a problem or a risk , we should all do our best to minimise it.

Having soakaways or lagoons which prevent water running to a watercourse should be our aim. 

Connecting to a storm drain r ditch is the fastest way of getting your water into the river, to be someone else's problem.

 

These huge floods we see are a collection of every individual raindrop upstream. They all add up.

 

So please try to lose or hold the water on site, with perhaps only an overflow going to the adjacent dyke.

 

Treatment tanks are designed for (from memory) about 110 litres per person per day. You flush a toilet and the equivalent 5 litres comes out of the other end some seconds later, and into your disposal system.

 

Where flooding is not a risk, it is still usually best to feed water into the ground, which is where it would otherwise have been.

[Kelvin]

Completely agree. We also have an attenuation field for rainwater. We could have argued that one away but there is a lot of flooding down stream from us and we didn’t want to contribute to that in any way. 

[IanR]

22 minutes ago, saveasteading said:

Lecture follows.

 

?

 

This is treatment plant discharge, it plays no part in adding to a flooding risk. It's several orders of scale smaller than surface water drainage. 

 

@Lincolnshire Ian just follow the General Binding Rules where Environment Agency, who are responsible for reducing surface water flooding, have worked out what is best to do with you treatment plant discharge.

Edited June 16 by IanR

[G and J]

(Maybe a teensy bit off topic, but….) We will be building in an urban environment, replacing a bungalow with a combined system.

 

We believe we are on very well draining sandy soil, and the one time I’ve dug down so far I hit pebbles and orange sand at 20”. 
 

Yet everyone in the trade I’ve talked to so far have said something like “save yourself aggro, just stay combined”.

 

Anglia Water reduce your bills by virtually nothing for spending extra and dealing with surface water locally.  There’s simply no incentive not to dump the problem on them.  Sigh. 

[saveasteading]

 

Easy for me to say I know. I don't know your site circumstances , or whether anyone in your team has either the interest or design skill in this subject.

 

I'm talking principles and best practice here. I've been doing these designs for decades, and I feel it shouldn't still be seen as radical.

I think the big developers have had some control in limiting the improvements in standards. and the EA , as government employees, are also constrained in their control.

 

 

2 hours ago, IanR said:

it plays no part in adding to a flooding risk.

Of course it does. if you add your 120 litres to the drains or watercourses, it has added to the rainfall quantity therein. 

Say 'negligible' instead of 'no' and I'd have to think about it a bit more.

When 120litres creeps over a dyke that is your 120 litres along with a lot of others'.

 

2 hours ago, IanR said:

It's several orders of scale smaller than surface water drainage. 

it depends on housing density of course, what percentage of the drainage is from the imported water going into drains. So yes, for a small house in the countryside. No for a house on an estate, but it all ends up in the drains, sewage works, rivers, flood plains downstream.

More water is more water.

 

 

 

3 hours ago, IanR said:

General Binding Rules where Environment Agency, who are responsible for reducing surface water flooding, have worked out what is best to do with you treatment plant discharge.

 

These are minimum standards. What is 'best' is to reduce water to drains and watercourses as much as reasonably practicable.

 

It's like driving past a school at 33mph because you won't get fined. 30mph max is the published standard. 20mph may be more considerate. All are permitted by the government.

 

Anyway this, as many other decisions, will be yours.

 

For general interest.  Not many people know that if you don't send any  rainwater to the sewers, you get a big cut in the charges, for this year and every year. 

And that sewage charges are based on the mains water used. Use less (barrels/ harvesters/turning off the tap) and you  pay less for water but also less for sewage., and quite right too.

 

 

[IanR]

16 minutes ago, saveasteading said:

Of course it does. if you add your 120 litres to the drains or watercourses, it has added to the rainfall quantity therein. 

Say 'negligible' instead of 'no' and I'd have to think about it a bit more.

When 120litres creeps over a dyke that is your 120 litres along with a lot of others'.

Of course it doesn't.

These are rural properties by their nature (off mains drainage). When flooding occurs it's with exceptional rainfall. Let's say the often quoted "a month's rain in 24 hours". As an underestimate call it 100mm of rain. A Hectare of ground will receive 1,000,000 litres of rain during the 100mm downfall. Density of rural housing, that in England has no access to main drainage, is on average substantially less than one property per hectare. It's several orders of scale difference to the treatment plant discharge that the OP is referring to.

 

Feel free to point to some research suggesting that treatment plant discharge has any bearing on flood risk and I'll happily read it and reconsider.

 

25 minutes ago, saveasteading said:

I think the big developers have had some control in limiting the improvements in standards. and the EA , as government employees, are also constrained in their control.

"big developers" are putting mains drainage in and not installing treatment plants.

 

27 minutes ago, saveasteading said:

I'm talking principles and best practice here. I've been doing these designs for decades, and I feel it shouldn't still be seen as radical.

 

I lose track of all your areas of expertise. Are you saying you have been designing small treatment plant installations for decades?

[saveasteading]

I'm not here to argue. But I do maintain that (x +120) is greater than x. 

 

12 minutes ago, IanR said:

Are you saying you have been designing small treatment plant installations for decades?

If you are really interested? Yes.

[Kelvin]

I simply worked on the principle that I didn’t want any more water running off our site after the house was built than it did when it was just a field. 

[joe90]

In my situation (very rural) no history of flooding locally (but @saveasteading is right, it all ends up downstream where flooding may occur), I was on very solid yellow clay so any drainage field would not work, the ditch I used carried all the surface and small amount of treated water away.