Installing Water Supply Pipe

[soapstar]

Hi,

 

Quick question for those of you who may have been involved with installing water supply pipe (even better if through Scottish Water). Basically we have a water mains connection point located in an adjacent farmers field, to reach our plot the supply would have to travel approx 100m down field and crossing a road (small country road) into our plot.

 

I have spoken with the farmer and he is good with us putting in the pipe when his crop (oil seed rape) is harvested. My issue is that i haven't been quite quick enough to get the ball rolling with Scottish Water - the usual rubbish has to be done filling in forms etc before we will get anywhere. My question is would I be good to go ahead myself to avoid missing the chance - without confirmation from Scottish Water - to put a length of 32mm pipe down this field ending beside the mains water connection? If so is there certain guidelines that would have to be adhered to?

 

Note this would certainly be the mains connection to which we will connect to. Neighbouring properties to our plot already have pipes from this connection - I know its stupid we didn't put a pipe in at the time they were built! hindsight is a wonderful thing!

 

Thanks!

 

[Nickfromwales]

6 minutes ago, soapstar said:

If so is there certain guidelines that would have to be adhered to?

Known ones would be the obvious. 

• Depth of trench
• Fines in the bottom and immediately over the pipe to protect it from stones / sharps etc
• Warning / Marker tape to identify the location of the pipe from future damage 
• Terminating the run accordingly, stopcock - NRV - drain off cock etc ( differing by location with Scotland being as fussy as they are in Wales according to @ProDave ).  

 

[Redoctober]

Interesting and timely thread for me - I too am in the process of notifying Scottish Water that I need a connection - all done online and received acknowledgement - just awaiting the quote.

However, I note you have chosen 32mm pipe - the choices were 25mm or 32mm - What are the differences and what impact would having one over the other be?

PW.

Edited August 2, 2017 by Redoctober
typo - for for fro

[soapstar]

3 minutes ago, Redoctober said:

Interesting and timely thread for me - I too am in the process of notifying Scottish Water that I need a connection - all done online and received acknowledgement - just awaiting the quote.

However, I note you have chosen 32mm pipe - the choices were 25mm or 32mm - What are the differences and what impact would having one over the other be?

PW.

Thats interesting. Where did you do this online? I was told to fill in and post back a WC1 form.

 

In terms of the pipe sizing I am going with the largest size possible without incurring extra charges. From what i can gather by reading other peoples recommendations 32mm pipe is the best option. Perhaps someone can shed some light on this? Before I order some!

 

 

[Redoctober]

Yes, sorry @soapstar I should have been more clearer - I downloaded the form WC1, filled it in and then e-mailed it to them as a scanned in document.

 

As for the pipe sizes, I too would welcome some guidance .

 

PW

[Onoff]

Is this Scottish Water document any use?

 

wfsv3may2015.pdf

[PeterW]

14 minutes ago, soapstar said:

In terms of the pipe sizing I am going with the largest size possible without incurring extra charges.

 

Question would be why ..?? Most meters are 15mm, and your supply through the house will be 22mm in all likelihood so having a 32mm will give you added cost and complexity for no real benefit (unless you are planning a fire hydrant..??!)

[Onoff]

Don't forget that across agricultural land, i.e. land that's likely to be disturbed you'll need to trench deeper than normal for services. What's the case with your electrical supply, do you have to run that too?

[Nickfromwales]

Bigger pipe = lower resistance and better flow rates.

I'd go for 32mm in a heartbeat, and the additional pipe cost is so low it's not worth worrying about. If it's over any reasonable distance then I'd actively avoid 25mm. This is an important consideration if the network mains is less than the aforementioned 'hydrant' . 

[soapstar]

8 minutes ago, Onoff said:

Is this Scottish Water document any use?

 

wfsv3may2015.pdf

 

Thanks. This gives some insight into design considerations. 

 

6 minutes ago, PeterW said:

 

Question would be why ..?? Most meters are 15mm, and your supply through the house will be 22mm in all likelihood so having a 32mm will give you added cost and complexity for no real benefit (unless you are planning a fire hydrant..??!)

 

This was my exact thoughts to begin with however I was convinced otherwise that using the largest pipe available would future proof any further developments around the plot. 25mm pipe would be a nice little saving though! Like i say i haven't had any involvement with Scottish Water yet, hopefully they can recommend the correct sizing.

 

 

[PeterW]

So taking the classic PVT and T temperature being a constant..... 

 

Yes you can get a higher volume but at a lower pressure. And if the pressure isn't great to start with, are you creating an issue further down the line ..?

[soapstar]

9 minutes ago, Onoff said:

Don't forget that across agricultural land, i.e. land that's likely to be disturbed you'll need to trench deeper than normal for services. What's the case with your electrical supply, do you have to run that too?

Thanks this did cross my mind. I assume we will lay this pipe at the same depth as the previous pipes once we find them - im assuming at least a metre. The more I read into this the more i need to wait on Scottish Water getting back to me, although it will be a pity to miss the opportunity to get the pipe in before the Farmer puts in his next crop

 

Electric wont be coming down this route fortunately!

[PeterW]

I would go 900-1000mm down and keep to a fence line if possible. That way a subsoiler won't drag the pipe upwards at any point in the future. 

[IanR]

In a similar install I went with 32mm. Any larger (in England) and you have to pressure test and chlorine flush the pipe work prior to connection. I chose not to go any smaller as, until the connection was made, I didn't know what pressure and flow rate I would have, so didn't take any chances.

 

In England there is a minimum 1100mm depth requirement (IIRC) across a ploughed field. But, a deeper depth requirement for a "deep ploughed field". As the field is out of your control you should go the deeper depth. Can't remember  the actual figure but it was only a little bit deeper, something like 1250mm

 

In England, this isn't something you can do ahead of the water company as they have to witness the trench before it is back filled.

Edited August 2, 2017 by IanR

[Nickfromwales]

1 hour ago, PeterW said:

So taking the classic PVT and T temperature being a constant..... 

 

Yes you can get a higher volume but at a lower pressure. And if the pressure isn't great to start with, are you creating an issue further down the line ..?

Pressure often rolls off to nearly nothing with dynamic / flow. Having a 32mm pipe is favourable over 25mm afaic to keep that flow at its highest rate vs distance. Upsizing the pipework is commonplace for mitigating against such resistance, but I wouldn't bother going bigger than 32mm for a domestic supply unless you can prove it's worthwhile and will actually ever consume that volume of water.

Its down to surveying the supply, as I've always maintained when designing / spec'ing anything. 

[ProDave]

My experience of Scottish water is the local surveyor is "GOD" and what he says goes, or does not go. He would not accept a pipe buried that HE had not inspected the track for.  They tried to refuse to connect a neighbour because they had not put the toby in exactly the right place.

 

In any case, the pipe across the field will be theirs ans they will choose the size. Your pipe does not start until after the toby which will be on your land.

 

On the good point, SW were the cheapest of all the people we approached for the road crossing. If any of your other services have to cross the road, install appropriate ducts ready for them while the road is up. I laid ducts for telephone and electricity while SW had the road up.  If you need that, insist on a cut trench, SW were mooting the idea of molling under the road until I mentioned I wanted to lay other ducts at the same time.

 

Also, knowing now how fussy SW were, I would recommend ALL you have on your site when they come for your track inspection is a standpipe very close to where the toby is going, nothing else, and you must have an in line double check valve connected to your stand pipe or they will refuse connection.

 

Regardless of farmers good will or not, SW will get a proper wayleave to lay the pipe and that might delay the process. In my case they dug up a bit of the field while in crop to make the connection.