95% wastewater

quartzz

With one meter installed, the waste water figure is a set "guess" figure, and it's 95%. So no matter what you do with your water, the billed amount going down the plug is 95% of what comes in.

So if you wash your car, water a large garden, you're being charged a waste water figure, for water that isn't actually there and doesn't exist (because it gets removed by evaporation obviously, and not a pipe)

Severn Trent managed to give me a unique, individual reply that wasn't from a template (/sarc), and probably included the words "best value for money for our customers".

So if you do the above [from the tap], you're getting charged for water that isn't there. And I think that's......super.

mmmmikey

Not sure about other suppliers but with Anglian Water you have the option of metering your garden tap and paying reduced drainage charges.

Slinky

If you can prove that you don't return huge amounts of waste water, you can get your bill reduced. We read our meters before having building work done where all the concrete was mixed on site. At the end of the building work I read the meters again and phoned Anglian Water, explained what had gone on, they could see that we'd had a 17% increase in water usage since the year before. They wrote off all the sewerage charges. There is mention on the bills that if you have something like a swimming pool they can make arrangements to amend your billing.

quartzz

I've had a brief email dialogue with ST, they've said the 95% is set in stone. I might try a phone follow up...

FlorayG

I contacted Wessex water to tell them I'm taking 10 gallons a day elsewhere for livestock (which I am) and that I'm watering a vegetable garden. My 'waste water' bill was reduced by £25 per quarter. Not much, but worth asking

quartzz

So it went a bit like this..

Severn Trents text: "95% of your incoming water is billed as outgoing - that means you drink 5% of it, and everything else goes out via a pipe and is charged"

My question. "is this 95% adjustable, for instance if 20% of it ends up watering the garden. can the amount of waste water be monitored". Because if not, Severn Trent would be charging me for waste water that doesn't exist.

On hold for 20 minutes. get cut off.
redial
"how are you today?"
[various responses possible]
[so anyway]
On hold for another 10 minutes. "the 95% cannot be changed"
[yes. this is what I thought, but worth checking anyway]
"If you look at your statement, you'll see the breakdown of the charges"
[yes. I know. that's why I'm making this phone call]
ok. ta.

Those CEO Mercedes aren't gonna buy themselves.

Green_hopeful

I can answer this. Water and sewerage companies publish their charges each year. This is Severn Trent’s household charges scheme for this year. https://www.stwater.co.uk/content/dam/stw/my-account/our-charges/2025/st-hh-charges-scheme-2025-26.pdf On page 28 it says it estimates 95 per cent of water used is discharged to the sewer. 

Section B3.1(viii) says if you think you should pay for less than 95 percent of water used then you need to prove how much water you are discharging to the sewer. 

It’s quite common in commercial properties but not so much domestic households. We use a lot of our grey water to water the garden so ours is probably nearer 50 percent but I can’t face getting a discharge metre. 

quartzz

I asked them if it was possible for it to be monitored or for me to be able to prove it (eg, getting a second water meter fitted) and got a "no"

FlorayG

Interesting. Wessex Water asked for photographs of my vegetable garden then took my word for it and reduced my charges by £25 per bill. Perhaps my water company just has a standard reduction not related to the actual amount you 'save' from the sewer, because they didn't ask me to supply any measurements of amount used

HampshireH

This has made me look at mine as I've never seen any associated text. My waste water is with Thames and I'm charged the same amount of units out as comes in via South East Water (on a meter). All 100% of them.

Having looked into why it's because allegedly their fees already factor in that 10% of water doesn't return to the sewer. Would definitely be clearer if they just charged 10% less.

Interesting post thankyou OP I learnt something this morning!

(Looking at today's news I expect that cost will increase again to cover their most recent fine)

Green_hopeful

quartzz said:

I asked them if it was possible for it to be monitored or for me to be able to prove it (eg, getting a second water meter fitted) and got a "no"

The call handler doesn’t know the answer. The link i posted says you can have a measuring device fitted and be charged on the actual amount you discharge. They can’t argue with their own Charges Scheme. If you ring back and refer them to the Charges Scheme the answer will be yes but I don’t know how much it would cost to install a waste water meter.