Do they still add Chlorine to Mains water/drinking water?

Andy From Sligo

Hello , i dont know if this right section to ask this question on boards but just wondering do the water company still add chlorine to the drinking water/mains water these days , and how would one go about checking to see if it is added to the water?
same I am wondering if they are adding Fluoride to the water as well and how would you know/check?

MacronvFrugals

Pretty sure they're still adding chlorine, i believe all the results are published on Irish Waters website for each area. Where I am in D18 really need to use a Brita filter to make it taste decent.

elperello

Both chlorine and fluoride are added to drinking water supplies.

https://www.water.ie/help/treatment-and-testing/drinking-water-tests

10-10-20

https://www.boards.ie/discussion/2058351158/do-they-still-add-chlorine-to-mains-water-drinking-water

As it's a pipe fed network it has to be chlorinated otherwise it wouldn't be potable (drinkable) by the time it reaches your toothbrush.

https://en.wikipedia.org/wiki/Drinking_water

And the method of determining whether water is safe to drink is called the BOD test.

https://en.wikipedia.org/wiki/Biochemical_oxygen_demand

If you understand why BOD is measured then you'll understand why chlorine is required. 👍️

Andy From Sligo

thanks - i fill up my Water jug for the fridge and it gets so scummy in the top part , which makes me think if there was chlorine bleach added then how does get so bad quickly.
plus shower head gets kind of brown crust, its not just Limescale plus I know that the shower head water comes from tank in attic but thats enclosed totally so all that will go in is just mains water, and the toilet cisterns again inside mucky . again I would have thought if chlorine was added the water would be cleaner.

I shall have to check out this result on the IW website then , but (for my own sake) how would I go about running some water from my cold tap into a jug and sticking something in it to check that chloride and fluoride has been added to the water? - is there like one of those things you can buy to dip into the water and it changes colour to detect the chloride and fluoride?

ongarite

All the issues you describe are from very hard water; water with a lot of lime scale potential.

https://www.water.ie/help/water-quality/hard-water/

chrisd2019

https://www.boards.ie/discussion/comment/122122356#Comment_122122356

You issues are not related to chlorination or fluorination.

Andy From Sligo

https://www.boards.ie/discussion/comment/122122353#Comment_122122353

thanks for that

Andy From Sligo

https://www.boards.ie/discussion/comment/122122445#Comment_122122445

Thanks, I have lived in hardwater areas before where it has 'furred' up the inside of the kettle with limescale - its not doing that and been in this area for a few years and kettle has remained clean , seems like dirt more than anything else , but if it had chlorine in it I would expect the Chlorine to act like a bleach and clean things rather than make them black with dirt

Padre_Pio

The amount of chlorine is tiny, not enough to act like a cleaning agent.

Otherwise your toilet would be sparkling.

Andy From Sligo

https://www.boards.ie/discussion/comment/122122596#Comment_122122596

ah right I get ya - is it enough to kill the bugs though then?

CoffeeImpala

https://www.boards.ie/discussion/comment/122122585#Comment_122122585

You might be now living in an area with permanent hardness that does not precipitate out when heated. In the past your water had temporary hardness.

dathi

https://www.water.ie/help/water-quality/

you can check your water by area here

Andy From Sligo

https://www.boards.ie/discussion/comment/122132008#Comment_122132008

Thanks - very handy that. Biased because they do their own tests though?
Results for my area:

Andy From Sligo

Chloride results for 2023 in our area:

I couldnt find Chlorine in the filter just Chloride - I wondered if Chlorine and Chloride is the same and it looks like Chlorine is a bleach and Chloride is a salt.

So for Chlorine would I be looking at Free Residual Chlorine?:

Here is results for Fluoride for 2023:

dathi

"Thanks - very handy that. Biased because they do their own tests though?"

https://www.wikihow.com/Make-a-Tin-Foil-Hat

"So for Chlorine would I be looking at Free Residual Chlorine?:"

correct the free residual chlorine shows that the disinfectant is still working and is taken at various places along the line between the water extraction plant and the final houses

10-10-20

The free residual chlorine is the chlorine available for further disinfection. Good info here:

https://www.cdc.gov/safewater/publications_pages/chlorineresidual.pdf

And chlorine vs chloride - Chlorine is the basic element straight off the periodic table - it will kill you. Chloride is what you get when a chlorine attaches to another element - ie - a salt such as sodium and chlorine becomes Sodium Chloride - it won't kill you.

And yes, as dathi pointed out, government sources of information such as the water quality reports should be considered reliable unless there are established facts prove otherwise. 👍️

prosaic

I notice particularly strong chlorine smell from the water sometimes, often in the late evening. Is it the case that they put higher concentration through in the late evening to clean the pipes a bit more?

While filling a water filter jug, I get the smell wafting up.

Chlorine has quite a strong effect on the taste of a cup of tea. Mineral water makes a fantastic tasting cuppa.

Shoog

https://www.boards.ie/discussion/comment/122133658#Comment_122133658

There are two things going on here, the plant operator will monitor the chlorine levels at the exit to their plant. They will set it high just before they go home at night to ensure that if the chlorination plant fails overnight there will still be enough residual chlorine at the tap to be legally compliant. This will be dependent on how confident he is in his chlorination equipment.

Second issue is clean water with high levels of chlorine residual will have very little smell despite the high levels of chlorine. The smell comes in when the chlorine combines with organic impurities in the water and creates complex aromatic organic chlorine compounds. There are limits on the levels of organic impurities allowed at the exit of the plant - but if the plant is marginal for the task this will be quite high. There is always the possibility of organics entering the distribution network through pipe leaks which could also have an impact. This is why it is essential to have chlorine residuals throughout the network. Unfortunately chlorine levels decay with distance travelled and the level of impurities so the chlorine levels have to be sufficient to ensure a residual at the furthest point of the network, which mean those closest to the plant can have quite high chlorine residuals.

So if you are smelling chlorine at the house you are either very close to the treatment plant (or a chlorine booster station) and/or your water is not very clean in absolute terms.

Andy From Sligo

https://www.boards.ie/discussion/comment/122133658#Comment_122133658

yes that was another thing I used to notice which I dont any more so I wondered if they still put chlorine in the drinking water these days. Yeah I used to smell that. Smells a bit like the swimming pool smell, well not a strong maybe