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Tuesday siren test

NewsIf you’ve ever heard a siren sound in the morning and wondered where it came from then wonder no more!

Residents near the Hampton Water Treatment Works on Lower Sunbury Road in particular will be aware that Thames Water store chlorine on site (used to cleanse the water supply) and have safety procedures in place to follow in the unlikely event of an accident or leak.

Although the amount stored on site is far less now and the chlorine is produced more on-demand these days, Thames Water still sound their emergency siren every Tuesday at 9am for 15 seconds or so to familiarise those who live or work nearby with the sound.

Thames Water leaflet buildings within a half a mile radius giving advice on what to do if they hear the emergency siren. Advice on hearing this includes going immediately going indoors, closing all windows/doors and staying tuned to the radio for updates.

Local community groups had expressed concern about storing and transporting near their homes and schools such large quantities of a dangerous substance that had previously been used as a poison gas during WWI.

Obviously the siren can be heard much further afield – across parts of Teddington too and because of its placement in between the town and Water Plant, some had assumed that the siren originated from the NPL but this is not the case.

If these leaflets are still handed out to nearby residents we would love to find out more up-to-date information about the advice that they provide, or indeed any more recent information about the chlorine store.

[Update 27/11/2013] Information from Thames Water – this leaflet was distributed to 1,000 homes near the Hampton water treatment works this summer. The advice is mostly the same as the info from the 1996 leaflet. Important bits:

Thames Water’s Hampton water treatment works has a large quantity of hazardous substances on site and the nature of the work carried out there means it is regulated through the Control of Major Accident Hazard Regulations (1999), COMAH.
Working with the emergency services and local authority, we will respond quickly and efficiently should an incident involving hazardous substances occur at Hampton water treatment works.
You will be notified by the emergency services or siren. Please read this leaflet carefully and follow the instructions given in the unlikely event of an emergency. Please also make sure all occupants of your household understand these instructions and keep the information in a safe place. If you are a business, please make sure this is prominently displayed on your premises.

What to do in the event of an emergency
at Hampton water treatment works
If you hear the siren (tested at 9am every Tuesday) or receive notification from the emergency services,
please follow these simple instructions:
• Go immediately indoors.
• Close all doors and windows. Turn off any ventilation system, air conditioning units or heating systems
that draw air from the outside.
• Where possible, go to an upper floor of the building.
• Tune into Capital Radio on 95.8 FM, 1548 MW or your local TV station for information.
• If you need to evacuate, the emergency services will tell you where to go.
• Please co-operate fully with the instructions and advice of the emergency services.
• Remain indoors until you receive instructions from the emergency services that it’s safe to open doors
and windows and to go outside, or you hear the ‘all-clear’ siren (which is three short bursts).


8 thoughts on “Tuesday siren test

  • Ivan Powell

    My leaflet dated July1996 says;
    On hearing alarm 1) Immmediately go indoors and close all windows and doors.
    2) Turn off ventilation fans and heating systems
    3) If possible go to an upper floor of the building
    4) Obey any instuctions you receive or hear from Emergeny Services
    5) Stay tuned to radio Tune to Capital Radio for News Flashes.
    It also gives reassurance about children in schools and what to do if one feels they need medical attention.

  • John Sergeant

    I live in West Molesey (since 1993). and I have heard that Siren every Tuesday ever since moving here. I always thought it was somewhere in Molesey. Today, for some reason, I decided to try and find out more. Have just read the article re chlorine test. I assume it’s ok at 9AM on a Tuesday but any other day/time means a problem. Are we likely to be affected in West Molesey?

    • tteditor

      Hi John, I wish I could tell you more but there is very little info around about this and after many attempts at getting anything from Thames Water themselves I have almost given up!

      It sounds as though nearby houses that would be most at risk have had leaflets a while ago so you might be outside this area?

  • The siren was clearly heard in Surbiton today.

  • katscratch1creative

    I’m relieved to read that it’s a real siren. I was beginning to wonder if it was a ghost siren from WW2 that only I could hear 🙂 lol

  • Never ever had a leaflet through the door i live 5 mins away from it!

  • YouTube discovered counting views within style is unreliable (and at the mercy of video gaming) some time ago.

  • I can hear this all the way over in Ham! I felt a bit unnerved by it so looked into it to work out what I was hearing.


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