How to Use a Millbank Bag: 6 Easy Steps

How to Use a Millbank Bag: 6 Easy Steps

Millbank bag stock number
A Millbank bag is really useful for removing turbidity from water. Photo: Paul Kirtley.

In producing drinking water, one of the contaminants we may have to deal with is turbidity.

A Millbank bag is a method of coarse filtration designed to remove sand, mud, silt or other suspended particulate matter such as decomposing organic material.

It’s important to remove such suspended matter from water before you drink it. Even if there are no waterborne diseases present, turbid water can irritate your digestive system.

In addition, turbidity can reduce the effectiveness of chemical treatments in deactivating pathogenic organisms.

What a Millbank Bag Does (and Doesn’t) Do

The removal of suspended particles that make water cloudy is a Millbank bag’s primary purpose.

A Millbank bag will not filter out pathogenic organisms, unless those organisms remain attached to the particles of mud, silt or other suspended matter that is filtered out.

Hence, we still need to use an additional form of purification – chemical sterilisation or heat – to kill off any viruses, bacteria and protozoa that may be present.

If the water you have selected to use is clear (i.e. not turbid) then there is no advantage to putting the water through a Millbank bag.

How to Use a Millbank Bag

Many Millbank bags have instructions attached to them like a tag on the inside of a piece of clothing:

Instructions for using a Millbank bag
Millbank bags come with instructions but sometimes the tag is lost. Photo: Paul Kirtley.

Even if the Millbank bag you are using does not have instructions attached, they are simple and easy to remember. I have repeated them below (in bold) with some additional notes for clarification/guidance:

1. Soak the bag thoroughly by squeezing under water. SOAK the bag is what it means. It is not enough to wet it. This does not have to be in clean water. You must keep it submersed and massage the bag so that the fibres become wet through. This is important. Otherwise it can take hours for a couple of litres to run through the bag.

2. Fill the bag to the top with water to be filtered.

3. Hang up, and allow water to run to waste down to the level of the black line. Let water run out of – and off – the bag onto the ground (i.e. not into a container) until it is down to the line. This is why filling to the top (step 2) is important. By the time water gets down to the line, it will only be water from inside the bag that is dripping. You can then start to collect it (step 4 below).

The line water should be allowed to drop to on a Millbank bag
Let water drop to this line on the Millbank bag before starting to collect the water dripping from it. Photo: Paul Kirtley.

4. Place water-bottle under bag, and fill. This should take about 5 minutes. Those who have used Millbanks will be laughing at this point. 5 minutes?! In my experience, they take a bit longer than this to fill a 1-litre bottle. Maybe 20 minutes. Those who have experienced the bags taking hours will undoubtedly not have soaked the bag enough in step 1. Spend 5-10 minutes soaking the bag in the first place. It’ll save you hours in the long run. If you are going to boil your water, you can drip it straight into a metal mug or pan. DO NOT drip water into your drinking bottle unless you are going to treat the water with a chemical sterilisation agent (step 6).

A Millbank bag set up and dripping into a collection vessel
Once the water has dropped below the line, start collecting the dripping water. Collect the water in the vessel in which you will sterilise it. Photo: Paul Kirtley.

5. Afterwards, wash any mud off the bag, and replace in pocket. If you carry a small nailbrush as part of your hygiene and clothes washing kit, this is ideal for scrubbing a Millbank bag. If the water has been heavily laden with silt or similar, the inside of the bag will need cleaning from time to time, otherwise the passage of water through the bag slows significantly. Turn the bag inside out and scrub off any sediment.

6. Sterilise water in water-bottle using tablets from sterilising outfit. This obviously applies if you are using a chemical sterilisation agent (such as chlorine, iodine or chlorine dioxide). As mentioned in my notes to step 4, if you are not going to use chemicals to sterilise the water, don’t drip water into your drinking bottle as you have no way of then sterilising the inside of your bottle, even if you subsequently boil the water. Drip straight into the vessel you will use for boiling if you are sterilising the water this way.

N.B. If filling is slow, repeat soaking and squeezing under water. I’ve already mentioned how important the initial soaking is. Here the official instructions are reminding you how important it is. If the Millbank is taking ages to empty, it is more than likely it has not been soaked enough. Empty the water and SOAK it. Re-fill and start again. You’ll save time in the long-run.

Full pot of water took all night
This Millbank bag was only wetted, not soaked. It took 12 hours to fill the pot below. Photo: Paul Kirtley.

When water is really muddy, Millbank bags can be a godsend. Remember, though, that in some places water can be discoloured by peat or iron in the local rocks. This won’t be removed by a Millbank bag but it’s nothing to worry about.

The main thing you are trying to do with a Millbank bag is remove any cloudiness. If the water is clear (even if it is a little brown from peat, say), then you don’t need to use a Millbank bag.

And if you are using your Millbank bag, remember to thoroughly SOAK it!

Related Articles On Paul Kirtley’s Blog:

Water Purification: 5 Contaminants You Need to Know About.

Essential Wilderness Equipment – 7 Items I Never Leave Home Without.

How to Build a Bushcraft Survival Kit.

56 thoughts on “How to Use a Millbank Bag: 6 Easy Steps

  1. Nice one Paul. Millbank bags are great in the right environment, saying that I never use mine in Northamptonshire due to all the chemical used on farms in the countryside. I do use it other places to save carrying water though.

    One thing I can say to anyone buying a new one, put it through the washing machine a few times to soften it and get rid of the coating on it. A few years back I was relying on a brand new one in South Wales and it took ages to fill a canteen, no amount of soaking improved its performance. I washed it when I got home and it worked a treat after that.

    Thanks for the article!

    1. Hi Chad,

      Good to hear from you. Thanks for sharing the tip re washing machine softening. This does work. A good scrub with a stiff brush also helps.

      All the best


    2. Hi Paul, Chad,

      I’ve had my bag for many many years now but never had to use it. But now I am planning an extended canoe trip on the west cost lochs and figured it was time to get it out.

      However no matter how much I soak it it takes FOREVER to filter one bag. So I was glad to see your comment about putting it in a washing machine. I will try this. #

      1 Question though, is this with normal detergent or just a plain water wash?

      I am washing load of kit at the moment using Nikwax Tech Wash , before starting to reproof it, but I guess TechWash might water proof the bag…not ideal.

  2. A good read Paul!
    That’s why it took me so long on my fundamentals.. I forgot the instructors said you have to soak it first..
    Where can you buy one?

    1. greenmanbushcraft.co.uk sell brand new ones.
      Reasonable price and good service

    1. Hi Bert

      You can often pick up Millbank bags on Ebay. They seem to be harder to find in army surplus shops these days.

      All the best


  3. Hi Paul,

    I am looking forward to the next instalment in this series. Water procurement and management are absolutely essential skills for wilderness travel. You explanatory notes are great. The instructions provided with the bag aren’t the clearest!

    Instruction No. 5 refers to a ‘pocket’. Should the Millbank be kept in a special pocket or is it a general reference to where it is stored? My Millbank is normally just thrown in the rucksack but I have to say that mine is rarely used. I tend to avoid turbid water, which does take a bit more effort when searching for a source. When I have had to rely on a turbid source, the Millbank has been fantastic.

    I brought mine off ebay. I couldn’t find one in the normal army surplus type stores. The sales staff didn’t know what a Millbank was either.

    Cheers Paul!

    1. Hi Matt

      Good to hear from you. Thanks for your comment. Good to hear you like my explanatory notes – having seen people struggle to use Millbanks in the past, it seemed worthwhile to add a bit of clarification.

      Step 5 refers to storing the bag in the standard military way in a water bottle pouch.

      I agree, avoid turbid water if you can. But sometimes, particularly if you have to dig in boggy ground to access water, you can’t avoid it. Like you, I always look for the visibly cleanest source.



  4. Your additional notes are useful Paul & the key to successful use is definitely in the soaking. I’ve read the advice that Chad gives elsewhere, softening the fibres in a washing machine does seem to help speed up the soaking process. It can be very annoying to have to spend more time soaking the bag than filling your billy or bottle, but it’s much less annoying than having an upset stomach from drinking bad water!

    I think the pocket referred to in the instructions that Matt is asking about (Hi Matt) is the one inside the British Army water-bottle utility pouch which separates the bottle & metal mug from the bag and stops the rim of the mug wearing a hole in the bag.

    1. Hi Steve

      Glad the additional notes are useful. Thanks for your your input re washing machine and pocket.

      The more clarity about all of this stuff the better!

      All the best


  5. Very clearly explained Paul, Been there done that, didnt soak mine properly the 1st time i used it and it took forever. but once you get the knack they are a fantastic bit of kit, and a lot cheaper than the pump purifiers. What Chad said about putting it in the washing machine a couple of times really helps, but if you are doing that Don’t use fabric conditioner that reduces the absorbtion capabilities of the material, so it doesn’t soak as easily.

    1. Hi Duane

      Good tip re fabric conditioner. I’ve seen the effects of this – it effectively mildly waterproofs the fabric.

      You can use this to your advantage with some outdoor clothing though….

      All the best,


      1. Paul,

        I am having trouble using the ‘Reply’ button. I keep getting redirected to the blog post. I have tried on my smart phone, work PC and laptop, all with the same result. I was trying to say HI back to Steve and thank him for the clarification on the storage of a Millbank – Hi Steve, hope you are well.

        I remember reading an article in Trail magazine a few years ago in which they compared various waterproofing products on the market. The most interesting finding was that normal fabric conditioner was almost as effective as a Granger’s product at waterproofing a synthetic material. It’s down fall was durability. It was removed after a relatively short amount of time when subjected to a controlled test.

        In my opinion, fabric softener could be an effective waterproofing treatment for a jacket that sees little wear. It could suit someone who doesn’t feel there is a benefit to buying the relatively expensive recommended treatments. Fabric softener, after all, is something that in general all households have in the cupboard.

        There’s my ten peneth’ worth anyway.


        1. Hi Matt

          Sorry to hear you’ve been having difficulties with the site. I’ll look into why this might be. How did you finally manage to post this reply? Did you just keep trying or did you use a different machine or browser?

          Good info re clothes conditioner/fabric softener.



  6. That’s spot on Duane, I forgot to mention that and it does have a negative effect. If anyone is looking for one of these try Endicotts, no affiliation with me, just an extremely satisfied repeat customer.


    I hope I’m alright putting this link up Paul, please remove if I shouldn’t!

    Great article as a Millbank weighs nothing compared to water. Just mind those dead sheep upriver!

  7. Thanks Paul,

    One of your last comments in the article clears up one mystery for me: The water that I often use from a local river always has a slightly brown tint to it, even after having been run through the Millbank. I often wondered why, and hadn’t considered peat or iron as the cause.

    1. Sean, you are very welcome. Good to hear the article was useful to you.

      Whereabouts in Australia are you?

      All the best


  8. great article paul. my bag works sound as a pound but the real issues with water purification and filtration nowadays is all the chemicals in the rivers on the fields and just about everywhere up here where i’m at. farmers spraying stuff they have no idea about, plus i live under an international flight path and i’ve been reading about chemtrails. you guys should look it up. barium and alluminium particles being purposely and scientifically dumped from high altitude planes for god knows what. the trails stretch for miles and then form clouds. its easy to tell the difference between planes that are dumping and not dumping. chemtrails are different from the normal small vapour trails left by none chem dumping planes. the environment agency did some water testing @ multiple sites in cumbria as they do, and large quantities of barium and aluminium have been found! what they are dumping that crap up here for i dont know. Its being done all over the world. If you have any tips on filtering that stuff it would be great dude. turbid water seems no worries when you read up on chemtrails. laterz, dave

    1. Thanks Dave,

      I’ve heard about chemtrails. I don’t know what to believe. Conspiracy theorist hokum or military testing of radar-confusing clouds? Blocking of satellite imagery or overactive imaginations?

      I guess time will tell….

      All the best


  9. Really enjoyed the Millbank article – have had one for some time but never really trusted myself to use it as I wasn’t too certain of the instructions. I am not normally a blog responder type but am enjoying the information a great deal – it feeds my old man’s dreams!!
    keep it up

    1. Hi Chris,

      Thanks for your kind comment. It’s much appreciated. Good to hear the Millbank bag article was useful to you. Let us know how you get on using yours! 🙂

      All the best


  10. Paul
    Enjoyed the Millbank bag filtration system..have not seen any here in the Canadian store I visit…how would I get my hands on one of those???What is the price range???keep the good stuff coming ..appreciate it…
    Yves Lessard

    1. Hi Yves,

      Thanks for your comment – good to hear you enjoyed the article. I don’t think you will find a Millbank bag in a typical outdoor store (such as MEC). Even in the UK you won’t find these. You will either pick one up in a military surplus story or on Ebay. Here they typically clear for between GBP10-20.

      All the best


  11. Great post Paul.

    Ive looked around my area, & i can’t seem to find these ?
    What are the cost of these, i assume not to much. I think it would be a great piece of kit to have in my day Pack. Cheers.

    1. Hi Dave

      I buy Millbank bags on Ebay. They aren’t always listed but I keep an eye out. In the UK a personal millbank bag (as opposed to the large 5-gallon group bags), sell for between GBP10 -20. They used to be cheaper but scarcity has driven up the price a bit.

      All the best


      1. The Bushcraft Store in Enfield sell the new version called the Brown Bag for about £26 ish. Ive used both Millbank and the Brown Bag and other than the colour ive not noticed any difference.

        Hope it’s ok to recommend a shop, if not please do remove.

        Love the articles Paul, very informative, I’m learning lots. Now if I could just find more time to be out practicing

  12. Re Dave Brannigan’s comment about chemtrails, didn’t the Chinese “seed” the clouds with silver particles to keep the rain away from the Beijing Olympics? Wonder if this is the same kind of thing, could explain why it has rained all summer.

    1. During the Vietnam conflict The Americans tried cloud seeding. Supposedly it contributed to extending the rainy season by several weeks.

  13. After reading the article I searched eBay and found one 🙂 It was bid for three times an my bid being the fourth was the highest. So for 7,50 pounds and 3,50 pounds shipping costs I will be the proud owner of a brand new millbank bag 🙂 Hope to receive it soon so I can test it.

    1. Hey Bert

      Good to hear you were able to track one down. You also got it at a reasonable price.

      Let us know how you get on with it.

      All the best


  14. Hi Paul,

    Sorry for the belated reply, but I haven’t looked at your site for a while: I’m in a small town called Mudgee in NSW.

    As another idea for those having trouble buying a Millbank, you could consider making, or having one made for you. There’s nothing magical about them, they’re just a canvas sock. I don’t have one in front of me at the moment, but from memory, when laid flat, they’re about 6in wide and 15in long.

  15. I’ve been using a millbank bag for many years and keep one in my water bottle pouch. According to a guy i know who runs a very well known and respected army surplus store, the MOD have stopped using them now and are selling of their stock, this is good as there are a lot on the market at the moment especially as a while ago they were as rare as rocking horse s**t, but when they’re gone they’re gone so get one while you can as apparently the EU have banned them now.


    1. Hi James,

      Thanks for you comment. Yes, they are no longer issued. The bag itself hasn’t been banned – it’s the chemical which was used to treat the bags to stop them going mouldy.

      Get one while you can…



  16. Hi Paul,
    I’ve just got hold of a surplus millbank bag and I’m wondering about how best to hang it now. Things like the length of paracord to attach, which knots and/or loops to use. I’m sure none of this is critical to filtering the water, but I would really like to know how you go about it.

    1. Hi Steve,

      Take a 50cm length of paracord, join the ends using a single- or double-fisherman’s knot (check my overhand knot video for details). Pass a bight through the brass eyelet then pass the rest of the loop through the bight to create a larksfoot/cow-hitch (see Attaching Continuous Loops Using a Cow Hitch in this article for details).

      Then, the key is not to hang the Millbank too high about the collecting receptacle, otherwise you’ll lose a fair bit of water through it splashing out of the container, particularly when it gets a bit more full.

      Hope this helps.

      Warm regards,


  17. I wash mine in a machine to ‘break it in’ use a synthetic ‘soap’ tho as if you fail to rinse proper soap properly the laxative effects are absolutely amazing!!!!

    1. Good tip Nobby. Not something I have suffered from but well worth passing on (no pun intended) to other readers… 🙂

      All the best,


  18. Hi Guys if you’re after a Millbank bag, Military Mart does them for £8.00 Currently out of stock, I know of somebody whose got one and it’s just like mine which is an MOD original. Other companies are charging humungous amounts

  19. Sorry troops the address is http://www.militarymart.co.uk Product code MILCXOIN59. These bags are easy to use and easier than most pumps. Follow Paul’s destructions and you won’t go far wrong

  20. I’ll immediately seize your rss as I can not find your e-mail subscription link or
    e-newsletter service. Do you have any? Please allow me recognize in order that I
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  21. I use a millbank when I go hiking, it’s a great bit of kit. I store mine in a waterproof bag and keep it wet, so soaking doesn’t talk as long the next time I use it.
    And I call peat coloured water, non alcoholic whiskey

  22. Hi Guys

    The newer version of the Millbank bag, known to me as a Brown bag, is available from Bushcraft and Survival magazine and also in a couple of sizes from the Bushcraft Store. Neither of which i am associated with, apart from being a customer of one and a reader of the other.

    Great article Paul and good tip of putting the bag through the washing machine, which i’m off to do now.

  23. I see there are two sizes of the “Brown bag” – a “regular” size and a larger “group” size. Does anybody have any idea of how many people you need in a group before it makes sense to use the larger size?

    1. I would say at least 6 but then you still might want to consider using several regular bags, depending on how you are dividing the work around camp.

      Warm regards,


  24. Hello, great article. My bag has the opposite problem. It’s flowing too fast. It’s empty by the time I’ve take 4 steps towards the bivi. I can always take another container with me to pour it into, but would prefer not to have to. I thought maybe the very cold temps might be causing the pores to contract too much to make enough of a seal, or maybe I need a better bag. I’ll experiment a bit more, then by a different brand if this fails.

    1. The one I’m having problems with is a Bushlander branded one. I’ve just tried running under the cold tap and it fine to a third full, but then around half full it reaches a kind of equilibrium and won’t fill any higher. I can’t remember what I’ve done with it in the past. Maybe I’ve ruined its integrity by putting in hot water or something.

      1. Decided to order a new one in the end. Brown’s Bushcraft – The Brown Filter Bag.

  25. Also pretty handy as a tool bag, tough and benefits from a beating, and saves some more precious space by having a dual function.

  26. I’m glad I clicked on this in an idle moment. The article is as wise as all Paul’s pieces, but the readers’ comments have also been valuable.
    Like many others who have commented, my Millbank bag sits in my pack “just in case”, and I have never needed to use it yet and I have now been saved hassle when least needed. (When the boat is sinking is not the best time to learn how to swim!) It’s coming up of the pack and going into the washing machine this afternoon before being given a trial run with water from the river at the end of the garden!

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