Basic disinfection of potable water in 3rd world 1

[brianslater]

Help
I'm not a water expert, just a humble engineer working on the borders of Laos/cambodia. We have a simple rain water harvesting system collecting into 5000l cement jars - a long established practice. However we do get outbreaks of jungle belly which I believe is due to poor management of the jars (I smelled and tasted the water). They dont practice roof flushing of first run off (for 10 mins say). we have a lot of birds and worse, the jungle chickens. they dont have effective covers over the jars, they dont flush out the gutters (not easy), we have a lot of trees and leaves.

It seemed to me that 4 drops of household bleach (sodium hypochlorite 5%vv) per litre would help sanitise the water but I cant find anywhere on the net that admits this as an ok practice. Do you see any problem with this?
Once the water is disinfected it should stay that way (assuming the covers are in place and no new rain arrives. After a week or so the chlorin will have gone anyway.

If this is ok, why dont they use this in Bangladesh, say?
Its cheap and cheerful. All this pious advice about boiling water for 15mins is of no use when you dont have firewood.

Secondly I was proposing to use a simple form of sand filter for the local pond/river water which is sometimes available, mainly to remove turbidity and vegetable matter, then dose with bleach. Any comments on this

Please excuse my ignorance if I am stating the obvious here. Its very frustrating to read the learned dissertations from 3rd World water.org to find they have told you nothing useful

Your guidance may reduce the incidence of child jungle belly, which I also get sometimes.

 

[BRIS]

Saxon - Boiling is a reliable means of disinfection. but there are a 101 reasons why it is not a solution. If I understand what you are saying it is that once it is demonstrated that drinking contaminated water leads to sickness then to death then if they don't do it then that is natural selection. I won't get involved in the morals of the arguments just in the practicalities.

1) Many millions have always drunk contaminated water and many have lived into their 80's. The argument is not readily apparent and is often not accepted. The indoctrination process is not a one shot (period) but a long learning process.
I have attended site visits in Pakistan and seen qualified engineers (some with Phd's) take river water in a bowl and blow the scum and floating debris to one side and drink out of the other. - The comment made to me was that we (westerners) are allergic to germs. How are you going to indoctrinate the uneducated masses when the educated elite fail to grasp the message?
2) Responsibility for collecting and storing water is generally that of the females. In many 3rd world societies we are faced with a gender problem. It is often impossible to get the message through to those that matter. (I have organised village training in Africa where the women - who nee to be the recipients of the training- have been obliged to sit at the back and face it the opposite direction).
3) Fuel for boiling is as often as scarce as or even scarcer than the water. Whether it is boiled with the preparation of the days meal or not it takes fuel.
4) Inevitably the water will not be boiled and disinfected it will be warmed and incubated.

I could go on and list the rest of the 101 points.

 

[brianslater]

Hi Bris
I agree with your camp, Saxon,s armchair republican views wouldnt reap much success where I am or have been. The ones who suffer most are the young children. The adults have usually gained some tolerance to dirty water(though not always).

When I was in Ikeja, lagos at the Airport hotel, it boasted an olympic sized swimming pool. The water was the colour of brown soup. A co-worker, made so bold as to dive in but forgot to close his mouth (bit of a dipstick, actually). He came out with some incurable stomach bug unknown to medical science, he had permanent diarrhoea, after 3 mnths he had lost 25% body weight and had to be shipped home to the Hospital for tropical diseases. I dont know if he was ever cured. Perhaps he should have boiled the swiming pool first.

BTW the women here in Thailand are the boss. They are the ones who would turn up to a village meeting. The men wouldnt bother

 

[saxon]

Gentlemen, As to the efficacy of the daily boil regimen, we managed to keep at least 3.5 million men healthy and alive in the jungles and atolls of the South, Central, North Pacific; and Southeast and Central Asia. I'll stand on its efficacy.

Hope this helps.
saxon

 

[BRIS]

Not a topic I wish to prolong, but out of the 3.5 million military personnel one can guess that at any one time 20% were suffering with diarrhoea and were being treated with drugs not available to the local population.

 

[brianslater]

Hi guys
One man's meat is another man's poison
And funnily enough we were chatting away about local water quality just this evening, with the local highways and facilities man who is the cousin of my wife (called an oh boh toh in thai)
Its the children who suffer, not big poofy marines.
I have been discussing the concept of dosing the cement jars with household bleach. We generally dont have nasty bugs like giardia or that other nasty I cant remeber the name of just now - somthing to do with beavers?. We are a simple rural environment.
I find this whole topic strange. Having spent my working life building control systems for the petrochem industry - with all their codes and standards - it seem to me that the water industry is incredibly amateurish by comparison, and I dont mean the guys who build dams or design water supply systems. Its just the concept of what is considered acceptable water. I remember some years ago listening to a reader at my uni, telling me that the regulations of water quality were extremely lax and concerned mainly with victorian principles of keeping Ecoli to the minimum. Troops in India and all that. There were no regulations about Nitrates of heavy metals. I guess things have changed a bit, but I dont see anything about the dangers of children raised on rainwater - with no mineral content - for example.
Excuse me if I am being naive here, but it seems to me that potable water is an incredibly precious commodity that has become increasingly scarce particularly for children.
If the petroleum industry offered a similarly poor quality of motor spirit or lub oil, engines would fail, heads would role, but it takes several years for rickets to develop or worse and of course, water comes naturally.
When I go back to the UK, london, I have to wean myself on bottled spring water for a few days, as the tap water tastes foul, to me. I usually have a stomache upset as well.
Let me pose this question, Do you have a statement of the contents of your tap water in the states? We dont have one in the uk, all food has to be labelled scrupulously, but drinking water (and beer for that matter) does need such a label. This doesnt seem right to me.

Any comments

 

[saxon]

brian, Try Army Amphibious. The Marines get stay on board ship where they have seawater stills, sleep in bunks, and get three cooked meals a day. Here in the States the Fed/State EPA have set up standards. At last count there were fifty parameters on the list. They run the gamut from turbidity, color and odor to gross alpha and beta radioactivity.

saxon

 

[dhdoyle]

Hi all,

A couple comments to summarize:
1. A solution starts with basic sanitation. You need to show the women the benefits of lifestyle changes like controlling human and animal waste, hand washing, soap, etc. Container and water disinfection isn't as effective when the living area and people are grossly contaminated. We don't normally think about things like dung on our feet - which quickly passes to hands and face.

2. One point of disagreement...
Quoting Saxon:
"...Gentlemen, As to the efficacy of the daily boil regimen, we managed to keep at least 3.5 million men healthy and alive in the jungles and atolls of the South, Central, North Pacific; and Southeast and Central Asia. I'll stand on its efficacy..."

Sorry, but the local National Guard unit went to Iraq with their potable water treatment plants. That equipent doesn't boil, and as far as I can tell from

http://www.quartermaster.army.mil,

none of the Army's currently stock-numbered purification equipment uses boiling. The personal and squad-level equiment currently issued is based on the MIOX process I mentioned earlier. Los Alamos National Lab, DARPA, and the Army funded the R&D.

FWIW - Most aide workers I know are agreed that boiling is not an environmentally sustainable option. Deforestation is happening fast enough just for cooking fuel.

Cheers!
Dave

 

[brianslater]

Hi DHD
Very good points there. The Iraqi environment would be difficult with no power to run water treatment plants and to pump fresh water. No doubt, water storage would be a highly contentious issue open to poisoning from malicious sources.

I think we have a conscensus that boiling is very good but not always practicable in difficult situations. It also wont get rid of turbidity, mud etc, so you have to filter it anyway and it make a cup of tea taste awful.

I have heard of purification tablets supplied to very up market campers at very expensive prices (several $ just for a one litre bottle). There are also some very expensive protable filters. Not suitable for a 3rd world scenario. However, I havent come across, instant chlorine tablets (or an iodine equivalent. I guess swimming pool suppliers have these and must get them in bulk from some process plant. We dont have many swimming pools here, just ponds and rivers.

I have searched into what pool suppliers do, but its mostly snakeoil.

What we also need is a simple source of natural minerals to put calcium and other trace elemnets back into the rainwater harvest. The locals here grind up fish, land crabs and snails (all uncooked) to get their calcium supplement. Its an unhealthy practice amongst Laos people and would give a westerner severe diarrhoea. Large amounts of Salmonella are ingested. They seem to be relatively immune, but it involves using excessive amounts of Chilli pepper which ultimately leads to gastric porblems.

FYI chilli has similar addictive properties to caffein (for westerners). My wife gets irritable if she hasn't had a plate of "som Tam" - a thai national dish of unripe pappaya, green mango, chilli and various salad items pounded together in a pestle and mortar. I have discouraged her from using Pla La (which is the ground up fermented land crabs etc - smells foul). The chilli serves to disinfect the raw ingredients, but you need a lot of it. Traditionally, the Laos living in the north east of thailand, were very poor, dirt farmers with very limited firewood (converted to charcoal). Much of their cuisine has evolved around raw ingredients with little cooking (except for sticky rice)and copious amounts of chilli, far too hot for westerners to stomach, yet toddlers seem to be weaned on the stuff.
A whole family can exist on $2/day, though more typically the income is $4/day. For all that, they are nothing like as poor as the people in Cambodia where wages are half the thai average of $4/day for labour. Our local admin services are pretty good (schools, hospitals, police, main roads etc). They are almost non-existant in Cambodia.

So I appreciate the experiences that you guys have to share as you obviously have at some time been there, done that and got the tee shirt. As I noted before, I find the academics and self styled alternative (or is it intermediate - they cant seem to agree on that either) technologists too concerned with chasing conference junkets and government research funds to share real knowledge (not all, but benefit wise surprisingly limited.)

 

[saxon]

dhdoyle, So what happens when you get cut off from the support groups or you lose your equipment for whatever reason?

brian, As for iodine and its derivatives, they aren't 100% effective against giardia or cryptosporidium. Your getting to the point that the only real solutions are the identification of a relatively clean source, filtration and boiling regimen in rather primitive conditions, solar stills can also be an effective solution, although the output is rather limited.

Hope this helps.
saxon

 

[hydrae]

brianslater
In response to your earlier comment and I quote

"Do you have a statement of the contents of your tap water in the states? We dont have one in the uk, all food has to be labelled scrupulously, but drinking water (and beer for that matter) does need such a label. This doesnt seem right to me."

We in the US do have a statement of content, the EPA requires that all water utilities produce and distribute a consumer confidence report (CCR). It is due out by June 30 of each year and covers the prior calendar year.

quoted from the epa website
"While water systems are free to enhance their reports in any useful way, each report must provide consumers with the following fundamental information about their drinking water:
the lake, river, aquifer, or other source of the drinking water;
a brief summary of the susceptibility to contamination of the local drinking water source, based on the source water assessments that states are completing over the next five years;
how to get a copy of the water system's complete source water assessment;
the level (or range of levels) of any contaminant found in local drinking water, as well as EPA's health-based standard (maximum contaminant level) for comparison;
the likely source of that contaminant in the local drinking water supply;
the potential health effects of any contaminant detected in violation of an EPA health standard, and an accounting of the system's actions to restore safe drinking water;
the water system's compliance with other drinking water-related rules;
an educational statement for vulnerable populations about avoiding Cryptosporidium;
educational information on nitrate, arsenic, or lead in areas where these contaminants are detected above 50% of EPA's standard; and
phone numbers of additional sources of information, including the water system and EPA's Safe Drinking Water Hotline (800-426-4791). "

Depending upon utility size, list the types of publication, from a copy to every household and consumer via mail to posting on the utility's web site and local news paper.

Hydrae

 

[brianslater]

Hi Saxon & Hydrae
btw I thought Hydrae was a multi headed serpent from greek mythology, and also some low life pond dweller?? ;-}

Yes Saxon, I learnt very quickly in Nigeria always to have a back up plan , and a backup one for that, havbing nearly been totalled twice over there. But I didn tknow the basics of emergency potable water. Lagos belly was rife and I had to resort to coca cola and a teaspoon of salt for my rehydration.
Happiness then was a dry fart on an outgoing plane.

H

thank you for you info on US regs. I rather felt that you would have something pretty draconian, but does it make the water taste good? When I was in Texas, Corpus, the good ole boys wouldnt let anything past their lips that fish had made love in. Buts thats Texas, yeehaa - bless them.

I hope we can see here from the spirited discourse that we all agree that water is a very important resource that has been taken for granted and largely overlooked in by the future planners. I could tell you some watergate stories about the privatisation of the uk water authorities some 20 years ago but I might get terminated like the recent UK weapons expert.

As the legendary Mae West said, "If you want to water my melons, then hold your drink" {

 

[hydrae]

Brainslater

Does not a water system look like a multiheaded serpent, such that when you cut one head off (solve one problem) more grow in its place? (some also have compared me to a low life pond dweller) LOL

Taste, odor and items that contribute to taste and odor are considered 'secondary' contaminates, which are in the list, but offically the operator does not have to do anything about them.

As for your original solution 4 drop of bleach, some brands of bleach add other cleaning agents besides NaOCl to the product.

Hydrae

 

[matsalleh]

I am probabaly late on the draw for this thread, but figured why not throw my hat in the ring.

Perhaps bleach is not recommended as the cure-all because it doesn't kill everything. Some protozoa like Giardia and Cryptosporidium are resistent to chlorine. You may have heard of an outbreak in the US about 10 years ago in Milwaukee's water system that the chlorine disinfection system did nbot kill.

Given that boiling is not an option, you can go with bleach with the proviso that you may not kill everything, but it is a step in the right direction. To get the most bang for your bleach, filter first. Solids are homes for those nasty critters and they can effectively hide from the disnefecting chemical inside solids.

Now I assume you cannot get everyone to go out and buy a $100 filter, but how about something like cheescloth or coffee filter type material...diatamaceous earth if you have it in that part of the world. Filter first to remove as much of the fine solids, then add the bleach. I would recommend this over adding to the concrete barrels directly where there may be solids which interfere with your disinfection.

 

[brianslater]

Hi Mat
Thanks for your input, the advice on filtering is good. Sometimes the obvious is overlooked.
WE dont have diatomaceous earth here. Would you suggest using sand and crushed charcoal in a barrel as a filter?

I suggested using a small dose of household bleach in the water because its collected from rain falling on a house roof.
The water is normally crystal clear. You have to keep the leaves out and clean the gutters once a year. It is unlikely to be contaminated by animal fecal matter, but birds are an unknown factor.

I would like to be able to carry out some field tests on biological content, but dont know what to use?

Any ideas - microscope?

 

[hydrae]

Brianslater

Any of the many coliform tests used by water systems would be a very good indicator. Coliforms will be present in biologically contaminated water.
The colilert method is simple, fill the bottle with sample, add packet, incubate for 24 hours at 35 deg C, look to see if the bottle is clear, no coliforms present, yellow, coliform present, flourescence under black light, fecal coliform present. Cost, about $8 to $10 a test, special equipment, incubator
For an attached number use the heterotropic plate count method. prepare sample and filter, flow water through filter, inclubate, count colonies of specific colors. need a bit more equipment, takes a little more time.

http://www.hach.com

has all the equipment, or there may be local labs in the area.
Hydrae

 

[brianslater]

hy hydrae

thanks for the tip, cant get any prices from this site as I have to become a registered user and give all kinds of personal info first. Can you imagine walking into your local store and being asked for such details before you can get to the counter. You would walk straight out again. This is quite typical of many so called ecommerce web sites. Customer care is way down on their list of priorities (top of the list is your email id and credit card no. first before they will talk to you)

Will pursue the agar plates in other areas

thanks

 

[countryham]

WITHOUT RE-STATING THE OBVIOUS NEED OF CLEANLINESS--and not becoming over technical----There is absolutely nothing wrong with the use of sodium hypochlorie if it is not made from a byproduct (spent acid) that may contain heavy metals......In any case, all benefits of bleach far outweigh the odds of any potential harmful effect.... As to the concentration required... This would be highly vairable because there must be a "FREE" chlorine residual above the chlorine demand in contact with micro organisms for twenty (20)minutes.... The chlorine demand is created by the amount of chlorine that must be used to oxidize "ALL ORGANIC MATTER" in the water...This matter could be from decaying trees,dead animals, or sewers,etc.,etc. A FREE CHLORINE RESIDUAL SHOULD BE REALIZED ONLY AFTER TWENTY (20) MINUTES OF CONTACT....FURTHERMORE, YOU DON't NEED A TEST KIT BECAUSE WHEN YOU CAN SMELL THE CHLORINE AFTER TWENTY MINUTES YOU HAVE ADDED ENOUGH AND- IF YOU HAVE ADDED TOO MUCH,- JUST HEAT THE WATER AND DRIVE THE CHLORINE OFF AS A GAS...Regards, Countryham

 

[brianslater]

Hi Countryman

thanks for your input, as you can see from the thread, my simple question has generated some very sound responses. My orignial query was that, when I searched the "alternative technology" type sites I couldnt find an obvious reference to household bleach - which is very cheap and plentiful here. All the high minded academics said you must boil the water. They have obviously never strayed far from their stipendiary seats.
Boiling is not always a viable option.

here's the bottom line

Rain water here is harvested from roofs and stored in 5000 litre ferro-cement jars.

The gutters flow into a large funnel. A simple gauze across the top of the funnel keeps the leave out. This is important because decaying vegetable matter produces potentially toxic by products when in contact with chlorine
THMs trihalomethanes.

A fine gauze is needed over the top of the jar to keep out mozzies

A syphon hose weighted at one end to draw water from the bottom of the tank.

The tanks are cleans once a year during the dry season

I put one bottle 700ml of household 6% bleach in once a year at the beginning of the rainy season, once the tank is 3/4 full. Slight smell of chlorine which goes after 2 days

This should take care of nasties from bird droppings on the roof (very slight possibility of contamination)

Must make sure there are no jungle chickens roosting on the roof. they produce copious droppings

The water comes out crystal clear and the only problem i now have to solve is a simple way to put natural minerals into the water (calcium in particular)

Any ideas here? no-one has solved this one (like take 1kg of calcium bicarbonate and throw into the tank - wont do the trick, just produces Co2 and insolluble calcium carbonate)

 

[dhdoyle]

So Brianslater sez:
> The water comes out crystal clear and the only problem i now have to solve is a simple way to put natural
> minerals into the water (calcium in particular)

> Any ideas here? no-one has solved this one (like take 1kg of calcium bicarbonate and throw into the tank
> - wont do the trick, just produces Co2 and insolluble calcium carbonate)

Brian,
I think you're trying a bit too hard here. Calcium carbonate isn't exactly insoluble under these circumstances. Considering the long retention time you have, you might get good results by simply adding cleaned, disinfected oyster shell. It should provide a fair quantity of calcium and magnesium and you can montitor with a simple hardness kit. Heck, crushed oystershell or coral makes an alternative mineral supplement.

The only concern I have is that it doesn't sound like you don't have access to an analytical lab to check for heavy metals. Lead can accumulate in shell and that news has caused a media backlash here about its use as a nutritional supplement. It might be OK in your neighborhood.

Cheers!
Dave

 

[brianslater]

Hi Dave

Oyster shells, that sounds like an excellent idea.
We have out here (in the Moon river - 2nd largest in Thailand) a species of freshwater oyster, freely available. I have eaten these, they are a bit chewy, like snails or whelks. The shells can reach palm size. They could certainly be cleaned up and boiled, then pounded in a mortar. Will certainly give that a try.

You say Im trying too hard, but in fact, calcium deficiency is a problem here because everyone drinks rainwater and its not so clever for growing kids who get bone problems in some areas. Hardened water would solve the problem. They cant always afford UHT milk and there is no natural chalk in the area (all laterite red earth, iron oxide mud and sand)
Strangely the poorer kids in the far northeast fare better than the central areas because they are Lao- Isaan. These people have developed a cuisine that uses almost no cooking fire. Its all raw vegetables, edible insects, snails and small land crabs. These are all put into a mortar and pounded to a pulp with lots of very hot chillies, green papaya, vinegar and some sugar and a foul smelling fermented fish sauce called Pla Lah. A westerner trying such fare would likely

a) have his tongue burnt raw
b) get severe dysentary or salmonella.

however the locals are immune to it, even the kids and the crustaceans provide the mineral input

They've been living like this for centuries. they also raise dogs for culinary purposes, but dont eat lizards or snakes (fear of bad spirits).

Never a dull moment out here

Cheers

Brian