Syria - Deir Ez Zour issue of oil refining contaminating water supplies.
We are planning to distribute wash kits consisting of Aquatabs and some flocculating/chlorination kits in Deir Ez Zour (Syria) in a project with a local partner. However, our concern is that people have been refining illegally oil in their backyards and we are getting many reports of the land, water , etc polluted from the oil. The people get their water from the river, which we are told is polluted with the oil and oil runoff.
I am trying to figure out what is the best way to support the people so that they can ensure their water is safe to drink
1 - What type of WASH kits should be distributing? Is Aquatabs appropriate? What type of filters should be used? Can you recommend filter kits that we could use and distribute that would be appropriate for this situation?
2- What information should we include so that people know how to properly treat their water?
3- What issues or questions should we be asking to ensure we have a proper understanding of the oil pollution in the water?
4- What is the health risks of the oil in water that people are drinking? what are the risks to the agricultural land?
Thank you for your assistance
Oil Contamination and Implications for Drinking Water
Crude oil is a complex mixture of many chemicals, each having an associated toxicity. It is the mixture of these compounds, however, that has the potential to be the most toxic. Many of the chemicals in crude oil are made up of hydrogen and carbon, but may also contain sulphur, nitrogen, heavy metals and oxygen compounds.
The composition of crude oil varies slightly by its source, but the toxic properties are consistent. Chemicals such as benzene and polycyclic aromatic hydrocarbons (PAHs) are extremely toxic components of crude oil and of high concern. These and many other chemicals in crude oil are volatile, moving from the oil into the air, where they have the potential to expose many people.
Exposure to these compounds can occur through skin contact, inhalation of contaminated air or soil and the ingestion of contaminated food and water. Different types of exposures can occur simultaneously. Exposure may result in localized symptoms (e.g., irritation of the skin following contact), but most health effects are not localized because toxic compounds can move throughout the body.
Health effects vary based on the duration of exposure and concentrations of harmful compounds in crude oil. Differences in effects may also result from location, work and personal activities, age, diet, use of protective equipment, and other factors.
The duration of exposure will determine the severity of the effects; therefore, reducing the time of exposure to chemicals found in crude oil will minimize adverse health effects.
For brief exposures at relatively high levels (known as acute exposures), crude oil may cause irritation of the skin and mucous membranes on contact. Irritant effects can range from a slight reddening of the skin to burning, swelling, pain and permanent skin damage. Commonly reported effects from acute exposure to crude oil through inhalation and ingestion include difficulty breathing, headaches, dizziness, nausea, confusion and other central nervous system (CNS) effects.
Long-term exposure at relatively low levels (known as chronic exposure) should be avoided, if at all possible, due to the possibility of serious effects including lung, liver and kidney damage, infertility, immune system suppression, disruption of hormone levels, blood disorders, gene mutations and cancer.
Susceptible populations to the toxic effects of crude oil include:
Children are vulnerable to the toxic chemical compounds in crude oil as their brains are highly susceptible to neurotoxins, in addition, exposure to crude oil can cause abnormal growth and infertility in children. Adverse affects can be experienced by people taking medications that reduce their detoxification ability (including aspirin) or who have nutritional deficiencies (or even concurrently drink alcohol ). Pregnant women and the developing foetus are also at risk due to the fact that many of the chemicals in crude oil can cause skeletal deformities and incompletely formed immune and detoxification systems.
The real problem with your question is that, for completely understandable reasons, it is not possible to give an idea of the degree and nature of the contamination, i.e. higher or lower specific ... (more)
Weighing the risks of microbial versus chemical contamination, the WHO Guidelines for drinking water quality recommends that, where local circumstances require that a choice must be made between meeting either microbiological guidelines or guidelines for disinfectant by-products, the microbiological quality must always take precedence and, where necessary, a chemical guideline value can be adopted corresponding to a higher level of risk. Efficient disinfection must never be compromised. World Health Organization. Guidelines for Drinking- Water Quality, 2nd edn, Volume I-Recommendations. WHO, Geneva (1993).
1- Activated Carbon Filters: I would tend towards adding an activated carbon based filter to the WASH kit. Aquatabs will do nothing beneficial for the oil contamination, but can still be used after oil removal for disinfection. Disinfection is still by far the most important water treatment step. Assuming gross contamination & any easily separable oil has been removed, the water could then be passed through an activated carbon filter prior to disinfection using the Aquatabs or a similar product. You could instead use a combined activated carbon plus membrane or ceramic filter that would take out the oil compounds and disinfect in a single unit (reducing the need for the Aquatabs) but a measurable disinfectant residual is often desirable.
2- Assuming you can distribute activated carbon filters, I would suggest: a) Firstly look at the raw water and don’t use it if you can see evidence of oil (any sheen on the surface of the water) b) If you are forced to use water where you can see oil, leave it to settle in a container and take the water from below the surface, disposing of the oil on top c) Pass the water through an activated carbon filter d) Smell the treated water if it still smells of oil (or otherwise strange) seek assistance e) Disinfect the treated water using Aquatabs as per the instructions f) Taste the disinfected water and if it still tastes of oil seek assistance
3- You may want to check the water for benzene, ethylbenzene, toluene, xylenes and VOCs (Volatile Organic Carbon).
Oil is a mixture of various compounds, many of which have very low solubility in water and can be removed by simple floatation separation (oil floats on water so ensure there is no abnormal sheen on the water). As one of the lightest fractions, petrol is the lowest molecular weight hence most soluble, so its compounds may be of greatest concern. WHO don’t set a guideline value for petroleum products as it is considered that one would mostly be able to taste or smell soluble aromatic hydrocarbons at lower concentrations than would be of health concern with short-term exposure. For this reason it would make sense to recommend that people do not drink water that smells or tastes of oil. WHO recommend a context specific risk assessment, this won’t be easy if you have multiple backyard refineries as there will be great variability in the pollution. There are some petroleum compounds that are given guideline values, for example benzene (0.01 mg/l - treatable with GAC or air stripping), ethylbenzene (0.3 mg/l - treatable by air stripping), toluene (0.7 mg/l - treatable with air stripping) & xylenes (0.5 mg/l treatable by GAC or air stripping). You’ll see from this that air stripping is the common theme. I am not however convinced that you would be able to set up a WASH kit with adequate system for air stripping, due to the likelihood of inadequate operation ... (more)
From James: One thing to consider and it is a remote possibility. It is possible to get a "oily" sheen on water from natural breakdown of leaves etc in water. But I have only seen this on small patches of stagnant water in marshy environment. I assume this not the case here given the geographic location!!
This kind of sheen is relatively ease to confirm in my experience as it fractures when the surface is disturbed whereas an oil layer will distort.
one means of removing gross contaminants is to pump water from ground and not surface water. If this is possible this could be very short term option as the sand/rock should remove free product (ie.liquid hydrocarbons) but if the pollution is that bad then likely to have some dissolved hydocarbons present as well.
Seems to me the key actions are as harriet says :
Do not use except as extreme emergency use and then only if some form of filtration in place to remove free product. To be honest any significant free product would make it undrinkable, even trace amounts of kerosene will taint water to make it disgusting (personal experience!).
Get samples tested asap. Simplest test for total petroleum hydrocarbon but if possible get speciated hydrocarbon analysis.
Provide alternative supplies to young/old or go upstream of polluted areas.
Not sure where you are precisely but if you can get activated carbon (gac) supplied then this could be filter medium, worth asking around and we can look at treatment "design" but need to know flow rates required etc etc. However gac costly and probably cheaper to bowser in water in short term.
We too seeking internal advice but suspect no magic solutions.
From John, Does the water smell? Hydrocarbons are generally detectable in minute quantities, I would have to check but less than 1 ppm of VOC's has been enough to render ground water aquifers unusable in contaminated land cases.
This might render treatment moot, as if the water smells and tastes of oil and chemicals people are unlikely to drink it? So the question I would ask is what source are people drinking from now and is it acceptable? If the water is contaminated with hydrocarbons then the the liquids will be imiscible? You could try leaving a sample to settle to see if the liquids seperate. Depending on what fractions of the oil are present you could potentially tap water from storage at different levels; from the bottom if LNAPL or from the top if DNAPL. This might work at household level, but is likely not to be feasible at process level as the flow rates required to prevent mixing would be low. For testing I would look at the Palintest photometer range, the 7100 can detect certain VOC's, BOD & COD. You most likely would need to establish the BOD:COD ratio. Over 3.5 would indicate heavy pollution. I can't check at the moment but the WHO Water ... (more)
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My immediate response is not to drink it and to only take water from upstream of the polluting area. My responses to your questions are below:
1 Aquatabs will not be effective in removing the oil - such kits are aimed at bacteriological contamination.
2- If contamination is gross, can leave to settle and remove oil from the surface, but people are unlikely to drink water with oily sheen anyway, and could have health problems from dissolved constituents. If the hydrocarbons are "heavy" you might remove most of them by filtering through material with high natural carbon content such as (coconut fibre) charcoal. Treatment systems are available commercially. If light, they will vaporise but significant storage times needed (they will also be removed by carbon, but are more mobile), and may not feasible on a household basis. Maybe one of the other RedR Experts has info on household size carbon filter treatment - it is done in the west, but probably expensive. I suggest bringing in certified clean water for babies and young children
4- Health risks to people - mainly carcinogenic; agricultural land - short term not an issue, long term - human health ingestion of hydrocarbons
Other thoughts: You need to analyse the water to establish how polluted it is. What is the geology? Could you use unpolluted groundwater? Could you take river water and spread it on the ground and then take from shallow wells?
Regards Harriet N
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