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Key physicochemical parameters for surface water - volcanic soils post earthquake

related country: Papua New Guinea

Following the recent earthquakes, there are reports of surface water contamination. Given the locations, these are presumed to be natural contamination rather than due to extractive industries. Surface and rainwater are the main sources of potable water in the affected areas.

There is a lack of easily-accesible pre-earthquake physicochemical parameter tests, and multiple current annecdotal accounts of an oil-like veneer on the surface of water, and 'rotten egg' smell of hydrogen sulfide.

A partner is set to order a series of consumables for a range of tests: any experiences on what might be the key parameters to be looking for in such conditions?

1 Answer


OK, very simple answer. The WHO recognise various water quality parameters, e.g. physical, chemical, microbial and radiological. However one aspect is often overlooked and it is the most important and that is "aesthetic". If the water looks, smells and tastes odd/ unpleasant then people won't drink it. So whilst knowing the cause is nice to know, it may be very expensive and difficult to find out - even if the testing equipment is available. Even if you do not know what the chemicals are, you still need a practical way forward.So accept the water does not meet the standards as it's yukky. If you wouldn't drink it then it's not good enough. The problem is people may prefer good tasting surface water (but polluted with bacteria) than horrible tasting groundwater (even if it's bacteriologically safe).

So... - carry out a sanitary survey/ water source survey to look for any obvious sources of contamination/ sudden changes in water quality. This might help identify the type of pollution. - chemical pollution is often a long-term problem (e.g. a bit of arsenic for a few weeks is less of a problem than drinking a little over 20 years). Microbial contamination is much more of a short-term concern. - chemical treatment is often hard and expensive, even if you know the problem - consider rapid RWH if rainfall is enough - even if just for drinking water. Simple tarpaulin systems work e.g. - consider temporary HHWT such as a filter (settlement/ chlorination systems don't necessarily reduce chemicals and may not work well anyway) - that may improve taste enough. - consider trucking/ bottled water for drinking only / for vulnerable groups.


Thanks Brian, Indeed and agreed. Nonetheless remain with the question of which parameters might be issues in volcanic soils? Equipment to test would be available if we could figure out what to test for eg. from the 150+ Wagtech reagents. The more obvious ones like hydrogen sulphide would make it undrinkable before getting to anything threatening health, but what about less obvious ones? Probably 90% of population rely on creeks / streams, probably same % illiterate / uneducated, extremely difficult to work in the area, and extremely limited number of actors / coverage. Following earthquake, have had multiple reports of 'changes' which cant be obviously attributed to the landslides / sediment load / decreased oxygen 2-months down the line e.g. hydrogen sulphide (rotten egg smell), so presumably variety of gases being released to some springs. May only be to allay populations fears, or indeed figure out what might need to be promoted over the coming dry months.

dalford gravatar imagedalford ( 2018-04-26 14:40:29 )