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The problem

• a shitty field

• a shortage of space

• lots of people

Possible solutions

• Don’t use it – but the alternative may be worse so Chris will have to weigh up risks

• Best solution – scrape if off – may not be possible – we are talking about say 20cm and even then no guarantee that there is not some pollution left

• Next best – cover it – same problems as scraping it off – a lot of earth

In-situ treatment needs:

o High pH – lime would help but would not disinfect only reduce the time required by a modest percentage through raising the pH

o High temperature – but Feachem et al quote for composting figures of 62C for 1 hour, 50C for 1 day, 46C for 1 week, 43C for 1 month and 42C for 1 year for the inactivation of all excreted pathogens with the possible exception of Hepatitis A

o Low humidity – almost certainly a challenge in Sri Lanka and little that can be done?

o Time – measured in months, see above – we assume that Chris does not have this luxury

o So on balance any on site treatment may be tokenism with the exception of scraping or covering

Karen and I are well aware that we have not come up with a magical solution, but unless someone else does, perhaps the best we can offer is confirmation that one does not exist - apart from scraping or covering.

Tim Foster

The problem

• a shitty field

• a shortage of space

• lots of people

Possible solutions

• Don’t use it – but the alternative may be worse so Chris you will have to weigh up risks

• Best solution – scrape if off – may not be possible – we are talking about say 20cm and even then no guarantee that there is not some pollution left

• Next best – cover it – same problems as scraping it off – a lot of earth

In-situ treatment needs:

o High pH – lime would help but would not disinfect only reduce the time required by a modest percentage through raising the pH

o High temperature – but Feachem et al quote for composting figures of 62C for 1 hour, 50C for 1 day, 46C for 1 week, 43C for 1 month and 42C for 1 year for the inactivation of all excreted pathogens with the possible exception of Hepatitis A

o Low humidity – almost certainly a challenge in Sri Lanka and little that can be done?

o Time – measured in months, see above – we assume that Chris does not you don't have this luxury

o So on balance any on site treatment may be tokenism with the exception of scraping or covering

Karen and I are I'm well aware that we have not come up with a magical solution, but unless someone else does, perhaps the best we can offer is confirmation that one does not exist - apart from scraping or covering.

Tim Foster