This requirement depends on an assessment of various factors including the location of the site, local geography, history of events in local area etc. Taking all thing into consideration the most likely events relating to local activities should be identified and control measure put in place. This should also include a system of monitoring these issues and other sources of information.
For example, if you are bottling water at source, you would be very interested in local activities such as farming practices, mining operations, waste disposal (legal and illegal) environmental contamination, effluent from other nearby industries etc.
A system of control in this case may require, daily checking and recording of events such as 'spreading' on farms, an increase in mining activities, or specific emergencies. Methods might include visual inspections, monitoring local planning application, maintaining open contact lines with local businesses and authorities, and monitoring the media. Records of these issues should be recorded and where required trigger a management review process with actions etc.
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