Safe Quarry - Health and Safety Authority

PART 6 EXCAVATIONS INCLUDING (QUARRY FACES), TIPS AND LAGOONS
(6) The operator shall ensure that -
(a)
(b)
any significant findings, and
any conclusions reached and the reasons
for those conclusions made under an
appraisal or a site investigation pursuant to
this Regulation are recorded by the
competent person or the geotechnical
specialist, as the case may be.
An appraisal is intended to be a straightforward
exercise to determine which excavations tips and
lagoons, proposed or existing, would pose a significant
risk if they failed, or in the case of a tip or
lagoon, move significantly more than that allowed
in the design, and so merit an assessment by a
geotechnical specialist. The relationship between
the appraisal and assessment are illustrated in the
flow chart in figure 43.
Some appraisals will only identify those hazards
from isolated minor failures, such as falls of a
single rock or a small amount of sand. A geotechnical
assessment does not focus on such hazards.
While isolated falls of ground can be serious, they
can generally be rectified immediately and be
adequately controlled by routine daily inspection,
use of appropriate equipment and working
methods.
The appraisal should be carried out with enough
detail and sufficient expertise to decide, on the
basis of the guidance in this Section, if an excavation,
tip or lagoon poses a significant risk from
collapse or movement. It is not normally necessary
for appraisals to be carried out by a geotechnical
specialist, though advice from one is appropriate
where the level of hazard is unclear.
When carrying out an appraisal there is no need
to duplicate work already done, as long as all the
matters detailed in this Section are adequately
addressed. In some cases it is obvious that any
failure of an excavation, tip or lagoon could prove
fatal, for example, an excavation, or tip or lagoon
near a public roadway, house or above quarry
offices. In these cases the initial appraisal can be
very brief as a geotechnical assessment by a
geotechnical specialist will be needed.
Areas where no one is at risk from a collapse of
part of an excavation must be included in the
appraisal because failure in such areas could affect
the stability of the remainder of the excavations.
Appraisal of such areas may also provide information
relevant to the safety of other parts of the
excavation.
Among other things, the appraisal should take
account of the material to be excavated or tipped,
its structure, water content/drainage, the
proximity of watercourses, roadways, workplaces,
residential accommodation or abandoned
workings, and any evidence or history failures.The
matters covered in inspections are also relevant.
Significant hazard
To determine if the hazard is significant or potentially
significant it is necessary to consider how an
excavation, tip or lagoon might feasibly fail and
the likely consequences of any such failure. The
likely consequences are crucial when deciding if a
particular hazard is significant. The probability of
such a failure actually happening is not relevant
in this context. The consequences depend on the
likely scale of the failure and the area that could
be affected by it, and whether people are likely to
be injured.
The hazard should be considered significant or
potentially significant if such a failure would directly
or indirectly, be:
liable to endanger premises, roadways or other
places where people are likely to be found offsite;
or
likely to cause serious or fatal injuries to
persons on or off-site.
If the degree of hazard is not clear and the excavation,
tip or lagoon is not in the categories
described in the “Excavations” or “Tips/Lagoons”
Sections overleaf, the advice of a geotechnical
specialist should be sought.
Where a geotechnical specialist has been involved
in design work or in geotechnical assessments he
or she may provide written, practical guidance on
what constitutes a significant hazard or potential
significant hazard in the context of that particular
site. Any such guidance should explain the basis on
which it was produced.
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SAFE QUARRY GUIDELINES TO THE SAFETY, HEALTH AND WELFARE AT WORK (QUARRIES) REGULATIONS 2008