Agriculture Reference
In-Depth Information
plant under adequate pressure, which in the mains
pipeline should be at least 20 psi. Hot and cold water are
necessary, the hot, from a central heating system, distrib-
uted at 45°C for cleaning wash-hand basins and at 82°C
for cleaning of equipment and tools. On-site water
storage tanks holding at least one day's consumption are
usual. Storage tanks must be covered to protect the water
from contamination. Should contamination occur, it
must be possible to completely drain, flush and sanitise
the system (Table 3.2).
If non-potable water is used for steam production,
refrigeration or fire control, it must be carried in separate
lines and identified as such.
It is increasingly important that for environmental
protection reasons water use in meat processing estab-
lishments should be minimised. The first step in this
process is to carefully analyse water use, as is demon-
strated for pig slaughter in Figure 3.2.
rule, floor drains should be fitted at the rate of one drain
for each 40 m
2
of floor area.
Where blood tends to collect, for example, under
dressing rails, special provision must be made to supply
drainage valleys which should slope to drains in the
valleys at a gradient of at least 1:25. The valleys them-
selves should be 60 cm wide and should continue under
dressing lines for the collection of all blood and bone
dust. Blood and wastewater solids must be collected
separately from the wastewater and dealt with in accord-
ance with by-products legislation (see Chapter 8).
Catch basins
for grease recovery and
traps
and
vents
on drains must also be provided, both to be properly
sealed and easily cleanable and the latter to be effectively
vented to outside the building.
Special arrangements have to be made for dealing
with stomach and intestinal contents, the drains for
bovine material to be at least 20 cm in diameter and for
the smaller species 15 cm.
In the United Kingdom, by-products legislation requires
that drains in cattle/sheep slaughterhalls be trapped with
4 mm screens, to prevent the possibility of contamina-
tion of the effluent with pieces of nervous tissue greater
than 1 g - the possible infective dose of BSE. The material
collected by this screening is then dealt with appropriately
as specified risk material (SRM), Category 1 by-product.
Drainage
Water must not be allowed to 'pool' on the floors of
production areas. Floors in wet areas should slope
uniformly to drains, the gradient being 1:50. As a general
Table 3.2
Benchmark water consumption: Environment Agency,
The Red Meat Processing (Cattle, Sheep and Pigs) Sector
Cattle
700-1000 l/animal
Lighting
Adequate natural or artificial lighting must be provided
throughout the meat plant. Natural lighting should take
Pigs
160-230 l/animal
Sheep
100-150 l/animal
Lairage washing
3%
Knife sterilising
5%
Vehicle washing
5%
Cooling water
6%
Scald tank
7%
Personal hygiene
10%
Meat sprays and
rinses
31%
Floor and equipment
cleaning
33%
Figure 3.2
Typical water balance for areas in a pig abattoir: Environment Agency, The Red Meat Processing (Cattle, Sheep and Pigs)
Sector.
