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Guidelines
for Soakaway System
INTRODUCTION
Following
the implementation of the Livestock Waste Control Scheme in
1988 and the revised Livestock Waste Control Scheme in 1994,
livestock farmers in Livestock Waste Control and Restriction
Areas must comply with control requirements in the management
and disposal of livestock waste. A soakaway system is a viable
and practical option for waste treatment when a small quantity
of wastewater is generated from the livestock keeping operation.
The effectiveness of the soakaway system is thus a very important
element in the on-farm management of livestock waste. These
guidelines are prepared with a view to providing livestock
farmers and waste treatment system designers with general
information on the provision of a soakaway system for the
abatement of pollution caused by livestock waste. It should
be noted that it is an offence under the Waste
Disposal Ordinance (WDO) to allow a soakaway system to
overflow. An offence under the WDO may constitute a violation
of other legislation (including the Water
Pollution Control Ordinance, the Public
Health and Municipal Services Ordinance and the Waterworks
Ordinance, etc.).
The installation
of a soakaway system in a farm is not always feasible, especially
for pig farms, and its suitability is affected by the following
factors:
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a.
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Size
of farm operation (and the amount of wastewater generated) |
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b.
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Amount
of solids in the wastewater |
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c.
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Permeability
of the soil |
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d.
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Level
of underground water table |
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e.
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Site
topography |
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f.
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Site
location (and the distance from watercourses etc.) |
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g.
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Availability
of land area |
Before
adopting a soakaway system, a responsible farm operator must
carefully evaluate the above factors and organize a site percolation
test to ascertain whether the soil at the farm is suitable
for a soakaway system. A simplified procedure for carrying
out the site percolation test is given in para
v(b).
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