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:
- Size of farm operation (and the amount of wastewater generated)
- Amount of solids in the wastewater
- Permeability of the soil
- Level of underground water table
- Site topography
- Site location (and the distance from watercourses etc.)
- 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).
