Pollution control

Controlling pollution and contamination on farms can help profit as well as the environment. Over-use of fertiliser wasts money and adds unwanted nutrients to creeks and rivers. Agricultural chemical sprayed near watercourses are a waste and a hazard.

The issues in pollution control that apply to land use are:

• fertiliser use
• agricultural chemical use
• chemical residues
• waste management

• Agricultural chemicals will be used as little as possible, and only if fully justified.

Care must be taken to prevent unwanted side effects of chemcal use including liss of non-target plants and soil organisims. Particular care needs to be taken near open water and drainage lines to reduce risk to aquatic organisms.

• Chemical residue areas will be identified

Areas containing chemical residues will be outlined and recorded in property maps, information publications and on a Global Positioning System. This will enable others to learn from how the College has dealt with these problems and will put them in the public domain.

The areas in question are:

• organochloride residues in the main yards
• organochloride residues from foundations of the former cottage at Bona Vista, now the rainforest plot
• possible chemical residue from the past use of dieldrin super to control black beetle on dairy pastures in 1971 in Lagoon, Section IIA, Section IIC, Section IIIA3 and Windmill paddocks
• the former chemical disposal pit in Quarry paddock
• the previous chemical storage site between Apple and Horse paddocks - this was bunded and well maintained but shoud be montiored into the future
• the old timber treatment sites using copper chromium arsenate (CCA) in Run and Quarry paddocks.

• Dairy waste management. The College dairy uses a two pond aerobic and anaerobic treatment system. After treatment the liquid wastes are pumped out onto pastures. The system needs ongoing monitoring and management to ensure that effluent does not seep into watercourses. Milk from the dairy that may be unsuitable for delivery to the factory will be drained into the dairy effluent ponds before spraying on pastures. This is only suitable for small quantities. It is important the milk not enter watercourses.
• College effluent disposal. Effluent is sprayed on the Horse paddocks after it is treated in the College treatment plant. This is approved by the Environmental Protection Authority and subject to licence conditions. Performance of the treatment plant is monitored according to the guidelines set down by the EPA and Public Works. Treated water is checked regularly for phosphate, nitrate and ammonia.
• Disposal of dead animals. In the past, animals have been disposed of by burying, dropping into open pits and burning. There are difficulties with all of these methods, and alternatives need to be considered. A composter is used at the Numeralla chicken farm for dead birds. Large animals are disposed of in a pit, which is covered with fill. Where possible, a local pet food supplier is contacted before the death of a large beast.
• Disposal of rubbish. No rubbish, refuse or other material is to be dumped on the property except for a specific purpose. This means that no parts of the farm should be used as a dump. All refuse is to be removed and taken to the appropriate council-approved facilitiy. Sometimes clean fill is needed for road building, yard base or similar works. This is the only type of dumping permitted. At times piles of wind-thrown timber will be burnt, and CCA-treated timber, metal fittings or non-flamable materials will not be added to these piles. College educational activities and the College dining hall produce a large amount of rubbish. A satisfactory recycling system will be investigated to deal with this rubbish.
• Quarry Creek Wetlands. The wetlands area in Racecourse paddock collects the discharge from Quarry Creek. Pollutants from the catchment of this creek, which is not on college land, will be stripped from the water by wetland vegetation before it re-enters Webbers Creek and thence to the Paterson River. This measure will guard against the problems of pollution caused by any closer settlement in the headwaters of this creek system.

Bird composter at Numeralla chicken farm, Tocal