WINETECH Technical Yearbook 2019

PHOTO 4. Liquid storage pond at Affco meat processing plant near Palmerston North.

PHOTO 5. The municipal wastewater treatment dam at Feilding near Palmerston North.

PHOTO 2. The cows had to be housed indoors due to wet conditions outside.

PHOTO 3. The wastewater dam with its warning sign at Massey University dairy farm near Palmerston North.

phosphorus (P) and potassium (K) levels. There are guidelines in New Zealand for the wastewater dams and storage. Sludge is removed from the wastewater dams every three years. The size of the storage dam that is required to store the dairy wastewater can be calculated using an effluent dairy storage calculation. Inputs include parameters such as climate, soil, solids, catchments and irrigations. The storage dam should also have a lining. The wastewater is used to irrigate farmland. There are guidelines about the amount of N that can be applied to an area. This amount is variable. In the Palmerston North region, the amount of N that can be applied via the wastewater is 150 kg N per ha per year. In addition, the application of irrigation should not cause drainage or run- off. No soil sampling or monitoring of the effluent water quality is required.

AFFCO MEAT PROCESSING PLANT NEAR PALMERSTON NORTH The wastewater from the Affco meat processing plant near Palmerston North does not contain a lot of blood, because there is an excellent recovery of blood in the facility. Thus, the wastewater contains less N than in the past. The P content in the wastewater has to be managed. The P comes from the stomach contents. The P also doesn’t break down or change form. The solids from the processing plant are collected in a solid pond. The solid pond contains green waste with floatables in it. The solids could be used for composting. The associated compost results in a lot of weeds, because the animals have living weed seeds on their bodies. Therefore, composting is not a high priority. Water is drained off from the solid pond. For the liquids (Photo 4), there is an anaerobic

large effluent dams. In New Zealand, cows are generally not kept indoors, because it is not cold enough. Though, when conditions become very wet, the cows have to be housed indoors. In the cow houses where they are housed (Photo 2), they eat PHOTO 6. Composting of sludge at Feilding municipal wastewater treatment plant.

a lot and generate substantial amounts of dung and urine. The waste is collected and stored in a wastewater dam (Photo 3), which is clearly marked with a danger sign. Cow house shelters yield wastewater with poor water quality, and high nitrogen (N), PHOTO 7. Cut and carry process used at Feilding municipal wastewater treatment plant.