Death and Degradation by Phosphates

Additional soil nutrients delivered via storm water, household drainage, septic tanks, animal waste and dumped garden rubbish can increase the concentration of nutrients in the soil at the bushland-residential interface.

waterfallThe Hawkesbury Sandstone soils of our local area are especially noted for their low fertility, particularly nitrogen and phosphorus. Native plants are well adapted to low-nutrient soils, and can be adversely affected when exposed to higher concentrations of nutrients.

The dramatic increases in soil nutrient concentrations, particular phosphates, in urban bushland are accompanied by the invasion of exotic plant species and weeds. Therefore the locally endemic plant species are killed, prevented from regeneration or outcompeted by environmental weeds.

Phosphates that make it into our local creeks and rivers continue to cause imbalance of aquatic plants and algae. Algal blooms are a worldwide problem. When due to increased phosphorus levels in the water, cyanobacteria occur in excessive numbers, they have a detrimental effect on farm stock and the environment, and can cause severe economic losses to aquaculture, fishing, and tourism.

Phosphates are used in many laundry products because they help to soften the water and break down dirt. Once they get to creeks and rivers they have a harmful effect.

As consumers are becoming more aware of the damage done by detergents containing phosphates, their demand for more environmentally friendly detergents is influencing the supermarkets’ product range.

To reduce phosphate levels coming from your household, look for the NP symbol on detergent packets, wash the car on the lawn, use fertilisers efficiently to minimise waste, ensure septic tanks are working effectively, and control livestock access to creeks and rivers.

Also, see our recent article on the Importance of Water.