Reducing Phosphorus in our waterways

​Ruapehu District Council encourages use of household cleaning products that are low in phosphorus, or phosphorus free.

Once in our waterway, phosphorus feeds algae and stimulates growth of aquatic plants. These plants block sunlight from getting into the water, killing off other plants and organisms. When the plants die, they use up oxygen from the water, also killing off other organisms that need oxygen to live. The excessive supply of nutrients such as phosphorus and nitrogen is strongly linked to the growth of plants, algae, blooms of cyanobacteria, odour problems, and health issues.

Any wastewater containing phosphorus that leaves your property will need to be treated at a Ruapehu District Council Wastewater Treatment Plant before it can be discharged. There are a number of ways for Wastewater Treatment Plants to remove phosphorus including chemical and biological treatments, but these treatments come at a considerable cost to ratepayers.

80% of nutrients enter water ways from agricultural, natural and urban runoff, however phosphorus from point sources (commercial, industrial and domestic use) are a significant source of the total load.

Research shows that up to 30% of phosphorus in domestic wastewater derives from domestic laundry products, dishwashing detergents and food scraps (DEFRA 2008).

By shifting consumer habits towards phosphorus-free detergents we have the potential to reduce phosphorus loads to wastewater treatment plants and to our rivers.

Page reviewed: 25 Aug 2017 12:01pm