Project Round
Project Number
315 - 001
Research Organisation

Impact of Source Management on Domestic Wastewater Quality

The Challenge

With the rise in domestic use of grey water, its actual composition and the sources of contaminant materials contained in it are of increasing interest to both users and regulators. This report evaluates the contribution household and personal care products to biohazardous concentrations in domestic wastewater. It comprehensively reviews the composition and origin of contamination and examines the implications for product labelling and wastewater management.

The Project

A range of 156 household and personal care products for use in the bathroom, laundry, kitchen and toilet were analysed using standard water and wastewater analytical methods.

The loads and distribution of the subject elements in the wastewater streams from bathroom, laundry, kitchen and toilet in a one person household were recorded and used to simulate the effect of a range of strategies on the quality of wastewater. These data can be used to evaluate a larger range domestic of scenarios.

The use of “environmental label” brands and products with low element concentration was found to reduce the load of chromium, cobalt, chloride, fluoride, selenium and particularly phosphorus discharged by a typical household.

Antimony and molybdenum were found to be below detection in most household products. Consequently the inclusion of labeling on products for these contaminants has minimum effect on waste water quality.

Non-product sources of contaminants make a significant contribution of nitrogen which comes mainly from human excreta and fluoride which is supplied in fluoridated tap water. Therefore labelling for these elements in products has less influence on waste water quality.

The Outcome

Householders can improve the quality of wastewater by specifically selecting products with low elemental content.

However, householders are currently hampered in the selection of products by limited publication of information about product formulation. Labels, such as “biodegradable”, “low P” or “environmentally friendly” refer only to the environmental impact of phosphorus. Labels currently do not provide adequate guidance on the environmental impact associated with use of wastewater in watering and irrigation applications where the presence of heavy metals and inorganic compounds can degrade soil and damage plant health.