Beachfront stormwater solution

Five years after its installation, an innovative stormwater treatment and reuse project at Manly Beach continues to save council over $28,000 per year.

In 2001, Manly Council worked with the Atlantis Corporation to develop and implement a system that not only collected stormwater for reuse; it actually filtered and purified the water before reuse took place.

The 2.6 heactare site selected as the catchment area included road and carpark areas fronting Manly Beach, adjacent to the area's historic Norfolk Pines.

Using a system include pervious paving, infiltration tanks, subsurface storage tanks and pumps for reuse, the system today has delivered data that warrants further interest from Australian councils and government authorities.

Latest results* collected over the nine-month period June 2005 and February 2006 offer savings in water costs and reduced pollution loads.

• Estimated annual stormwater reuse volume of 19 ML, saving $28,120.
• Estimated annual stormwater pollution loads reduced by 4000 kg for suspended solids, 6 kg for total phosphorus and 50 kg for total nitrogen.

The collection and filtering of pollutants by the Atlantis designed and installed system have continued to provide encouraging results (monitored weekly) including: faecal coliforms (cfu/100 mL) 90 minimum, 870 maximum; total phosphorus (mg/L) 0.02 min, 0.36 max; total nitrogen (mg/L) 0.3 min, 1.32 max; copper (g/L) 0.01 min, 0.21 max; lead (g/L) 0.02 min, 0.19 max; zinc (g/L) 0.05 min, 0.32 max; and turbidity (NTU) 0.9 min, 23 max.

Treated stormwater and supplementary groundwater is pumped from the underground storage and spray irrigated on a 4 heactare area of foreshore lawns and heritage-listed Norfolk Island pines. Council tankers can also fill from the storage tank for cleaning and watering.

The results of the project add considerable weight behind the case for point-source stormwater management solutions and, as reinforced by Atlantis Corporation's managing director, Humberto Urriola, all councils should make decisions based on both environmental protection and responsible management.

"The state of the environment should always be a prime consideration, especially in urban areas where stormwater contamination is at its highest," said Mr Urriola.

"The benefits this particular project provided not only include purified water for reuse, it is protecting an Australian icon (Manly Beach) from serious pollution," said Mr Urriola.

Data sourced from NSW Dept of Environment & Conservation Stormwater Management Guidelines publication, 2006.