Dry weather and wet weather flows! thats the difference

Even though storm water and drainage from rain is separate to sewage, and uses different infrastructure, inadvertently storm water and rainwater does effect the flow to sewage plants.





Sutherland Council as opposed to Sydney water deals with the rain water and storm water systems of the Sutherland Shire. So i think it best to ask their view.

Guy Amos or gamos@ssc.nsw.gov.au is the go to man about storm water in the Sutherland Council.

Guy told me that although the storm water system and the sewage system were separate, storm water often got into the sewage system via illegal methods of re-directing rain water from roofs into the sewers.

So during heavy rain sewage treatment plants are under pressure to deal with a great deal more flow than on dry weather days. Guy informs me that in the past since the upgrade at Cronulla this has resulted in a bypass of the tertiary treatment of the sewage. .......

Furthermore the difference between dry weather and wet weather flows is disscussed by Courtney May, Brad Crossmand and Fiona McPherson in their study of the impact of the upgrade of Cronulla sewage plant on water quality at Sutherland beaches:

This study states that in response to rainfall "faecal contamination at ocean beaches increases. To what extant this happens depends on the level of development and the condition of the sewerage system"

I think the library and some old newspaper browsing is in order again.......tomorrow.