Impacts of Climate Change on Wastewater Systems

Australia has been severely affected by a prolonged drought with the inflow to many water storages reduced to 50% of the recent long term average. There have been substantial programs of capital works to secure reliable water supplies. Other impacts and consequences of the observed and predicted changes to climate are being recognized, these include significantly higher rates of corrosion of sewers, increased frequency of breakage of sewers, increased tree root intrusion into sewers leading to dry weather overflows of sewage and sea water rise implications for sewers, sewage treatment, effluent reuse, stormwater and water sources. Sewage treatment processes will become more effective at higher average temperatures although any prolonged cold period will have adverse effects on performance particularly for small and medium size communities. Sewage treatment is not large user of energy on a per capital basis nor is it particularly a greenhouse gas intensive process but the cumulative energy consumption on a national or regional basis are a significant proportion of the total. The quantification and control of fugitive emissions, particularly of methane and nitrous oxide are current uncertainties as are the implications for any carbon pollution reduction scheme.