Biosolids in Australia: A Historical Perspective. Sludge >> Biosolids

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1 Biosolids in Australia: A Historical Perspective Daryl Stevens (PhD) Atura Pty Ltd, Docklands, Victoria, Australia daryl@atura.com.au Mobile: Ph: Sludge >> Biosolids Sludge produced during the primary, secondary and tertiary treatments of WWTPs. Includes processes: Concentration (dewatering, mass reduction), Stabilization, Disposal/Beneficial use

2 BS Production to End-use Humans SEWAGE TREATMENT PLANT Raw Sewage Screening Primary treatment BIOSOLIDS PRODUCTION PROCESSES CONDITIONING COMPOSTING THICKENING DEWATERING STABILISATION END USES Land application Production Agric. & horticultur Amenity horticulture (Landscape, oval, garden) Forestry Environmental (reclamation, mitigation) Food crop Secondary treatment Tertiary treatment Sludge DRYING Thermal Conversion Raw Material Recovery Effluent Liquid from the above biosolids production processes Structural fill Land disposal

3 South East Water s biosolids annual percentage usage Annual usage % (Used/produced) No treatment Biosolid risk assessment safety level Australian Guidelines? Secondary risk assessment with control measures Level of safety or risk mitigation for land application of biosolids Safe or Low risk No guideline with treatment Australia and International guidelines Tertiary risk assessment with control measures Level of knowledge Detail and knowledge used to assess risk

4 Changing uses of biosolids WEF, David Parry, Dave Taylor, Lynne Moss, Mike Moore, Ned Beecher, and Sam Hadeed. Charting the Future of Biosolids Management: Forum Findings on Trends and Driver. Webinar. Water Environment Federation, Biosolids in Australia NBRP ANZBP $ Research and Development Environmental benefits

5 Public image Understanding biosolids! Knowledge sharing!

6 GHG impacts Carbon foot print, renewable energy incentives WEF, David Parry, Dave Taylor, Lynne Moss, Mike Moore, Ned Beecher, and Sam Hadeed. Charting the Future of Biosolids Management: Forum Findings on Trends and Driver. Webinar. Water Environment Federation, Treatment technology changes Side stream treatment nutrient recovery Enhanced Hydrolysis Improved composting WEF, David Parry, Dave Taylor, Lynne Moss, Mike Moore, Ned Beecher, and Sam Hadeed. Charting the Future of Biosolids Management: Forum Findings on Trends and Driver. Webinar. Water Environment Federation,

7 Sewage Treatment Plant 5a 3a Air 2a 3a,5a Exposure Pathways 1a,b,c,d,e; 2a,b,d,e,f,g,h; 3a; 4a,b,c,d,h Biosolids Domestic 1a,b,c, d,e; 5b.c 2 b,d,f,g 5b,c Plants Air Animals 1c.d,e; 5b,c 2e 1d,e; 2b; 5c 2d 1b Public and occupational exposure 4c 2f 2e,h Soil biota Aquatic biota 2f; 4a Soil 4b,c 4a,b,c Exposed endpoint Release to environment 4d,h Surface water Primary exposure Secondary exposure Groundwater aquifer 4d Tertiary exposure Completion of cycle 4h Sediment 4h Meiofauna Detrimental Impact Drive GLs Guidelines still come primarily from the perspective of managing detrimental impacts from nutrients and contaminants Is it time to manage them more like fertilisers?

8 Soil Contaminant Rule Biosolids contaminants that where once a concern are slowly being managed better at source Is it time to reassess what contaminants are important and how they are regulated? Are guidelines keeping up Improvement: NLAR Rule FLAR Fertiliser Loading Application Rate (FLAR) Residual soil N Rule Residual soil P Rule Soil contaminant Rule Add Organic chemical Rule Carbon Stevens, D., A. Surapaneni, N. Albuguerque, B. Meehan, D. Smith, P. Uren, and P. Hansen. Repeat Application of Biosolids in Agriculture Land. Water Journal 39, no. 5 (2012):

9 Organic Chemical Rule? Stockholm Conventions POCs The initial twelve POCs , Aldrin , Toxaphene , Chlordane , Mirex , DDT , Hexachlorobenzene (HCB) 1, 2, , Dieldrin 1 Various, Polychlorinated biphenyls (PCBs) 2, , Endrin 1 Polychlorinated dibenzo-p-dioxins (dioxins) , Heptachlor 1 Polychlorinated dibenzofurans (furans) 3 The proposed additional nine chemicals Various, Commercial pentabromodiphenyl ether 2 (cpenta BDE) (BDE209) , Commercial octabromodiphenyl ether 2 (cocta BDE) (BDE 196, 197 and 203) , Hexabromobiphenyl 2 (HBB) , Chlordecone , Pentachlorobenzene 1, , Lindane , Alpha hexachlorocyclohexane , Beta hexachlorocyclohexane , Perfluorooctane sulfonate 2 (PFOS) and PFOS related substances

10 AGWR AGBUB (Beneficial Use of Biosolids) Aim is to ensure (as much as possible) that recycled water is safe before use A coordinated approach from source to point of use Reduces reliance on recycled water testing (too little, too late) Source Sewer Environment Receptor

11 Potential soil loss Conclusion Land disposal >>Land application>> Beneficial uses Beneficial uses have diversified Research has increased to: support these diverse uses manage the increasing no of risks identified A national framework/guideline is required that: allows individual site risks to be assessed maintains a national database of hazards in biosolids, associated risk and control measures

12 Thank you!