1. Odor Control without Chemicals MWEA/AWWA Joint Conference August 11, 2010 Mark Prein, P.E.

2. Why Odor Control? Be a Good Neighbor – Public Image Issue Health and Safety Asset Management

3. Treat the Symptom or the Disease Big choice Do you / can you prevent it from ever happening? Potential huge cost ramifications

4. Where is it coming from? Different processes have different smells Once ID, how do you collect odor laden air? If contain, then corrosion?

5. Not All Odors Are the Same Sulfur Compounds Ammonia VOCs Other

6. Treatment Options Chemicals  Caustic, Hydrogen Peroxide, Bioxide or equivalent Scrubbers Masking Agents Salts Enzymes Carbon Ozone Seal it and forget it.

7. The Solution to Odor is Dilution

8. Case #1 – Feasibility Study What about using the odor laden air?  Collect and use as feed air for treatment process  Caution needed  Quantity of air  constant vs. end use  Quality of air  Depends on source  Potentially cost effective  Understand risks

9. Case #2 – NKSA Collection EPA recommends laminar flow of wastewater Significant Odor Issue System Sealed to prevent odor complaints Collection System failure(s) from H2S Corrosion

10. Case #2 – NKSA Collection

11. Proposed Alternate  System Reconstruction Required  Add carbon filters and open the system up  Add re-aeration to system (turbulence)  Use available grade  Prevent from becoming anaerobic

12. Case #2 – NKSA Collection Results  Eliminated odor complaints  No active odor treatment in reconstructed lines  Eliminated H2S generation  Reduced overall construction cost

13. Case #3 – NKSA Four Mile LS Original Built in 1968 Significant Odor and Corrosion Problem Located in Residential Neighborhood Previously Tried Chlorine Scrubber Station Sealed

14. Case #3 – NKSA Four Mile LS Biofilter  Treatment for wet well  150 ppm ave. Hydrogen Sulfide, Mercaptans  Air Volume = 2,000 scfm  Two Modules (package)  36 second bed time  Negative pressure  Redundant blowers  Roof Discharge

15. Case #3 – NKSA Four Mile LS The Plan

16. Case #3 – NKSA Four Mile LS Constructed

17. The Look and What Smell Case #3 – NKSA Four Mile LS

18. Case #4 - MCWMS Rehab of Existing Odor Stripper and Treatment  Rehab odor reduction building  Replace control gates and mixers  Update electrical  Address issues with significant chamber corrosion  Still issue with channels – long term proposed to cover  Estimated cost ~$750,000 Proposed alternate – eliminate both!

19. Case #4 - MCWMS Alternate - Plant Feed Rerouting  Prevent the odor from ever getting to the air  Simple  No active treatment system, eliminate existing system  Complete as part of overall system improvement  Eliminate O&M costs  Capital cost ~$600,000

20. Case #4 - MCWMS

21. And No More Channel

22. Case #5 – NKSA CWP Process Control  NKSA Biosolids Holding Tanks  Avoid odor issues  Minimize Energy  Accomplish with Process Control  SCADA with DO and ORP probes  Cost – Minimal cost for probe and programming  Saving – Significant reduction in operating costs

23. Case #5 – NKSA CWP West Tank

24. Case #5 – NKSA CWP SCADA Control

25. Case #5 – NKSA CWP Tracking -Trend Screen

26. Case #6 – NKSA CWP

27. Biofilter  Treatment for Headworks and Solids Handling Rooms  Air Volume = 15,000 scfm  Hydrogen Sulfide, VOCs, Mercaptans, Ammonia  30 second bed time  Built in Place – equipment cost 310K  Positive Pressure  Redundant blowers w/VFDs Cost of Biofilter Equipment = $310,000*

28. Case #6 – NKSA CWP

29. The Plan

30. Case #6 – NKSA CWP Support Grading  Collect all Headworks and Solids Handling Room air

31. Case #6 – NKSA CWP Lower Irrigation  Maintain negative pressure in rooms Upper IrrigationLower Irrigation

32. Case #6 – NKSA CWP Upper Media  No hazardous chemical usage

33. Case #6 – NKSA CWP Polishing Media  Treat to none detectable levels – Nose test

34. Case #6 – NKSA CWP Covers and Pipe  Consider freezing issues

35. Case #6 – NKSA CWP Most Frequent Comment?

36. Thank you.