1. Biofilter Ventilation System: Treating Odor and Corrosion Issues in Macomb County Sewers Macomb County Public Works Commissioner Anthony V. Marrocco MWEA WWAdCon 2015 Frankenmuth, MI January 22-23, 2015 Jason Matteo, PE Chief Engineer – Wastewater Services Macomb County Public Works Office Steve Siklich, PE Project Manager Giffels Webster

2. Presentation Overview  Background  Past System Failures  Issues Plaguing Macomb County Interceptors  Proactive Versus Reactive Measures  Recent System Studies  Positive and Negative Pressure Conditions  Biofilter Ventilation System  Other Current and Future Projects

3. Macomb and Oakland Counties 00

4. Summary of System

5. Service Area  70 MGD (Average Daily DWF)  Flows to Detroit WWTP  OMIDDD: Approx. 830,000 People Served  OMID District includes:  11 Macomb County communities  13 Oakland County communities  MIDDD: Over 500,000 People Served  MIDDD: Tributary Sewered Area Over 142 sq-mi

6.  Interceptor system built by Detroit Water & Sewerage Department (DWSD) in 1970 and 1971  Transfer of ownership from DWSD to OMIDDD in 2009  Macomb County purchased Macomb Interceptor Drain in 2010  Macomb County constructed North Gratiot Interceptor in 2012 History RGDFAGGAFGFAFG DFGH DFTGG GGDFA G

7. Sinkholes!  Three catastrophic failures under DWSD ownership  Most recent failure in 2004: sinkhole on 15 Mile Road between Moravian and Hayes Roads while system owned by DWSD

8. 15 Mile Road Collapse 15 Mile and Corridor Collapse (1980)Failure After Excavation (2004)  Significant sewage discharge and environmental impact  Loss of sewer service  Cost of $200 million (in current dollars) to repair

9. Environmental Impact of Collapse Material Loss: 7,000 cubic yards 130’ 245’

10. Issues Plaguing MCWDD: Corrosion  Collapsed sewers and degrading facilities  Affects metallic and concrete materials throughout system  Reduces useful life of sewers, manholes, and facility equipment Garfield Road Sewer (Better Condition)23 Mile Road Sewer (Surface Damage)

11. Issues Plaguing MCWDD: Odor and Pressure  Odor complaints  Decrease in quality of life  Positive pressures have caused some damage to existing facilities  These issues are interrelated…  Positive pressure causes headspace air to escape through structures  Escaping air is the source of the odor  Pressurized system combined with turbulent flow conditions generates sulfuric acid and corrodes system

12. Goal: Implement Proactive Measures In Addition to Current Rehab  Macomb County Public Works taking proactive approach with ongoing odor and corrosion issues  Proactive measures to help prevent defects from forming and extend the useful life of our assets  Reactive measures after part of the system has failed or is expected to fail within next 10 years  What issues are currently affecting MCWDD?  How can we combat these issues with long-term solutions?

13. Study 1: 2011 Corrosion Identification and Control Study Legend Metering Station Interceptor Monitoring Location OMID and MID Sampling and Monitoring Locations  Goal  Provide comprehensive assessment of odor and corrosion problems in OMID and MID  Determine areas of MID with most severe hydrogen sulfide-induced corrosion

14. Study 1: 2011 Corrosion Identification and Control Study W W  Wastewater entering 15 Mile Road Interceptor contained some of highest predicted sulfides  Result

15. Study 2: 2011 Chemical Dosing Test  Goal  Control sulfide levels to reduce corrosion and odor W  Result: Addition of Iron Salt is most economical/effective solution to control H 2 S

16. Study 3: 2012 Fan Test  Goal  Determine RPM required to maintain consistently negative pressures in MID  Determine volume of air necessary to depressurize interceptors Tim e (

17. Study 3: 2012 Fan Test  Result  Running testing fan at 900 RPM maintained consistent negative and near neutral differential pressures throughout the MID, especially at 15 Mile and Garfield Roads Example Zone of Influence

18. Study 3: Differential Pressure Readings at 15 Mile and Garfield Roads Time (9AM to 3PM) Differential Pressure (inH20)

19. Conclusion of Studies  Corrosion issues plaguing MID are accelerated due to poor ventilation of system Positive Pressure: Air and odor leave system Negative Pressure: Air enters system and odor stays in system Ventilation Effect of Decreasing Slope

20. Ventilation Dynamics of Drop Shaft Air Eduction  Increasing velocity of sewage creates a negative-pressure environment, forcing air into the interceptor  However, turbulence generated from the drop releases high amounts of H 2 S gas, causing corrosion

21. Odor Removal Options  What options are available to alter headspace air ventilation dynamics, generate negative pressures, and minimize the alteration of sewage flow dynamics? Source: Water Environmental Federation: Lee, Morton, Tang, Friess, and Maguin

22. Biofilter Ventilation System  Require no chemicals  Little O&M  Cost-effective technology  Designed to blend in with surrounding landscape

23. What is a Biofilter?  Odor control system that absorb and oxidizes odorous compounds using microorganisms growing in soil or compost substrate  Past uses been very successful in treating hydrogen sulfide

24. Biofilter Plan and Profile

25. Past Use of Biofiltration: Plum Creek Timber Company  2008: Columbia Falls, Montana  Largest bio-filtration system in the world according to Plum Creek Timber Co.  16-foot stainless steel ducts  Exhaust released from 2 stacks and is 98% clean

26. Existing Site

27. Underground Vault and Fan  Underground concrete vault houses 20,000 CFM (75 hp) fan and related equipment  Necessary for removal of headspace air, subsequently reducing available room for generation of corrosive and odorous gases  Flows are monitored via a control panel onsite

28. Fan Vault Construction

29. Foul Air Fan

30. Existing Gate Control Structure

31. Gate Structure and Foul Air Duct  Existing system tapped into and air is drawn through system of interconnected piping by fan  Underground HDPE piping varies in size from 36” at existing gate structure, increasing to 48” coming out of the fan vault, and gradually stepping down in size as air moves towards media beds

32. FAD Construction

33. Flow Element Structure

34. FAD Construction

35. Biofilter Media Beds  Stone media  Chemically-resistant granite  Even distribution of air Stone Media  Organic media  Fractured wood pieces where most of odor and VOC removal takes place  Microorganisms in biofilm growing on media. Organic Media W W W W W

36. Biofilter Media Bed

37. Biofilter Bed Construction  Bed area excavation  Bed liner with drain line  FAD piping penetrates bed vertically (Tee shown)

38. Biofilter Bed Construction

39. Organic Media and Irrigation System

40. SCADA System Interface  Supervisory Control And Data Acquisition (SCADA) system allows County to monitor and control Biofilter remotely  Variable Frequency Drive (Blower)  Exhaust Fan  Sump Pumps

41. SCADA Interface

42. Final Thoughts  $1.84 million construction cost  Exact zone of influence TBD  Long-term, low- cost solution to major ventilation problems

43. Conclusion and Results  Provide low-cost alternatives for long-term treatment of serious issues plaguing wastewater collection systems and facilities  Biofilter  Chemical Addition  Biotrickling facility  Future Biofilter systems Current Biofilter Future Biotrickling Facility Future Biofilter Future Chemical Addition Current Biofilter Future Biotrickling Facility Future Biofilter Future Chemical Addition Lakeshore Interceptor 15 Mile Road Interceptor Romeo Arm

44. Macomb County Public Works Commissioner Anthony V. Marrocco 21777 Dunham Road Clinton Township, MI Jason Matteo, PE Chief Engineer – Wastewater Services (586) 469-5343 jason.matteo@macombgov.org Steve Siklich, PE Project Manager (586) 781-8950 ssiklich@giffelswebster.com Thank You