1. I/A Systems Performance and Use Considerations Susan Rask, M.S., R.S. Barnstable County Department of Health and Environment February 9, 2009

2. Barnstable County I/A Management Program 2005 – begin use of web-based database Wastewater operators report directly to database Database tracks status of –O&M contract –Inspection events –Sampling events and results BCDHE uses database to ensure systems are inspected and sampled BCDHE tracks and analyzes system performance

3. I/A systems Topics for discussion How well do they work? What are the short and long term costs of installation and use? Management issues How do they fit with town’s Wastewater Planning efforts?

5. Current Number of I/A systems Permits by Town Number% of total Barnstable664.7% Bourne1107.9% Brewster342.4% Chatham1158.2% Dennis19313.8% Eastham1269.0% Falmouth17712.7% Harwich271.9% Mashpee27519.7% Orleans423.0% Provincetown181.3% Sandwich251.8% Truro171.2% Wellfleet856.1% Yarmouth856.1%

6. Falmouth I/A systems 178 permitted as of January 2009 78 FAST (45 with 3 or more nitrogen samples) 34 RSFs (16 with 3 or more nitrogen samples) 10 Bioclere (4 systems with 3 or more nitrogen samples) 30 RUCK (very little data available) 13 Singulair 1 Amphidrome 2 Waterloo Biofilter 4 OAR

7. Wastewater Treatment for Nitrogen Reduction Can be configured in many ways. All have: Anaerobic (septic tank )(urea → NH 4 ) Aerobic component where nitrification (NH 4 → NO 3 ) occurs Anaerobic component where denitrification (NO 3 → N 2 gas) occurs

8. Bioclere (Trickle filter)

9. Individual Residential On-site I/As Factors affecting Performance To keep costs low and to keep maintenance minimal for homeowners, most are designed to be as simple and as passive as possible Gravity flow where possible Water flows through system by hydraulic displacement i.e. Water In = Water Out

10. Factors affecting Performance No Surge Capacity results in varying amounts of residence time and therefore treatment of individual “slugs” of water Results in inconsistent levels of treatment

11. Factors affecting Performance Residential Wastewater is highly variable in strength and composition –From residence to residence –From hour to hour and day to day within one residence –Results in inconsistent levels of treatment

12. Note effluent TN levels

13. Variability in performance due to system operation At present, no standard operating and sampling procedures for many technologies Any wastewater operator can operate any technology Operator determines follow up actions, if any, when effluent does not meet limits

14. Data Considerations All that glitters is not gold The 19 mg/L total nitrogen requirement What does it really mean? What are the assumptions? 19 mg/L

15. Concentration vs. Load The 19 mg/L discharge concentration referenced in DEP nitrogen-removal system Approval Letters assumes An influent wastewater concentration of 40 mg/L ( may or may not be true ) 50% removal of nitrogen Title 5 flows (110 gal/day/bedroom)

16. 50 % N Removal? Influent TN cannot be not measured Not really possible to know if 19 mg/L represents 50% removal For example – if influent TN=60 mg/L, effluent TN=19 mg/L represents 66% TN removal –if influent TN=30 mg/L, effluent TN=19 mg/L represents 33% removal –if influent TN=80 mg/L, effluent TN=40 mg/L represents 50% TN removal, but does not meet 19 mg/L limit

17. About the Data Barnstable County data from 1999 - May 2007 557 individual systems 487 single-family 70 multi-family many of these systems had only a small number (≤ 3) of samples Data analysis focused on systems with ≥ 4 samples 297 single-family 50 multi-family 60 single-family systems with ≥ 10 samples. Samples from these systems represent 864 out of a total of 2,308 samples, or roughly 37% of all data analyzed.

18. Barnstable County Single Family – All Technologies Combined (four or more samples)

19. FAST system process (fixed activated sludge)

20. FAST Results—Barnstable County systems with 3 or more samples 69% of all systems had median TN ≤ 19 mg/L

21. Single-Family FAST Barnstable County Results (Systems with eight or more samples)

22. FAST Results— Falmouth 33 out of 43, or 77% had TN ≤ 19 mg/L 38 out of 43, or 88% had TN ≤ 25 mg/L Systems with ≥ 3 samples

23. Bioclere (Trickle filter)

24. Single-Family Bioclere Barnstable County Results (four or more samples)

25. Bioclere Results --Falmouth 4 systems with 3 or more samples 4 out of 4 systems, or 75%, had median TN ≤19 mg/L

26. Recirculating Sand Filter (RSF) trickle filter

27. Single-Family Recirculating Sand Filter Barnstable County Results (four or more samples)

28. 12 of 16, or 75% had TN ≤ 19 mg/L 15 of 16, or 94% had TN ≤ 25 mg/L RSF results—Falmouth 16 systems with 3 or more samples

29. Nitrex

30. Nitrex process summary Wastewater is passed through septic tank, then through an aerobic unit where it is nitrified. Nitrified wastewater flows through the Nitrex unit by gravity. The unit contains a proprietary nitrate-reactive media. Inside the unit, the wastewater is denitrified, with loss of nitrogen as N 2 gas.

31. Eastham Nitrex multi-family housing

32. Mashpee Nitrex mixed use commercial and residential Note influent TN levels

33. MASSTC Nitrex

34. Summary 90 %

35. Performance Conclusions No innovative/alternative (I/A) onsite septic system technology has demonstrated performance to the degree necessary to gain General Use Approval for 19 mg/L or less Total Nitrogen at the discharge. The true efficacy of I/A technologies is obscured somewhat by the absence of water use and influent nitrogen concentration data from homes served.

36. Bottom Line Hard to know how much variability in effluent quality is due to –Inherent ability of each I/A technology to remove N –Operator actions (or lack thereof) –Variability in individual home wastewater strength and flow –Inconsistency in way systems are sampled Likely that performance will not improve until we can control more of these variables

37. I/A Systems: Considerations for Use Perception that I/A systems are quick and inexpensive fix Not True –Variable performance –At best, remove 50% of nitrogen –Costly over life of system –Stringent O&M and sampling requirements when used for nitrogen reduction –Impose management burden on town

38. I/A Systems: Economics Individual I/A on-sites are not inexpensive Installation cost: $10,000 above cost of Title 5 system Significant Annual Costs Operation and Maintenance contract ($1200) Electricity costs ($350) Effluent Sampling ($400, included in cost of O&M) Total annual cost to operate= $1550

39. I/A Systems: Economics Present value cost of I/A system Present value analysis brings all costs associated with system installation, maintenance and operation of the system, over the entire life of the system, into present dollars i.e. How much money would I have to set aside today to cover all costs associated with the system over it’s life span?

40. I/A Systems: Economics Present value cost of I/A system Assumptions: –Installation cost $10,000 –Annual O&M contract $1200/yr –Electricity to operate $350/yr –Quarterly inspection and effluent sampling –20 year life of system –5% interest rate Yields present value of roughly $35,000.

41. I/A Systems: Economics Present value cost of I/A system including Title 5 components Initial costs: I/A unit $10,000 Title 5 components $10-20,000 Brings total initial cost to $20-30,000 Brings present value cost to $45-55,000

42. Economics of I/A systems Eastham Study Assume present value for each I/A system is $45,000 Use conservative assumption of 1000 I/A installed Total projected wastewater infrastructure cost present value =$45,000,000. Is this the best use of $$$?

43. Management is a Big Issue All I/A systems have O&M and sampling requirements Each system must have an operator, O&M contract →Follow up Systems must be inspected, usually quarterly, to ensure all components are operating properly → Follow up System water quality must be sampled, often quarterly, to ensure it meets required standards → Follow up System operators must report results to Boards of Health and DEP

44. I/A Management Issues People want to put these systems in the ground and forget about them, the way we’ve always been able to do with our Title 5 systems. Homeowners resist paying annual costs, so maintenance contracts lapse, O&M and sampling are not performed

45. Management for performance –Many systems do not always operate optimally and, unless followed up by Health Dept. staff, many operators seem to show little interest in re-visiting a system to adjust its performance. –Extra visits by the system operator to adjust system cost owners extra operator and lab fees. –Financial disincentive for operators to follow up poorly performing systems aggressively, for fear that extra costs will cause owner to contract with a less expensive operator.

46. Management Real estate transfer: –Current owner is required to notify buyer of presence of I/A system and associated O&M and sampling requirements. –Notification frequently does not occur, leaving buyers unhappy, resistant to complying with expensive requirements, in need of education about what is required of them.

47. Management Seasonally occupied homes –Estimate 40% of all systems county-wide are likely seasonal use –All technologies work by biological treatment of wastes. It takes at least 4-6 weeks after start up to bring the bacterial populations up to effective levels. –Full nitrogen reduction is not achieved until 4-6 weeks after seasonal start-up. –Difficult to follow up on systems that perform poorly, because season ends and house is closed

48. Management Is there adequate Health Department or other staff time to ensure systems –Have O&M contract –Are inspected –Are sampled as required –Are adjusted as needed to optimize performance A management plan is needed before committing to a large number of these systems

49. EPA guidance http://www.epa.gov/owm/septic/ pubs/onsite_handbook.pdf

50. Management Issues I/A treatment systems are performance based US EPA recommends that performance-based systems be operated and managed by Responsible Management Entity (RME)

52. US EPA management models 5 levels Barnstable County fits Level 4: “Areas of moderate to high environmental sensitivity where reliable and sustainable system operation and maintenance is required (sole source aquifers, wellhead or source water protection zones, critical aquatic habitats, and outstanding value resource waters)”. US EPA Recommends creation a Responsible Management Entity (RME) for Operation

53. Responsible Management Entity RME can be –Town wastewater district –Municipal operators –Regional wastewater district

54. Coming Soon! Barnstable County trial mini-management district 25 systems Standard operating procedures Standard sampling procedures Water use and occupancy data Active adjustment of poorly performing systems Better understanding of performance (i.e. does 19 mg/L TN =50% TN removal) Does use of SOPs improve performance?

55. Wastewater Planning How do I/A systems fit in with larger wastewater planning efforts in town? –Is the town in the process of creating a Comprehensive Wastewater Facilities Plan? –Where will I/A systems fit in this plan?

56. Town Wastewater Planning I/A System Benefits Some % nitrogen is removed These systems are available now May be good answer in areas –where sewering is too costly due to low housing density –sewering won’t happen in foreseeable future –for large developments in areas not intended for sewering

57. Town Wastewater Planning –A planned approach is better than installing systems randomly all over town. –For example: Will systems be used to remediate or prevent a problem in a specific area, in a planned way? Or will they be installed randomly when systems needing upgrades with variances come before the Board of Health? –Systems installed randomly will likely have little impact on improving groundwater nitrogen levels

58. Town Wastewater Planning Installation of I/A systems may preclude better wastewater solutions –Once owners have spent the money to upgrade their system to I/A, they are unlikely to support cost of sewering their neighborhood

59. Questions ? QUESTIONS?