Diagnosing Performance. Mark Gross, Ph.D., P.E.

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1 Diagnosing Performance Mark Gross, Ph.D., P.E. Troubleshooting 17 May 2010

2 Diagnosing Poor System Performance

3 First Things First Water usage? Residential Strength Wastewater? System location? Condensate, sump pump, downspout, etc. going into system? Then. System Diagnostics

4 Water usage? Water meter? Turn off water and check for pressure drop

5 Residential Strength Wastewater?

6 System location? In a hole? Under a downspout?

7 Condensate, sump pump, downspout, water softener regenerate going into system?

8 Starting Point for Diagnostics Turbidity less than 15 NTU s Dissolved Oxygen between 4 and 6 mg/l ph 6 to 8

9 Primary Treatment Won t Work If... Tanks aren t watertight Tanks aren t large enough to... Settle the sludge Float the scum Digest the wastewater

10 Secondary Treatment Won t Work If... Treatment unit doesn t provide enough air and time to... Decompose organics Transform ammonium nitrogen to nitrate

11 Two Basic Needs for Successful Treatment Watertightg tanks fittings connections Air In the drainfield In the media filter In the Activated Sludge Unit

12 Symptoms of Leaking Tanks and Connections High water alarms Surfacing water over soil absorption systems Low water alarms Excessive pump p run times Excessive pump cycle times

13 Leaks in the Riser Connection Leak around the riser connection This is a concrete culvert set on top of a concrete tank No sealant between riser and tank Note the iron stains and water on top of the tank

14 Leak Around the Tank Outlet Leak in the tank penetration Note the 2 X 4 enlarger fitting Four-inch pipe through the tank sidewall This was sort of grouted around the tank outlet When you pulled on the outlet pipe, it wiggled around in the outlet penetration hole QuickTime and a decompressor are needed to see this picture.

15 This System Has Never Been Used

16 Tree Roots in Septic Tank

17 Tree Roots in the Septic Tank

18 Overflowing peat filter Tank leaked around the riser and the pump dosed the excess water to the filter

19 Same Peat filter The water level had been over the tops of the distribution ib ti piping Caused by leaking riser Surfacing Effluent QuickTime and a decompressor are needed to see this picture.

20 Top seam inside tank Tank was from a manufacturer certified by Department of Health for making watertight tanks

21 Fixed Film Treatment Atmospheric air has 275 mg/l oxygen

22 No Air in the Drainfield Serial distribution Initial long-term acceptance rate was relatively good After 3 years of operation, the LTAR slowed This mass of slime came from the drainfield lateral After 2 summers of resting (summers only), these laterals recovered the LTAR to within nearly 85% of original QuickTime and a decompressor are needed to see this picture.

23 No Air in the Drainfield Tight soil, no way to move air into it The OD in BOD stands for Oxygen Demand.

24 No Air to Media Filter Odors, poor performance, high turbidity effluent Testing showed little or no air movement Added d a venturi aerator and a larger pump Increased aeration and aerosols on orifice shields solved the problem No more odors, good performance, low turbidity

25 No Air to Media Filter

26 Venting? Not Really

27 Smoke Testing No smoke came out the roof stack vents

28 Old Tank Left in Line During Repair Filled with solids and plugged air flow

29 Unit Processes for Wastewater Treatment Primary Aeration Final Sedimentation Sedimentation Grit and Gross Solids Removal Primary Sludge and Scum Return Sludge Waste Sludge Disinfection

30 QuickTime and a decompressor are needed to see this picture. Individual Home Activated Sludge Plant Have to manage Food to microorganism ratio Sludge age If not, the BOD will not be removed The sludge will not settle properly Aeration Chamber Final Clarifier

31 Failure to Manage Biosolids in Activated Sludge Biosolids were not managed Burped over into discharge

32 Solids That Wash Out of the ATU Get Carried Into the Distribution System and Soil

33 Need to Close and Bolt the Lids In addition to having extra creatures living in the media the air flow can be short-circuited and not move through the media properly

34 Electrical Connections Splice Box Wire nuts Wire size Control panel Floats

43 Polyethylene tank used for a pump tank On the approved products list in this state still with no restrictions 32 of these tanks were installed in the same subdivision 32 tanks collapsed No tanks covered under the tank warranty

47 Is This System Okay? Yes, effluent testing showed that it was producing highquality effluent

48 Water Softener Regenerate

49 Water Softener Regenerate

50 Water Softener Effect Inside Chamber

51 Water softener regenerate Trench bottom media in system Receiving water softener backwash

52 Solutions for Decentralized Wastewater Treatment Orenco Systems, Inc.

Pump Tank and Pretreatment Inspection & Troubleshooting. Sara Heger University of Minnesota

Pump Tank and Pretreatment Inspection & Troubleshooting Sara Heger University of Minnesota sheger@umn.edu Evaluate Presence of Odor Odors are improper venting Check seals Lid Conduit Tank Access a. Access