Taylor Creek Treatment Plant. Metropolitan Sewer District of Greater Cincinnati

Transcription

1 Taylor Creek Treatment Plant Metropolitan Sewer District of Greater Cincinnati

2 Who is this guy and what is he talking about? Brad Blankenship Taylor Creek Operator 3.5 years MSD Operator 5.5 years (total) Topics Taylor Creek Overview Taylor Creek s Future Taylor Creek s Operational Challenges Taylor Creek s First Violation

3 Taylor Creek Treatment Plant Completed in 1992 Started treatment in 1997 Platinum Award Winner (through 2014) Replacement for several package plants 2.5 MGD average flow (2015) Extended aeration plant Sanitary collection system Staff Operations (2); Maintenance (6); Truck Driver (1)

4

5 TCTP Drainage Basin Colerain Township Green Township Whitewater Township Miami Township

6

7 Influent Pumping Wesselman Pump Station Located ¼ mile from the plant Provides 90% of influent flow 10 MGD maximum pumping capacity 4 submersible raw sewage pumps MGD pumps (non VFD) 2-5 MGD pumps (non VFD)

8

9 Influent Pumping Miamitown Pump Station Completed in 2008 On site Provides 10% of influent flow Room for expansion 0.92 MGD capacity 2 submersible raw sewage pumps 0.46 MGD per pump (max)

10

11 Preliminary Fine Screens 2 Headworks automated fine screens 8.46 MGD each Conveyor system for removal 3 cubic yard dumpsters are used for storage Bar Rack 10 MGD

12 Preliminary Grit and Skims Aerated grit chamber / skim trough Traveling bridge Grit classifier 3 cubic yard dumpsters are used for storage

13

14 Preliminary Recycle Well and Pumps Main Drain Well and Pumps Influent Sampling Sampling occurs downstream of the recycle and main drain pumps

15 Secondary Aeration basins million gallons per tank Rotating bridge (rim drive) design Blowers 3 125HP multistage centrifugal blowers Manufacture: Lampson 2 computer controlled; 1 manual controlled

16

17

18 Secondary Secondary Settling 2 1 million gallon tanks Rotating bridge design (rim drive) Return Activated Sludge 3 screw pumps 2,390 GPM (3.44 MGD) capacity per pump Non-VFD

19

20

21 Ultraviolet Radiation 2 banks 80 bulbs per bank PLC controlled Trojan 3000 plus Banks are setup in series Post Aeration Cascade Effluent Sampling Disinfection

22

23

24 Sludge Handling Waste Batch wasting Typical wasting 90, ,000 gallons per day Average 8,000 mg/l WAS Batch size is determined by MXL-SS and RAS-SS MXL target Activated by a SCADA controlled valve on a timer Wasting is accomplished by gravity and supplemented by pumps if needed

25 Solids Handling Holding Tanks 2 90,000 gallon tanks 2 automatic floating decanters Siemens Auma valve Level sensors PLC control; No SCADA (future)

26

27

28

29

30 TSS (mg/l) TSS Influent

31 Secondary Characteristics Summer MXL: mg/l SVI: Sludge Age: Days Winter MXL: mg/l SVI Sludge Age: Days

32 Effluent TSS < 3 mg/l 98.5% removal ph: BOD < 4 mg/l 99% removal Fecal Coliform: < 200 colonies per 100ml Ammonia 1.6 mg/l

33 Operational Challenges Rim Drive Snow causes drive wheel to lose traction Aerating ¼ of the basin Maintenance on a rotating arm Can become frozen to the ground Has more moving parts

34 Operational Challenges

35

36

37

38 Operational Challenges Screw RAS Pumps No flow meters Difficult to determine flow Emergency power does not support RAS pumps The new generator for Miamitown Pump Station (on site) is large enough to power the whole plant but it not connected

39

40 Operational Challenges Influent Sampling Sampling occur after main drain and recycle pump discharge Inaccurate influent characteristics Personnel Staffed 8 hour per day; 5 days per week Monitored nights and weekends from MCTP (30 minutes away)

41 TSS (mg/l) TSS Influent

42 Operational Challenges Rollercoaster Flows Caused by RSP without VFD s Varying loading rates Varying UV contact time Multiple on/off equipment cycles

43

44 Operational Challenges UV Banks in Series in One Channel Multiple channels needed during high flow

45 Operational Challenges Floating Decanters Freeze in the winter No SCADA control (future) Sludge clogs decanters causing them to float above the water line

46

47 Operational Challenges Aeration Influent Gate Valves Controls flow into each aeration basin Opens to offline tank during high flow periods Controlled by flow (influent or effluent) Failures are disastrous Too much flow to one secondary train Wastewater backs up into preliminary Causes flooding of tanks, screens, clarifiers, and recycle well Flooding spills onto grass, gulley, and driveway

48

49 TCTP Future Expected to have tightened permit limits NH 3 Current average: 1.6 mg/l (see graph) Addition of new permit items Phosphorus Current average: 3.23 mg/l (see graph) E. coli Currently not monitored Fecal Coliform tested

50 mg/l NH

51 mg/l Total Phosphorus Total Phosphorus

52 TCTP Future Expected increase in flow Current average flow: <2.5 MGD 20 year projected flow (2038): 3.0 MGD Original 20 year design flow from 1993: 5.5 MGD

53 TCTP Future Convert one aeration basin to a BNR tank Utilize the other aeration basin as a surge basin Upgrade RAS to centrifugal pumps Upgrade SCADA (in progress) Add UV s to multiple channels Automate gate valves (in progress)

54 The First Permit Violation (and how it s mostly not my fault) During the month of March in 2015 TCTP had its first permit violation The ammonia level exceeded the weekly limit of 10.5 (average) All other violations were avoided (barely)

55 Permit Violation Week 1 (no violation) Grit and skim collection is offline/broken Clarifier #1 is frozen in place Aeration #1 is down Fixed by weeks end Major snow melt along with a major rain event coincide Aeration #2 breaks Causes a tank change during peak flow Both aeration basins become filled quickly but only #1 is online Operator (me) takes off for the birth of his son

56 Born 8:58pm Weight 9lbs 10oz Length 22 inches Likes: Naps, Eating, Water, Car Rides, Tom and Jerry, and Screaming at Dad Dislikes: Mornings, Doctors, St. Louis Cardinals, and Sleeping on a Schedule

57 Permit Violation Week 2 (no violations barely) Low solids content in aeration #1 Low solids content in RAS Clarifier #1 is put online by weeks end Aeration #2 (still down) is drained for maintenance Contributing to higher flows Operator is off until Thursday Ammonia is rising!

58 Permit Violation Week 3 (Violation Week) High flow continues Plant reseeded from Polk Run MXL and RAS are starting to build up Ammonia violation Aeration #2 is still draining (still offline) Aeration #2 was filled a few times during wet weather events

59 Permit Violation Week 4 Monday RAS solids are low but #1 clarifier has a heavy blanket #2 clarifier has no blanket Clarifiers are put on separate RAS pumps #2 RAS was suppressing #1 RAS from coming up to the common well Grit and grease may have partially clogged the RAS line for #1 clarifier Since TCTP is only staffed 5 days per week no one was able to catch this in time Returning sludge from aeration #1 into both aeration basins

60 Permit Violation Week 4 MXL becomes too high by Wednesday Wasting and hauling are increased Effluent became worse (NH 3 and SS) before it improved Plant is back to normal by the end of the week

61 Permit Violation Lessons Learned Check both sludge blankets every day Scheduled an operator to check TCTP during off hour (wet weather) Don t take off for the birth of a child (or take off more time to avoid all the blame) Increase preventative maintenance techniques for aeration basin rim drives Thaw tanks in advance to prevent freezing Move solids to holding tanks temporarily

62 Preventing a Future Violation Running both treatment trains during wet seasons Hired more operators to help cover shifts Increased predictive maintenance techniques Increased training for the West section

63 Questions?