City of Columbus Water Storage Tanks:

Transcription

1 City of Columbus Water Storage Tanks: Tank Maintenance and Engineering Controls that Improved Water Quality Ronald Christian: Plant Maintenance Supervisor I Michele Gilkerson: Water Research Analyst II

2 Legged tanks constructed in 1966 and 1980 Both 1 million gallon tanks Last legged tank constructed in the system

3 Joyce Tank was the Steel Tank Institute tank of the year in 1996 Standpipe construction

4 Hydro pillar has been the standard tank in the system since 1968 Typically construct a 2 million gallon tank Acquire enough land for future expansion

5 Water Storage Tanks

6 Booster Stations & Pumps

7 Pressure Reducing Valves

8 Tank Maintenance Electronic System Technicians Electricians Mechanics

9 Electronic System Technicians Calibrate tank levels Check cathodics Over-flow sensors Door alarms Antennas on tops of tanks Vents

10 Electricians Upgrades to electric service Aircraft lights Interior/exterior lights Service drops Vents

11 Mechanics Maintain and set tower water levels in summer and winter months Maintain altitude valves Exercise yard valves and get valve counts Maintain cleanliness of tanks(maintain bathrooms & entry doors) Maintain tank yard (litter pick-up, tree trimming, snow removal & driveway sealants)

12 Washouts Each tank gets washed out every 3 years Minimum of 7 people An average washout is 4 hours

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14 1 Electrician Climbs to the top replacing light bulbs Opens top hatch for light and airflow Check aircraft lights Checks top vent screens Documents coating conditions of roof

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16 1 Pumper Operator Stays at the pumper during the wash out Maintains fuel levels Maintains radio contact with the wash supervisor Raises and lowers pressure as needed

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18 1 Ground Man In charge of equipment layout and pick up Operates the flush and drain valves Maintains radio contact to complete duties as needed Documents valve counts, locations and number of turns

19 1 Condensate Man Raises equipment to the cat walk level Assists the ground man Climbs after wash out to assist in equipment retrieval

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21 Hose Operators 1 Electrician and 1 Mechanic Check air quality with monitor Opens belly hatch Sweep bowl with wash out brooms

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24 Wash Out Supervisor

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27 Wash in progress

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32 Exterior of Tank Log condition of fence, gate & coatings Check the foundation for cracks, missing grout & exposed rebar Look for exterior corrosion on anchor bolts, clevis & support rods Note the amount of fading and expected life expectancy

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34 Exterior of Tank Ladders on exterior of tank needs to be 8 ft from ground. Check the vandal guards on ladders Inspect ladders for missing rungs, corrosion & install a safety rail system Check screens on overflows 42 high handrails, mid rail required & 4 toe kick plate with ¼ gap max

35 Exterior of Tank Roof man ways on legged tanks should be locked Condensate level areas on hydros should be locked Check exterior top hatches for corrosion check vents, aircraft lights Check screens for holes

36 Coatings Program NACE Coatings Level III SSPC QP I & II

37 Anniversary Inspection

38 Fail Spot

39 Structural Repairs BEFORE AFTER

40 Structural Repairs

41 Helpful Tips

42 Helpful Tips When negotiating cell towers or anything else mounted on tanks put in the contract that the company will disassemble when it is time to paint Painters rings mounted to ceiling 20 ft apart Seam weld not stitch welding Spec fiberglass grating

43 Helpful Tips Have the paint representative give a good estimate of the amount of paint needed and request that the contractor keep all empty containers Ladders are for climbing. Do not attach anything to them Ask landscape crew to blow off the tank when they blow off the driveways

44 Helpful Tips Schedule 80 or SS wash line the best for corrosion control 4 mud valves should be installed

45 Water Quality

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47 Distribution Monitoring Panels

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51 Joyce Avenue Tank Water Quality Profile Attendants: Jeff Kauffman, Duane Stokes, Michele Humphrey, Matt Steele, Claudine Pekula, Rich Rutherford, Bic Boyles April 12, 2007 Sampling 9:45 and 11:45; Depth is given as feet below surface; Total depth was ~ 55 feet; Total volume was ~ 3.85 MG Center of Tank Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 Turbidity TTHM HAA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) (NTU) ( g/l) ( g/l) Surface Approximate dead zone (no chlorine) is 0.8 MG and approximate water age is 6 weeks. Sidewall of Tank (near drywell) Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 Turbidity TTHM HHA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) (NTU) ( g/l) ( g/l) Bottom Middle Surface Data from Online Panel in adjacent Booster Station Temp Conductivity ph Free Cl 2 Turbidity Comments (C) ( S/cm) (mg/l) (mg/l) (NTU) Flow was bypassing the tank

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53 Valve Installed

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56 Joyce Avenue Tank Water Quality Profile Attendants: Michele Humphrey, Matt Steele, Rich Rutherford, Bic Boyles, Rod Dunn, Ron Christian August 29, 2012 Sampling 9:00 and 11:30; Depth is given as feet below surface; Total depth was ~ 60.0 feet; Total volume was ~ MG Center of Tank Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 Turbidity TTHM HAA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) (NTU) ( g/l) ( g/l) Surface Sidewall of Tank (near drywell) Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 Turbidity TTHM HHA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) (NTU) ( g/l) ( g/l) Bottom Middle Surface

57 Mixing Systems

58 Mixing Systems for Water Tanks Currently have two types of mixing systems active and passive First mixing system installed in 2006 Currently 7 mixing systems in the system 4 passive and 3 active Evaluated several products through the years Solar, air, manifold systems, standpipes, motorized

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60 Lazelle (South)Tank Water Quality Profile Attendants: Michele Humphrey, Rod Dunn, Duane Stokes and Greg Horn September 26, 2012 Sampling 9:00 and 11:30; Depth is given as feet below surface; Total depth was ~ 60.0 feet Center of Tank Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 TTHM HAA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) ( g/l) ( g/l) Surface

61 Lazelle (North)Tank Water Quality Profile Attendants: Matt Steele, Bic Boyles, Tim Huffman, Greg O'Brien September 26, 2012 Sampling 9:00 and 11:30; Depth is given as feet below surface; Total depth was ~ 60.0 feet Center of Tank Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 TTHM HAA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) ( g/l) ( g/l) Surface Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 TTHM HHA5 Comments Next to the Mixer (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) ( g/l) ( g/l) 50' Surface

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63 Taylor East Tank(2MG) Water Quality Profile Attendants: Duane Stokes, Rod Dunn, Cindi Fitzpatrick and Greg Horn October 16, 2013 Sampling 9:45 and 10:45; Depth is given as feet below surface; Total depth was ~ 40 feet; Total volume was ~ 10 MG Center of Tank Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 TTHM HAA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) ( g/l) ( g/l) Surface Over flow 985.5' Water level 983'. 2.5' down Sidewall of Tank Depth Temp Conductivity Dissolved Oxygen ph Free Cl 2 TTHM HHA5 Comments (ft) (C) ( S/cm) (mg/l) (mg/l) (mg/l) ( g/l) ( g/l) Bottom ' Middle ' Surface

64 Questions?