city of columbus’ water storage tanks...city of columbus’ water storage tanks: tank maintenance...

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

• Legged tanks constructed in 1966 and 1980

• Both 1 million gallon tanks

• Last legged tank constructed in the system

• Joyce Tank was the Steel Tank Institute tank of the year in 1996

• Standpipe construction

• 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

Water Storage Tanks

Booster Stations & Pumps

Pressure

Reducing

Valves

Tank Maintenance

• Electronic System Technicians

• Electricians

• Mechanics

Electronic System Technicians

• Calibrate tank levels

• Check cathodics

• Over-flow sensors

• Door alarms

• Antennas on tops of tanks

• Vents

Electricians

• Upgrades to electric service

• Aircraft lights

• Interior/exterior lights

• Service drops

• Vents

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)

Washouts• Each tank gets washed out every 3

years

• Minimum of 7 people

• An average washout is 4 hours

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

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

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

1 Condensate Man

• Raises equipment to the cat walk level

• Assists the ground man

• Climbs after wash out to assist in

equipment retrieval

Hose Operators

• 1 Electrician and 1 Mechanic

• Check air quality with monitor

• Opens belly hatch

• Sweep bowl with wash out brooms

Wash Out Supervisor

Wash in progress

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

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

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

Coatings Program

NACE Coatings Level III

www.nace.org

SSPC QP I & II

www.sspc.org

Anniversary Inspection

Fail Spot

Structural Repairs

BEFORE AFTER

Structural Repairs

Helpful Tips

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

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

Helpful Tips Schedule 80 or SS wash line the best for corrosion

control

4” mud valves should be installed

Water Quality

Distribution Monitoring Panels

Depth Temp Conductivity Dissolved Oxygen pH Free Cl2 Turbidity TTHM HAA5 Comments

(ft) (C) (S/cm) (mg/L) (mg/L) (mg/L) (NTU) (g/l) (g/l)

Surface 10.3 381 11.1 7.5 0.00 0.2 59.4 77.3

2.5 10.3 382 11.0 7.2 0.00 0.8

5.0 10.6 383 10.9 7.6 0.06 0.5 60.9 80.6

7.5 10.5 383 11.0 7.6 0.03 1.2

10.0 10.5 382 11.0 7.6 0.05 1.9 57.3 78.4

12.5 10.4 383 11.0 7.7 0.20 1.1

15.0 10.5 383 10.9 7.5 0.07 1.8 61.6 78.0

17.5 10.4 381 11.0 7.6 0.40 0.3

20.0 10.4 382 11.0 7.6 0.42 0.2 58.6 78.1

22.5 10.5 384 10.9 7.5 0.43 0.2

25.0 10.3 383 11.0 7.5 0.41 0.3 59.9 78.4

27.5 10.4 384 11.0 7.6 0.44 0.2

30.0 10.3 384 10.9 7.5 0.43 0.2 65.7 77.7

32.5 10.4 385 11.0 7.5 0.40 0.2

35.0 10.3 385 11.0 7.6 0.30 0.5 58.6 78.7

37.5 10.2 386 11.0 7.6 0.42 0.3

40.0 10.2 392 11.0 7.6 0.42 0.3 60.3 75.8

42.5 10.1 399 11.0 7.5 0.49 0.3

45.0 10.1 399 11.0 7.5 0.49 0.4 48.6 65.6

47.5 9.9 423 11.1 7.6 0.67 0.3

50.0 9.6 446 11.2 7.7 1.05 0.3 48.4 62.1

Depth Temp Conductivity Dissolved Oxygen pH Free Cl2 Turbidity TTHM HHA5 Comments


Bottom 9.5 445 11.2 7.7 0.43 0.5 58.5 45.0

Middle 10.1 383 11.1 7.7 0.38 0.3 59.9 78.9

Surface 10.2 381 11.0 7.6 0.40 0.5 43.1 76.4

Temp Conductivity pH Free Cl2 Turbidity Comments

(C) (S/cm) (mg/L) (mg/L) (NTU)

10.6 438 7.3 1.51 0.07

Profile @ Center of

Tank

Flow was

bypassing the tank

Joyce Avenue Tank Water Quality Profile

Sampling began @ 9:45 and ended @ 11:45; Depth is given as feet below surface; Total depth was ~ 55 feet; Total volume was ~ 3.85 MG

Attendants: Jeff Kauffman, Duane Stokes, Michele Humphrey, Matt Steele, Claudine Pekula, Rich Rutherford, Bic Boyles April 12, 2007

Approximate dead

zone (no chlorine)

is 0.8 MG and

approximate water

age is 6 weeks.

Data from Online

Panel in adjacent

Booster Station

Profile @ Sidewall of

Tank (near drywell)

Valve Installed…

Depth Temp Conductivity Dissolved Oxygen pH Free Cl2 Turbidity TTHM HAA5 Comments


Surface 0.49 70.9 34.3

2.5 26.2 615 8.9 7.2

5.0 26.3 611 8.5 7.3 0.20 75.2 33.4

7.5 26.1 610 8.9 7.2

10.0 26.3 610 8.7 7.2 0.08 74.4 33.9

12.5 26.1 609 8.7 7.2

15.0 26.2 610 8.2 7.2 0.15 74.2 34.4

17.5 26.1 613 8.8 7.2

20.0 26.3 609 8.1 7.2 0.22 74.4 32.7

22.5 26.1 616 8.7 7.2

25.0 26.4 612 8.0 7.3 0.43 71.5 34.2

27.5 26.1 617 8.7 7.2

30.0 26.2 614 7.9 7.4 0.42 81.9 32.4

32.5 26.1 616 8.7 7.3

35.0 26.2 616 7.9 7.4 0.64 63.2 31.6

37.5

40.0 26.2 619 7.9 7.4 0.68 70.4 33

42.5

45.0 26.2 619 7.9 7.4 0.79 66.4 32.9

47.5

50.0 26.1 620 8.0 7.3 0.17 66.7 30.9

52.5

55.0 26.0 623 7.9 7.2 0.47 65.6 34

57.5

60.0 26.1 640 8.4 7.4 0.52

Depth Temp Conductivity Dissolved Oxygen pH Free Cl2 Turbidity TTHM HHA5 Comments


Bottom 26.3 612 8.6 7.5 0.09 70.1 32.4

Middle 26.3 619 8.6 7.4 0.75 66.6 32.1

Surface 26.3 613 8.6 7.4 0.64 66.3 33.0

Profile @ Center of

Tank

Joyce Avenue Tank Water Quality Profile

Sampling began @ 9:00 and ended @ 11:30; Depth is given as feet below surface; Total depth was ~ 60.0 feet; Total volume was ~ MG

Attendants: Michele Humphrey, Matt Steele, Rich Rutherford, Bic Boyles, Rod Dunn, Ron Christian August 29, 2012


Tank (near drywell)

Mixing Systems

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

Depth Temp Conductivity Dissolved Oxygen pH Free Cl2 TTHM HAA5 Comments

(ft) (C) (S/cm) (mg/L) (mg/L) (mg/L) (g/l) (g/l)

Surface 19.7 280 8.2 7.3 0.70 69.8 42.2

5.0 19.7 280 8.1 7.4 0.80 64.6 41.7

10.0 19.6 280 8.0 7.4 0.81 66.0 41.2

15.0 19.6 280 8.4 7.4 0.86 68.8 42.7

20.0 19.6 280 8.5 7.2 0.92 62.5 41.2

25.0 19.6 280 8.7 7.1 0.59 64.0 44.0

30.0 19.6 280 8.3 7.0 0.40 62.1 40.7

35.0 19.5 281 8.6 7.0 0.26 59.7 40.4

40.0 19.5 284 8.4 6.8 0.04 65.0 40.0

Lazelle (South)Tank Water Quality Profile

Attendants: Michele Humphrey, Rod Dunn, Duane Stokes and Greg Horn September 26, 2012

Sampling began @ 9:00 and ended @ 11:30; Depth is given as feet below surface; Total depth was ~ 60.0 feet

Profile @ Center of

Tank



Surface 19.4 293 8.6 7.6 0.92 58.3 38.0

5.0 19.4 293 8.7 7.5 0.95 54.1 38.3

10.0 19.4 294 8.9 7.6 0.97 64.6 36.3

15.0 19.4 294 8.8 7.6 0.84 66.0 37.5

20.0 19.4 294 8.8 7.6 0.91 55.3 37.3

25.0 19.4 294 8.7 7.5 0.83 58.4 39.1

30.0 19.4 293 8.7 7.6 0.93 60.6 37.7

35.0 19.4 294 8.3 7.5 0.89 57.5 39.3

40.0 19.4 294 8.4 7.7 0.71 58.2 38.4

45.0 19.4 302 8.5 7.6 0.78 58.7 38.5

Depth Temp Conductivity Dissolved Oxygen pH Free Cl2 TTHM HHA5 Comments


50' 19.4 302 8.7 7.6 0.85 55.6 41.1

Surface 19.4 294 8.8 7.6 0.88 54.7 38.0

Next to the Mixer

Profile @ Center of

Tank

Lazelle (North)Tank Water Quality Profile

Sampling began @ 9:00 and ended @ 11:30; Depth is given as feet below surface; Total depth was ~ 60.0 feet

Attendants: Matt Steele, Bic Boyles, Tim Huffman, Greg O'Brien September 26, 2012



Surface 18.7 269 7.7 7.5 0.80 62.6 50.8

15.0 18.7 269 7.9 7.4 0.75 61.5 52.5

20.0 18.7 269 7.9 7.4 0.61 67.2 52.4

25.0 18.7 268 7.9 7.4 0.82 58.5 50.8

30.0 18.6 269 8.7 7.3 0.89 60.8 51.8

35.0 18.5 269 8.6 7.1 0.83 57.6 51.7

40.0 18.6 270 8.7 7.1 0.72 52.8 51.6

45.0 18.8 273 8.8 7.1 0.81 55.8 51

Depth Temp Conductivity Dissolved Oxygen pH Free Cl2 TTHM HHA5 Comments


Bottom 18.6 266 7.8 7.4 0.80 60.9 49.3 30'

Middle 18.6 269 7.9 7.4 0.85 55.6 52.3 15'

Surface 18.6 269 7.7 7.5 0.75 56.2 51.3

Profile @ Center of

Tank

Taylor East Tank(2MG) Water Quality Profile

Sampling began @ 9:45 and ended @ 10:45; Depth is given as feet below surface; Total depth was ~ 40 feet; Total volume was ~ 10 MG

Attendants: Duane Stokes, Rod Dunn, Cindi Fitzpatrick and Greg Horn October 16, 2013

Over flow 985.5'

Water level 983'.

2.5' down


Tank

Questions?