Painting 23 Acres of Steel Water Tanks

46 Pages·2008·3.89 MB·English

Painting 23 Acres of Steel Water
Tanks
Jerry Duppong, Corrosion Specialist, CH2M HILL
Brigitte McCarty, Project Manager, AWWD
Matt Leach, Construction Manager, CH2M HILL
Project Description
(cid:127) Painting and structural modifications
(cid:127) Two projects
(cid:127) Schedule A
– Canyon Park (3 MG)
(cid:127) Schedule B
– Reservoir No. 2 (28 MG)
– Reservoir No. 3 (20 MG)
Predesign Activities
(cid:127) Record review
– Dimensions
– Construction components
– Type of paint and repaint dates
(cid:127) Visual Observations
(cid:127) Physical Testing
– Metal thickness
– Paint thickness
– Metal content
Schedule A – Canyon Park
(cid:127) 3 MG ground level steel
tank
(cid:127) 72 feet diameter, 92 feet
tall at center
(cid:127) 1982 construction
(cid:127) Self supporting steel roof
(cid:127) 60,000 sq ft (interior and
exterior)
(cid:127) Impressed current
cathodic protection
Canyon Park Interior
(cid:127) Coal tar enamel (wall
and floor)
– Up to ½-inch thick
– Fair to poor adhesion
– Water behind coating
– Low lead levels
(cid:127) Coal tar solution
(roof)
– Nominal 16 mils thick
– Very poor condition
Canyon Park Exterior
(cid:127) Zinc primer, aluminum alkyd finish
(cid:127) Original paint (no recoat)
(cid:127) Relatively good condition on wall
(cid:127) Poor condition on roof (rust in places)
(cid:127) 3 to 5 mils thick
(cid:127) Lead content 3.6%
Schedule B - Reservoirs 2 and 3
(cid:127) Reservoir 2
– 28 MG ground level steel tank
– 370 feet diameter, 45 feet high at center
– 1968 construction
(cid:127) Reservoir 3
– 20 MG ground level steel tank
– 370 feet diameter, 37 feet high at center
– 1976 construction
(cid:127) 930,000 square feet, interior and exterior
(cid:127) Impressed current cathodic protection systems
Reservoirs 2 and 3, Canyon Park
© Google
Reservoir 2 Interior
(cid:127) Coal tar enamel (wall
and floor)
– 50 to 300 mils thick
– Puddles
– Fair to good adhesion
(cid:127) Coal tar solution
(ceiling)
– Very poor condition
– Rust on ceiling
(cid:127) Low levels of lead
Reservoir 2 Exterior
(cid:127) Lead based primer,
aluminum alkyd
finish
(cid:127) Topcoated in 1992
(cid:127) Good adhesion
(cid:127) Nominal thickness of
6 mils
(cid:127) Lead content 20%