Summary
A three person crew spent less than one day cleaning and inspecting both storage tanks. They also checked the cathodic protection systems in both tanks. No issues were found that need correction. Work was done by:
CW Divers/CWD Services Inc.
903 N. Watson
Farmington, NM 87401
Bill Donohue
cwdivers [at] msn [dot] com
505-327-2830
505-330-2531 (cell)
Note that CW Divers reversed the two tank numbers. In their material, they refer to the larger tank as #1 which we refer to is as #2.
Preparation
The two tank drains, overflows, and the tank site storm drain all feed into one drain pipe that comes out in the arroyo NE of the tank site, above the Cienega Canyon Road cul de sac in Ranchos de Placitas. To avoid water flowing down the arroyo and washing mud onto the cul de sac, Phil put a flange with reducers on the end of the drain pipe. Before the divers started, he connected fire hoses and ran them down the arroyo and across the cul de sac.
Process
The setup brought in by CW Divers included a trailer with all their equipment, including air compressors, generator, etc. Inside is a station with video and audio links to the diver.
Rather than using a pump (with accompanying hoses) to clean sediment, they used a steel plate, about one foot in diameter with a cam lock hose connection attached to a hose with vacuum head. The diver put the plate over the tank drain pipe, and the tank drain valve was slowly opened, sealing the plate to the drain. Then sediment was pulled through the hose and down the drain pipe all the way to the discharge at the Cienega Canyon Road cul de sac.
(Click on any photo to enlarge.)
Tank #1 (100,000 Gallons)
- Report on Tank #1
- Video of Tank #1 Cleaning
- Video of Tank #1 Inspection
- Video of Tank #1 Recommendations
Tank #2 (200,000 Gallons)
- Report on Tank #2
- Video of Tank #2 Cleaning
- Video of Tank #2 Inspection
- Video of Tank #2 Recommendations
Learning for next cleaning
Before putting substantial water down the drain pipe, flush it out and make sure there is free flow all the way through the fire hoses. When we started the November 2020 cleaning, a small bottle cap that probably washed down the storm drain caused blockage at a hose fitting, and the drain pipe backed up all the way to the storm drain.
Make sure to have a drawing of the site, showing the tanks and all the valves and piping.