Limitation of Investigation 

A hands-on, visual inspection was performed on site of the steel water tank. This  inspection was limited to the exterior of the steel tank. The tank was inspected in as-is condition.  The tank currently serves as the only functioning tank providing drinking water to the community  of the Town of Ft. Myers Beach, Florida. As such, at the time of inspection, the tank could not be  drained and emptied to allow for proper inspection. However, personnel from Vetor Contracting  Services performed a preliminary dive inspection of the interior of the tank to determine the  condition and amount of deterioration and corrosion. The preliminary dive inspection included video footage of the interior tank which was reviewed by Cronin Engineering. In addition, Cronin  Engineering spoke with the divers to better ascertain the actual condition of the interior of the tank.  Cronin Engineering has reviewed the previous inspection report prepared by Liquid Engineering  Corporation. Engineering plans of the steel tank and foundation were not available at the time of  the inspection. 

Observations 

During the inspection, vegetation growth was observed and present at the base of the tank between the steel flange and concrete foundation as shown in Figures 3 and 4. In small, random  areas, the paint is flaking off the concrete foundation on the top surface. Deterioration and section  loss were observed on the circumferential weld at the based of the steel tank. See Figure 5. In  addition, impacted rust on the underside of the steel tank flange and the concrete foundation was  observed. Rusting coming through the paint was also evident on the steel tank flange. A crack on  top of the concrete foundation was visible as shown in Figure 6. At the base of the exposed anchor  rod connection of the steel tank to the concrete foundation, there was up to 50% section loss due  to corrosion as shown in Figures 7 and 8. These anchor rods are approximately 1½” diameter in  size. At a connection of an anchor rod, there was deterioration and section loss at the base of the  nut as observed in Figure 9. There was up to 25% section loss and deterioration at the base of the  nut on hinge connection to the manhole access door. See Figures 10 thru 12. An emergency repair  of approximately 1/4” by 12” by 12” in size steel plate was observed on the steel tank at the base  as shown in Figure 13.  

On the exterior, steel access ladder, there were random areas of rust and corrosion  throughout. See Figures 14. On the exterior steel wall of the tank, there were areas of rust staining  that was running down the sides from the top. Rust and corrosion with section loss at top of the  tank along circumferential weld at dome connection was observed. This condition occurs every  couple to several feet along the weld around the tank. See Figures 15 and 16. Rust and  deterioration of weld on side of the steel tank as shown in Figure 17. Rust with areas of section  loss on connections of inlet pipe on side of the steel tank as shown in Figure 18. Rust and  deterioration of bolts on top of dome of the tank as shown in Figure 19. Rust and corrosion on all  surfaces around the hatch access door opening on top of the steel tank. See Figure 20.

Tank Interior – Preliminary Dive Inspection 

Significant signs of rust, deterioration and section loss was observed on the welds o on the  interior of the tank. Section loss and pitting was observed on the interior surfaces of the steel tank.  The interior tank ladder was missing requiring the diver to be lowered into the tank using a winch  type device for safety purposes. The interior exhibited signs of deterioration on the bottom of the  tank and sides. Also, on the bottom of the tank, there had been pooling of chlorine, rust, sand, grit,  and tank debris from deterioration. See Figures 21 and 22.  

Recommendations 

Overall, the condition of the tank was in fair to poor condition. This is based on conditions  observed on site regarding the condition of the protective paint and active corrosion and  deterioration on exterior and interior tank. Recommendations are provided herein so emergency  repairs may be performed until a proper inspection of the interior of the steel may be performed.  These recommendations are based on our investigation and the previous inspection report by  Liquid Engineering Corporation. Immediate repairs include the following items. 

1. ‍‍An immediate repair was performed on a vertical weld at 18” from the base  of the north side of the steel tank. This included welding a repair plate that was 12” by  12” by ¼” thick as shown in Figure 13. Vetor has performed this emergency repair. 
2. Install a like material, such as Aquatapxy A-6 thick, to all heavily corroded  welds that are within reach on the in the interior of the steel tank. Vetor has performed  this emergency repair. 
3. Coat external fillet welds made on the exterior welded repair plate with like  product such as Aquatapxy A-6 thick after inspected by field engineer. Vetor has  performed this emergency repair with oversight from Cronin Engineering. 
4. Determine the depth or thickness of the reinforced concrete foundation. Core  drill the 2” diameter hole to a depth based on the determination of the concrete slab (a  minimum embedment depth minimum of 10”). Replace all deteriorated steel rods as  determined by the engineering in the field with new 1½” diameter stainless steel rods. 
5. Install the stainless-steel rods to the concrete slab with EM5-2 Gel Epoxy or like  product. The new stainless-steel rods are to be placed in the middle of all existing  deteriorated steel rods. Install gussets plates as needed to attach the new stainless-steel  rods to the existing steel tank. Remove all deteriorated steel rods. 
6. Empty contents of tank and perform a full inspection of the interior and  exterior of the steel tank within six (6) months of the date of this report. Based on the  age of the steel tank and the full inspection of the tank, there could be a  recommendation to replace the steel tank with a new tank at that time. 
7. For safety compliance and access, obtain and have available on site at all  times an aluminum ladder that can extend from the bottom of the tank to three (3) feet  above the top access port.

‍