ILLUSTRATIVE SAMPLE. The data, tank and findings below are example values that show the format and depth of a condition report. They do not describe a real tank, and client and site details are redacted. Your report reflects your tank, the agreed scope and the inspector’s findings.

Tank Condition Assessment Report

Sample Tank T-1: Bolted Steel Potable Water Storage

Owner: Redacted Water Authority
Site: Redacted, OH
Tank: Bolted epoxy-coated steel, aluminum geodesic dome
Size: 52 ft dia × 32 ft high, approx. 508,000 gal
Built: 2007 (19 years in service)
Inspected: Out of service, drained and washed down
Report no.: SAMPLE-0001

Bolted steel storage tanks used to illustrate the sample report

1Executive summary

FAIR

Serviceable with priority repairs.

Shell and roof in good structural condition. Localized floor pitting and seam sealant deterioration in ring 1 need action within six months.

The shell retains at least 90% of nominal wall thickness at every reading, and the upper three rings show negligible loss. The highest wall loss, 21% at a single location, was measured in the floor within roughly 8 ft of the outlet sump, under lining holidays where the coating had broken down. At the measured rate the floor in that area has about 17 years to the illustrative minimum thickness. The rate under open holidays usually accelerates, so the repair is listed as Priority 1.

Six weeping locations were found on vertical seams in ring 1, along with 38 cracked or missing bolt caps. These are routine maintenance items, but left alone they become the next corrosion site. We recommend shortening the next full inspection to three years (2029) to confirm the floor repair is holding.

2Scope & methods

Activity	Method / reference	Coverage
Exterior & dome survey	Drone imagery and visual from grade and roof	100% of shell and dome
Ultrasonic thickness	ASTM E797, calibrated to the step block on site	24 readings per ring, 40-point floor grid
Coating thickness (DFT)	SSPC-PA 2	Each zone, per the PA 2 frequency
Adhesion	ASTM D3359 (tape), ASTM D4541 (pull-off) at spot locations	Interior and exterior
Holiday detection	Low-voltage wet sponge, AMPP SP0188	Floor and lower 4 ft of ring 1
Blistering & rust rating	ASTM D714, ASTM D610	Interior, by zone
Seams, bolts & sealant	Visual, with location by ring / seam / degrees	All vertical and horizontal seams

3Ultrasonic thickness data

Location	Nominal (in)	Readings	Average (in)	Minimum (in)	Max loss	Rate (mpy)	Min. required* (in)	Est. remaining life	Status
Shell ring 1 (bottom)	0.312	24	0.304	0.281	9.9%	1.6	0.250	19 yr	Monitor
Shell ring 2	0.250	24	0.247	0.241	3.6%	0.5	0.200	>40 yr	Acceptable
Shell ring 3	0.188	24	0.186	0.183	2.7%	0.3	0.150	>40 yr	Acceptable
Shell ring 4 (top)	0.141	24	0.139	0.136	3.5%	0.3	0.100	>40 yr	Acceptable
Floor (sampled grid)	0.250	40	0.238	0.197	21.2%	2.8	0.150	17 yr	Action

Rate = (nominal − minimum) ÷ 19 years in service, in mils per year. Remaining life = (minimum − minimum required) ÷ rate. *Minimum required thicknesses are illustrative. In a real report they come from the tank’s design basis and the governing standard.

4Coating survey by zone

Zone	Avg DFT (mils)	Adhesion	Holidays	Blister / rust	Condition
Exterior shell, rings 1–4	7.4	4B (D3359)	n/a	None / 10	Good
Interior vapor zone (top 3 ft)	8.1	3B	Not tested	#6-F / 9	Fair
Interior immersion, rings 2–4	8.6	4B; 1,150 psi pull-off	Not tested	None / 10	Good
Interior ring 1, lower 4 ft	8.2	3B	4	#8-F / 8	Fair
Floor	7.9	2B near sump; 4B elsewhere	14 (11 within 8 ft of sump)	#4-M / 6 locally	Poor (local)

Blistering per ASTM D714 (size-frequency), rust grade per ASTM D610 (10 = no rust). Adhesion ratings per ASTM D3359 unless noted.

5Key findings

Lining disbonded from the floor near the outlet sump, with corrosion beneath — **F-01**Floor, 4 ft from the sump at 210°. Lining disbonded with active corrosion beneath. Pit depth 0.053 in. Action

Weeping vertical seam on ring 1 with mineral tracking — **F-02**Ring 1, vertical seam at 95°. Sealant hardened and weeping, with mineral tracking. One of six locations. Action

Cracked bolt caps and surface rust on bolt heads — **F-03**Rings 1–2, multiple seams. 38 bolt caps cracked or missing, with surface rust on the exposed bolt heads. Monitor / repair

Interior corrosion along a horizontal seam in the vapor zone — **F-04**Vapor zone, horizontal seam ring 4/roof. Blistering and light rust at the seam line. No measurable wall loss. Monitor

6Prioritized recommendations

Priority 1: within 6 months

Abrasive-blast and spot-reline the floor within 8 ft of the outlet sump. Holiday-test the repair to 100%.
Remove and replace sealant at the six weeping ring 1 seam locations (F-02).
Disinfect per AWWA C652 before returning the tank to service.

Priority 2: within 6–24 months

Replace 38 cracked or missing bolt caps, and clean and coat the exposed bolt heads (F-03).
Add continuous coating monitoring (for example, HolidayGuard™) or commission interior cathodic protection on the floor and ring 1.
Repair vapor-zone blistering at the roof seam (F-04) during the next planned outage.

Priority 3: plan for 2–5 years

Carry a full floor reline in the capital plan, and confirm or defer it at the 2029 inspection.
Run a repair, reline or replace lifecycle comparison before the next budget cycle.
Next comprehensive inspection: 2029 (shortened from five years because of the floor loss rate).

7Inspector certification

Field inspection and report
CCI inspection team
API 653 Aboveground Storage Tank Inspector, cert. no. 00000

Coating survey
CCI inspection team
AMPP Certified Coating Inspector (CIP), cert. no. 000000