TCEQ Logo

RG-411 Investigating and Reporting Releases
from Petroleum Storage Tanks (PSTs)

Figures and Descriptions


Figure 1 PST Release Investigation - Initial Steps

This flow chart explains the initial steps involved in the PST release investigation with respect to suspected and confirmed releases. All suspected releases require a system check. If the system check detects problems, repair them and perform a site check and proceed to Figure 2. If the system check detects no problems and no environmental impact is noted, the Release Determination Report Form (TCEQ-0621) should be submitted as documentation. Confirmed releases with a known environmental impact and source will proceed to Figure 2.

Figure 2 PST Release Investigation - Release Reporting

This flow chart describes the reporting process for releases of known environmental impact.  Environmental Samples collected during the site check are compared to the TCEQ Action Levels. If no detections of the COCs listed on Table 3 are noted, a Release Determination Report Form (TCEQ-0621) must be submitted. Any detection of TPH in the greater than C12 carbon range requires PAH analysis. If any detected COCs other than TPH exceed action levels in soil or tank hold water, or if NAPL is present, a Release Determination Report Form must be submitted. The release will be assigned an LPST number and is subject to 30 TAC 334 rules.

Figure 3 Tank Hold Sampling Locations:  No Water Present,  Tanks up to 5 Feet in Length

Fig. 3 illustrates the tank hold sampling location with tanks up to 5 feet in length and water not present. Collect one discrete grab sample under fill port.

Figure 4 Tank Hold Sampling Locations:  No Water Present, Tanks Greater Than 5 Feet up to 20 Feet in Length

Fig. 4 illustrates the tank hold sampling location with tanks greater than 5 feet up to 20 feet in length and water not present. Collect two samples under tank ends.

Figure 5 Tank Hold Sampling Locations:  No Water Present, Tanks Greater Than 20 Feet in Length

Fig. 5 illustrates the tank hold sampling location with tanks greater than 20 feet in length and water not present. Collect one sample under fill port and two under tank ends. If fill port is within 3 feet of tank end, sample from the middle under the tank instead.

Figure 6.  Tank Hold Sampling Locations:  Water Present (Cross Section)

Fig. 6 illustrates the cross section view of the tank hold sampling location with water present. Collect samples immediately above soil-water interface, two samples on each end if tank hold has single tank less than 10 feet in length, or four samples if the tank hold has multiple tanks or a single tank greater than 10 feet in length.

Figure 7.  Tank Hold Sampling Locations:  Water Present (Plan View)

Fig. 7 illustrates the plan view of the tank hold sampling location with water present.

Figure 8.  Pipe Trench Sampling Location (Cross Section)

Fig. 8 illustrates the cross section view of the pipe trench sampling location. Collect one native sample per 20 feet length of piping.

Figure 9.  Pipe Trench Sampling Locations (Plan View)

Fig. 9 illustrates the plan view of the pipe trench sampling location.

Figure 10.  Dispenser Sampling Locations

Fig. 10 illustrates the dispenser sampling locations. Collect one sample from the supply side of each dispenser, 1 foot into the native soil under the dispenser piping. For dispensers within 5 feet of each other, collect one sample halfway between the dispensers.

Figure 11.  Tank Hold Sampling Locations for Tank Systems Remaining in Place

Fig. 11 illustrates the sampling locations for tank system remaining in place. Drill soil borings within 3 to 5 feet of the tanks angled in toward and under the tanks, one about every 25 feet of the tank hold perimeter. Collect samples from the borings one foot deeper than the bottom of the tank hold.

Figure 12.  Typical Sampling Locations at Tank System Removal (Plan View – No Water Present)

Fig. 12 illustrates the plan view of the comprehensive sampling locations at the tank system removal when no water is present at the excavation.

Figure 13.  Placement of Custody Seals

Fig. 13 illustrates where custody seals should be placed on the transport shuttle.

Figure 14.  Release Reporting – Analytical Considerations

This flow chart describes the analytical requirements to be considered during release reporting. When COCs exceed action levels, an LPST number will be assigned. When COCs are not detected or detected less than action levels and the SDLs are less than action levels, submit the laboratory data package documenting that all detections and non detections are less than action levels. If COCs are not detected but SDLs are greater than the action levels, request the lab to lower the SDLs.  If unable to lower SDLs, resample and reanalyze, or consider the COC detected at that SDL.

Back to top.