### August 27, 2009 Installation Date Profile Update

- Revised 1

Task Order No. 3003

—Task 2, Subtask e TDD #18

—

New UST Installations

Installation Date Profile Update Revised 8/27/09
E2 Inc. assisted EPA’s Office of Underground Storage Tanks (OUST) by compiling and updating information on new UST installations in the United States (U.S.) for 2002

- 2008. This work expands on the analysis conducted under TDD #25 of TO 1010

-A1 (New UST Installations). Sixteen s tate and eight regional (Indian Lands) databases were used to extract information on the number of new UST installations for calendar years 2007 and 2008 and updates were made to the data previously extracted for calendar years 2002

- 2006. 1 For state data, data from the years 2002 on for which the state had the full year of information were extracted (see accompanying Appendix for state database timestamps) ; all the data available for the years 2002 through 2008 were extracted from the Indian Lands databases

. The information for Indian Lands installations may be slightly under counted for 2008, because the tribal databas es only contain data through September 2008.
E2 Inc. filtered each database to include only federally regulated USTs. Some states indicated whether tanks were federally regulated by stating this on their Web sites or containing a column within their datab ases to specify this (see Appendix). For states that did not indicate federally regulated tanks, E2 Inc. employed a filtering process removing: aboveground storage tanks ; t anks with capacities of 110 gallons or less ; tanks storing heating oil for consumpti ve use on the premises ; and f arm or residential tanks storing 1,100 gallons or less of motor fuel. For some states, the above criteria were easily identifiable from the data fields (e.g., there was a data field for tank type specifying “farm” for a 1,000 g allon tank) ; for other states, E2 Inc. used its best professional judgment to eliminate tanks that met these criteria (e.g., there was no data field for tank type specifying “farm” for a 1,000 gallon tank, but the owner was named “Maple Valley Farm”). This analysis includes currently in use, temporarily closed , and permanently closed USTs. For the most part, no ne or only a few tanks per database per year were removed via the filtering process

. Af ter filtering , the number of tanks installed in each year w as summed and recorded in the spreadsheet accompanying this report

. When data were available, for each year, the number of new tanks only that we re secondarily contained (with no secondary containment on the piping system) , the number of new tanks with pip ing systems that were secondarily contained (with no secondary containment on the tank) , and the number of new tanks and piping systems that were both secondarily contained were counted

. When secondary containment was indicated for a given tank and piping system and interstitial monitoring information was available, interstitial monitoring use was determined

. Interstitial monitoring was counted for tanks when tanks only had secondary containment ; for pipes when pipes only had secondary containment; and for both the tank and pip es when both the tank and pipes had secondary containment. Interstitial monitoring was not counted when both the tank and pipes had secondary containment, but only the tank or piping syste m had interstitial monitoring. Overall, secon dary containment and interstitial monitoring data were available for about half of the 24 databases used in this analysis. The following types of tanks were considered secondarily contained: double walled, totally contained, jacketed , those with internal or external liners, and those with vaults ; all double walled pipes were considered secondarily contained. For those databases that included different installation dates for tanks and piping, only the tank installation date was used. For a few databases, inf ormation was only available for the UST ( Missouri, Ohio , and South Dakota) , but not the pipes

. These data were recorded in the “On UST but not on Piping” column of the spreadsheet. For each year, the numbers of tanks were summed across databases (Table 1)

.

1 Exceptions are Al abama and Tennessee. No updates were made for Alabama because no database was available for Alabama. No updates were made for Tennessee because the database was the same as that used for TO 1010

- A1.

### August 27, 2009 Installation Date Profile Update

- Revised 2

Table 1 : Number and Percentage of Actual New Installations with Secondary Containment and Interstitial Monitoring for 24 State and Regional Databases

Year Total # New USTs On UST but not Piping On Piping but not UST On both UST & Piping

Sec Cont I nterstitial Mon Sec Cont Interstitial Mon Sec Cont Interstitial Mon # % # % # % # % # % # % 2002 3,806 265 16 47 6 160 15 144 15 491 45 170 22 2003 3,034 270 18 52 7 128 14 92 13 408 44 200 28 2004 2,669 261 18 97 12 133 15 65 8 482 56 259 33 2005 2 ,664 281 22 103 19 44 7 42 7 424 67 211 39 2006 2,925 430 34 99 19 45 8 27 5 350 60 179 34 2007 2,680 300 29 77 16 55 10 47 10 384 67 169 35 2008 2,493 237 28 73 18 35 7 26 7 368 78 182 46
The data extracted from the 24 available databases were used to estimate the total number of n ew installations in the entire U.S. during 2002 through 2008 and the numbers of these new installations with secondary containment and interstitial monitoring

. 2 Percentages for secondary containment and interstitial monitoring are based on the numbers of new tanks and piping installed. These values are dependent on the numbers reported in state databases and whether a state tracked secondary containment information for tanks, piping, both, or neither. The annual number of new installations in the U.S. wa s calculated by multiplying the number of total active tanks in the U .S. by the ratio of new tanks to active tanks in the sample according to the equation: 3

New USTs Total = Active USTs Total * (New USTs Sam pl e / A ctive USTs Sam pl e ) Similarly, for each year, the total numbers of active tanks in each category of secondary containment and interstitial monitoring were calculated by multiplying the number of new installations in each category by the ratio of the total active USTs to the number of active tanks in each category a ccording to the equation:

Active USTs IMorSCTotal = New USTs IMorSCSample * (Active USTs Total / Active USTs Sample ) The extrapolation results are show in Table 2 below

. Table 2 : Extrapolated Total Number s of Active Tanks in the United States with Secondary Containment and Interstitial Monitoring

Year Number of

Active Tanks * Number of

New Tanks On UST but not Piping On Piping but not UST On both UST & Piping

Sec Cont Interstitial

Mon Sec Cont Interstitial Mon Sec Cont Interstitial Mon 2002 697,966 12,270 1,441 505 1,284 1,206 3,941 1,828 2003 682,870 9,870 1,496 564 1,030 999 3,283 2,171 2004 672,297 8,623 1,700 1,056 1,367 708 4,953 2,820 2005 653,621 8,528 2,146 1,510 596 569 5,741 3,093 2006 641,881 9.1 97 3,264 1,446 606 394 4,713 2,615 2007 629,866 8,425 2,271 1,121 738 684 5,155 2,461 2008 623,319 7,833 1,793 1,081 476 385 5,003 2,696 *The values in this column are the only actual values in the table. The rest were extrapolated.

2 The number of states and tribal regions for which dat a in each category were available varied slightly by year. 3 For each year, the total num ber of active USTs in the U.S. wa s acquired from second half fiscal year reports at http://www.epa.gov/oust/cat/camarchv.htm

.