April 2009 1 Task Order No. 3003 T ask 2, Subtask b, Item 1 Technical Directive No. 7

Summary of Frequency of Overfill Protection Device Data from State Databases

E2 Inc. compiled available data on overfill protection devices from state databases ( obtained from the re sult s of TO3003, TDD 5 ) into an Excel file ( attached as an Appendix to this summary) and calculated overall frequenc y totals and percentages from these data. This report provides a summary

of key results and includes the following appendices:

1. Tanks Currentl y in Use 2. Tanks in Temporary

Closure

Methods
Twenty

- three s tate databases were investigated to determine the information they contained regarding overfill protection devices (Table 1) . Ten states had adequate data to provide information specific to the frequency of use of the three overfill devices: ball float valves, automatic shutoff devices, and overfill alarms. The following general rules were applied to data:

 only data from the 10 states that had adequate data on the three overfill devices w ere utilized;

 databases that reported device types other than the three specified in this analy sis were categorized as “ other” types of devices;

 b lank entries in the database were considered “unknown ” ; and

 every overfill device was counted, even in cases where there w as more than one device noted for a specific tank or the tank was exempt from requiring a device.

Seven states had information indicating whether or not tanks had overfill devices
, but inadequate data to determine what types of devices were used

. Six states did not have any information regarding the use of overfill devices (Table 1)

.

Table 1: State D atabase Information for Overfill Protection Devices A dequate D ata for This Analysis Inadequate D ata for This Analy sis N o D ata

State Region State Region State Region New York Virginia Florida North Carolina South Carolina Arkansas Texas Missouri Utah Washington 2

3 4 4 4 6 6 7 8 10 Massachusetts New Hampshire Maryland Georgia Mississippi Tennessee Montana 1 1 3 4 4 4 8 Michigan Ohio Wisconsin Nebras ka Hawaii Nevada 5

5 5 7 9 9April 2009 2 Results for Tanks Currently in Use (Appendix 1 )

For the 10 states that had adequate data for this analy sis, t otal and percentage values for automatic shutoff valves, ball float valves, overfill alarms, and other devices at t anks currently in

use are provided in Table 2

. Ninety

- four percent of all tanks currently in use employ

some typ e of overfill device. Automatic shutoff valves and ball float valves are used with the highest frequency , each representing 39 percent of overfill protection devices on all tanks currentl y in

use.

Table 2 : Total and Percentage Values of Overfill Devices for Tanks Currently in Use

Tanks Automatic

Shutoff Valve Ball Float

Valve Overfill

Alarm Other

Device Tanks with

Overfill Device Total Number 184,193 71,749 71,287 25,731 36,790 173,068 Percentage of total tanks 39% 39% 14% 20% 94 % Percentage of total tanks with an overfill device 4 1 % 4 1 % 1 5 % 2 1 %

Results for Tanks in Temporary Closure (Appendi x 2 )

For the 10 states that had adequate dat a for this analy sis, t otal and percentage values for automatic shutoff valves, ball float valves, overfill alarms, and other devices at tanks in temporary

closure are provided in Table 3

. Results indicate that 73 percent of all tanks in temporary

closure employ

some type of overfill device. Automatic shutoff valves are used most often, installed in 34 percent of the tanks in temporary closure.

Table 3 : Total and Percentage Values of Overfill Devices for Tanks in Temporary Closure

Tanks Automatic

Shutoff Valve Ball Float

Valve Overfill

Alarm Other

Device Tanks with

Overfill Device Total Number 12,227 4,140 2,669 632 3,028 9,461 Percentage of total tanks 34% 22% 5% 25% 7 7 % Percentage of total tanks with an overfill device 4 4 % 28 % 7% 3 2 %