Design of a UST Management

System

Joshua HoltgreweMAESC 2005

Tank 1 Tank 2 Tank 4Tank 3

Automatic Tank Gauge

Introduction to USTs Memphis, Light, Gas, & Water currently

stores fuel for its motor vehicle operations in 20 tanks at 11 sites throughout Memphis and Shelby County

This fuel is stored in underground storage tanks (USTs)

The double walled tanks must be monitored in order to ensure compliance with Tennessee Dept. of Environment and Conservation (TDEC) regulations

Current monitoring of USTs

Automatic tank gauges (ATGs) These ATGs contain

microcontrollers that monitor the tanks employing probes and sensors

Electric & Systems OperationsCovington Pike, Memphis, TN

Covington Pike Location

Monitoring

Employees gather receipts at all sites

Proof of passed leak test must be logged for one year every day and complied in yearly reports

120VAC Panel

ATG

Probes

Interstitial sensors

Why is a New Solution Needed? End of usable life of system Difficulty meeting regulatory

compliance Labor cost can be reduced by

implementing a more efficient monitoring system

Design Objectives

New system must be able to perform same operations as existing system

Use of existing tanks and sensors Offsite monitoring via network

based software Real-time monitoring

Alternative A Monitors up to

eight tanks Broadband

connection and software for offsite management

Alternative B Monitors up to 12

tanks Economical Broadband

connection and software

Local vendor

Alternative ComparisonDesign Criterion Alternative Alternative

A B

Real-time monitoring X X

Printer for on-site data collection X X

Software for off-site monitoring X X

E-mail alerts from ATGs X

Ability to monitor 8 tanks X X

Continuous testing ability X X

Use of existing probes/sensors X

Multiple language support X

Alternative A Total CostsQty Item Unit Price Total Price

11 ATG Console-PC Version 1,870.00$ 20,570.00$ 11 Ethernet TCP/IP Module 795.00$ 8,745.00$ 11 Static Probe 162.50$ 1,787.50$ 20 Magnetic 8' Probe 1,040.00$ 20,800.00$ 8 Probe Install Kit 145.00$ 1,160.00$

12 Diesel Probe Install Kit 145.00$ 1,740.00$ 20 Interstitial Sensor 245.00$ 4,900.00$ 20 Piping Sump Sensor 135.00$ 2,700.00$ 20 4" Cap and Ring Kit 85.00$ 1,700.00$ 20 Sensor Cap Kit 55.00$ 1,100.00$ 1 Remote Software 1,295.00$ 1,295.00$ 1 Installation Fee 3,000.00$ 3,000.00$ 1 Freight Fee 2,000.00$ 2,000.00$ 1 Sales Tax @ 9.25% 6,613.52$ 6,613.52$

TOTAL 78,111.02$

Qty Item Unit Price Total Price11 ATG Console-PC Version 1,395.00$ 15,345.00$ 11 Ethernet TCP/IP Module 535.00$ 5,885.00$ 11 Static Probe 162.50$ 1,787.50$ 17 Magnetic 8' Probe 990.00$ 16,830.00$ 8 Probe Install Kit 145.00$ 1,160.00$ 9 Diesel Probe Install Kit 145.00$ 1,305.00$

17 Interstitial Sensor 235.00$ 3,995.00$ 17 Piping Sump Sensor 135.00$ 2,295.00$ 17 4" Cap and Ring Kit 48.82$ 829.94$ 17 Sensor Cap Kit 65.00$ 1,105.00$ 1 Inform Software 1,150.00$ 1,150.00$ 1 Installation Fee 4,400.00$ 4,400.00$ 1 Freight Fee 1,500.00$ 1,500.00$ 1 Sales Tax @ 9.25% 5,326.84$ 5,326.84$

TOTAL 62,914.28$

Alternative B Total Costs

Choice: Alternative B Savings of $15,000 as

compared to Alternative A

Some existing probes and sensors are used

Some existing ATGs may not need to be replaced

Same manufacturer/vendor of existing ATGs

Met all of design objectives

Screenshots of Software

Site Manager Site Editor Alarm History

Connectivity

RouterATG

LAN

Wireless

Connectivity

Network connections required to the eleven ATGs

Two types of solutions exist: LAN (local area network) or WLAN (wireless local area network)

LAN vs. WLAN at Covington Pike Wireless adapters can be located in enclosure

with ATG No need for site adaptation Access point can be located at the hub or switch

in the facility Attenuation not a problem since the enclosures

housing the ATGs are within 200 feet of a nearby office that will contain the hub or switch

Encryption provides security for wireless network

LAN Costs for Covington Pike

TRADITIONAL NETWORKING - COST ANALYSIS FOR MLGWQty Units Item Unit Price Total Price

125 LF Concrete Demolition/Replacement 17.00$ 2,125.00$ 125 LF PVC Schedule 40 1/2" Conduit 1.70$ 212.50$

8 20' Sect.Category 5e Networking cable 8.95$ 71.60$ 1 Sales Tax @ 9.25% 234.89$ 234.89$

TOTAL 2,643.99$

Source: RSMeans Electrical Cost Data, 28th Edition

WLAN Costs

WIRELESS NETWORKING - COST ANALYSIS FOR MLGWQty Item Unit Price Total Price

11 D-Link / DWL-810+/ Ethernet Wireless Bridge 64.99$ 714.89$ 11 D-Link / Air / DI-514/ Cable/DSL / Wireless Router 44.19$ 486.09$ 1 Sales Tax @ 9.25% 117.10$ 117.10$

TOTAL 1,318.08$

Note: This price is the cost for 11 sites.

Source: www.dlink.com

Replacement Recommendation Alternative B with wireless network

connections Use of IEEE 802.11b hardware Meets and exceeds operating

temperature ranges Meets and exceeds signal range

for connectivity with the switch or hub onsite

Costs Includes the new UST monitoring

system featuring the ATGs of Alternative B, its probes, sensors and software

The wireless routers and access points necessary for the communication in real-time

Installation by trained technicians $64,232.40

Benefits of Solution

Relief of on-site labor responsibility and the cost associated with this labor

Real-time monitoring More effective method for

regulatory compliance

Economic Benefits

This design solution will eliminate over $5,000 a month of labor

Over the 10 year life-cycle of the new system the present worth of the alternative is $371,853.53

The solution has a payback period of approximately 13 months.

Overview of ATG System

Tank 1 Tank 2

Tank 4Tank 3

Automatic Tank Gauge

Control Wire

Overview of Networking

RouterAutomatic Tank Gauge with Wireless Adapter

Overview of Networking System

Allen Brunswick Davis Covington Pike

Heavy Hickory Hill

Lichterman

McCord

North Sheahan South

PC at MLGW Headquarters

Conclusion

Improved regulatory compliance Reduction of labor costs Real-time offsite monitoring Return of capital investment in

13 months

Any Questions?

MainOffices

Allen Brunswick Davis Covington Pike

Heavy Hickory Hill

Lichterman

McCord

North Sheahan South

Questions…….. Introduction ATG Tanks/Site Alternatives Costs Software LAN vs WLAN Costs of Networking Benefits

MARR Probes Microcontroller Sensors Volumetric Calculatio

ns Wireless

MARR

Minimum attractive rate of return The interest rate at which one can

expect to receive due to the time value of money

6%-8%

Present Worth Analysis

Initial Cost: $64,232.40 Annual Maintenance Costs: $750 Employee Productivity Savings:

$60,000

PW = -64,232.40+ -750(P/A,i,n)+ 60,000(P/A, i, n)

MARR Table

MARRPresent Worth of

Alternative

6% $371,853.537% $351,915.908% $333,341.03

Microcontroller

CPU 256K Internal Memory PROM Connectors for printer, fax,

communications modules, other peripherals

Inventory Probes A voltage is induced

by the current flowing from the change in magnetic field.

The magnetic field changes due to the distance between the top part of the probe and the bottom

Hall effect

Leak detection Interstitial liquid

sensor Vapor sensor-

located in backfill to detect vapor being absorbed by soil

Volumetric Calculations

H R

R unfilled da

R

a RSinCos V 1 2L

R

H RSin

R

H R H H R RL

R L V unfilled 1

2

2

1 2

2

R

HRSin

R

HRHHRRL

LRV filled 1

2

21

2

2

H

R a

  

Wireless

802.11b signals have an outdoor range of 1640 ft

Adapter output power of 15dBm Signal degradation in a variety of

ranges (1MBps, 5.5MBps, 11MBps)

Wireless Ranges

11 MBps within 800ft.

5.5 MBps from 800ft. to 1300ft.

1 MBps from 1300ft. to end of range

1600 ft.

800 ft.

1300 ft.