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.