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2011 In-Water Testing of Aquatic Nuisance Species Dispersal Barriers IIA And IIB with Increased Voltage and Frequency Operating Parameters

Co ns tr uc tio n

En gi ne er in g

R es ea rc h La bo ra to ry

Michael K. McInerney, Brianna S. Aubin, Jonathan C. Trovillion, Carey L. Baxter, Ethan T. Trovillion, Vincent F. Hock, Jr., and David M. Weir

August 2011

Approved for public release; distribution is unlimited.

ERDC/CERL TR-11-23

August 2011

2011 In-Water Testing of Aquatic Nuisance Species Dispersal Barriers IIA and IIB with Increased Voltage and Frequency Operating Parameters

Michael K. McInerney, Brianna S. Aubin, Jonathan C. Trovillion, Carey L. Baxter, Ethan T. Trovillion, and Vincent F. Hock, Jr.

Construction Engineering Research Laboratory U.S. Army Engineer Research and Development Center 2902 Newmark Drive Champaign, IL 61822

David M. Weir US Army Engineer District Chicago 111 North Canal Street Chicago, IL 60606-7206

Final report Approved for public release; distribution is unlimited.

Prepared for U.S. Army Corps of Engineers Washington, DC 20314-1000

Under Project 114532, “CSSC Dispersal Barrier II, ERDC-CERL Safety Studies”

ERDC/CERL TR-11-23 ii

Abstract: US Army Engineer District – Chicago operates an electric field-based aquatic nuisance species dispersal barrier system in the Chicago Sa-nitary and Ship Canal (CSSC), Romeoville, IL. The barriers were con-structed to prevent the movement of invasive species, such as Asian big-head carp (Hypophthalmichthys nobilis) and silver carp (Hypophthal-michthys molitrix) between the Mississippi River and Great Lakes basins.

The objective of this project was to perform a series of in-water tests on the barrier addressing field-strength mapping, sparking potential during barge fleeting and collision, voltage potentials between barges traversing the barriers, personnel in-water shock potential, stray-current corrosion potential, and optimal settings for the parasitic barrier system. Test results and analysis indicate there is no significant risk of personnel shock hazard in the fleeting area during barrier operations for any operating configura-tion. Also, while some operational scenarios were found to increase spark-ing risk if barges collide with each other or separate metal objects, analysis indicates that concerns about coal dust explosion hazard from sparking are not supported by the technical literature. A detailed set of data, analy-sis, conclusions, and recommendations is provided in the report text and four appendices.

ERDC/CERL TR-11-23 iii

Executive Summary

In an ongoing effort to test and define the relative safety of the three inva-sive species dispersal barriers on the Chicago Sanitary and Ship Canal (CSSC) at Romeoville, IL, the Engineer Research and Development Center

– Construction Engineering Research Laboratory (ERDC-CERL) and Chi-cago District performed in-water safety testing using various operational settings and configurations. The work was performed from 4 - 12 February and 12 - 16 June 2011. The seven objectives established for this testing ef-fort: (1) map field strengths, (2) determine sparking potential during fleet-ing operations, (3) determine sparking potential in the event of a collision in the fleeting area, (4) measure voltage potential between barges travers-ing the canal over the barriers, (5) determine personnel shock potential at the bollards at the fleeting area, (6) determine corrosion potential, and (7) determine the optimal settings for the parasitic barrier system. Each ob-jective was accomplished for six different target operational configura-tions: (A) IIA at 2.0 V/in., IIB at 2.3 V/in., (B) both IIA and IIB at 2.3 V/in., (C) both IIA and IIB at 2.0 V/in., (D) IIA alone at 2.3 V/in., (E) IIB alone at 2.0 V/in., and (F) IIB alone at 2.3 V/in. The measurements and observations recorded during these tests were compiled and analyzed to determine the in-water safety concerns associated with each of the various operational configurations.

The field strength testing and analysis indicated that larger areas of risk to a person-in-water are present when operating barriers IIA and IIB concur-rently. However, only a small increase in the area of risk results with an increase of operational parameters from 2.0 V/in. to 2.3 V/in. Sparking was observed during fleeting operations, mainly during the insertion pro-cedure when both barriers were in operation. No significant increase in risk of sparking was observed due to the increase in operations from 2.0 V/in. to 2.3 V/in. There is a significant increase in risk of sparking when a tow spanning both IIA and IIB with both operating (versus barrier IIA op-erating alone) collides with barge in fleeting area. The likelihood of spark-ing causing an explosion or fire at the coal-loading facility due to coal dust is negligible. Operation of the barriers does not adversely affect corrosion potential for in-water steel structures at Midwest Generation fleeting area.

No risk of personal shock hazard was observed at the bollards in the fleet-ing area. Test results did not provide any clear evidence to refute that the

ERDC/CERL TR-11-23 iv optimal parasitic electrode configuration is consistent with SRI recom-mendations that only two of the three parasitic structures are connected together such that they are the outermost structures adjacent to the active arrays.

ERDC/CERL TR-11-23 v

Table of Contents Executive Summary ..................................................................................................................................... iii

List of Figures and Tables...........................................................................................................................vii

Preface ........................................................................................................................................................... ix

1 Introduction

1.1 Background

1.2 Objective

1.3 Approach

2 Experiments

2.1 Field mapping (Objective 1)

2.1.1 Procedure

2.1.2 Analysis

2.1.3 Results and observations

2.1.4 Conclusions

2.2 Sparking potential testing at fleeting area (Objectives 2 and 3)

2.2.1 Procedure

2.2.2 Analysis

2.2.3 Results and observations

2.2.4 Conclusions

2.3 Long tow voltage potential test (Objective 4)

2.3.1 Procedure

2.3.2 Analysis

2.3.3 Results and observations

2.3.4 Conclusions

2.4 Shock potential at fleeting dock bollards (Objective 5)

2.4.1 Procedure

2.4.2 Analysis

2.4.3 Results and observations

2.4.4 Conclusions

2.5 Corrosion potential (Objective 6)

2.5.1 Procedure

2.5.2 Analysis

2.5.3 Results and observations

2.5.4 Conclusions

2.6 Parasitic grid configuration testing (Objective 7)

2.6.1 Procedure

2.6.2 Results and observations

2.6.3 Conclusions

ERDC/CERL TR-11-23 vi

3 Conclusions and Recommendations

Conclusions Recommendations

4 Unabridged Data Tables

References

Appendix A: Instrumentation and Data Reduction ..............................................................................A1

Appendix B: Electric Hazard Analysis .................................................................................................... B1

Appendix C: V12 Electric Field Plots ..................................................................................................... C1

Appendix D: V12 Electric Field Maps .................................................................................................... D1

Report Documentation Page

ERDC/CERL TR-11-23 vii

List of Figures and Tables

Figures

Figure 1. Relative locations of Barriers I, IIA, and IIB in the canal

Figure 2. Electrode array for voltage gradient and current mapping

Figure 3. Relative locations of areas of likely harmful effects for the four pulser configurations of Table 5 (continued to next page)

Figure 4. Locations of likely harmful effects for the six pulser configurations in Table 5, Chapter 4

Figure 5. Sparking potential testing scenario for a tow with barges in series, 5 February

Figure 6. Instrumentation for testing of a tow with barges in series

Figure 7. Sparking potential testing scenario for a tow with barges in parallel, 5 February

Figure 8. Instrumentation for testing of assembling a tow with barges in parallel

Figure 9. Sparking potential testing scenario for inserting a barge into a tow on 5 February

Figure 10. Instrumentation for testing of inserting a barge into a tow

Figure 11. A tow over Barriers IIA and IIB contacting a moored barge in the fleeting area on 7 February 2011

Figure 12. Electrical measurements between a tow over Barriers IIA and IIB and a barge moored in the fleeting area

Figure 13. Long tow consisting of five barges and two towboats traversing the barriers on 8 and 10 February when the pulsers were in configuration Bravo and Parasitic 2 was on

Figure 14. Diagram of five open-circuit voltage measurements (V1–V5) simultaneously captured for each barge in the long tow

ERDC/CERL TR-11-23 viii

Summary Tables

Summary Table A. Target operational scenarios

Summary Table B. Range of greatest extent of voltage gradients ( ≥0.05 V/in.) sufficient to cause harmful physiological effects (see Table 3 and Table 4, Chapter 4)

Summary Table C. Summary of sparking observations based on test results for sparking potential during fleeting operations (see Table 6, Chapter 4)

Summary Table D. Summary of estimated energy based on results for sparking potential during fleeting operations (see Table 6, Chapter 4)

Summary Table E. Test results for sparking potential during collision simulations, conducted on 7 February 2011 (see Table 7, Chapter 4)

Summary Table F. Outline of test results for long tow traversing Barriers IIA, IIB, and I, conducted on 8 and 10 February 2011 (see Tables 8–10, Chapter 4)

Summary Table G. Voltage differences between outside barges and towboats

Summary Table H. Concise results for bollard voltage potential and 500-ohm current tests at fleeting area, conducted on 7 February 2011 (see Table 11, Chapter 4)

Tables

Table 1. Environmental conditions during testing

Table 2. Pulser and parasitic configurations and approximate run times for field mapping, conducted on 11 and 12 February 2011, and 14 June 2011

Table 3. Locations of Barriers IIA and IB voltage gradients sufficient to cause harmful physiological effects

Table 4. Locations of Barrier I voltage gradients sufficient to cause harmful physiological effects

Table 5. Pulser settings and target in-water field strengths for each test configuration

Table 6. Test results for sparking potential during fleeting operations

Table 7. Test results for sparking potential during collision simulations

Table 8. Test results for long tow traversing Barrier IIA, conducted on 8 and 10 February

Table 9. Test results for long tow traversing Barrier IIB, conducted on 8 and 10 February

Table 10. Test results for long tow traversing Barrier I, conducted on 8 and 10 February

Table 11. Test results for bollard voltage potential and 500-ohm current tests at fleeting area

Table 12. Barge corrosion potential measurements taken with Cu/CuSo4 reference electrode, conducted on 5 February 2011

Table 13. General corrosion rates for steel in fresh water

ERDC/CERL TR-11-23 ix

Preface

This study was conducted for the US Army Engineer District – Chicago under Project 114532, “CSSC Dispersal Barrier II, ERDC-CERL Safety Stu-dies.” The technical monitor was Charles B. Shea, CELRC-PM-PM.

The work was performed by the Materials and Structures Branch (CF-M) of the Facilities Division (CF), US Army Engineer Research and Develop-ment Center – Construction Engineering Research Laboratory (ERDC- CERL). At the time of publication, Vicki L. Van Blaricum was Chief, CEERD-CF-M; L. Michael Golish was Chief, CEERD-CF; and Martin J. Sa-voie was the Technical Director for Installations. The Deputy Director of ERDC-CERL was Dr. Kirankumar Topudurti and the Director was Dr. Ilk-er Adiguzel.

COL Kevin J. Wilson was the Commander and Executive Director of ERDC, and Dr. Jeffery P. Holland was the Director.

ERDC/CERL TR-11-23 x

ERDC/CERL TR-11-23 1

1 Introduction

1.1 Background

US Army Engineer District – Chicago is safely operating an electric field-based aquatic nuisance species dispersal barrier system in the Chicago Sa-nitary and Ship Canal (CSSC), Romeoville, IL. The barriers were con-structed by Smith-Root, Inc., sole licensees of US patent 4,750,4511

Figure 1

, to prevent the movement of invasive species, such as Asian bighead carp (Hypophthalmichthys nobilis) and silver carp (Hypophthalmichthys moli-trix) [12], between the Mississippi River and Great Lakes basins. The bar-rier project consists of two distinct parts: the demonstration barrier (Bar-rier I) and Barrier II. Barrier I, which consists of steel cables fastened to concrete supports that rest on the bottom of the canal, sends a low-voltage, pulsing direct current (DC) through the water in order to repel invasive fish. Barrier II, also a pulsed DC apparatus, is located 800 to 1,300 ft downstream of Barrier I. Barrier II is able to generate a more powerful electric field over a larger area. It consists of two sets of electrical arrays and control houses, known as Barriers IIA and IIB. Each control house and set of arrays can be operated independently. Barrier IIA is operated during maintenance activities or as otherwise needed, and Barrier IIB is fully operational. shows the relative locations of Barriers I, IIA, and IIB.

Figure 1. Relative locations of Barriers I, IIA, and IIB in the canal.

1 Smith, David V. Fish repelling apparatus using a plurality of series connected pulse generators to pro-duce an optimized electric field. United States Patent 4,750,451, issued 14 June 1988.

ERDC/CERL TR-11-23 2

Before August 2009, Barriers I and IIA were operating at maximum in-water field strength at the water surface of 1 volt/inch (V/in.) with five pulses per second at a frequency of 5 hertz (Hz), and each pulse 4 millise-conds (ms) in duration. The US Army Corps of Engineers (USACE) and Smith-Root are engaged in an ongoing research program to identify the most effective combination of electric field strength, pulse frequency, and pulse duration for deterring all sizes of Asian carp. After environmental DNA (eDNA) monitoring indicated that Asian carp may have migrated closer to the barrier system than previously thought, the operating para-meters at Barrier IIA were increased in August 2009 to levels recommend-ed based on the research completed at that time: a maximum in-water field strength at the water surface of 2 V/in. with a pulse rate of 15 Hz and a pulse duration of 6.5 ms. The operating parameters at Barrier I were not changed because the equipment at Barrier I is not capable of operating at the higher recommended operating parameters.

Increasing the Barrier IIA operating parameters raised concerns about conducting barge and boat operations safely, and the potential hazards to a person who accidentally fell into the water while traversing the barriers.

During preliminary discussions between ERDC-CERL2

Research into the optimal operating parameters to deter all sizes of Asian carp has continued. The latest research indicates that operating at a pulse rate of 30 Hz, pulse duration of 2.5 ms, and a maximum in-water field strength at the water surface of 2.3 V/in. may be most effective for deter-ring even small Asian carp. USACE is considering changing the Barrier II operating parameters to the latter. Testing for safety concerns in the wa-terway along with ground currents and electromagnetic radiation (EMR)

, the Ninth US Coast Guard (USCG) District and Captain of Port Lake Michigan, and Chi-cago District, it was emphasized that it is crucial to identify and under-stand the risks associated with the new operating parameters. Additional tests were completed in August and September 2009 by teams from ERDC-CERL and Coast Guard Office of Design and Engineering Standards (CG 521) with Barrier IIA operating at 2 V/in., 15 Hz, and 6.5 ms pulse width. Test results were shared with the USCG that resulted in changes in the rules of navigation to allow the safe passage of barges carrying com-bustible or flammable liquid in bulk (i.e., red-flag barges) and recreational boats across the barriers.

2 Engineer Research and Development Center - Construction Engineering Research Laboratory, Cham-paign, IL.

ERDC/CERL TR-11-23 3

in the air were conducted in February 2011 to determine the effects of these new operational parameters. The results of the in-water testing are included in this report; safety testing results for ground currents and EMR will be documented in a separate report. The results of the safety testing will be a key element in recommendations about optimum operating pa-rameters.

Barrier IIB has been operational since April 2011, and has undergone test-ing that verified it can perform at the specified parameters. Also, new pa-rasitic structures have since been installed in the canal as part of Barrier IIB construction. These structures, typically referred to as “parasitics” in this report, are electrode arrays configured as steel grids and mounted to concrete curbs that rest on the bottom of the canal. These are located down-canal from Barrier IIA, up-canal from Barrier IIB, and between IIA and IIB. They collect the stray currents on one side of a barrier and, via an electrical bus on shore, provide a low-impedance path for those currents to return to other side of barrier.

The southernmost parasitic grid is designated as 1; the middle grid as 2;

and the northernmost grid as 3. Each grid is connected to the electrical bus on the western shore by metal cables that are welded to the grid structure.

There are several switches that allow each parasitic to be connected to and disconnected from the bus. By closing each switch (i.e., setting it to the on position), the parasitics are connected to each other via bus. By opening a switch (i.e., setting it to the off position), a parasitic may be disconnected from the bus. The positioning of these switches is presented throughout the report.

The in-water testing was undertaken to evaluate the effects of changing the barrier operating parameters, including operation of the parasitics on the safe operation of Barrier IIB.

1.2 Objective

The objective of this project was to support the Chicago District by per-forming a series of tests on the barrier to:

1. map and quantify the voltage gradient and current potential across Barrier I, Barrier IIA, and Barrier IIB in order to evaluate the voltages and currents a person would be subjected to while in the water in the barrier area

ERDC/CERL TR-11-23 4

2. quantify and evaluate the potential for sparking during fleeting opera-tions at the Midwest Generation, LLC, power facility fleeting area

3. quantify and evaluate the possibility of sparking between fixed barges at the fleeting area and a moving long tow that is traveling south over Barrier IIA and Barrier IIB while contacting a moored barge in the fleeting area

4. quantify the voltage potential between barges in a long tow while pass-ing over Barrier I, Barrier IIB and Barrier IIA

5. assess the potential shock hazard between the fleeting area dock bol-lards and a fixed barge

6. assess the corrosion potential of in-water steel structures in the fleeting area

7. determine the most effective method for operating the parasitic system.

1.3 Approach

Barrier IIA and IIB were adjusted to operate according to each of the test-ing objectives outlined above. The operational parameters were verified, and actual values were recorded during testing. Environmental data such as ambient temperature, humidity, and water conductivity were recorded throughout all testing.

The watercraft used for field mapping was a 22 ft fiberglass-hull Guardian Boston Whaler owned by USACE. The sparking potential, corrosion poten-tial, and long-tow tests were performed with towboats and barges provided by commercial material-transfer companies.

The main text of this report includes summary tables, most of which are derived from the raw test data. The unabridged tables of raw data are pre-sented separately, in Chapter 4, for more detailed examination.

Details on the instrumentation used for data collection and the data reduc-tion procedures are presented in Appendix A.

ERDC/CERL TR-11-23 5

2 Experiments

Tests were completed for the pulser target operational configurations listed in Summary Table A. Throughout all testing, environmental data such as ambient temperature, humidity, and water conductivity were rec-orded. The unabridged data are presented in Chapter 4, Table 1.

Summary Table A. Target operational scenarios.

Barrier IIA Barrier IIB Barrier I A (Alpha)* 2.0 V/in., 15 Hz, 6.5 ms 2.3 V/in., 30 Hz, 2.5 ms 1 V/in., 5 Hz, 4 ms B (Bravo)* 2.3 V/in., 30 Hz, 2.5 ms 2.3 V/in., 30 Hz, 2.5 ms 1 V/in., 5 Hz, 4 ms C (Charlie)* 2.0 V/in., 15 Hz, 6.5 ms 2.0 V/in., 15 Hz, 6.5 ms 1 V/in., 5 Hz, 4 ms D (Delta)* 2.3 V/in., 30 Hz, 2.5 ms OFF 1 V/in., 5 Hz, 4 ms E (Echo)* OFF 2.3 V/in., 30 Hz, 2.5 ms 1 V/in., 5 Hz, 4 ms F (Foxtrot)* OFF 2.0 V/in., 15 Hz, 6.5 ms 1 V/in., 5 Hz, 4 ms

* Actual test field strengths approximate.

2.1 Field mapping (Objective 1)

2.1.1 Procedure

Field mapping was conducted for each of the six operational scenarios.

Measurements of voltage (1) between horizontal electrodes spaced 1 – 6 ft apart were used to map the horizontal electric field, and (2) between two vertical electrodes spaced 5 ft apart were used to map the vertical field.

Measurements of current (1) through a 100-ohm (Ω) resistor between two horizontal electrodes spaced 1 ft apart was used to simulate current flow through the chest, (2) through a 500 Ω resistor between two horizontal electrodes spaced 6 ft apart was used to simulate current flow through a body floating prone in the canal, and (3) through a 500 Ω resistor between two vertical electrodes spaced 5 ft apart was used to simulate current flow through an upright body. A schematic of the testing apparatus is shown in Figure 2.

ERDC/CERL TR-11-23 6

Figure 2. Electrode array for voltage gradient and current mapping.

Data were continuously collected as the boat traversed the barriers from south of the fleeting area to north of the pipeline arch. (See section 2.4.1 for layout illustrations.) This extends the data-collection region well beyond Barrier I to the north and Barrier IIA to the south.

Geopositional data were taken concurrently with the voltage and current measurements during field mapping to allow them to be georeferenced. A minimum of six passes — two along the center of the canal, two along the east wall, and two along the west wall — were taken at each of the pulser configurations shown in Summary Table A.

2.1.2 Analysis

Field mapping data were used to determine voltages and currents a person would be subjected to while in the water in the barrier area. The critical threshold voltage levels published in a Navy Experimental Diving Unit (NEDU) report [6] were used as the basis for computing the range of harmful physiological effects that would result from the measured values.

The NEDU based its threshold voltage levels for harmful effects on Inter-national Electrotechnical Commission (IEC) Publication 60479-1, Effects of Current on Human Beings and Livestock - Part 1: General Aspects [11].

5 feet 10 feet6 feet

Water Surface

Measurements V12 (open circuit) I12 (100 ohm) V13 (open circuit) I13 (500 ohm) V14 (open circuit) I14 (500 ohm) V45 (open circuit

1 foot

3 feet

6 feet

1 2 3

4 5

5 feet 10 feet6 feet

Water Surface

Measurements V12 (open circuit) I12 (100 ohm) V13 (open circuit) I13 (500 ohm) V14 (open circuit) I14 (500 ohm) V45 (open circuit

1 foot

3 feet

6 feet

11 22 33

44 55

ERDC/CERL TR-11-23 7

Table 13 in IEC Publication 60479-1, reproduced in Appendix B of this re-port as Table B1, defines four zones of physiological effects to the human body due to DC pulses. The zones are differentiated by duration of current pulse and body current. The most harmful effects occur in Zone DC-4;

these include cardiac arrest, breathing arrest, and burns or other cellular damage.

The NEDU computation [6] is for the worst-case effect: current through the chest of a body upright over the barrier. For this scenario, the mea-surements of the open-circuit voltage with 1 ft electrode spacing at approx-imately 1 ft below the surface (referred to as V12) are used.3

The actual field strength measured during this testing may be seen in the figures presented in Appendix C. Actual field strength sometimes exceeded the target operational configurations for these tests. In an effort to deter-mine the impact of these higher values, sensitivity analysis was conducted (see Appendix B). Mapping runs which had at least one range of harmful effect values corresponding to one of the two greatest-extent values (one north of the barriers and one south) were selected from configuration Bra-

vo. The entire dataset from these runs was scaled by +/- 20%. The change in the extent of the safety zones (+/- 0.05 V/in. man-overboard criteria) north and south of barriers IIA and IIB was then reevaluated using the scaled datasets.

Minimum electric field strengths required to induce physiological effects were de-rived using the formulas and methods given in [6]. Details of the analysis are presented in Appendix B and summarized in Table B3. A worst-case value of 0.05 V/in. was determined to be the threshold for ventricular fi-brillation. Worst-case values of 0.03 V/in. (for pulse width 2.5 ms) and

0.02 V/in. (for pulse width 6.5 ms) were determined to be the threshold for involuntary muscular contractions. The geographic limit values were obtained for each run by examining the electric field plots and estimating where the voltages crossed the threshold limit lines.

2.1.3 Results and observations

Pulser and parasitic configurations along with the approximate run times are listed in Table 2 (see Chapter 4). Electrical field strength data for V12

3 Although five voltages and three currents were measured, only the V12 measurement is needed to perform the analysis in this report. The other voltage and current measurements were made for future analyses.

ERDC/CERL TR-11-23 8

are presented in Appendices C and D. The zero point on the x-axis of these figures is centered on Barrier IIB’s narrow array (see Figure C1). This is where the electric field strength of Barrier IIB is the strongest.

Peak voltage potential was measured. No filtering was applied to some of the images, such as run 16 on February 11 and run 4 on February 12, so background noise is evident in some cases. This noise is caused by radio interference from nearby transmitters and 60 Hz (and harmonic) stray electrical currents originating from the Midwest Generation electric power station. To improve graphical presentation, filtering was applied to some of the data in order to remove noise and clutter when it obscured the use-ful data. Peak voltages are not affected by the filtering.

No geo-tracking data were available for run 18 on February 11 and runs 17 and 18 on February 12 due to periodic changes in the GPS satellite constel-lation, which prevented adequate carrier phase lock to determine geoposi-tional data through direct observation. Geo-referencing was accomplished by estimating the speed of the boat based on the travel time between IIA and IIB and between IIB and I. Because the geo tracks were interpolated, these runs were not used in the analysis of harmful effects.

The electric field dataset for run 16 on June 14 was incomplete. The data recorder stopped prematurely. Therefore, this run also was not used in the harmful-effects analysis.

The derivation of the hazardous electrical field levels and the procedure for finding the range of likely harmful effects are presented in Appendix B.

Table 3 and Table 4 (see Chapter 4) present the range of voltage gradients sufficient to cause harmful physiological effects for each run completed over each barrier. The greatest range of effect is shown in Summary Table B. The worst case (maximum extent) occurred, as expected, for pulser con-figuration B with all parasitics off. The best case (minimum extent) oc-curred, as expected, for pulser configuration D when Barrier IIB was not operating and parasitic 1 and 2 on. The best case with both Barrier IIA and IIB operating occurred for pulser configuration B with all parasitics on.

One would expect that the ranges of greatest extent for configurations E and F of Barriers IIA and IIB would be nearly the same as for configura-tion D. In all three cases, only one pulser is operating — pulser IIA for con-

ERDC/CERL TR-11-23 9

figuration D and IIB for configurations E and F. It is thought that the pa-rasitic settings affect the measured field strengths and, consequently, the ranges of physiological effects. In configuration D, parasitics 1 and 2 are on, both of which are directly adjacent to the Barrier IIA arrays. In confi-gurations E and F, parasitics 1 and 3 are on. Parasitic 3 is directly adjacent to the Barrier IIB arrays, but parasitic 1 is not. Parasitic 1 is on the down-stream side of Barrier IIA (as shown in Chapter 4, Figure 3) Pulser current from Barrier IIB is being directed from parasitic 3 to parasitic 1, raising the electrical field levels upstream from parasitic 1. Thus the field strength increases between parasitic 1 and 3, as reflected in configuration A, B, and C data. If parasitics 2 and 3 had been on in pulser configurations E and F, the range of greatest extent would be confined to the region immediately adjacent to Barrier IIB, as it is confined to the region immediately adjacent to Barrier IIA for configuration D with parasitics 1 and 2 on. In June, it was not possible to test with parasitics 2 and 3 on for configurations E and F due to electrical/mechanical problems with parasitic 2. Once parasitic 2 is repaired, mapping should be repeated with only parasitics 2 and 3 on.

The results of the sensitivity analysis (see Appendix B) show that the 20% increase or decrease in the voltage amplitude will result in a 10% increase or decrease in the extent of the safety zones associated with ventricular fi-brillation north and south of barriers IIA and IIB. The 10% change equates to an increase or decrease of 120 ft (36 m) in the extent of the safety zone based on the 0.05 V/in. man-overboard criteria.

Summary Table B. Range of greatest extent of voltage gradients ( ≥0.05 V/in.) sufficient to cause harmful physiological effects (see Table 3 and Table 4, Chapter 4).

Pulser Configuration

Parasitic Settings Range of Greatest Extent

1 2 3 Barriers IIA and IIB, in ft (m) Barrier I, in ft (m)

≥ 0.05 V/in (ventricular fibrillation)

≥ 0.03 V/in (involuntary muscular reactions)

≥ 0.02 V/in (involuntary muscular reactions)

≥ 0.05 V/in (ventricular fibrillation)

≥ 0.03 V/in (involuntary muscular reactions)

≥ 0.02 V/in (involuntary muscular reactions)

A (Feb 12) On Off On 1,231 (375) 2,083 (635)* 1707 (520) 263 (80) 2149 (655)* N/A

B (Feb 11) Off Off Off 1,394 (425) 2,083 (635)* N/A 296 (90) 2,083 (635)* N/A

B (Feb 11) On Off On 1,197 (365) 2,100 (640)* N/A 296 (90) 2,100 (640)* N/A

B (Feb 11) On On On 1,131 (345) 1,411 (430) N/A 263 (80) 607 (185) N/A

C (Feb 12) On Off On 1,165 (355) N/A 1658 (505) 263 (80) 2149 (655)* N/A

ERDC/CERL TR-11-23 10

Pulser Configuration

Parasitic Settings Range of Greatest Extent

1 2 3 Barriers IIA and IIB, in ft (m) Barrier I, in ft (m)

≥ 0.05 V/in (ventricular fibrillation)

≥ 0.03 V/in (involuntary muscular reactions)

≥ 0.02 V/in (involuntary muscular reactions)

≥ 0.05 V/in (ventricular fibrillation)

≥ 0.03 V/in (involuntary muscular reactions)

≥ 0.02 V/in (involuntary muscular reactions)

D (Feb 12) On On Off 607 (185) 804 (245) N/A 247 (75) 542 (165) N/A

E (June 14) On Off On 1050 (320) 1181 (360) N/A 295 (90) 492 (150) N/A

F (June 14) On Off On 1001 (305) 1132 (345) 1296 (395) 344 (105) 525 (160) N/A

* Range of harmful effects extends from south of Barrier IIA to north of Barrier I, there is no safe zone between barriers.

2.1.4 Conclusions

Figure 3 shows the areas of likely harmful effects for the six pulser confi-gurations given in Chapter 4, Table 5. Areas associated with involuntary muscular contraction (yellow) are larger than those associated with ventri-cular fibrillation (red) due to lower threshold voltage values (Appendix B).

Figure 3. Relative locations of areas of likely harmful effects for the four pulser configurations of Table 5 (continued to next page).

ERDC/CERL TR-11-23 11

Figure 3 (concluded).

The six areas associated with ventricular fibrillation have been combined into Figure 4.The threshold values derived for pulser configurations Alpha, ERDC/CERL TR-11-23 12

Charlie, and Foxtrot are lower (≥ 0.02 V/in.) than pulser configurations Bravo, Delta, and Echo (≥ 0.03 V/in.) due to the longer pulse width as it was incorporated in the calculations. These six areas are shown with the harmful effect zone from 2009, when Barrier IIA was operating alone at

2.0 V/in. The results of the sensitivity analysis suggest that these areas represent worst-case estimates of the actual hazard zones.

For pulser configurations E and F, the harmful-effect zones are similar to configurations A, B, and C because field mapping was conducted with only parasitics 1 and 3 on. Electrical/mechanical problems with parasitic 2 pre-vented it from being used in the mapping. Once parasitic 2 is repaired, mapping should be repeated with only parasitics 2 and 3 on.

If the operating parameters of a barrier are changed, then the electric field strengths in the water must be mapped again to determine the areas of harmful effects. However, the approach laid out in Appendix B would still be applicable and can be used to evaluate the new field mapping results.

ERDC/CERL TR-11-23 13

Figure 4. Locations of likely harmful effects for the six pulser configurations in Table 5, Chapter 4.

2.2 Sparking potential testing at fleeting area (Objectives 2 and 3)

2.2.1 Procedure

Sparking potential testing was completed for each of four operational sce-narios. Three configurations for assembling a tow were utilized for testing sparking potential during fleeting operations: assembling a tow with the barges in series (Figure 5 and Figure 6), in parallel (Figure 7 and Figure 8), and insertion of a single barge into a tow (Figure 9 and Figure 10).

ERDC/CERL TR-11-23 14

Figure 5. Sparking potential testing scenario for a tow with barges in series, 5 February 2011.

Figure 6. Instrumentation for testing of a tow with barges in series.

Figure 7. Sparking potential testing scenario for a tow with barges in parallel, 5 February 2011.

Figure 8. Instrumentation for testing of assembling a tow with barges in parallel.

ERDC/CERL TR-11-23 15

Figure 9. Sparking potential testing scenario for inserting a barge into a tow on 5 February 2011.

Figure 10. Instrumentation for testing of inserting a barge into a tow.

A fourth test simulated the collision of a tow consisting of five barges in series with two towboats (one on each end of the tow) spanning both Bar-riers IIA and IIB with two parallel barges moored in the fleeting area. The tow passed over the electrode arrays of Barrier IIA and Barrier IIB while approaching the fleeting area (Figure 11 and Figure 12).

In all cases, barge fleeting occurred at the Midwest Generation fleeting area at bollard 2 and southward. The following measurements and obser-vations were recorded:

1. the open-circuit voltage potential between moored and moving barge as the tow approached and touched three times

2. the electric current flowing between moored and moving barges as the tow approached and touched three times.

3. observations of whether sparking occurred while the moving barge made and broke contact with the fixed barge three times.

ERDC/CERL TR-11-23 16

Figure 11. A tow over Barriers IIA and IIB contacting a moored barge in the fleeting area on 7 February 2011.

Figure 12. Electrical measurements between a tow over Barriers IIA and IIB and a barge moored in the fleeting area.

ERDC/CERL TR-11-23 17

Sparking occurs when barges contact and separate. Therefore, for each tow configuration, the moving tow was positioned in close proximity to the moored barge that it made contact with. The contact points are shown on Figure 5, Figure 7, Figure 9, and Figure 11. The tow initially made contact with the moored barge and then slowly scraped the moored barge as it moved away. This was repeated at least three times. Key personnel were positioned to look for sparking during each contact and separation for each test. Voltages and currents between the fixed barges and the moving tow were alternately measured throughout this process. The measurement locations are shown on Figure 6, Figure 8, Figure 10 and Figure 12.

All barges used in the testing were fully loaded to achieve maximum un-derwater hull exposure. The moored barges for each sparking potential scenario were connected to the dock with soft line and to each other with wire rope. The steel barge-hulls were in contact with the wooden bumpers on the concrete dock walls providing a highly resistive ground path. The tow boat and moving barge were connected with wire rope. This mooring configuration—soft lines to shore and wire rope between barges and barges to tow boat—was consistent throughout testing.

2.2.2 Analysis

The percentage of sparking events for each pulser configuration was com-puted and peak voltages and currents at the time just before a bumping / collision event were visually estimated from plots of the data.

Rudimentary analyses of the electrical characteristics of a sparking event were performed using the voltage and current data. Voltage, or electric po-tential, is the amount of energy available to perform work on an individual charge. It is the energy per unit charge. The current is the rate at which the charges are moving. In the case of a steel barge hull, the charges are elec-trons.

From the voltage and current data, a rough estimate of the amount of energy in each pulse may be calculated using the formula ptIVE ××= where

E = energy (joules)

ERDC/CERL TR-11-23 18

V = voltage (volts) I = current (amps) tp = time (pulse length in seconds).

This estimation method is analogous to the way energy use is recorded by a common residential electric meter. The value of tp for each pulser confi-guration is listed in Table 5. Note that for the same voltage and current, longer pulses have more energy. The average voltage and current for each pulser configuration and parasitic setting were used for the energy compu-tation.

2.2.3 Results and observations

Data for the sparking potential tests during fleeting operations are listed in Table 6, and data for the sparking potential tests during simulated colli-sion are listed in Table 7. Sparking observers consisted of representatives from the test team at ERDC-CERL, one representative from Chicago Dis-trict, one representative from the Coast Guard Marine Safety Unit, and barge crewmen.

During fleeting operations testing, an observer saw sparking on 1.9% (1/52) of the series (fore and aft) mooring tests, on 0% (0/49) of the paral-lel mooring tests, on 38% (18/ 48) of the insertion tests. During the colli-sion tests, observers saw sparking on 100% (36/36) of the tests when bar-riers II A and II B were operating, on 100% (8/8) when only IIB was oper-ating, and none 0% (0/6) when only Barrier IIA was operating. During the collision tests, significant voltages and currents were measured (see Table 7). In summary, sparking was observed during operational scenarios A, B, C, E, and F but never during D when only Barrier IIA was in operation.

Summary Table C compiles the basic sparking observation results during simulated fleeting operations in the fleeting area. There is little difference in the frequency of observed sparking between pulser configurations A, B, and C and the state of the parasitics; however configurations E and F had the lowest frequencies. Sparking was observed most frequently during the insertion process.

ERDC/CERL TR-11-23 19

Summary Table C. Summary of sparking observations based on test results for sparking potential during fleeting operations (see Table 6, Chapter 4).

Pulser Configuration

Parasitic Settings

# Sparking Observations / # barge contacts

1 2 3 Series Parallel Insertion

A (Feb 5) On On On 0/6 0/6 4/6

A (Feb 5) On Off On 0/6 0/7 1/6

B (Feb 5) On On On 0/6 0/6 4/6

B (Feb 5) On Off On 0/6 0/6 2/6

C (Feb 5) On On On 0/6 0/6 3/6

C (Feb 5) On Off On 0/6 0/6 4/6

D (Feb 5) On On Off 1/6 0/6 0/7

E (June 15) On Off On 0/4 0/2 0/2

F (June 15) On Off On 0/6 0/4 0/2

Voltage values where sparking was observed ranged from 4.7 – 10 volts, while the values where no sparking was observed ranged from 1.0 – 9.9 volts. Similarly, the current values during sparking were in the same range as values measured where no sparking was observed.

Summary Table D compiles the voltage, current and estimated energy re-sults for the simulated fleeting operations, based on the data presented in Chapter 4, Table 6. Note the consistently lower energy, throughout all barge and pulser configurations, when parasitics 1, 2, 3 were all on. The average reduction was 46% and the maximum was 75%.

Summary Table D. Summary of estimated energy based on results for sparking potential during fleeting operations (see Table 6, Chapter 4).

Barge Configuration

Pulser Configuration

Parasitic Settings

Average Peak voltage (volts)

Average Peak Short Circuit Current (Amps)

Estimated Energy (mJoules) 1 2 3

Series A (Feb 5) On On On 6.5 1.1 44.8

Series A (Feb 5) On Off On 6.6 1.5 62.6

Series B (Feb 5) On On On 7.2 0.9 17.0

Series B (Feb 5) On Off On 8.4 1.6 33.5

Series C (Feb 5) On On On 6.0 0.8 29.5

Series C (Feb 5) On Off On 8.2 1.5 81.7

ERDC/CERL TR-11-23 20

Barge Configuration

Pulser Configuration

Parasitic Settings

Average Peak voltage (volts)

Average Peak Short Circuit Current (Amps)

Estimated Energy (mJoules) 1 2 3

Series D (Feb 5) On On Off 4.4 0.3 2.9

Series E (June 15) On Off On 2.0 0.3 1.3

Series F (June 15) On Off On 1.2 0.2 1.6

Parallel A (Feb 5) On On On 2.3 0.3 4.7

Parallel A (Feb 5) On Off On 3.2 0.4 8.0

Parallel B (Feb 5) On On On 2.5 0.3 1.8

Parallel B (Feb 5) On Off On 2.5 0.4 2.6

Parallel C (Feb 5) On On On 2.6 0.4 6.6

Parallel C (Feb 5) On Off On 2.8 0.6 11.0

Parallel D (Feb 5) On On Off 1.6 0.2 0.7

Parallel E (June 15) On Off On 0. 6 0.1 0.2

Parallel F (June 15) On Off On 0.5 0.1 0.3

Insertion A (Feb 5) On On On 6.7 1.0 43.3

Insertion A (Feb 5) On Off On 6.9 1.7 75.9

Insertion B (Feb 5) On On On 6.3 1.3 20.7

Insertion B (Feb 5) On Off On 8.6 1.7 35.5

Insertion C (Feb 5) On On On 5.5 1.0 34.4

Insertion C (Feb 5) On Off On 8.2 2.5 132.0

Insertion D (Feb 5) On On Off 1.6 0.2 0.9

Insertion E (June 15) On Off On 1.5 0.2 0.8

Insertion F (June 15) On Off On 1.3 0.2 1.7

The range of peak voltage measured for each operational configuration with all three parasitics in the on position was not significantly different than the ranges measured with only two of the parasitics connected. The estimated energy was consistently lower with all three parasitics in the on position in comparison to estimates with only two of the parasitic con-nected.

The collision tests (Table 7, with results compiled in Summary Table E) showed a range of peak voltages during sparking from 35.0 – 96.6 volts, in comparison to 15.3 – 19.2 volts when no sparking was observed. However, it should be noted that sparking was observed in every test of pulser confi-gurations A, B, C, E, and F, but not during scenario D. No such range dif-ference was observed in the electric current measurements.

ERDC/CERL TR-11-23 21

Summary Table E. Test results for sparking potential during collision simulations, conducted on 7 February 2011 (see Table 7, Chapter 4).

Pulser Configuration

Parasitic Settings Sparking

Observations Peak Voltage

Estimated Energy

1 2 3

A (Feb 7) On On On 6/6 68.6 V – 78.4 V 5,667 mJ

A (Feb 7) On Off On 6/6 60.3 V – 69.3 V 5,207 mJ

B (Feb 7) On On On 6/6 67.4 V – 72.7 V 1,973 mJ

B (Feb 7) On Off On 6/6 60.7 V – 72.6 V 1,941 mJ

C (Feb 7) On On On 6/6 85.9 V – 96.3 V 12,033 mJ

C (Feb 7) On Off On 6/6 19.8 V – 96.6 V 11,121 mJ

D (Feb 7) On On Off 0/6 15.3 V – 19.2 V 727 mJ

E (June 15) On Off On 4/4 35.0 – 62.0 V 2,774 mJ

F (June 15) On Off On 4/4 68.0 – 72.0 V 2,581 mJ

During collision tests there was not a significant difference in the esti-mated energy between parasitic settings for each pulser configuration.

This result was due to the tow spanning both barriers and all parasitics.

Sparking is caused by the separation of barges. When barges are posi-tioned parallel with the stray current from the barriers, maximum poten-tial difference between them may be observed. However, when barges are perpendicular to current, minimum potential difference and minimum current flow will be seen.

A limited literature review was conducted on the topic of electrical spark-ing. The US Occupational Safety and Health Administration (OSHA) has published several documents that discuss sparking, mostly related to ma-chinery and protecting personnel from burns. OSHA has a web page about safety for the electric power generation, transmission, and distribution in-dustry.4

The review identified one document pertaining to explosion ha-zards in the coal industry, including coal-fired power plants [10]. This document suggests that the primary danger is from coal dust in a confined space. Concerning coal storage outside, the author states that http://www.osha.gov/SLTC/powergeneration/index.html http://www.osha.gov/SLTC/powergeneration/index.html�

ERDC/CERL TR-11-23 22

The raw coal for a pulverized fuel system is usually re-ceived from a variety of sources and the size is gener-ally limited to approximately 2 inches or smaller. This raw coal is typically stored on an outside stockpile where it is moved around by frontend loaders. The fire and explosion hazards associated with this stock-pile are usually limited to spontaneous combustion [10].

Further information on the potential ignition of coal dust from an electric-al spark was provided through an examination of the Midwest Generation facility electrical safety provisions. Coordination with Midwest Generation environmental and electrical specialists provided information on the clas-sification of various areas of the facility.

National Fire Protection Association (NFPA) Code 70, or the National Electric Code (NEC), is a US standard for the safe installation of electrical wiring and equipment. Chapter 5 of the code addresses electrical wiring in special occupancies and establishes various classifications. Of concern to the Midwest Generation facility are the classified areas defined by Class II (locations that are hazardous due to the presence of combustible dust), Di-vision 1 (locations where hazardous concentrations are present in the air continuously, intermittently or periodically under normal operating condi-tions) and Group F (atmospheres containing carbon black, coal dust, or coke dust). These NEC provisions are related primarily to the use of proper enclosures, wiring trolleys, bronze hooks, stainless steel chain, or wire rope to provide the necessary spark resistance.

Electrical safety provisions of the plant were examined with respect to the above classification and it was determined that the coal stockpile did not require any special provisions. However, explosion-proof equipment has been installed in areas that contain enclosed rooms. This includes under-ground tunnels and the tripper room inside the plant. No area outside, in-cluding the stockpile and conveyors, is required to have explosion-proof equipment.

2.2.4 Conclusions

It is concluded that there is greater risk of sparking during the insertion fleeting operation than during series or parallel tow operations. It is also concluded that the operation of both barriers at the same time increases

ERDC/CERL TR-11-23 23

the potential for sparking during fleeting operations. There is consistently lower energy per pulse when parasitics 1, 2, 3 are all on. For coal-handling operations in the barge loading and fleeting area, and in the open storage area, the pertinent literature does not support concern for electrical spark-ing to create an explosion hazard.

2.3 Long tow voltage potential test (Objective 4)

2.3.1 Procedure

Long tow testing was completed for each of the barrier operational scena-rios. In these tests a tow of five fully loaded barges in a single line made a minimum of three trips traversing from the fleeting area to above the aeri-al pipeline arch (Figure 13 and Figure 14).

This testing was designed to measure the voltage potential between the barges and tow boats within a long tow during the operation of all three barrier systems. This was accomplished by recording six channels of barge open circuit voltage potentials as the long tow traverses the barrier region.

The voltage potentials between adjacent components of the long tow (V01, V12, V23, V34, V45, and V56) were measured as shown in Figure 14. Unlike previous testing, this time there were two towboats, one at each end of the five-barge tow. The boats are designated 0 and 6, the barges 1 – 5, which resulted in six measurement channels. All components of the tow were connected using wire rope, as is typical for transit on the canal.

ERDC/CERL TR-11-23 24

Figure 13. Long tow consisting of five barges and two towboats traversing the barriers on 8 and 10 February when the pulsers were in configuration Bravo and Parasitic 2 was on.

Figure 14. Diagram of five open-circuit voltage measurements (V1–V5) simultaneously captured for each barge in the long tow.

ERDC/CERL TR-11-23 25

2.3.2 Analysis

The voltage plots were examined for each run, and the peak values when boats and barges passed over the barriers were noted.

2.3.3 Results and observations

Results of the long-tow voltage potential tests are listed in Chapter 4, Ta-ble 8, Table 9, and Table 10. The salient results are outlined below in Summary Table F.

Summary Table F. Outline of test results for long tow traversing Barriers IIA, IIB, and I, conducted on 8 and 10 February 2011 (see Tables 8–10, Chapter 4).

Pulser Configuration

Parasitic Settings

Range of voltage Differences between Barges

1 2 3 Over Barrier I Over Barrier IIA Over Barrier IIB

A On On On 0.44V – 1.33V 1.60V – 3.23V 1.93V – 3.77V

A On Off On 0.39V – 1.20V…