Mig Ie AN (Gard 2 Miscellaneous Paper CERC-96-8 December 1996 US Army Corps of Engineers DOCUIMEaArr ; PIGUIVIEN l bi&pap Waterways Experiment W WiIDAARY oods Hole Oceanographic institution Station Pilot Study to Characterize Ordnance Contamination Within the Sea Bright, New Jersey, Sand Borrow Site by Joan Pope, Richard Lewis, Andrew Morang, Timothy Welp Approved For Public Release; Distribution Is Unlimited Prepared for Headquarters, U.S. Army Corps of Engineers The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. no G9 PRINTED ON RECYCLED PAPER Miscellaneous Paper CERC-96-8 December 1996 Pilot Study to Characterize Ordnance Contamination Within the Sea Bright, New Jersey, Sand Borrow Site by Joan Pope, Richard Lewis, Andrew Morang, Timothy Welp U.S. Army Corps of Engineers Waterways Experiment Station 3909 Halls Ferry Road Vicksburg, MS 39180-6199 0 0301 0091505 4 AULA Final report Approved for public release; distribution is unlimited Prepared for U.S. Army Corps of Engineers Washington, DC 20314-1000 US Army Corps of Engineers Waterways Experiment Station Ei ol i i . re \ Vw inl or ae a OR DECRMATION CONTACT : PUBLIC AFFAIRS OFFICE U.S. ARMY ENGINEER WATERWAYS EXPERIMENT STATION AREA OF RESERVATION © 27 sqiso Waterways Experiment Station Cataloging-in-Publication Data Pilot study to characterize ordnance contamination within the Sea Bright, New Jersey, Sand Borrow Site / by Joan Pope ... [et al.] ; prepared for U.S. Army Corps of Engineers. 76 p. : ill. ; 28 cm. — (Miscellaneous paper ; CERC-96-8) Includes bibliographic references. 1. Ordnance — Evaluation. 2. Ordnance disposal units — New Jersey — Testing. 3. United States — Army — Ordnance and ordnance stores. 4. Sea Bright (N.J.) I. Pope, Joan. II. United States. Army. Corps of Engineers. Ill. U.S. Army Engineer Waterways Experi- ment Station. IV. Coastal Engineering Research Center (U.S. Army Engi- neer Waterways Experiment Station) V. Title. VI. Series: Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; CERC-96-8. TA7 W34m no.CERC-96-8 Contents ITCLACE penye Mem entre me eset es he RRC ee ma nen eM tee) pei tece Meee vii Conversion Factors, Non-SI to SI Units of Measurement .............. ix Ie INOGUCHOR:, ctevec Maras seayse un. rele gacere nee BMT A ace a. Oh Rehm 1 2—Background on Fort Hancock, Sandy Hook ............... we... 4 S—Pilot:Shidy Overview: sits. 20. die cee eee eee ooo a 10 Backeround) ost BE ee aren Plog wate at cp Une eo ho taal an 10 Inert:Ordnance; Test!Bed i) 28h cue Whe EBs cone Raa eu en ena 12 4—Acoustical' Systems) a & aoa aa Beenie ge pee, GE aa ean 18 Side-Scan'Sonaty (45s cyst oe tew key eel ses ee ee ye ee 18 DRS tars cy ees ee ital leapt ad A aa a a wl aati ce aa 18 S—Video Camera, oo o/s: 552i cecsiesuings cowed Ae tee a IS oe 21 G—Mapnetometen area custove a: Space rapier peetenines elec hon aye te 22 Introduction spo ie og aren ert ae aaa hs ple y Ae appre p ae cree pk 22 Mheoretical Background heise is ees als Sieee eg eee nanos & 22 Instrumentationy ee 05 ty eee ki ieee cr ae ay Act eee yee | OU 23 STRESE:S ite ys eceaetes pein els Clasico ee pa 23 SmnallSite ss ss2he ea cae al a onan Satara Ne Ma Sees te 24 Leone Eines eee hiseee satiate ss ee elect ese goo cee ents ae ca 24 Target Location and Analysis by Maximum EikelihoodsEstimation;Method (oy)e aa. ee a eee a 26 Magnetic location Conclusionsiian-) were sai ee 27 7—Cartographic Display and Data Summaries .................... 49 $—Summiary of; Findings se i cacy ance acheter eee aioe ee Ce dice 50 9—Recommendations and Conclusions Relative to a BullScalesSurvey, arse pete Me ee a ase Pe ROE ne a 52 References Appendix A: Analysis of Magnetometer Targets fromong)/Masnetometemmines@ er ee eine Al List of Figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Location map of Sea Bright borrow area relative toPRort/Hancock 2 sens ht emerges hee enters an Crater is PS) EortiHancockibatteries ane ce eee 6 Borrow area and bathymetry ..................... 13 Underwater video survey lines. Borrow area 1A shown for reference ..................... 14 X-star subbottom profiler survey lines. Borrow area 1A shown for reference ............... 15 Magnetometer survey lines, northern portion‘of borrow arcaslA es aaa Meta, ee ees 16 Long magnetometer survey lines. Overall Sea Bright borrow area shown for reference ........... 17 Side-scan sonar record showing sand waves ........... 20 X-star record from along line of ordnance placed'foritestiofisystemia ea a ee) ee ee 20 Custom-fabricated mount for cesium-vapor SENSOLS! 2s eosin tne Sue es ican Renee Onrclee Bree eae ae 28 Example of horizontal magnetic gradient recorded during calibration tests with inert ordnance test targets, passnumber5 ............ 29 Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Example of horizontal magnetic gradient recorded during calibration tests with inert ordnance test targets, passnumber6 ......... Horizontal magnetic gradient recorded in ordnance disposal area, magnetic line 16 (referenceykigurelO) meee ia ene Horizontal magnetic gradient recorded in ordnance disposal area, magnetic line 17 .......... Horizontal magnetic gradient recorded in ordnance disposal area, magnetic line 21 .......... Horizontal magnetic gradient recorded in ordnance disposal area, magnetic line 19 .......... Altitude of V-fin and cesium-vapor magnetometers on magnetic line 19 ............. Plot of long magnetic traverses showing track lines on left and zones of magnetic response on the right. Scales are in feet measured from arbitrary zero points - locations do not represent State!Planeicoordinatess ae ee eee Horizontal gradient recorded on long magnetic traverse number 8. X-axis represents State Plane:cOordinate ns icks- see ee eek) Seas Horizonial gradient recorded on long magnetic line number 1. X-axis represents State Plane COOPGINA te te. SR he a Rd aN cei a Horizontal gradient recorded on long magnetic line number 2. X-axis represents State Plane COOrdifiate! clN Mile aie ae We tan ta eaeuly, eaten eae Horizontal gradient recorced on long magnetic line number 3. X-axis represents State Plane COOLGINATE RS Se rs beers cet oe ee ee tat Raa 40 vi Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Horizontal gradient recorded on long magnetic line number 4. X-axis represents State Plane COOTCINALE Tere tae te eter eee eon ones aice oI = noe POR Horizontal gradient recorded on long magnetic line number 5. X-axis represents State Plane COOrdINAtS AE reer. oes aeusene Rene «peu cue ce Ems eo eels Horizontal gradient recorded on long magnetic traverse number 6. X-axis represents State Plane (07000) (010 Re ae PL nas a Nicene ROR RCUSAE CR 6 Anam ARS Horizontal gradient recorded on long magnetic traverse f number 7. X-axis represents State Plane Coordinate erry sep eset dace na scene, cpr tne aa as Altitude of V-fin and magnetometers on PCOS Jl, SAKA TS ago o oo doobes occu poees Anomaly strength (peak signal magnitude) of 100 samples selected from the north-south magnetometer lines. (Plot provided by AETC) ......... Cross-track locations, 100 analyzed samples. Shaded area indicates computed detection range of array used in the field. (Plot provided by AETC) ........... Computed depth from seafloor to center of objects. Negative values correspond to dipole fits where the center of object is above the bottom. Most objects are lying on the seafloor. (Plot provided by AETC) ........ Distribution of apparent sizes of the 100 test objectss. (Plot provided by AEI©)—..5r eee Distribution of sizes of ordnance recovered during 24-hr test raking operation ................. Preface The field study and analysis described in this report were performed by the U.S. Army Engineer Waterways Experiment Station's (WES’s) Coastal Engineering Research Center (CERC) and Geotechnical Laboratory (GL) for the U.S. Army Engineer (USAE) District, New York. A Pilot Study was designed and conducted off the north New Jersey shore at the approved sand borrow site for the Sea Bright Beach Erosion Control Project during September 1995 to test and evaluate various technologies for characterizing ordnance contamination. USAE Division, Huntsville, reviewed and approved the pilot study safety plan. USAE District, New York, provided survey vessel support. The U.S. Coast Guard Station at Sandy Hook provided dockage, logistical support, and an operation base. Rangers at the Fort Hancock National Park and Explosive Ordnance Disposal (EOD) team members at Fort Monmouth and Earle Naval Air Station provided valuable input on the nature and history of ordnance use and finds in the study area. CERC coordinated the overall study, analysis, and reporting. GL coordinated the magnetometer data collection and data analysis. CR Environmental provided the research vessel with Global Positioning System (GPS) position controls used for the magnetometer survey, Edgetech conducted the side-scan sonar and X-star surveys, and Geometrics furnished and operated the magnetometer. Additional magnetic data processing was conducted by Messrs. Douglas DeProspo, Erick Cleary, and Thomas Bell of Arete Engineeering Technologies Corporation (AETC). USAE District, New York, personnel responsible for project oversight include Mr. Joseph Zaraszczak and Ms. Lynn Bocamazo. WES participants in the field study were Messrs. Timothy Welp, Michael Tubman, Douglas Lee, and William Kucharski from CERC's Prototype and Analysis Branch (PMAB); Ms. Joan Pope, Chief of CERC's Coastal Structures and Evaluation Branch; and Dr. Richard D. Lewis of GL's Engineering Geophysics Branch. Contract personnel contributing to the field effort were Messrs. Alfred Ackerknecht and Lynn Edwards (Geometrics), Mr. John H. Ryther, Jr. (CR Environmental), and Mr. William Charbonneau (Edgetech). Participants in the field investigations from USAE District, New York, were Messrs. Joseph Mayers, Ronald Burns, Douglas Wilson, Joseph Zaraszczak, Daniel Petrie, and Frank Santangelo. Mr. Timothy LaFontaine of USAE District, New York, coordinated the support of the U.S. Army Corps of Engineers Survey Vil Vili Vessel “Sentry” and crew. Mr. Wayne Galloway, USAE Division, Huntsville, reviewed and coordinated the safety plan. The project Geographic Information System (GIS), including reference maps, survey controls, and spacial database, was developed by Dr. Andrew Morang of CERC. A number of individuals from the study area provided immeasurable assistance in coordinating logistical support, assisting with operational safety and security, and providing insight into the history of Fort Hancock and the occurrence of ordnance contamination. In particular, the authors wish to acknowledge the assistance of Mr. Thomas Hoffman, U.S National Park Service (Fort Hancock); Messrs. James Mullins and Douglas Wilson, USAE District, New York (Sea Bright Project Office); LT Amos Gallagher and Chief Warren, Earle Naval Air Station (Explosive Ordnance Disposal Team (EODT)); LT William Downer; Fort Monmouth (EODT); and LT Londratowiz, MK3 Daniel Newman, and BMI Fred Squirini, U.S. Coast Guard (Sandy Hook). Work in CERC was performed under the general administrative supervision of Mr. William Preslan, Chief, PMAB; Mr. Thomas W. Richardson, Chief, Engineering Development Division; Mr. Charles C. Calhoun, Jr., Assistant Director, CERC, and Dr. James R. Houston, Director, CERC. GL general administrative supervision was provided by Mr. Joseph Curro, Chief, Engineering Geophysics Branch; Dr. Arley G. Franklin, Chief, Earthquake Engineering and Geophysics Division; and Dr. William F. Marcuson, Director, GL. Ms. Pope of CERC was the Principal Investigator for this study. Dr. Lewis coordinated the magnetometer data collection and conducted the analysis of the magnetic data. Mr. Welp of CERC coordinated the field logistics. Mr. Tubman coordinated the acoustical systems, and Mr. Lee operated the remotely operated vehicle. Dr. Morang coordinated the development of the project GIS. Ms. Pope, Drs. Lewis and Morang, and Mr. Welp are the authors of this report. Mses. Mary Claire Allison and Robin Hoban (CERC) and Dr. Cary Cox (WES Information Technology Laboratory) assisted in developing the GIS and in the post- processing of magnetometer data. Ms. Janie Daughtry assisted in text preparation. Director of WES during publication of this report was Dr. Robert W. Whalin. Commander was COL Bruce K. Howard, EN. The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. Conversion Factors, Non-Sl to SI Units of Measurement Non-SI units of measurement used in this report can be converted to SI (metric) units as follows: knots (international) square miles pounds (mass) kilograms ee ee ee 1. Introduction The U.S. Army Corps of Engineers (USACE) and the state of New Jersey are constructing the largest beach restoration project ever undertaken in the United States, known as the “Atlantic Coast of New Jersey, Sandy Hook to Barnegat Inlet, Section I, Sea Bright to Ocean Township.” Its purpose is to protect 12 miles’ of heavily eroded and highly developed north New Jersey shore from coastal storm damages. The total initial project cost is estimated at $165 million (Federal and non-Federal costs). The primary source for the beach quality sediment is a 3-square-mile area located 1 to 3 miles offshore of the southern end of Sandy Hook (Figure 1). Ocean-going hopper or cutterhead dredges excavate sediment (initial project construction total of 18.5 million cu yd) from the authorized borrow area and, with the assistance of nearshore pump-out facilities, transport the material onto the beaches. The project is scheduled to be constructed in four phases as individual contracts are awarded per section of beach and designated area within the authorized borrow area (i.e., contracts 1A, 1B, 2, and 3). Construction started in 1994 with the award of contract 1A and contract 1B was awarded in 1995. Fifty years of periodic beach renourishment are programmed into this project. Within a very short period after initiation of Contract 1A, ordnance were discovered on the newly constructed beaches. Expensive cleanup operations were required to locate and remove the ordnance from the beach. The source of this material was determined to be ordnance mined along with the borrow, although there had been no preproject data suggesting the presence of this contamination. To eliminate further risk of ordnance ingestion, the project dredges where fitted with 1.5-in. square grates over the dragheads. These grates prohibit excavation of the ordnance, thus protecting the dredge and the resultant beach area from unexploded ordnance (UXO) contamination. However, the grates also reduced the efficiency of the dredging operation by an estimated 20 percent. Over the 50-year project life, the presence of these grates and the reduced dredging efficiency could cost hundreds of millions of dollars in lost productivity. The U.S. Army Engineer District, New York (NAN) asked the U.S. Army Engineer Waterways Experiment Station (WES) to evaiuate and make recommendations on a means of characterizing the ordnance contamination in the aL i ; ake ‘ A table of factors for converting non-SI units of measurement to SI units is presented on page ix. Chapter 1 Introduction conventional manner (1.e., without the grates on the dragheads) or to design a practical and safe predredging cleanup operation. Of particular interest would be data which may confirm that certain sections of the borrow area are not contaminated or that the ordnance is confined to the surface or near surface. WES conducted a review of several technologies and recommended a "pilot study" to test oceanographic/geophysical systems for their suitability in detecting ordnance at the Sea Bright site. NAN concurred with this recommendation and requested that WES proceed with the pilot study, which is reported here. Chapter 1 Introduction + ao + ey 4 eA + 00006123 + 000012e3 + ATLANTIC OCEAN SANDY HOOK N600000 N600000 LS) w a a ° ° ° ° ES = = = Lon] — Lond = c c c = m m m m o a 2p) n N590000 N590000 SEA BRIGHT BORROW AREA N580000 NEW JERSEY N570000 570000 U.S. ARMY CORPS OF ENGINEERS COASTAL ENGINEERING RESEARCH CTA. SEA BRIGHT ORDNANCE CONTAMINATION PILOT STUDY RUMSON NECK PROJECT AREA N.J. STATE TRANSVERSE MERCATOR NAD27 SHORE FROM NOAA CHART 12324 06/94 ARTILLERY AANGES IN MILES EHOOOR}eCS + 7 Figure 1. Location map of Sea Bright borrow area relative to Fort Hancock Chapter 1 Introduction 3 2 Background on Fort Hancock, Sandy Hook Coastal fortifications and military posts have been located at the northern end of Sandy Hook, NJ, since the mid 1700's. This strategic location guards the major navigation routes into New York Harbor. Construction of Fort Hancock began in 1857, and by 1874 Sandy Hook was designated as the Army’s first proving grounds for munition and weapon testing. Consequently, various generations of large shore-based artillery and mortar batteries were built at Fort Hancock at the north end of this sand spit (Figure 2). Remnants of the fortifications constructed from the 1890's until the 1940's are still in place at this formerly used defense site and maintained by the National Park Service. From 1874 until World War I, a 4-mile stretch of beach and coastal dunes extending to the south and the offshore in several directions were used as target areas for the nation’s primary artillery proving ground. Various naval and army artillery and experimental rounds were tested along with proof firing of barrels for government acceptance. This long-term use of Sandy Hook for military training and artillery proofing has resulted in ordnance contamination of large sections of Sandy Hook proper and the nearshore (U.S. Army Engineer (USAE) District, St Louis 1993). A wide variety of ordnance (light artillery to 15-in. cannonballs), dating from the Civil War through World War II, have been and are currently being recovered from Sandy Hook and adjacent areas. During the pilot study reported here, each remnant battery and proving station at Fort Hancock was located and its position determined using a hand-held Global Positioning System (GPS) receiver. These positions were entered into the project Geographic Information System (GIS) database and are plotted in Figure 2. This mapping analysis was conducted to locate the Sea Bright borrow relative to Fort Hancock and its documented firing ranges to ascertain the potential for Fort Hancock to be the source of the observed ordnance contamination. In addition, an historical summary of the various batteries (caliber, range, firing zones, etc.) was developed (Table 1) based on information available through the Fort Hancock National Park.’ It is known that the coastal batteries trained on targets that were towed in the Atlantic. Firing fans tended to cover the hemisphere from the north through the eastern quadrants to the south-southeast (directly down the line of the 1 Personal Communication, Thomas Hoffman, National Park Service, Fort Hancock, Sandy Hook, N.J. Chapter 2 Background on Fort Hancock spit) with ranges generally on the order of 7-9 miles (maximum of 20 miles). The borrow area in relation to the battery positions is presented in Figure 1. Note that the entire borrow area is within the quoted firing fans and range potential for most classes of artillery tested at Fort Hancock. Discussions with Explosive Ordnance Disposal (EOD) team members at Fort Monmouth (Army) and Earle Naval Air Station (NAS) confirmed that the age and caliber of recovered ordnance from the general vicinity suggest that Fort Hancock is a likely source for the bulk of this material. They referenced finding Civil War-era cannonballs, parrot rounds, and a common array of 3-in. hollow rounds and 10-in. rounds filled with ball bearings which were known to have been tested at Fort Hancock from 1875-1919. However, they also pointed out that 90 percent of the World War II ordnance shipped to Europe went out of New York Harbor. Some of these vessels were sunk by German U-boats just outside the harbor. In addition, some ordnance cargo may have been lost or dumped off ships outside the harbor entrance. Thus, there is potentially a more modern source of ordnance contamination to the area, and more modern (circa WWII) pieces have been found in the offshore. It was not the intent of the subject study or this cursory review of potential ordnance sources to conduct a complete historical assessment. However, the information presented here does indicate the potential for a wide variety of ordnance types and sizes to exist throughout the borrow area. A more in-depth archival review would be needed to better characterize the caliber, vintage, location, and volume of expected ordnance contamination. Chapter 2 Background on Fort Hancock 00008123 000e8T eS O00r8tes 00098124 00088124 00006TeA N600000 + + + + + + N600000 N598000 N598000 N596000 N596000 S JV SATIN O'F N594000 N594000 N592000 N592000 N590000 + + N590000 N588000 aP te + oF oP + + P oP + N588000 U.S. ARMY CORPS OF ENGINEERS COASTAL ENGINEERING RESEARCH CTR. + + + + ap N586000 SEA BRIGHT ORDNANCE CONTAMINATION PILOT STUDY FORT HANCOCK DETAIL ‘. fs + + N584000 if + + 4 N.J. STATE TRANSVERSE MERCATOR NAD27 BATTERY LOCATIONS: GPS SURVEYS 9/95 | SHORE FROM NOAA CHART 12324 06/94 000981¢e3 Figure 2. Fort Hancock batteries 2 Chapter 2 Background on Fort Hancock Table 1 Fort Hancock, Sandy Hook, NJ, Battery Statistics Active Battery Period 1903-1942 3° 15 Ib for projectile + ‘ eT cartridge case was about 15 more pounds 30 Ib per fixed round 15 Ib for projectile + cartridge case was about 15 more pounds 30 Ib per fixed round a5 ae Primary Range Direction (miles) of Fire North end of Sandy Hook toward NYC Could fire 360 deg but mainly north toward NYC North end of Sandy Hook toward NYC could train to the east 360 deg field of fire guns mounted on Barbette carriages 360 deg swivel Barbette carriages Constructed 1898 disarmed 1918 fires north to east Constructed 108 Ib 360 deg Barbette carriage 1903 18" long 360 deg swivel 10" 700-1,080 Ib 12° 700-1 ,000 Ib 700-1 ,080 Ib Completed 1894, first fired 1892 Built in 1896 Armed in 1897-98 Fired 1898 to 1943 Chapter 2 Background on Fort Hancock Northeast to southeast ae Northeast to southeast Maximum range was up to 9 miles, but accurate up to6 miles “Pop up” guns disappearing carriages 140-145 deg swivel 2.5 to 4 or 5 ft long “torpedo” shell elevator platform guns Counterweight disappearing carriage Mortar pits 360 deg swivel. Four concrete firing pits, four mortars/pit Sheet 1 of 3 Table 1 (Continued) Primary Active Range Direction Battery Period (miles) of Fire Gunnison Northeast to Disappearing southeast guns converted in 1943 to 2-6" Barbette carriages from battery Peck Converted in 360 deg swivel 1943 to Barbette carriages Old Proof 1874-1900 Small 3.5+ mile Southeast over | All American 1874-1886 arms fange ocean and ordnance and converted machine south down also foreign rifled guns oceanside ordnance were Rodman field, beach and test fired at the guns were siege, sand dunes of Sandy Hook test fired and Sandy Hook Proving Ground Navy artillery 1 to 16" New Proof | 1901-1919 Small 3.5+ mile Southeast over arms range ocean and machine south down guns oceanside field, beach and siege, sand dunes of and Sandy Hook Navy artillery 1 to 16" Battery WwwI 12" 975 Ib From 1919 to Barbette carriage Kingman 1941, 360 deg 360 deg swivel field of fire. Casemating in 1941 limited guns to about 145 deg northeast to southeast ‘Sheet 2 of 3 8 Chapter 2 Background on Fort Hancock Table 1 (Concluded)' Primary Active Range Direction Period (miles) of Fire 1909-1919 3 260 Ib Southwest to Disappearing north guns - battery was located on bayside of Sandy Hook - could cover Sandy Hook Bay and lower New York Harbor 12" 975 Ib 360 deg from Barbette carriage 1919 to 1942 - 360 deg swivel guns were roofed over in casemated in WWII which 1942, limiting limited traverse field of fire to northeast to southeast 52nd 8" rifles Moved 1917 Several rail spurs Coast 260 Ib moved in the sand dunes Artillery 1938 260 Ib on the ocean side Hdq moved 1917 of Sandy Hook battery C 12” mortars | 700 Ib battery - on railway 12’ mortar ; flat cars E battery - 8" rifles Anti- Wwil Projectile Horizontal Antiaircraft Aircraft 1942-1946 21 Ib range batteries active in 90mm 23.4 Ib 11-12 WWII 4 guns at 24 Ib and near battery Peck, and 4 guns in sand dunes overlooking ocean - north of battery Gunnison 1922-1945 Projectiles Horizontal weighed range 8-9 12.8 Ib 15.5 Ib 24.3 Ib and 26.2 Ib ’ Per Thomas Hoffman, National Park Service, personal communication, 1995. During WWII (1942-43) some field artillery was probably employed, probably 75-mm and/or 105-mm guns. Sheet 3 of 3 Chapter 2 Background on Fort Hancock 10 3 Pilot Study Overview Background Previous to this investigation, the ordnance contamination characteristics of the offshore borrow area were unknown. Data were lacking on the ordnance density per sector and ordnance distribution, and it was not known if the ordnance were proud (i.e. located on the surface), shallow-buried, or situated deep in the sediments. In order to investigate the possibility that more efficient dredging can be conducted in certain areas or if the ordnance fields may be suitable for efficient clean-up operations, it is necessary to characterize the degree of contamination. The challenges of mapping an underwater ordnance contamination field are significant and have received recent attention at other USACE projects (Pope, Lewis, and Welp 1996; Welp et al. 1994) and within the Military Research and Development Program. A review of available and emerging technologies was made and a pilot offshore geophysical survey designed with the intent of testing geophysical and oceanographic techniques which might be suitable for use at Sea Bright. The results of this pilot study would be used to determine the potential for application as part of a large-scale survey and to identify the appropriate development and equipment integration needed for an efficient operational-scale survey. The ultimate goal of the pilot study was to develop a recommendation and reasonable cost estimate for a full-scale study. Equipment adapted and mobilized to the project site included a research vessel with GPS positioning, two underwater video cameras, two acoustical systems, and a magnetic gradiometer. In addition, a number of inert pieces of ordnance were used on site calibration testing of the equipment. The underwater video system and two acoustical systems were “off-the-shelf” items which required no further development for their use at this site. The two acoustical systems included a high- frequency side-scan sonar and sweep frequency subbottom profiler (i.e., X-star). Some field experimentation was conducted to improve system deployment and evaluate the performance of each system in detecting ordnance-like objects. Most of the effort during this pilot study was expended in adapting a state-of-the- technology cesium-vapor magnetic gradiometer for underwater deployment and towing. This involved the design and fabrication of a water-tight tow containing two magnetometers, integration with an altimeter for controlling elevation, and adaptation of data processing software. A sea trial of the fabricated system was conducted in California prior to shipment to Sandy Hook. Chapter 3 Pilot Study Overview The pilot study was conducted during 8-15 September 1995, and included the following sequence of activities: a. Mobilized equipment and personnel to study site (8-9 September). b. Assembled magnetometer and conducted deployment tests (10 September). c. Constructed equipment calibration range using inert ordnance in shallow water (10 September). d. Conducted tests of magnetometer over the calibration range and deepwater deployment tests (11 September). e. Assembled subbottom and conducted tests over calibration range (11 September). Jf. Conducted side-scan sonar survey of northwest corner of borrow area 1A from NAN vessel (12 September). g. Conducted magnetometer survey along long lines adjacent to borrow area 1A (12 September). h. Conducted dense magnetometer survey of northwest corner of borrow area 1A (13 September). I. Conducted video camera drift surveys along long lines adjacent to borrow area 1A from NAN vessel (13 September). jJ. Conducted subbottom (X-star) surveys of northwest corner of borrow area 1A and long lines adjacent to 1A (14 September). k. Obtained video footage of northwest corner of borrow area 1A using towed video and Remotely Operated Vehicle (ROV) (14 September). l. Briefed NAN staff during onsite visit (14 September). m. Removed equipment calibration range (14 September). n. Conducted magnetometer and side-scan sonar surveys in northwest corner of 1A and long lines adjacent to 1A (15 September). o. Coordinated background information with EOD detachments at Fort Monmouth and Earle NAS and determined position of historical batteries (15 September). p. Packed equipment and demobilized from site (15 September). After completion of the pilot study, the survey tracklines were captured and entered into a GIS database, and the individual data sets were processed. The surveys were conducted in water depths of 30-50 ft (Figure 3). The survey Chapter 3 Pilot Study Overview 11 12 coverage obtained per system (i.e., video camera track lines, X-star track lines, and magnetometer track lines) is illustrated in Figures 4-7. Inert Ordnance Test Bed An ordnance calibration and test field was temporarily installed in a protected cove adjacent to the Sandy Hook Coast Guard (CG) Station (near CG dock shown on Figure 2). A jet pump was used during low tide to bury (approximately 0.7 m below the sand surface) a cluster of several pieces of inert ordnance. This created a buried target approximately 0.5 by 0.5 m’. In addition, nine pieces of inert ordnance of various calibers (generally ranging from 75 mm to 105 mm, including a 155-mm piece) were placed 3 m apart in a line parallel to shore at a location where approximately 2 to 2.3 m of water would exist during high tide. The single inert ordnance piece closest to the cluster was buried approximately 0.3 m below the sand surface. Each ordnance target was marked with a witness buoy. Prior to the installation of the ordnance test bed, the area had been “swept” with a hand-held magnetometer to confirm that no other ferrous metal objects were present. There were, however, a number of pieces of wood and stone in the test bed area. The magnetic gradiometer and the X-star were towed over this test bed several times during high tide in an attempt to evaluate the performance of these two instruments in a controlled test. After completion of these tests, the inert ordnance was removed and the site was returned to its pretest condition. 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Anomaly strength (peak signal magnitude) of 100 samples selected from the north-south magnetometer lines. (Plot provided by AETC) & Number of Occurrences (=) Cross-Track Location (meters) Figure 29. Cross-track locations, 100 analyzed samples. Shaded area indicates computed detection range of array used in the field. (Plot provided by AETC) Chapter 6 Magnetometer = MW ow -£ Ss oo 3 %p) ® oO (= o — _—= 3 O =_ fo) _ o 2 iS =} Zz Depth (meters) Figure 30. Computed depth from seafloor to center of objects. Negative values correspond to dipole fits where the center of object is above the bottom. Most objects are lying on the seafloor. (Plot provided by AETC) Number of Occurrences *) oY Apparent Size (cm) Figure 31. Distribution of apparent sizes of the 100 test objects. (Plot provided by AETC) Chapter 6 Magnetometer Ordnance Recovered by “Miss Kathy" 24-hr Test Raking Operation on baa i) <2) fb) iL ® > {o} (o) () o (2) 33 we xe} O Qe oO fe) CZ, Lies i i 15 — 20 Shell size (cm) Figure 32. Distribution of sizes of ordnance recovered during 24-hr test raking operation 48 Chapter 6 Magnetometer Chapter 7 Cartographic Display and Data Summaries 7 Cartographic Display and Data Summaries Data used in the Sea Bright Pilot study were derived from several sources. This included magnetometer and acoustic geophysical information collected from survey boats in the field and hydrographic soundings provided by the National Oceanic and Atmospheric Administration. Table 2 lists sources and projections of the original navigation data provided with these data. For display in this report, all data were converted to a uniform projection and coordinate system: New Jersey Transverse Mercator, NAD27. Horizontal and vertical units of feet were used to maintain compatibility with historical maps and with the units currently used by USAE District, New York, project charts. Data display and projection conversion were performed with Terramodel software (Version 8.33 for DOS- based personal computers). Magnetometer data were processed using MATLAB software (Version 4.0 for personal computers running Microsoft Windows). Magnetometer plots in Appendix A were generated with MATLAB. Table 2 ————— Units, and ee of Positioning ——————— Hydrographic NOAA - National Geophysical Data Latitude, longitude, depths NAD27 =e Rear ee in eee ea below MLW | shoreline | NOAA chart 12324 | NOAA chart 12324 (lune 1994) 1994) N.J. | NJ. State Plane Grid -feet | Plane Grid - feet | Naber | Sub-bottom profiler DGPS collected via X-STAR survey Latitude, longitude NAD27 system Magnetometer DGPS collected via SEAMAG system Latitude, longitude NAD27 (Sandia Laboratories) Fort Hancock battery Magellan NAV 5000 hand-held DGPS Latitude, longitude NAD83 locations receiver North Star 800x Latitude, longitude 49 50 8 Summary of Findings Findings of the pilot study are summarized as follows: Qa. The entire Sea Bright borrow area is within the historical impact area for Fort Hancock and has the potential to be contaminated with ordnance. Some evidence of a spatial concentration to the ordnance contamination could be determined within the context of this very limited pilot study. Preliminary evidence suggests that there may be a trend of decreasing magnetic returns toward the south and there may be limited zones which are clear of magnetic objects. . X-star has limited use in determining if there are hard object targets (could be ordnance, stones, or even wood) buried in the sediments. X-star does not add any substantial additional data capability. . Side-scan sonar could and should be used to provide a reconnaissance level assessment of obstructions/large objects and bottom texture. . The magnetometer adapted for and tested during this pilot study is superior to other commercially available systems and is the recommended work horse for a full-scale survey. It is extremely sensitive and is able to detect individual ferro-magnetic objects of the size of ordnance. It can also be used to sweep an 8-m-wide and 8-m-deep zone during a single tow and can be used to indicate relative size, shape, orientation, depth of burial, and location of metal targets. However, the magnetometer would need some further development prior to use in a full-scale operating mode. Some laboratory and field calibration tests would be needed to better interpret the magnetic signature for different classes of ordnance versus other magnetic objects. Additional deployment and data acquisition improvements are needed. Chapter 8 Summary of Findings 8. The presence of extensive sand wave zones and other bottom texture evidence observed via the underwater video and the side-scan sonar suggest that the bottom sediments are quite mobile and it is likely that there will have been some scour and burial of bottom siting ordnance (particularly in the northern section of the borrow). However, the finite magnetometer data collected and analyzed during this study suggest that most of the ordnance-like targets are at or close to the sand surface and appear to be mobile, having oriented themselves parallel to the predominate wave crests. Chapter 8 Summary of Findings 51 52 9 Recommendations and Conclusions Relative to a Full-Scale Survey The pilot study was successful in documenting the capability of the cesium- vapor gradient magnetometer to characterize ordnance contamination at the.Sea Bnight borrow area. This system can be used to document size, shape, orientation, depth of burial, and location relative to the tow of ordnance-like targets and other metallic objects. A full-scale, operational magnetometer survey which includes the use of side-scan sonar for reconnaissance, an underwater low-light video camera, DGPS, survey design and tracking software, and EOD trained divers for limited ground-truthing is feasible and appropriate for detecting the presence, density, approximate caliber, and location of ordnance at this site. The potential value and application of the results of such a full-scale survey would be in locating any areas within the borrow which are not contaminated with ordnance (i.e., possibly to the south or further offshore Asbury Park borrow). Conversely, any areas which are so littered with large size ordnance that it would be appropriate to keep the dredging operations clear of these areas for safety reasons would also be documented. The data collected during a full-scale survey could be used to design a cleanup operation (for example, using a surface rake). A repeat survey after cleanup would determine the effectiveness of the cleanup. Finally, an operational survey of other proposed borrow areas in this vicinity may be appropriate prior to initiating other mining operations in order to ascertain the presence of ordnance contamination at these sites. Several lessons learned from the pilot study should be incorporated into the design of any proposed full-scale operational survey: a. An additional archival search (possibly by the St. Louis or Rock Island District) to document historical information, firing fans, ranges, caliber, etc. which may have impacted the offshore borrow would help in planning and interpreting the results of the survey. b. A full-scale survey should include EOD-certified divers for select ground truthing of the data. Chapter 9 Recommendations and Conclusions . Integrating a non-magnetic signature low light or acoustical line scan camera with the magnetometer might provide real-time imaging of targets, providing additional ground-truthing. . Commercially available survey planning and tracking software would improve the efficiency of the survey and assist in determining the confidence limits for the survey coverage. . Positioning improvements to better control the magnetometer tow and document absolute position are also needed to be able to assign confidence limits on survey coverage. Some improvement to the magnetometer system is warranted to ruggidize the _ tow for continuous operation and streamline signal post-processing. Processing of the magnetometer data should be continuous throughout the survey. The assembly of a magnetometer system tailored specifically for use on this project is recommended. Calibration of the magnetometer arrays must include field tests using ordnance with their long axes oriented both parallel and perpendicular to the earth’s magnetic field. . Considering the size of the borrow and a line spacing of 8 m, a full-scale operational survey would require a large, non-magnetic research vessel to transit a total of 1,300 nautical miles. Such a survey would take 4-6 weeks of 24-hr data collection. Chapter 9 Recommendations and Conclusions 53 References Bell, T., DeProspo, D., and Prouty, M. “MagAID: PC-based target characterization software for use with total field magnetometer survey data.” Proceedings of the 9th Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP). Environmental and Engineering Geophysical Society (EEGS), Englewood, CO (in press). Pope, J., Lewis, R.D., and Welp, T. (1996). “Beach and underwater occurrences of ordnance at a formerly used defense site: Erie Army Depot, Ohio,” Technical Report CERC-96-1, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS. U.S. Army Engineer District, St. Louis. (1993). “Archives search report for Fort Hancock, Sandy Hook, New Jersey: DERP-FUDS Site No. C02NJ0032,” unpublished report prepared for U.S. Army Engineer Division, Huntsville, dated August 1993. Welp. T., Clausner, J., Pilon, R., Pope, J., and Lewis, R.D. (1994). “Unexploded ordnance (UXO) and dredging.” Dredging ‘94, Proceedings of the Second International Conference on Dredging and Dredged Material Placement. American Society of Civil Engineers, New York, 48-55. References Appendix A Analysis of Magnetometer Targets from Long Magnetometer Lines Appendix A Analysis of Magnetometer Targets Al A(left) & B(right) 3905 5.39 5.3895 on wo oo o 5.3885 5.388 0 G(east) & H(north) x qe G:rt*8577.mat-N Section 6 Feet Feet Northing 4480 4470 4460 4450 4440 T 4420 4410+ 4390 4380 -10 0 10 20 30 Easting Appendix A Analysis of Magnetometer Targets x Fie G:rt8534.mat-S Section 52 ) A(left) & B(right Feet 20 15 “a o 34] G(east) & H(north) Appendix A Analysis of Magnetometer Targets Northing 2600 2590 2580 2570 2560 2540 2530 2520 2510 2500 -40 -30 -20 Easting -10 A3 A(left) & B(right) x Fie G:rtx8494.mat-N Section 50 5.39 1.541 5.3895 1.54 5.389 5.3885 1.539 5.388 1.538 5.3875 0 20 40 60 80 Feet 1.537 Lo>) c = ° Zz 1.536 1.5354 = 3 1.534 Ss ae oS = w & 1.533 Oo 1.532 0) 20 40 60 80 20 30 40 50 60 Easting A4 Appendix A Analysis of Magnetometer Targets . Fite G:rtx8494.mat-N Section 49 x 10° 1.531 1.53 1.529 1.528 1.527 x 4 N 50 100 So Feet aN D == £ Se = 1.526 a 5 Z | 2 Z BE + 1.524 7 1825) = 4 1.522 1.521 0 50 100 40 50 60 70 Feet Easting A5 Appendix A Analysis of Magnetometer Targets oO (es) foe) © uO oo oo SS) A(left) & B(right) 5.386 §.385 5.384 0 20 “a a i=) on 34] G(east) & H(north) -5 A6 Feet Northing 1.125 1.124 1.123 1.122 a ae ine) ae 1.119 1.118 1.117 1.116 40 Wee 50 60 70 Easting Appendix A Analysis of Magnetometer Targets x File G:rtX8462.mat-S Section 13 5.391 5.3905 5.39 B 5.3895 o (e%) [o) (e) 5.3885 A(left) & B(right) 5.388 5.3875 5.387 5.3865 0 20 40 _G(east) & H(north) 0 20 40 Feet Appendix A Analysis of Magnetometer Targets 60 60 80 80 2090 Northing 2080 2070 2060 ae 2050 NS SMMAannna \ x iyo) oO pS oO 2030 2020 2010 2000 1990 30 40 50 60 Easting 70 A7 ¥ te G:rtx8462.mat-S Section 9 3620 3610 3600 A(left) & B(right) 3590 3580 50 100 Feet Northing wo o N oO 3560 3550 3540 G(east) & H(north) 3530 3 3520 0 50 100 S116 ONES OME 4 OEEeToO -120 Easting ne) Appendix A Analysis of Magnetometer Targets 52 Fite G:rtX8367.mat-S Section 33 a ph bh on bh o 1140 a rs ww A(left) & B(right) - — - - 1130 \ \ \ \ \ \ \ 5.39 ey SN \ $4 \ 1120 \ \ aS \ 5.38 SESE 0 50 100 150 eae Feet ee so) ~ X“ a> x= ~ XN V £14110 ws Si = SS IQ S : Wy Ss ° & =x [of = wo & O 1070! y -500 1060 0 50 100 150 < -10 0 10 20 Feet Easting Appendix A Analysis of Magnetometer Targets AQ x File G:rtx8367.mat-S Section 27 & B(right) oOo ow Loe} wo A(left) G(east) & H(north) A10 Feet 50 Feet 100 100 3550 3540 3530 3520 3510 Northing (ev) uo [@) oO 3490 3480 3470 3460 3450 50 60 70 80 90 Easting Appendix A Analysis of Magnetometer Targets f neede ; : : any other aspect of this collection of i gph ! Pe Fes Cann Wee an eas Gorton Drains FEN Oo eee 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the | SSS Washington, DC 20503. | 5. FUNDING NUMBERS 14. TITLE AND SUBTITLE Pilot Study to Characterize Ordnance Contamination Within the Sea Bright, New Jersey, Sand Borrow Site AUTHOR(S) Joan Pope, Richard Lewis, Andrew Morang, Timothy Welp . PERFORMING ORGANIZATION REPORT NUMBER Miscellaneous Paper CERC-96-8 . PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Anny Engineer Waterways Experiment Station 3909 Halls Ferry Road, Vicksburg, MS 39180-6199 10. SPONSORING/MONITORING AGENCY REPORT NUMBER . SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) U.S. Army Corps of Engineers Washington, DC 20314-1000 12b. DISTRIBUTION CODE l12a. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution is unlimited. 113. ABSTRACT (Maximum 200 words) The U.S. Army Corps of Engineers and the state of New Jersey have undertaken the largest beach restoration project in U.S. history, known as the “Atlantic Coast of New Jersey, Sandy Hook to Bamegat Inlet, Section I, Sea Bright to Ocean Township.” Within a very short period after the initiation of construction in 1994, ordnance were discovered on the newly constructed beaches. The expensive cleanup operations that were required to locate and remove the ordnance from the beach included fitting project dredges with 1.5-in. square grates over the dragheads. These grates prohibit excavation of the ordnance, thus, protecting the dredge and the resultant beach area from unexploded ordnance contamination. However, the grates also reduce the efficiency of the dredging operation by an estimated 20 percent. Over the 50-year life of the project, this could cost hundreds of millions of dollars in lost productivity. The U.S. Army Engineer District, New York, asked the U.S. Army Engineer Waterways Experiment Station to evaluate and make recommendations on a means of characterizing the ordnance contamination in the borrow area. Once the coverage and extent of the contamination have been determined, it may be possible to identify sections that can be dredged in a conventional manner or to design a practical and safe predredging cleanup operation. WES conducted a review of several technologies and recommended a “pilot study” to test oceanographic/geophysical systems for their suitability in detecting ordnance at the Sea Bright site. The New York District concurred with this recommendation and the pilot study conducted | by WES is reported herein. 114. SUBJECT TERMS 15. NUMBER OF PAGES Dredging un 76 Ordnance contamination 16. PRICE CODE Sea Bright, NJ . SECURITY CLASSIFICATION |18. SECURITY CLASSIFICATION |19. SECURITY CLASSIFICATION |20. 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