Cout # iy Monitoring Surveys of the New Haven Capping Project, 1993 - 1994 Disposal Area Monitoring System -DAMOS Pa ood x he % \ ae cx vi 4 oe ve Dot aye . ek wo x pS oe 7 WO : e ~c wi ” o wn G oe TS se Pa a Or a a ee ACY Wed € Cy ee Xe; dl . 0 Ce ae ett ve hd a @ da va \ NS a \ ? _ \ DISPOSAL AREA MONITORING SYSTEM Contribution 111 July 1996 _. US Army Corps __ of Engineers New England Division Form approved REPORT DOCUMENTATION PAGE Public reporting concer for the collection of information is estimated to average 1 hour per persons inculding the time for reviewing instructions, searching exsisting data sources, gathering and measuring data needed and correcting and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collectikon of information includin Ais gestions for pes aeine this burden to Washington Headquaters Services, Directoriate for Information Observations and Kecords, Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302 and to the Office of Management and Support. 3. REPORT TYPE AND DATES Final Report 2. REPORT DATE 1. AGENCY USE ONLY (LEAVE BLANK) July 1996 4. TITLE AND SUBTITLE 6. FUNDING NUMBERS MONITORING SURVEYS OF THE NEW HAVEN CAPPING PROJECT, 1993-1994 6. AUTHORS f : : , John T. Morris, Judith Charles, and David C. Inglin 7. PERFROMING ORGANIZATION NAME(S) AND ADDRESS(ES) Science Applications Intenational Corporation 221 Thnid Street Newport, RI 02840 8. PERFORMING ORGANIZATION REPORT SAIC No. 319 | 9. SSONSORING/MONITORING AGENCY NAMES(S) AND ADDRESS(ES) US Army Corps of Engineers-New England Division 424 Trapelo Road Waltham, MA 02254-9149 DAMOS PROGRAM MANAGER Regulatory Division, USACE-NED 424 Trapelo Road Waltham, MA 02254-9149 | 12a. DISTRIBUTION/AVAIABILTY STATEMENT 12b. DISTRIBUTION CODE | Approved for public release; distribution unlimited 13. ABSTRACT 10. SPONSORING/ MONITORING AGENCY DAMOS Contribution Number 111 “11, SUPPLEMENTARY NOTES — Available trom: Dredging of the New Haven Harbor Channel and five private marine terminals occurred between October 1993 and February 1994. These projects involved removal of an estimated barge volume of 500,000m3 of unacceptably contaminated dredged material (UDM) from the inner portion of the federal channel and about 90,000 m3 from the five private terminals. The UDM was approved for open water disposal and sediment ceppine at Central Pooe Ulead Sound Disposal Site (CLIS). A total barge volume of 569,000 m3 (506,000m3 federal and 63,000m3 private) of cap dredged material (CDM) was used to establish a sediment cap over the UDM deposit. : A taut-wired, moored Disposal Area Monitoring System (DAMOS) disposal buoy “NHAV” was deployed in the center of a basin-like feature created by aring of seven historical disposal mounds. The ring of mounds , which requried ten years to construct, would serve as a jateral containment measure, limiting the spread of the initial UDM deposit and facilitating e icient capping eperations: Capping material was placed at various points surrounding the NHAV buoy to ensure sufficient coverage of the UDM mound. The end result of disposal activity at CLIS was the development of a flat, stable, confined aquatic disposal (CAD) mound. Science Applications International Corporation (SAIC) completed five precesion bathymetric surveys (baseline, interim disposal, precap, interim cap, and postcap), two Remote Monitoring of the Seafloor (REMOTS) surveys, and three geotechnical conne surveys of the NHAV 93 mound. The strategic repetition of the survey activity over the NHAV 93 mound has given the SAIC and NED an excellent peseccive on CAD mound development and insight toward the disposal and oceanographic processes that affect the bottom feature. The athymetric data provided “snapshots” of the developing mounds, allowing time-series comparisons of the various stages of CAD mound construction. The REMOTS photographs were used to determine relative shear strength of the containment ring as well as the areal extent of the UDM deposit. Geotechnical cores and grab samples were used to define the physical characteristics, document the bulk density, and estimate the consolidation of the NHAV93 mound. Comparisons between the baseline, interim disposal, and precap monitoring surveys revealed a UDM deposit 510m in _ diameter and 2.5m in height, containing a volume of 312,000m3 of new material. A significant amount of consolidation was detected over the apex of the disposal mound before capping operations commenced. The NHAV 93 mound was then capped to a thickness of 0.5 to 1.0m with CDM from the outer harbor, resulting in a total mound diameter of 600-800m and height of 2.5 at the apex. Volume difference calculations based on the baseline, precap, interim cap, and the postcap surveys detected 402,000m3 of cap material overlying the initial UDM deposit anda | total mound volume of 714,000m3. | Although 402,000m3 of CDM was placed over the initial UDM mound, there was no increase in net mound height at the apex. It has been determined through precision bathymetric surveying and geotechnical coring that consoildation ofthe UDM deposit and _ | compaction of the basement sediments had occurred during the middle stages of CAD mound construction. Asa result, no apparent changes in | the mound height were detected after the completion of capping operations over the NHAV 93 mound. | Monitoring of NHAV 93 mound has continued through 1995. The long-term focus of these operations has pertained to _ mound stabilty and compaction/consoildation of the NHAV 93 mound; REMOTS sediment-profile surveys have determined the recolonization rate of the mound; and additional sediment cores and grab sampls investigated the potential for migration of contaminents into overlying cap material. The results of these datasets have been submitted to NED under seperate DAMOS report titles. 14. SUBECT TERMS 1S.NUMBER OF PAGES Central Long Island Sound (CLIS) , Capping , bathymetric survey , Remote Monitoring of the Seafloor ‘ (REMOTS) , open water disposal, dredged material 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT 18. SECURITY CLASSIFICATION |19. SECURITY CLASSIFICATION 0.LIMITATION OF UNCLASSIFIED OF THIS PAGE OF ABSTRACT ABSTRACT MONITORING SURVEYS OF THE NEW HAVEN CAPPING PROJECT, 1993 - 1994 CONTRIBUTION #111 July 1996 Report No. SAIC Report No. 319 Submitted to: Regulatory Division New England Division U.S. Army Corps of Engineers 424 Trapelo Road Waltham, MA 02254-9149 Prepared by: John T. Morris Judith Charles David C. Inglin Submitted by: Science Applications International Corporation Admiral's Gate 221 Third Street Newport, RI 02840 (401) 847-4210 US Army Corps of Engineers New England Division o ue ial mes Deccan TABLE OF CONTENTS Page TSO RGPABICES i cst raat acre Bceati aie \aes. aiken eine anid eran nine mln Seee bem clan seb ciss tah. ae Rene iV PET SHIM ORABIG URES i ossiiss Sah and ssa eh cSltotearads oe te ete als Saas ec A a ade Vv EX CUMVE;SUMMARY fecin csstcasats sn ccenie ncacnc eine Hees core stoned en snes aancliseetea eee ree Vili IRORINIER © DW CIION eis az voila tease eeryeute varsere eee meiecra tara eae ane cicaloe Urn cea ae a ee 1 2.0 DECISION PROCESS FOR THE DREDGING OF NEW HAVEN HARBOR........ 10 DmleehySicalmlestin gsOfe Sediment. o. re. seeteaetectee ce en ene e ate See ete ec eae eee 10 ZeenChemicaleMesting Of SeGimentse7 sa... ecstatic eee 1 Dr DMMet als) Pentecost toe ls cue ance atte o aa tere NE SN aa Ah Re ae 12 222-2 Organic -COmpPounds :fcnuu. swacctitaeet ee cee teeta nee aes eee ne ee ree 12 2-5¢Bioaccumulation/Bioassay: NestSi..52. eters. te anas-e ee eeesn cn eckete ene eee 14 ZEA) Disposalyand( Capping: Operations sco. cesk see oe sence ones sais eee 15) Zale Disposalkot, WDM ei sieca rss senate cen sada cee eee antennae ae eae 15 2rAe) Capping Operationsys-.--2e ee see see jee eee ste ce teal me attcfealiteaocuatea sire ne 15 SRO BVO DS et cami toes she cu ctecmseccect ais oceun sae ucicen neincteas scenes Miki aaa anel aa ee 18 Selebrecision:Bathymettic: SUEVEYS cance: ue ce sot gecccc seccesenee heen one eee eter 18 SO REMOMS2Sediment-Profile: Surveys as. eon eee ee ee eee I) Be MB ASCLINEHOULVEY, so. ei ccieeana tasks nec cetine CaN Cee ete A ee eee Ee 19 Slee ELeCAP I SUBVEY ccen cen cet ecrasen cc seee ee ee ne ane ey eS 21 35) Geotechnical: Cores/Suntace Grabs eatin sce c se eee acme nsee see cecosee sien enanenanes 21 ZA OBER SETS Gia spent tater tamer Sein See entre meee la neaitrammnacaeiens sem eee see teen tana Coe ene ne 24 4eiRepetitive: Bathymetric: SURVEYS). 40 ccc sasceses. ec oec sa aeosae oo ian aseaadnceteeen sate 24 4/11 Baseline Survey) (19-20 September 1993) 2.0.22. ....2.2..00s.t00ccseeneniee 24 4.1.2 Interim Disposal Survey (23-25 October 1993) ..................c00c00e: 24 alesyPrecap survey (2-3) November l993) mk. nesnaea- ene sete eee eee oee DAY 4.1.4 Interim Cap Surveys (23-24 November 1993 and PES January sl O94) ine cciaee cate cuces sactican sacnielac ee eek ince neces 32 415i Postcap Survey (13-14 March t994)in ek... ches. seedaescsceeecsde ce ssaeces 52 4-2 REMOMS=Sediment-Profile Surveyshescee sss ee ee 41 A) Grain} SiZepDisthibUllOnie. ae ce sec aoesk smacstereca ee acerca meee 41 An) prismibenetration Depth tes. cesess: aaaceeee esac ecco een 41 4.2.3 Mean Apparent Redox Potential Discontinuity (RPD) Depth.......... 42 4274 iInfaunaly SuccessionalliS tases. ase sac es seen eeceecs auc een oases see 42 4) Organism-Sedimentindicesi(OSI) pees hee eerie aes tone eee 45 TABLE OF CONTENTS Page 5:0 DISCUSSION sicie. sis che cusses oe eae eelelesamtereee Uae siinttapa oc ttoreisis loge See eee eee 46 6.0, CONCLUSIONS 3.554. cescnsens c actetas Bele seem ae ets Selassie Se oee crc ee nar arse ates 54 7:0 REFERENCES 3 eso sui sacctean cepa cada ne oe Posie arene cca ai amiais cattle tie eee et ee eee Eee 55) INDEX APPENDICES il Table 1-1. Table 1-2. Table 2-1. Table 4-1. LIST OF TABLES Page Summary of Monitoring Surveys for the New Haven Capping Project Septembersl!993) tor March 994 mys eeeeaamaeeeeeee eer aeeceeeeeaete es 4 Amounts of Sediments Dredged from New Haven Harbor, October 1993 tonhebruamylOO4:.: 25 Mise as ec cana Na eth eiastcte ge aatthetiat cc ae ssieatectoe 9 New England River Basins Commission (NERBC) Classification of Dredged Sediment iia 2 ssiticecustens setemes cer eoeeenc cee aise se aces seeeraoes 13 Summary of Volume Difference Calculations for the New Haven Capping: Project; September 1993/to March 19945 ere 3 ceeceescmeesesesecose D7, Figure 1-1. Figure 1-2. Figure 1-3. Figure 1-4. Figure 2-1. Figure 2-2. Figure 3-1. Figure 3-2. Figure 4-1. Figure 4-2. Figure 4-3. LIST OF FIGURES Page Location of the federal navigation channel, Gulf Oil, Mobil Oil Corporation, the New Haven Terminal, Northeast Petroleum, and Wyatt Incorporated in)New; Haven Harbor 23a.) nedee cee eeeceeaccsececie-nccee D Timeline of disposal and environmental monitoring activity during thesNewsHaven! Gapping? Projectyl993= 1994 Tana seetececceebe eerie eeenen 3 Location of the Central Long Island Sound Disposal Site (CLIS) ................ 7 Location of the NHAV buoy over the basin created by seven historic disposalimoumdsiaee ce Nesus. ive Me ROE Is Pee as Sn ce esha earn 8 Sediment and benthic sampling locations in the federal navigation channel-sNew Haven) Harbor unin iage ein toes fortinae adecsccteneee cerleoee tesie netstat 11 Cap placementilocations}at)@IEIS M199 3 raiinis: eraser ctr bisects pie clecior serrate 16 Station replicate locations for the baseline REMOTS® sediment-profile survevaconducted’2-22) September 1993 ana eee se ceeesee eee meee ee 20 Station locations for the precap REMOTS® sediment-profile survey conducted 4 November 1993 with dredged material thickness seen in REMOTS® analysis and 0.5 m contour from bathymetry .............. 22 Contoured bathymetric chart around the disposal point following disposal of 50% of the sediments for the federal inner harbor dredging, project; October 1993i(depthiinimeters))<.).0- 22h... sesec2+scceesces cies DS Depth difference contour chart (in meters) based on the comparison of the interim disposal (October 1993) and baseline (September 1993) lop tio hyve td CTU ni e\ oe uaaadanasbednaseocodeae dacasonsAbebdocbesoHopsdpqondacodcesoac ode 26 Contoured bathymetric chart of the mound complex at precap status or 100% completion of the dredging of the inner harbor sediments plus approximately 76,000 m’ of cap material, 2 November 1993 (Cale oYtaVsTMST NETS) Ue padpadosbone Soar dsc benes es oe acadcas doay oben anunnonscegadqdosdaaodoue 28 Figure 4-4. Figure 4-5. Figure 4-6. Figure 4-7. Figure 4-8. Figure 4-9. Figure 4-10. Figure 4-11. Figure 4-12. Figure 4-13. LIST OF FIGURES (continued) Page Depth difference contour chart (in meters) based on the comparison of interim disposal (October 1993) and precap (November 1993) bathymetric/Surveysic2 ecedes. tee cue sie eat ioe oom c ounce ce eacee tee neae ee emeree 29 Bathymetric profile plots of survey lane 35 from the interim disposal survey (October 1993) and precap survey (November 1993) ................... 30 Depth difference contour chart (in meters) based on the comparison of the precap (2 November 1993) and baseline (September 1993) bathymetric SURVEYS): :ii2 Seas ceeeee eee nee eee eee ele tciace ee eee ceeee eeeeeee Sil Contoured bathymetric chart of the mound complex following completion of 50% of the capping operations, 23 November 1993 (depth in meters)..... 33 Contoured bathymetric chart based on data collected by Ocean Surveys, Inc. at the completion of the private dredging operations, January 1994 (depth in-Meters) joe eseot. ete sneks i aeismetnale cadet tacis Ae occas ce oiecie seta mene Rte eee 34 Depth difference contour chart (in meters) based on the comparison of the interim cap (23 November 1993) and precap (2 November 1993) "bathymetric SULVEYS! ee sehemacce tee cock semen aeinnee saeee er oaneee eee nraee 35 Depth difference contour chart (in meters) based on the comparison of the Ocean Surveys, Inc. interim cap (January 1994) and SAIC baseline (September 1993) bathymetric surveyS ..................scceeeee eee eee ees 36 Depth difference contour chart (in meters) based on the comparison of the SAIC precap survey (2 November 1993) and the Ocean Surveys, Inc. interim cap survey (January 1994)..............ccc cee ee eee e eee es Sy Contoured bathymetric chart of the mound complex following completion of the capping operations (postcap), March 1994................... 38 Depth difference contour chart (in meters) based on the comparison of the postcap (March 1994) versus baseline (September 1993) bathymetricySUnveySic. c5. 5... cesacmaasecesocesen nosene neem ee een csteeeet cer 39 vi Figure 4-14. Figure 4-15. Figure 4-16. Figure 5-1. Figure 5-2. Figure 5-3. LIST OF FIGURES (continued) Depth difference contour chart showing apparent cap material thickness (in meters) based on the comparison of the postcap (March 1994) versus precap (2 November 1993) surveys ................+5- Mean RPD and OSI values for the five disposal mounds and the east-southeast valley feature during the baseline REMOTS® survey....... Infaunal successional stages at the five disposal mounds and east- southeast valley feature during the baseline REMOTS® survey............. Suggested pattern of future disposal at CLIS to maximize site capacity and construct a network of containment cells ......................ceeeeeeeeeee July 1994 subbottom data. Contour plot of subbottom layer 1 (cap thickness) 1600 x 525 m analysis area over the NHAV 93 mound, OwSemicontounsintenvialle: Vests cae eee eon emai ee nous renee ie July 1994 subbottom data. Contour plot of subbottom layer 1 (cap thickness) overlaid onto cap material footprint plot of March 1994, 1600 x 525 m analysis area over the NHAV 93 mound. .................. Vii Page ie se 51 ai 52 ne ; i i ¥ iD. EXECUTIVE SUMMARY Dredging of the New Haven Harbor Channel and five private marine terminals occurred between October 1993 and February 1994. These projects involved removal of an estimated barge volume of 500,000 m? of unacceptably contaminated dredged material (UDM) from the inner portion of the federal channel and about 90,000 m3 from the five private terminals. The UDM was approved for open water disposal and sediment capping at the Central Long Island Sound Disposal Site (CLIS). A total barge volume of 569,000 m3 (506,000 m3 federal and 63,000 m3 private) of cap dredged material (CDM) was used to establish a sediment cap over the UDM deposit. A taut-wired, moored Disposal Area Monitoring System (DAMOS) disposal buoy "NHAV'" was deployed in the center of a basin-like feature created by a ring of seven historic disposal mounds. The ring of mounds, which required ten years to construct, would serve as a lateral containment measure, limiting the spread of the initial UDM deposit and facilitating efficient capping operations. Deposition of UDM from the federal project was completed at the NHAV buoy, while the privately dredged UDM was disposed at a point to the southwest of the buoy. Capping material was placed at various points surrounding the NHAV buoy to ensure sufficient coverage of the UDM mound. The end result of disposal activity at CLIS was the development of a flat, stable, confined aquatic disposal (CAD) mound. The decision to cap the material was based on the results of the Ampelisca bioassay test using the sediments sampled from the federal channel project. Biological testing of the private marine terminal projects was not pursued due to a cooperative plan for capping both the federal and private projects, providing a cost-efficient method of disposal. Science Applications International Corporation (SAIC) completed five precision bathymetric surveys (baseline, interim disposal, precap, interim cap, and postcap), two Remote Monitoring of the Seafloor (REMOTS®) surveys, and three geotechnical coring surveys of the NHAV 93 mound. The strategic repetition of survey activity over the NHAV 93 mound has given SAIC and NED an excellent perspective on CAD mound development and insight toward the disposal and oceanographic processes that affect the bottom feature. The bathymetric data provided "snapshots" of the developing mounds, allowing time-series comparisons of the various stages of CAD mound construction. The REMOTS® photographs were used to determine the relative shear strength of the containment ring as well as the areal extent of the UDM deposit. Geotechnical cores and grab samples were used to define the physical characteristics, document the bulk density, and estimate the consolidation of the NHAV 93 mound. Vill EXECUTIVE SUMMARY (continued) Comparisons between the baseline, interim disposal, and precap monitoring surveys revealed a UDM deposit 510 m in diameter and 2.5 m in height, containing a volume of 312,000 m3 of new material. A significant amount of consolidation was detected over the apex of the disposal mound before capping operations commenced. The NHAV 93 mound was then capped to a thickness of 0.5 to 1.0 m with CDM from the outer harbor, resulting in a total mound diameter of 600-800 m and height of 2.5 m at the apex. Volume difference calculations based on the baseline, precap, interim cap, and postcap surveys detected 402,000 m3 of cap material overlying the initial UDM deposit and a total mound volume of 714,000 m3. Although 402,000 m3 of CDM was placed over the initial UDM mound, there was no increase in net mound height at the apex. It has been determined through precision bathymetric surveying and geotechnical coring that consolidation of the UDM deposit and compaction of the basement sediments had occurred during the middle stages of CAD mound construction. As a result, no apparent changes in mound height were detected after the completion of capping operations over the NHAV 93 mound. Monitoring of the NHAV 93 mound has continued through 1995, including additional precision bathymetric surveys, subbottom profiling, REMOTS® sediment-profile photography, sediment surface grab samples for chemical analysis, and geotechnical coring. The long-term focus of these operations has pertained to mound stability and compaction/consolidation of the NHAV 93 mound; REMOTS® sediment-profile surveys have determined the recolonization rate of the mound; and additional sediment cores and grab samples investigated the potential for migration of contaminants into the overlying cap material. The results of these datasets have been submitted to NED under separate DAMOS report titles. 1.0 INTRODUCTION From October 1993 to February 1994, the New Haven Harbor was dredged to improve navigational access within the federal channel and operations efficiency at five area marine terminals (Figure 1-1). As part of the Dredged Material Management Plan, formulated by the New England Division (NED) of the US Army Corps of Engineers (USACE), the federal channel project sediments were sampled and subjected to a variety of tests to determine their physical and chemical properties. The results of a standard Ampelisca bioassay test indicated that the federal channel project material was not suitable for unconfined open water disposal and required capping. Capping is a subaqueous containment method which uses dredged material determined to be suitable for unconfined open water disposal to overlay and isolate the unacceptably contaminated dredged material (UDM) from the environment (Fredette 1994). The process was introduced to the Central Long Isiand Sound Disposal Site (CLIS) in 1979 with the formation of the Stamford-New Haven mounds (STNH-N and STNH-S; SAIC 1995). Subaqueous capping is the most cost effective and environmentally sound approach to manage large volumes of UDM. Results of the Stamford-New Haven Project suggested that careful navigational controls and point deposition techniques at a taut-wired buoy could be used to form a discrete mound of UDM (SAIC 1995). In addition, these results suggested that precise deposition of cap dredged material (CDM), both at the center and at the flanks of the UDM mound, could be accomplished with tight navigational control and project planning. As a result of the operational success of the 1979 capping project, additional capping projects were conducted at CLIS. These include the Mill-Quinnipiac River mound (MQR), Norwalk mound (NORWALK), and two Experimental Cap Sites (CS-1 and CS-2). Physical monitoring of the mounds indicates that they have been stable even after the passage of three hurricanes (SAIC 1995). A successful capping project requires an effective monitoring program in addition to predisposal planning and well-organized dredging and disposal operations (SAIC 1995). Science Applications International Corporation (SAIC) conducted a series of five environmental surveys including the collection of various types of data at each stage of the dredging project (Table 1-1). The data collected at CLIS includes precision bathymetry, Remote Ecological Monitoring of the Seafloor (REMOTS®) sediment-profile photographs, sediment grab samples, and geotechnical cores (Figure !-2). The strategic repetition of survey operations over the disposal site during the New Haven Capping Project provided SAIC and NED a wealth of information on the developing mound. The baseline survey conducted from 19 to 20 September 1993 was intended to define the predisposal conditions at the site to provide a baseline for comparison to the future survey Monitoring Surveys of the New Haven Capping Project, 1993-1994 MILL RIVER : - QUINNIPIAC Wyatt, Inc. a Seinen RIVER "Pink Tank Berth" S SS *~Gulf Oil Wyatt, Inc. "ARCO Berth" oo ™~ New Haven Terminal, !nc. A Marine Terminal . | Northeast Petroleum Marine Terminal Figure 1-1. Location of the federal navigation channel, Gulf Oil, Mobil Oil Corporation, the New Haven Terminal, Northeast Petroleum, and Wyatt Incorporated in New Haven Harbor (adapted from HMM Associates, Inc. 1993) Monitoring Surveys of the New Haven Capping Project, 1993-1994 > © 2 oD =| qSy [or 5°) 5 F < =n) Postcap Bathymetry z ss Geotechnical Coring s fey) c= a cI E 5 & = iS°) i= ‘ ep 0 Oo 4 = E pre OSI Interim Cap Bathymetry 5 x |e & ‘S = a a : o 3 : ia Sediment Grabs E =| + Interim Cap Bathymetry 2 € a) [o) > ro) (o) co) 5 aie : @ a Geotechnical Coring a © x t REMOTS® 3 o og bats Precap Bathymetry gs 3 © aS) VE S Interim Disp. Bathymetry aS Sediment Grabs 2 D =2o o ES Ea Baseline Bathymetry REMOTS® Geotechnical Coring Figure 1-2. ~ [ok oO Op) Monitoring Surveys of the New Haven Capping Project, 1993-1994 Table 1-1 Summary of Monitoring Surveys for the New Haven Capping Project, September 1993 to March 1994 Event Baseline Interim Precap* Interim Interim Postcap (Predisposal) | Disposal Cap Cap" Precision 9/19-20/93 10/23-25/93 | 11/2-3/93 11/23- 1/12-13/94 | 3/13- ee Bathymetry 24/93 REMOTS® 9/21-22/94 11/4/93 Sediment Profile Sediment 9/21/93 11/10/93 3/15/94 Cores Sediment 10/25/93 11/24/93 Grabs Vessel M/V R/V R/V M/V M/V Beavertail UCONN UCONN Beavertail Beavertail *This survey also included 76,000 m’ of cap material deposited at the northeast corner of the mound. * Survey conducted by Ocean Surveys Incorporated. data. The baseline survey included bathymetry, REMOTS®, and geotechnical cores. The interim disposal survey, completed after 50% of the UDM dredged from the federal channel was disposed (23-25 October 1993), included bathymetry and sediment grab samples. Bathymetry, REMOTSS®, and geotechnical cores were collected during the precap survey, performed following the completion of the federal inner harbor dredging (2-3 November 1993). This survey was designed to provide an accurate map of the distribution of UDM to facilitate complete cap coverage. An interim capping survey was completed from 23 to 24 November 1993 using bathymetry and sediment grab samples to document the distribution of cap material. A final survey was conducted following the completion of all dredging activities to evaluate the coverage of the UDM deposit by the outer harbor CDM. This postcap survey included bathymetry and geotechnical cores and was completed from 13 to 15 March 1994. The geotechnical cores were collected by SAIC and University of Rhode Island (URI) scientists in close proximity to the NHAV disposal buoy and within the central portion of the dredged material mound. Results provided an estimate of consolidation within the basement sediments and inner harbor dredged material. In addition, the geotechnical coring results Monitoring Surveys of the New Haven Capping Project, 1993-1994 were used to verify the completion of the cap material thickness requirements established by NED. A sediment plume study was conducted during the initial phase of dredging (25 October to 18 November 1993) to monitor the potential for material dispersion (Bohlen et al. 1994). Nine plume tracking surveys were conducted by Dr. W.F. Bohlen of the University of Connecticut while Great Lakes Dredging Company was operating in New Haven Harbor; results will be provided under a separate report. Further survey activity over CLIS during the New Haven Capping Project included bathymetric and sediment-profile photography surveys (12-13 January 1994). Ocean Surveys, Incorporated completed these field tasks following the disposal of UDM generated from the private marine terminal projects in the harbor. Since 1977, monitoring cruises have been conducted at CLIS as part of the Disposal Area Monitoring System (DAMOS) Program for the US Army Corps of Engineers, NED (NUSC 1979). These surveys assessed both the stability of the dredged material disposed at the site and any potential for adverse long-term environmental effects, particularly in terms of the postdisposal recovery of benthic ecosystems. The objectives of these surveys included documenting and monitoring the location and physical characteristics of dredged material mounds, as well as any postdepositional dispersion of material. A total of eighteen inactive disposal mounds currently exist within the 6.85 km? area of CLIS. CLIS, located approximately 5.6 nautical miles (nmi) south of South End Point, East Haven, Connecticut, continues to be one of the most active containment sites in New England (Figure 1-3). The 2 nmi long by | nmi wide rectangular area, centered at 41°08.950' N, 72°52.850' W, receives sediments dredged from the New Haven, Stamford, and Norwalk Harbors as well as adjacent coves and embayments. In addition, the large volumes of material deposited at CLIS have been subject to a variety of dredged material management strategies. The strategy at CLIS during the 1993 New Haven Harbor Capping Project was to form a large scale, stable confined aquatic disposal (CAD) mound. A CAD mound is a dredged material disposal mound constructed in conjunction with artificial or natural containment measures. The containment measures are structures that surround a given area limiting the lateral spread of UDM to facilitate efficient sediment capping operations. The taut-wire moored buoy "NHAV" was deployed at 41°09.122' N and 72°53.453' W, over the center of a basin created by the planned placement of seven historic disposal mounds: CLIS- 87, CLIS-88, CLIS-89, CLIS-90, CLIS-91, SP, and NORWALK (Figure 1-4). The basin region was utilized for the disposal of a total volume of 1,159,513 m3 of material; 590,229 m3 of UDM and 569,287 m3 of CDM (Table 1-2). The precision disposal and Monitoring Surveys of the New Haven Capping Project, 1993-1994 6 capping operations performed by the Great Lakes Dredging Company and the technical support provided by SAIC aided NED in forming a stable CAD mound with a diameter of 550 m, a height of 2.5 m, and a CDM to UDM ratio of 0.96 to 1.0. The successful completion of the NHAV 93 mound represents the end of a ten-year dredging cycle in the central Long Island Sound region. NED estimates that major maintenance dredging of New Haven Harbor must be conducted every ten years to provide adequate water depths for commercial, military, and private vessels utilizing the harbor. Thoughtful management of smaller volumes of dredged material over the last decade not only facilitated the safe disposal of over a million cubic meters of dredged material, but also demonstrated a management strategy that can serve to maximize the site capacity of CLIS as well as other DAMOS disposal sites. Monitoring Surveys of the New Haven Capping Project, 1993-1994 Central Long Island Sound, Connecticut STRATFORD LONG ISLAND SOUND WEST HAVEN ~ EASTHAVEN |<. LIGHTHOUSE(@ Ss SOUTH Siccep g| END POINT a a : 4 : [Ss SS © fe 41°10'N STRATFORD POINT Central Long Island Sound Disposal Site Figure 1-3. Location of the Central Long Island Sound Disposal Site (CLIS) Monitoring Surveys of the New Haven Capping Project, 1993-1994 (srqjaur ut yidap) €661 Jaquiajdag ul payonpuos Adains aur[aseq oY} JO S}[Nsoi sy} SMOYS JVYD INIWAYIeq PoINoWOdS sy L, ‘spunoul jesodsip d110)sty UdAas Aq payeaio uIseq dy} 12A0 Aong AVHN 2} JO UONRD0T = *p-T JANI SJ3}OW MO-ST €S 220 MO-O€ €S 220 MO" Sb €S 220 MO" 00 tS 220 oo9 00S OOr OO€ O02 O00! W G'Q - |eAJa}U] INOWJUODD JOJEDayy :uoNOa!OIg No-Sp 80 TY €6/02-61/6 AjewAujeg auljeseg SID NO”~ OO 60 Iv NO°~OO 60 Tt NO°-O€ 60 Tr MO~-O€ 2S 220 MO°- St 2S 220 MO"~O0O0 €S 220 MO-ST €S 240 MO-O£€ €S 2240 MOS wd 6p 030 NO° ST 60 Tv a NO°-O€ 60 Tr -}- MO"-O€ 2S 220 MO°- Sb 2S 220 MO°-00 €S 220 MO°ST €S 220 MO-O€ €S 220 MO°-Sb €S 220 MO" Sb €S 220 MO-O0O tS 220 + - MO~0O tS 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 23 and bathymetric surveys over the NHAV 93 mound and to carry out numerical computations of settlement and volume changes. Results of URI's analysis of the sediment cores and surface grabs have been submitted in a separate report (Silva et al. 1994b). Twenty good quality cores with lengths from 69 cm to 302 cm were recovered during the baseline, precap, and postcap surveys using the LGC system (Appendix D). Before splitting the cores (core liners), a Multi- Sensor Core Logger (MSCL) was used to obtain profiles of sediment bulk density. Visual descriptions (and photographs) were recorded and subsamples extracted for analysis of the physical properties (grain size, water content, Atterberg limits, and specific gravity). Consolidation behavior was measured through analysis (void ratio versus effective stress, compression index, and consolidation stress) and permeability data (direct and indirect measurements). Monitoring Surveys of the New Haven Capping Project, 1993-1994 24 4.0 RESULTS 4.1. Repetitive Bathymetric Surveys CLIS is located in a depositional area of Long Island Sound, characterized by mild bottom current regimes and subject to shallow, wind-driven waves. Since 1984, the DAMOS site management strategy at CLIS has been to create a ring of disposal mounds for the deposition of large volumes of dredged material. The New Haven Capping Project marks the first instance that an artificial containment measure was designed and utilized for the deposition of dredged material. The entire CAD mound development process was observed, scrutinized, and documented by SAIC in support of the DAMOS Program. Results of the precision bathymetry and depth difference analyses for the five surveys conducted at CLIS between September 1993 and March 1994 are presented below including 1) baseline (predisposal), 2) interim disposal, 3) precap, 4) interim cap, and 5) postcap. 4.1.1 Baseline Survey (19-20 September 1993) Results of the baseline bathymetry indicate, with the exception of shallower water depths over the mounds, water depths in the area range from 19 m in the northern half of the surveyed area to 21 m in the southern portion (Figure 1-1). Water depths over the mound centers were as follows: CLIS-87 and CLIS-88 16 m, CLIS-89 17 m, CLIS-90 19 m, CLIS-91 19 m, NORWALK 18.5 m, and SP 19.5 m. The historic NHAV-74 mound is visible in the southeast corner of the bathymetric chart with a minimum depth of 17.0 m before extending beyond the survey area. 4.1.2 Interim Disposal Survey (23-25 October 1993) The interim disposal survey was completed when the federal inner harbor dredging was 50% complete. Development of the mound is readily apparent in the bathymetric analysis of the interim survey (Figure 4-1) when compared to the baseline survey (Figure 1-1). The water depth at the center of the NHAV 93 UDM mound was 17.0 m. The depth difference comparison between the baseline and interim disposal surveys (Figure 4-2) showed a mound approximately 400 to 450 m in diameter and 3 m in height. The total volume of the mound based on successive bathymetric surveys was 238,000 m? (Table 4- )) Monitoring Surveys of the New Haven Capping Project, 1993-1994 25) (siagjour ul ydap) €66] 19q019G9 ‘190afo1d SuUIspoIp JOGIeY IOUUI [e1aPsJ IY) JO} s}UIWIIpas ay} JO %O¢ Jo yesodsip Burmoyjo} yurod yesodsip ay) punore jeyo dowAYyeq pomMowWoD *{-p vans MO~-O0O €S 2240 MO" ST -€S 220 MO-O€ €S 220 MO-Stv €S 220 MO-O0O tS 240 lW G’Q - JEAJa}U| NOJUOD a LNG : : NOwarired) v0 JOJEDAYW :UdI}OaIOIg ee 3 - : j €6/S7-EZ/0L AnewAujeg : jesodsiq wiaju| STO = ) “YL AVHN NO-OO 60 Tv aE l ate = ee NO-O0O 60 Tv MOR OSs 2:55 12720 MOS Sb 2S 220 MO-OO €S5 220 MO= SIT iiSiaerZ.0) MOORES erciZiO} MO-Sb £95 220 MO- 00 tS 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 26 skaains oinawAteq (€66] Jequiaidag) sutfaseq pure (€661 13q019Q) jesodsip witsaj}ur ay} Jo UOSTIedUIOD By) UO pase (SI}JOUI UL) WLYD INOJWOS ydU9IAjJIP yWdeq = *7-p sans MO-0O €S 240 mMO~-ST €S 220 MO-O€ €S 220 MO- Sb €S 2240 MO-0O *S 240 W G’Q - [esau] JNOJUOD JOyedEy-; UOOeIOId - No" Sb 80 Th GE6O - aouaayiG ujdeq jesodsiq way] SITIO = ——— 9 Oh + + NO-OO 60 Tt CL BOVE ( NO°Sb 80 Tv €6/p7Z-EZ/LL AjawAujeg Way WSs ale : deg wueju) S10 NO~- OO 60 TY a MO-O€ 2S 2240 MO°-Sbv 2S 240 MO~-O0O €S 2240 MO-ST €S 220 MO-O€ €S 220 MO° St ©€S 220 MO-00 tS 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 (siajoul ut dap) peo] Arenuey ‘suonerodo Sutsporp ajeatid ay) JO uonajdwios ay) ye “oul ‘skaAING UeIdO Aq P9}da][09 BIep UO paseq WeYd INeWAYIeG PsNo}JUOD =“ G-p BANS MO-O0O €S 240 MO-ST €S 220 MO-O€ €S 220 MO°-Stv £€S 240 MO-0O0 tS 220 W G’Q - JeAJa}uy JNO}UOD JOJEHUAYW :UOHDaIOId VE/EL-ZL/L AjawAuyjeg Aaning ‘au ‘shaving uea90 S119 NO-O0O 60 Tt MO" Oe ¢S 220 MO°- Sb 2S 240 MO-OO €S 2240 MO” ST MO" O€ €S 220 MOK Svs €:Sh 2:20) MO-OO tS 220 34 Monitoring Surveys of the New Haven Capping Project, 1993-1994 35 SADAINS DINIWAIeG (€G6] JAQUIDAON Z) desoid pue (E661 JOQUIZAON €Z) ded wii9}u1 dy} JO uOSTIeduIOD dy) UO paseq (SIDI! UT) RY INOjWOD sdUaIIIJIP YId9q = *-p JANI MO"-O0O €S 220 MOSSE Se Sed/Z0 MO-O€ €S 2240 MOS Sv. 16'S 2/210 MO°-O0O ~S 2240 W GZ‘ - |JEAIaj}u| JNOJUOD JOJedIayJ :uONIelOId dedaig snsiaA dey wisia}u| + No-Sp 80 Ty aoualayig yjdeq deg wiayu| S10 NO°- OO 60 Tr MO-O€ 2S 220 MO-Sb 2S 2240 MO-O0O €S 220 WOF Sit CS 22ZO) MOm OE NSE 220 MO-Stv €S 220 MO~-00 tS 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 36 SADAINS DINAWIAYIEQ (E66 Jaquiaidas) auljaseq DITVS pue (p66] Arenues) deo wissyur “uy ‘SAaAINS UkIdQ 9} JO UOSTIedWIOD aYi UO paseq (SI9JOUI Ul) Wey INOWUOS sduaJayJIp ydoq «= “OT -p eANsIy SISISIN MO-O00 €S 220 MO-ST €S 220 ™MO-O€ £S 240 MO-Sb ES 220 MO-00 ¥%S 220 009 00S 00% O0€ O02 O0b 0 W G'Q - JeEAJayuy JNOJUOD JOJEDayY :UOI}DalOId auljaseg snsiaA deg wia}u| +. No-S¥ 80 Th aouaayig ujydaq GAINS ‘ou SABAINS UBBIO SITD NO"-00 60 It S ae S % - NO-00 60 Tt NO°O€ 60 TPH + ++ NO”~O€ 60 TY MO-O€ 2S 240 MO" Sb 2S 220 MO~-O0O €S 220 MOseSils SeiSeeeiZ10. MORO co Se 2720: MO°- Sb €S 220 MO-00 tS 240 Monitoring Surveys of the New Haven Capping Project, 1993-1994 37 (p66] Arenuer) Adains deo wisajur “ouy ‘shdAIng ueIdD_ JU} pue (€66] JOQUIDAON Z) Agains desaid OT VS a) Jo uostIedur0d at UO paseq (S19}9UI UT) 1eYD INOJUOD sdUaIAIJIp Idaq W GQ - JEAIa}U] INOJUOD JOJEDBYy :UODelO1Y deg wiuaj}uj snsiaa deoaig souaJaHIG yjdaq Aaning ‘ouj sAaaing uea99 S}19 NO" 00 60 Lv -{- NO-SL 60 Lv -|- NO-O€ 60 Lv —- MO- O€ ZS 220 MO”- Sb 2S 220 MO- OO €S Z2£Z0 -}- -}- MO”~ SL €S 2£Z0 MO-O€ €S 220 MO- Sv €S 220 MO- OO VS 220 + AON AVHN © TiS / 22% ° a cs -f- a + - MO- OO €S 220 MO~- SL €S 220 MO-O€ €S 220 MO~- Sb €S 220 MO- 00 VS 220 "TI-p aansiy NO" Sv 80 Lv NO"- 00 60 Lv NO-O€ 60 Lv Monitoring Surveys of the New Haven Capping Project, 1993-1994 38 $661 Yorey ‘(deojsod) suonessdo Butddes ay) Jo uoNatdwos Surmoy[o} xajdurod punouw sy) Jo WeYyd seWIAYIeQ poNOWWOD =* 7] -p aNd Sua}aW 009 00S O0F OOF MO-OO €S 2240 MO>ST €S 220 MO-O€ €S 240 MO° St €S 220 MO-O0O tS 2240 W G‘Q - JEAIa}U] INOJUOD JOJEDayy :udI}De!O1 4 AyjauAujyeg deajsoq S119 NO”~OO 60 Tr NO"~0O 60 TY 4+ MOOS: 2/5) -2jZO0 MO°- St 2S 220 MO-O0O €S 220 MO-ST €S 2240 MO”-O€ €S 2240 MOS SV. ES) 2220) MO-O0O tS 2240 Monitoring Surveys of the New Haven Capping Project, 1993-1994 sAJAINS IINAWIAIE (€66] Joquiajdag) ouljaseq SNSIIA (766 yore) deajsod ayy Jo uosteduo0s ay} uO paseq (S1d}9UI UT) 1IeYD INOWWOS soudJayJIp dsq = * ET -p 9aNsIY MO-OO £€S 240 MO- ST €S 2240 MO-O€ €S 220 MO-Sb £S 2240 MO-O0O tS 240 W GQ - JeAlaju] JNOJUOD JOJEDISBY\ :UONDE/OIg auljaseg SNsJeA deojsog soualayig yjdeq deojsod S119 NO-OO 60 TH UL a | i e= MO-O£ 2S 220 MO°-Sb 2S 220 MO"-O0OO €S 220 kona AVH MO” ST €S 220 N o LS MO~Of€ €S 220 MO°- Sb €S 220 MO-O0O ~S 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 40 SAQAINS (€66[ JOQUIDAON Z) desaid snsI9A (P66 YOIeJA)) deojsod su} Jo uostedwos dy} UO pase (SIO}9UI UT) SsaUyOIY) [eLIayeuI deo Juaredde Suimoys Jey InojUOD soUIAyJIP WIdoq = “pI -p 9aNsIy MO~OO €S 2240 MO[ ST €S 2240 MO-O€ €S 2240 MO°-Stb €S 2240 MO-OO tS 220 W G'Q - JeAlaju] JNO}UOD JOJCDIyy :UOIDelO1g desaidg snsiaA deo}sod o No’S? 80 Tt aouaayig yjydeq deojsod SI19 NO~ OO 60 TY = fa SS NO~-O0O 60 TY ) AVHN ® : NO°ST 60 Iv NOS STS 60) oy, NO”~-O€ 60 TY + NO”-O€ 60 Tr MO-O£€ 2S 220 MO°-Sb 2S 240 MO~-O0OO €S 2240 MOS SIT “2:9 2/20 MO-O€ €S 2240 MO" St €S 2240 MO-OO tS 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 278,000 m3. The comparison shows that federal cap material and the privately funded disposal and cap material were deposited on the southern side of the mound. The 76,000 m3 barge volume of additional federal cap material that was disposed to the northwest of the NHAV buoy location prior to the precap survey could not be accounted for in this comparison due to its deposition prior to the completion of the precap bathymetry. 4.2 REMOTS® Sediment-Profile Surveys The REMOTS® baseline survey was conducted over the following inactive disposal mounds: NORWALK, CLIS-87, CLIS-88, CLIS-89, CLIS-90, SP, and the east-southeast valley. The results were used to assess the stability of the disposal mounds, allow accurate placement of dredged material in the basin formed by these mounds, and to document the status of the benthic community. In addition, NED planned to place a sediment cap over the experimental FVP mound in the northeast quadrant of CLIS using any excess CDM generated by the New Haven Capping Project. Therefore, triplicate photographs were also obtained at the historic FVP mound during the precap survey to allow comparisons in the event that excess CDM was available for deposition. 4.2.1 Grain Size Distribution The major modal grain sizes over the majority of the mounds were very fine sand (4-3 phi) and some silt/clay (24 phi) sediments at the CLIS-87 and CLIS-88 mounds. Fine sands (3-2 phi) were the major mode at a few of the stations located on the CLIS-89 and SP mounds. Several stations had surface layers of coarse sands and gravel. The major modal grain sizes at the FVP mound were very fine sands (4-3 phi); some silt/clay (24 phi) sediments were present at stations 50E, 50W, 100W, and 100S. The range in grain size included gravel and very coarse sands to silt/clay. 4.2.2 Prism Penetration Depth Dredged material often has different shear strengths and bearing capacities than ambient bottom sediments. The prism penetration depth into the bottom sediments depends on the force exerted by the optical prism and bearing strength of the sediment. The optical prism of the REMOTS® camera penetrates the bottom sediment under a static driving force imparted by the weight of the descending optical prism, camera housing, supporting mechanism, and weight packs. Soft silt/clay sediments will generally produce photographs showing two-thirds to full penetration (15-20 cm), while coarser grained material yields lesser penetration values (sands 8-12 cm; gravel 3-10 cm). Monitoring Surveys of the New Haven Capping Project, 1993-1994 42 During the baseline survey, penetration depths of individual replicates over the five sediment mounds (CLIS 87-88 complex, CLIS 89, CLIS 90, NORWALK, and SP) ranged from 5.50 cm to 20.70 cm. The replicate-averaged mean penetration depths at the CLIS 87-88 mound complex ranged from 7.6 to 13.88 cm; CLIS 89 7.80 to 17.64 cm; CLIS 90 11.42 to 16.72 cm; NORWALK 9.83 to 17.35 cm; and SP 5.65 to 17.52 cm. The penetration depths from individual replicates on the FVP mound ranged from 5.76 cm (sediments with a surface layers of gravel and coarse sands over very fine sands) to 15.83 cm (sediments with a surface layer of coarse and medium sands over silt/clay sediments). 4.2.3 Mean Apparent Redox Potential Discontinuity (RPD) Depth Aerobic near-surface marine sediments typically have higher reflectance values relative to underlying hypoxic or anoxic sediments. Surface sands washed free of mud also have higher optical reflectance than underlying muddy sands. These differences in optical reflectance are readily apparent in REMOTS® images; the oxidized surface sediment contains particles coated with ferric hydroxide (an olive color associated with particles), while reduced and muddy sediments below this oxygenated layer are darker, generally gray to black. The boundary between the colored ferric hydroxide surface sediment and underlying gray to black sediment is called the apparent redox potential discontinuity (RPD). The replicate averaged RPD over the project area ranged from 1.10 cm to 3.06 cm during the baseline survey (Figure 4-15). The RPD values for the FVP mound during the precap survey ranged from 1.09 cm to 2.72 cm. 4.2.4 Infaunal Successional Stage The mapping of successional stages is based on the theory that organism-sediment interactions follow a predictable sequence after a major seafloor perturbation such as the disposal of dredged material (Rhoads and Germano 1990). All stations occupied during the baseline REMOTS® survey showed evidence of Stage I pioneering polychaetes (Figure 4-16). Stage I on Stage III communities were present at CLIS-87 and CLIS-88, CLIS-90, SP, and the east-southeast valley transect. Stage III taxa represent high-order successional stages typically found in low disturbance regimes. Evidence of Stage II taxa was present at CLIS-89, NORWALK, SP, and the east-southeast valley transect. Stage II organisms represent a transitional stage to Stage III and are characterized by tubicolous amphipods which can form extensive tube mats on the surface. All stations occupied over the FVP mound during the NHAV 93 precap survey were characterized by presence of Stage I organisms. One replicate at FVP station 50W showed signs of Stage III activity, and was designed as Stage I on III. These results Monitoring Surveys of the New Haven Capping Project, 1993-1994 43 ADAINS gS LOWAY Ulfoseq oy) SuLINp ainjeay Ad|[VA JSBIYINOS-jsevd ay} pue spunou [esodsip aAlj ay} JO} saneA [SE pue Gdy URI = *ST-p aANSLY Sua}aW MO-O0O €S 220 MO°-ST €S 220 MO-O©& €S 2240 MO-Sb €S 220 MO-0OO vS 2240 009 OOS OOF OOF OOZ OOL eo} ISO 4 Qdu OS OF Gl WoW: cB lL OGL 8L2 Joyediayy :uoNdefO14 €6/Z2-02/6 ATWMAON @SLOW3Y eulleseg SI1D oz < NO° St NO~ OO 60 Iv NO O£€ 60 Tv MO-O€ 25 240 MO-Sb 25 220 MO-00 £5 2£0 MO-ST ES 220 MO-Of ES 220 MO-Sb £S 220 mO-00 ¥%S 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 ADAINS gS LOWAY 2Ulaseq 3) SULINp o1Njeoy Ad|[VA JseayINOs-Isea pue spunoul [esodsip dA oy} Je Sase}s [eUOISSIIONS [eUNRJUT ~#“OT-p 9INsIy suaVaW MO~- OO ©€S 2240 MO-~ST,/€S 220 MO-O€ ©£S 220 MO°-Stv €S 220 MO-0O ~S 2240 009 OOS OOF OOE OOZ OOL oO abe\s WwW a ue ‘I : : jeuoisse99ns wv I soyeosayy :uonoafoig |) WN TMT “WT nm” ‘I lew @SLOWAY sulleseg S119 gy Z NO’ St LE ra fp Sessa Pia” Gaeta | vwvvvv he “yAVMRION NO~- OO 60 Tv * Y Wa: La me HI ‘I aS-3 LOASNVUL NO°ST 60 TY (06 SND ~ Vv VW I ‘1 I NO°O€ 60 TP MO"O€ 26 220 MO°-Sb 25 240 MO-00 £5 240 MO-SI £S 220 MO-O€ ES 220 MO-St €S 220 MoO-00 vs 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 45 indicate a continued lack of a stable, benthic infaunal population over the entire FVP mound. 4.2.5 Organism-Sediment Indices (OSI) The multiparameter Organism-Sediment Index (OSI), used to characterize gradients in habitat disturbance, can only be calculated at those stations where RPD and infaunal successional stage are also determined. The OSI is calculated automatically by the image analysis system after completion of all measurements from each REMOTS® image. Based on the compiled results of REMOTS® surveys during the past 10 years, OSI values of less than or equal to +6 are considered indicative of chronically stressed benthic habitats and/or those which have experienced recent disturbance such as disposal (Rhoads and Germano 1986). OSI values greater than +6 tend to represent relatively undisturbed habitats or habitats that have experienced a long period of recovery relative to bottom areas more recently disturbed. The replicate averaged OSI values over the disposal site ranged from 2.3 to 7.5 and were indicative of a patchy benthic environment in varying states of recovery (Figure 4-15). The NORWALK and SP mounds showed the most uniform values of OSI. Values at the FVP mound ranged from 3 to 5 with one value of 9; this was at the station with a Stage I on III community. Monitoring Surveys of the New Haven Capping Project, 1993-1994 46 5.0 DISCUSSION The subaqueous capping of dredged material was introduced as a disposal technique to the DAMOS Program in 1979. The practices behind this disposal technique were improved during the early-1980s and continue to be employed in the successful completion of capping projects at CLIS, the New London Disposal Site (NLDS), and Portland Disposal Site (PDS; SAIC 1995). Over the years, data have shown that both sand and silt are effective capping materials. The low permeability and chemically adsorptive properties of silt constitute good capping material. Although sand caps provide greater resistance to erosion during storm events, a 0.5 to 1.0 m layer of silt was used as capping material at CLIS due to its similarity to the ambient grain size, relative abundance, and availability to the New Haven Capping Project. The NHAV 93 disposal mound received an estimated barge volume of 1,159,000 m3 of material dredged from New Haven Harbor and the surrounding area as part of the New Haven Capping Project. The capping project conducted at CLIS during the 1993-1994 disposal season was atypical in several ways: 1) Dredged material was deposited in a depression formed by a ring of seven historic mounds to restrict the lateral spread of the UDM apron; 2) The resulting disposal mound was successfully capped with quantities of CDM less than the total volume of the UDM deposit; 3) A remarkable sequence of five precision bathymetric, two REMOTS® sediment-profile, and three geotechnical coring surveys were conducted by SAIC at various stages of NHAV 93 mound development, creating a comprehensive time-series dataset documenting the construction of the CAD mound. The data collected over the NHAV 93 mound indicate that lateral containment of the UDM deposit was critical in the completion of the New Haven Capping Project. Utilization of the basin-like feature, created by the ring of disposal mounds, to receive large volumes of UDM for environmentally sound and cost-effective disposal is the culmination of many years of thoughtful planning and disposal. Since the inception of the DAMOS Program, a ten-year cycle of dredging and disposal operations has been established in the central Long Island Sound region. With the development of the NHAV 74, NHAV 83, and NHAV 93 mounds, NED has estimated that large scale dredging operations must be conducted in New Haven Harbor and the Quinnipiac River every ten years to maintain adequate depths for commercial, military, and private vessels (Morris 1994). The ten-year time frame allows for the completion of many small dredging operations in regional harbors, channels, and docking facilities. The disposal of modest volumes of material aids in the preparation for large scale projects with the magnitude of Monitoring Surveys of the New Haven Capping Project, 1993-1994 47 the New Haven Capping Project. Dredged material generated by those smaller projects is now used to develop containment rings that concentrate deposition of large volumes of UDM and facilitate efficient capping. By continuing to build rings of closely spaced disposal mounds over the 6.85 km? area of CLIS, a network of containment cells, similar to honeycombs, will be produced (Figure 5-1). Over time, this network of cells will minimize the surface area occupied by each dredged material deposit and therefore maximize the overall capacity of the site. In the past, the management strategy at CLIS and other DAMOS disposal sites was to build many independent mounds over the given area of the disposal site. Each mound could be monitored individually, assessing mound stability, cap thickness, recolonization status, etc. Although this practice was highly successful, the overall capacity of the disposal site was reduced due to the unusable area between the discrete sediment mounds. This strategy changed at CLIS in 1983 with the placement of the SP mound to the northeast of the historic NORWALK mound (SAIC 1984). As dredging and disposal practices continued to improve, advancements in precision navigation and point deposition helped concentrate sediment mounds in smaller areas. By repositioning a taut-wire moored disposal buoy at the start of each disposal season, a ring of disposal mounds was formed and eventually completed in 1992 with the development of the CLIS 91 mound. At this time project plans for the large-scale New Haven Capping Project were being finalized. The reported volumes provided by the DAMOS Disposal Barge Logs state that approximately 590,000 m3 of UDM was deposited at the NHAV buoy, followed by an estimated volume of 569,000 m? of CDM. The wealth of data collected over the NHAV 93 project area suggests that the resulting mound is broad, stable, adequately capped, and exhibiting a CDM to UDM ratio of 0.96 to 1.0 (Morris 1994). In the past, CDM to UDM ratios varied from 2:1 to 6:1 when initiating a capping operation on a flat or gently sloping area of seafloor without natural (i.e., rock outcrops, glacial troughs) or artificial (i.e., disposal mound ring, geotextile fabrics) means of restricting the lateral dispersion of a UDM deposit (SAIC 1995). Lacking means of containment, the apron of UDM is free to spread into a wide, thin layer of material, increasing the amount of CDM required to completely cover the flanks of the mound. The NHAV 93 capping project was the first in the New England region to utilize an artificial containment cell to control the spread of UDM. The use of the disposal mound ring at CLIS significantly reduced the outward migration of the UDM mound apron. As a result, cap material was distributed over a much smaller area, decreasing the total volume of CDM required to cap the inner harbor sediments. Dredging operations in urbanized areas may not produce an abundance of CDM for use in capping operations. However, the Monitoring Surveys of the New Haven Capping Project, 1993-1994 48 S][99 JUDUTUTe}UOS JO YIOMIOU B JONIYSUOD puP AjIOeded JIS SZIUMTXeUL 0} STO Je [esodsip sinjNy Jo ulayed pojsassng *][-¢g aansIy julod jesodsiq paysabins - woos Wdo0or wig — lS M.00S°2S .c2 M.000°2S .cL M.00S°2S .cL M.000°ES 22 M.00S'ES cL M.000PS cL N .00S°80 oY a lone, N .000°60 .bV 66 AVHN > C v6 SI10 N .00S°60 .bY Aiepunog ays jesodsiq Ze6L GVN Ayawxujyeg yeep Aine U19}}JEq UOI}INIJSUOD |]9D JUBWUIeJUOD pasodolgd a}US |esodsig punos pueyjs| Huo7 jesjuay Monitoring Surveys of the New Haven Capping Project, 1993-1994 49 perfection of this disposal and containment technique allows NED to deposit moderate to large volumes of UDM, while requiring a minimum investment of CDM. The strategic repetition of precision bathymetric, REMOTS®, and geotechnical coring surveys was invaluable during the New Haven Capping Project. The five separate datasets allowed SAIC to document the progression of CAD mound development and advise NED upon the best course of action to achieve its ultimate goal. The results of each bathymetric survey provided a "snapshot" in time, allowing comparisons with previous surveys to document and quantify central mound consolidation, calculate overall growth of the CAD mound, and identify areas requiring additional cap material deposition. This comprehensive dataset also facilitates revisiting the various stages of the capping project to chronicle how disposal and oceanographic processes affected the dredged material, as well as to explore what knowledge of CAD mound construction was gained. During the baseline survey, REMOTS® sediment-profile photography was used to estimate the shear strength, as well as document the successional status of the containment ring. The flanks of the UDM mound were mapped by REMOTS® within the containment basin during the precap survey of the NHAV 93 mound. These data were used to ensure accurate placement of the dredged material during disposal operations and permit the calculation of target capping points along the mound apron (Figure 4-6). REMOTS® photography continues to be used to detect changes in various physical and biological parameters on the surface of the NHAV 93 mound. The surface layer shear strengths of the five mounds sampled during the baseline survey indicated that significant de-watering and consolidation had occurred in the surface sediments. The larger grain-sized and densely packed sediment deposits displayed higher shear strengths, indicating the potential to contain a ridge of new dredged material while maintaining the mound integrity. No structural failure was detected within the seven- mound containment ring during any of the five bathymetric surveys. URI estimated the relative consolidation of sediments occurring between the precap, interim cap, and postcap surveys using both theoretical models and data from the geotechnical cores. These estimates were required to determine cap material requirements; actual cap thickness was masked by consolidation of both the basement material (ambient sediments and historic dredged material) and the UDM deposit. Cores collected immediately following the construction of the mound included the basement material, UDM, and CDM. Results were used to establish the initial geotechnical characteristics of the completed mound. These data were used as a reference for future geotechnical and bathymetric surveys. Numerical computations will also be performed on settlement and volume changes. Monitoring Surveys of the New Haven Capping Project, 1993-1994 50 Following UDM disposal, the mound was 2.5 m in height and 510 m in diameter with a calculated volume of 312,000 m? based on comparisons of the baseline and precap bathymetric surveys. The final CAD mound is centered approximately 125 m to the south of the NHAV buoy location (Figure 4-13). The total volume of cap material accounted for by bathymetry was 402,000 m3, the diameter of the mound expanded to 800 m, and the mound height remained at 2.5 m due to significant consolidation of the underlying UDM deposit. According to DAMOS barge disposal logs, the total volume of dredged material was 1,159,000 m3; however, the total volume accounted for by bathymetry was 714,000 m3 (62% of the estimated barge volume). Results of previous DAMOS monitoring surveys have shown that accumulations of dredged material less than 20 cm thick in the flanks of a disposal mound are typically deposited in layers too thin to be detected by standard bathymetric techniques. The 38% difference in final volumes between bathymetric analysis and disposal logs is accounted for by consolidation of the underlying UDM deposit and the limits of the acoustic survey. Due to the complex scheduling of disposal activities during this project, it is difficult to determine what volumes of contaminated and cap material were present during each survey. The depth difference comparison between the precap and the postcap surveys provides the best indication of the overall distribution of cap material. This comparison indicates an apparent lack of cap material in the northwestern quadrant of the final disposal mound (Figure 4-14). However, disposal records indicate that 76,000 m? of cap material was disposed in this quadrant prior to the precap survey making it undetectable in the precap/postcap comparisons. In addition, subbottom profiling data and geotechnical cores collected over the NHAV 93 mound in July 1994 detected 0.5 to 0.75 m of silt cap material over the northwestern flank (Figures 5-2 and 5-3; Morris 1994). Results of the REMOTS® baseline survey showed that recolonization of the bottom invertebrate community from the disturbance of historic disposal operations has proceeded at a rate typical for open-water dredged material sites. Successional stages were dominated by pioneering Stage I polychaetes with evidence of more mature taxa in the Stage I to Stage II and Stage I on Stage III communities. Stage II taxa represent a transitional sere between Stage I and III and are associated with recovery of a disturbed benthic habitat (Rhoads and Germano 1986). Stage III taxa generally represent high-order successional stages typically found in low disturbance regimes. Organism-Sediment Indices were variable and indicative of a patchy benthic environment. Monitoring Surveys of the New Haven Capping Project, 1993-1994 al ‘[RAIOJUT INOJUOD W ¢Z'O ‘punow €6 AVHN ef} J9AO vale sIsAyTeue We SZS X OOOT (ssouysty) ded) | JaAe] WoNOQQns Jo jo]d InoJUOD ‘eIep WoNog|ns p66] AINE °7Z-S aaNsIy MOS STi cS) 2720) MO-O£€ €S 220 MO°- St €S 240 MO~- 00 tS 220 Ja}yord woyoqqns Aq payoajap se sseuyoiyu| deg NOo-Sv 80 Tr VE/OL-CL/L v66L SI1D NO~ OO 60 I¥ NO~OO 60 Tr - sishjeuy woyoqqns / yo wwe] NO~O&€ 60 TY +- NO°-O€ 60 TY MO O€ 2S 220 MO -Sbt 2S 220 MO~00 €S 2240 MO ~ST €S 220 MO-O€ €S 220 WOOF Si? 136} 7200) MO~-00 tS 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 52 ‘punow! €6 AWHN 2} JOAO ease sisdyeue UI GZS X OODT ‘P66T YR Jo 10] yuLIdjoo] jeiajyeur deo 0]U0 prepiaao (ssouyorty deo) [ Jake] Woyogqns jo Jo[d InojUoD “eIep Woogans pE6I AINE “E-g BANS aaW MO-ST €S 240 MO" OE ES 220 MO’ Sb €S 2240 MO°~ OO tS 220 00r OOF sseuyoiu, ded VE/9L-CL/L v66l SIND NO°St 80 TY AuyyawAyjyeg Aq payoajep jeuayew ded NO°-OO 60 Iv —|- NO°OO 60 Iv ory x sishjeuy == woyoqqns NO’SL 60 Ib 2 y 30 WUE] Jajlyoid woyoqqns Aq poayoajep jeayew ded NO-O€ 60 I¥b + NO-O€ 60 Iv MO-O£ 2S 220 MO°St 2S 2240 MO-O0O €S 220 MOS Si SSS 2/20 MO-O£€ €S 240 MOGSibeS 2/40 MO-OO tS 220 Monitoring Surveys of the New Haven Capping Project, 1993-1994 53 During the November 1993 precap REMOTS® survey of the FVP mound, there was a noticeable lack of Stage II and Stage III benthic infaunal activity. Although plans were made to cap the historic UDM mound, no excess CDM was available from the New Haven Capping Project to begin the placement of a sediment cap over the FVP mound. Another series of REMOTS® photographs collected in September 1995 indicate an increase in Stage III individuals within the surface sediments (Morris and Murray 1995). A total of ten stations displayed evidence of Stage III assemblages, compared to the single replicate of station 50W in 1993. However, the majority of those ten stations lie 200 to 300 m from the center of the mound, correlating to previous observations regarding the patchy benthic infaunal community near the center of the FVP mound. The original objective of FVP was to field verify existing predictive techniques for evaluating the environmental consequences of dredged material disposal under aquatic, intertidal (wetland), and upland conditions (Murray and Carey 1993). The mound is an uncapped UDM deposit formed by the placement of Black Rock Harbor sediments placed in the northeast corner of CLIS during the 1982-83 disposal season. Designed as a six- year, cooperative research project between the US Army Corps of Engineers, Waterways Experiment Station (WES) and the US Environmental Protection Agency (EPA), the UDM sediments have been monitored periodically for changes in benthic infaunal population and contaminant content. Now that the WES/EPA experimentation has concluded, plans have been made to cap the mound in order to isolate the UDM from the marine environment. Without the deposition of cap material during the New Haven Capping Project, an opportunity still exists to conduct a comprehensive physical, chemical, and biological assessment of the experimental mound 13 years post-disposal. An intensive bioaccumulation study on the invertebrate species inhabiting the sediments could determine the current amount of chemical uptake within the benthic infauna, as well as explore the stress and susceptibility levels of the organisms occupying the various domains of the mound. Monitoring Surveys of the New Haven Capping Project, 1993-1994 54 6.0 CONCLUSIONS Based on acoustically detected changes in depth at the NHAV buoy location, disposal and capping operations formed a CAD mound with a diameter of 800 m and height of 2.5 m. Depth difference calculations between the interim disposal and precap surveys detected a 100 m wide pocket of consolidation over the mound apex. It was determined that the majority of the material shifted to the northeast, forming a 150 m wide plateau at the top of the UDM mound. The primary factor causing the structural failure of the apex was likely to be the initial placement of CDM over the northwest quadrant of the NHAV 93 mound, building the apex beyond the critical angle of repose, causing redistribution of material downslope. A contributing factor to the collapse of the mound apex could have been the subsurface consolidation of the UDM deposit due to de-watering. A question had existed concerning the coverage of UDM in the northwestern quadrant of the NHAV 93 mound due to conflicts in the schedule of capping and survey operations. However, DAMOS disposal logs indicate an estimated barge volume of 76,000 m? was released over cap placement points A, F, and J before the completion of the precap survey. In addition, subbottom and geotechnical core data collected over the northern portion of the NHAV 93 mound in July 1994 indicate that 0.5 to 0.75 m of cap material is present northwest of the buoy location. Recolonization over the entire surface of the new CAD mounds is expected to progress at a rate typical of open-water dredged material disposal sites. This capping project demonstrated the successful execution of a long-term management strategy at the most active disposal site in New England. The strategy included the thoughtful placement of small to moderate volumes of dredged material in order to support the containment of large volumes of UDM and effectively isolate it from further interaction with the marine environment. Also, the continued use of this management approach will concentrate disposal into the formation and subsequent filling of containment cells, maximizing the finite capacity of the 6.85 km? disposal site. Although all primary indications suggest the attainment of all of NED's goals, monitoring at the NHAV 93 mound should continue for the next several years to assess biological recovery and long-term cap integrity (Morris 1994; Germano et al. 1994). The wealth of data generated by the repetitive survey operations during CAD mound construction and annual monitoring are providing a great deal of insight into the processes that continue to affect this and other dredged material mounds. The inspection of cap integrity and quantification of overall consolidation could lead to answers pertaining to dredged material mass balance, consolidation rates, material slumping, material de- watering, and physical changes in basement material. Monitoring Surveys of the New Haven Capping Project, 1993-1994 55 7.0 REFERENCES Bohlen, W. F.; Cohen, D. R.; Howard-Strobel, M. M.; Morton, E. T. 1994. DAMOS New Haven dredge monitoring cruise log summary, October 25-November 18, 1993. University of Connecticut, Marine Sciences Department, Avery Point, CT. Submitted to SAIC, Newport, RI. EPA/USACE. 1991. Evaluation of dredged material proposed for ocean disposal, testing manual. Publication 503/8-91/001. US Environmental Protection Agency, Office of Marine and Estuarine Protection, Washington, D.C. and Dept. of the Army, US Corps of Engineers, Washington, D.C. Fredette, T. J. 1994. Disposal site capping management: New Haven Harbor. Reprinted from Dredging '94, Proceedings of the Second International Conference, November 13-16, 1994. US Army Corps of Engineers, New England Division, Waltham, MA. Germano, J. D.; Rhoads, D. C.; Lunz, J. D. 1994. An integrated, tiered approach to monitoring and management of dredged material disposal sites in the New England Region. DAMOS Contribution No. 87 (SAIC Report No. SAIC-90/7575&234). US Army Corps of Engineers, New England Division, Waltham, MA. HMM Associates, Inc. 1993. Consultants for the US Army Corps of Engineers. Concord, MA. Lawless, W., Chief, Regulatory Divisions Operations Directorate for USACE New England Division. [Letter to Chief, Navigation Division]. 1991 December 23. Morris, J. T. 1994. Monitoring cruise at the Central Long Island Sound Disposal Site, July 1994. SAIC Report No. 327. Draft report submitted to US Army Corps of Engineers, New England Division, Waltham, MA. Morris, J. T.; Murray, P. M. 1995. Monitoring cruise at the Central Long Island Sound Disposal Site, September 1995: data report. SAIC Report No. 360. Data report submitted to US Army Corps of Engineers, New England Division, Waltham, MA. Murray, P. M.; Carey, D. A. 1993. Summary of monitoring results at the Field Verification Program aquatic disposal mound. SAIC Report No. 287. Technical report submitted to US Army Corps of Engineers, New England Division, Waltham, MA. Monitoring Surveys of the New Haven Capping Project, 1993-1994 56 Murray, P. M.; Selvitelli, P. 1996. DAMOS navigation and bathymetry standard operating procedures. SAIC Report No. 290. Final report submitted to US Army Corps of Engineers, New England Division, Waltham, MA. Naval Underwater Systems Center (NUSC). 1979. Disposal Area Monitoring System (DAMOS) annual data report - 1978. Submitted to US Army Corps of Engineers, New England Division, Waltham, MA. New England River Basins Commission (NERBC). 1980. Interim plan for the disposal of dredged material from Long Island Sound. New England River Basins Commission. Boston, MA. pp. 1-55. Rhoads, D. C.; Germano, J. D. 1986. Interpreting long-term changes in benthic community structure: a new protocol. Hydrobiologia. 142:291-308. Rhoads, D. C.; Germano, J. D. 1990. The use of REMOTS® imaging technology for disposal site selection and monitoring. In: Demars, K.; Chaney, R. eds. Geotechnical engineering of ocean waste disposal. ASTM Symposium Volume, January 1989, Orlando, Fla., pp. 50-64. SAIC. 1984. DAMOS summary of program results 1981-1984: volume II, part B, section II: Central Long Island Sound ongoing surveys. DAMOS Contribution No. 46 (SAIC Report No. 84/7521&C46). US Army Corps of Engineers, New England Division, Waltham, MA. SAIC. 1985. Standard operating procedure manual for DAMOS monitoring activities: volume I and volume II. DAMOS Contribution No. 48 (SAIC Report No. SAIC- 85/7516&C48)). US Army Corps of Engineers, New England Division, Waltham, MA. SAIC. 1995. Sediment capping of subaqueous dredged material disposal mounds: an overview of the New England experience 1979-1993. DAMOS Contribution No. 95 (SAIC Report No. SAIC-90/7573&C84). US Army Corps of Engineers, New England Division, Waltham, MA. Silva, A. J.; Brandes, H. G.; Veyera, G. E. 1994a. Geotechnical characterization: coring and core processing summary. DAMOS Project Central Long Island Sound, New Haven Harbor Maintenance 1993-1994. Draft report submitted to SAIC, Newport, RI. Available from: University of Rhode Island, Narragansett, RI. Silva, A. J.; Brandes, H. G.; Veyera, G. E. 1994b. Geotechnical laboratory testing summary. DAMOS Project Central Long Island Sound, New Haven Harbor Monitoring Surveys of the New Haven Capping Project, 1993-1994 Meee eee ee ee eee eee ee ee ee 7, Maintenance 1993-1994. Draft report submitted to SAIC, Newport, RI. Available from: University of Rhode Island, Narragansett, RI. Monitoring Surveys of the New Haven Capping Project, 1993-1994 aerobic, 55 anoxia, 55 barge, viii, 12, 24, 54 disposal, 24 benthos, 7, 16, 22, 29, 32, 54, 56, 59 ampeliscids, viii, 1, 22 amphipod, 56 bivalve, 22 polychaete, 22, 56 bioassay, vili, 1, 22 body burden bioaccumulation, 22, 23 bioassay, viii, 1, 22 boundary roughness, 29 buoy, viii, 1, 6, 7, 12, 24, 27, 32, 44, 54 disposal, viii, 6 capping, Viii, x, 1, 5, 6, 7, 22, 23, 24, 25, 27, 29, 32, 36, 39, 44, 54 Central Long Island Sound (CLIS) FVP, 32, 54, 55, 56, 59 MQR, | Norwalk (NOR), 1, 7 conductivity, 29 consolidation, x, 6, 35, 39 containment, vili, 1, 7, 29, 36 contaminant, x, 14, 22 New England River Basin Commission (NERBC), 18, 20 CTD meter, 29 density, 35 deposition, viii, 1, 36, 39, 44, 54 dispersion, 6, 7 disposal site Central Long Island Sound (CLIS), viii, 1, 6, 7, 8, 10, 19, 24, 36, 54, 55, 56 fish, 14 fisheries, 14 grain size, 14, 24, 29, 35, 54 habitat, 59 methane, 29 INDEX mud clast, 29 New England River Basin Commission (NERBC), 18, 20 oil and grease, 20 organics oil and grease, 20 polyaromatic hydrocarbon (PAH), 18, 19, 22, 24 polychlorinated biphenyl (PCB), 18, 24 total organic carbon, 14 recolonization, x, 32 reference area, 19 REMOTSS, viii, x, 2, 5, 6, 29, 30, 32, 54, 55, 56, 59 boundary roughness, 29 Organism-Sediment Index (OSI), 30, 59 redox potential discontinuity (RPD), 29, 55 RPD REMOTS8®, redox potential discontinuity (RPD), 29, 55, 59 salinity, 29 sediment chemistry, 22, 24 clay, 14, 20, 54, 55 gravel, 54, 55 plume, 6 sand, 14, 18, 54, 55 silt, 14, 20, 54, 55 sediment sampling cores, ix, X, 2, 5, 6, 24, 32, 35 grabs, ix, x, 2, 5, 6, 32, 35 shore station, 28 succession pioneer stage, 56 successional stage, 29, 56, 59 survey baseline, viii, x, 2, 5, 6, 28, 29, 30, 32, 35, 36, 39, 44, 54, 55, 56 bathymetry, viii, x, 1, 5, 6, 28, 29, 35, 36, 39, 44, 54 postdisposal, 7 predisposal, 1, 2, 5, 36 REMOTS8®, 32, 56, 59 subbottom, x temperature, 29 tide, 28, 29, 44 toxicity, 23 trace metals, 18, 22, 24 arsenic (As), 18, 20 cadmium (Cd), 18, 20, 24 chromium (Cr), 18, 20 copper (Cu), 18, 21, 24 lead (Pb), 18, 21 mercury (Hg), 18, 21 nickel (Ni), 18, 21 vanadium (V), 5, 12, 24, 27 zinc (Zn), 12, 18, 24, 27 volume difference, x waves, 28, 36 APPENDIX A Sediment Chemistry Results . Appendix A Sediment Chemistry Results Appendix A Table 1. Appendix A Table 2. Appendix A Table 3. Appendix A Table 4. Appendix A Table 5. Appendix A Table 6. Appendix A Table 7. Sediment Chemistry Results (Dry Weight) for the Inner Federal Navigation Channel, New Haven Harbor 1993 Sediment Chemistry Results (Dry Weight) for the Outer Federal Navigation Channel, New Haven Harbor 1993 Sediment Chemistry Results (Dry Weight) for Gulf Oil, New Haven Harbor 1993 Sediment Chemistry Results (Dry Weight) for Northeast Petroleum, New Haven Harbor 1993 Sediment Chemistry Results (Dry Weight) for the New Haven Terminal, New Haven Harbor 1993 Sediment Chemistry Results (Dry Weight) for Mobil Oil, New Haven Harbor 1993 Sediment Chemistry Results (Dry Weight) for Wyatt Incorporated, New Haven Harbor 1993 Appendix A Table 1 Sediment Chemistry Results (Dry Weight) for the Inner Federal Navigation Channel, New Haven Harbor 1993 INNER HARBOR C Station Latitude 42°17.94' | 42°17.73' | 41°17.45' | 41°17.23' Station Longitude 72°54.50' 72°54.60' | 72°54.75' | 72°54.69' GRAIN SIZE %Silv/cla mia: en ET es oer a nee aaa 7, ol ioe 5 a Aldrin Chlordane pp-DDT,DDE,DDD Dieldrin Endosuifan I, II Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Toxaphene alpha-BHC beta-BHC gamma-BHC Total BHC PCBs (ppb) Appendix A Table 1 (cont.) Fae edad eae ae Low Molecular Weight | | | Acenapthene Acenaphthylene Fluorene Phenanthrene Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Benzo(g,h,i)perylene Dibenzo(a,h)anthracene __Indeno(1,2,3-cd)pyrene | Appendix A Table 2 Sediment Chemistry Results (Dry Weight) for the Outer Federal Navigation Channel, New Haven Harbor 1993 aaa ee Station Latitude 41°16.94' 42°16.39' 41°15.60' | 41°15.16' | 41°14.50' 41°13.54' Station Longitude 72°54.80' 72°54.69' 72°54.81' | 72°54.97' | 72°54.97' 72°54.69' GRAIN SIZE | sien ___f}__es}_}__a)__)__v__ Aldrin Chlordane pp-DDT,DDE,DDD Dieldrin Endosulfan I, II Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Toxaphene alpha-BHC beta~-BHC gamma-BHC Total BHC Appendix A Table 2 (cont.) _ eee eed Low Molecular Weight Napthalene Acenapthene Acenapthylene Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Benzo(g,h,i)perylene Dibenzo(a,h)anthracene Indeno(1 ,2,3-cd)pyrene Appendix A Table 3 Sediment Chemistry Results (Dry Weight) for Gulf Oil, New Haven Harbor 1993 GRAIN SIZE % Gravel 0 0 0 0 % Sand 52.5 32.4 58.4 61.5 a ; 47. : 53. : % Silt/cla 46.6 36.8 42.3 38.4 40.1 55.7 46.6 Bee ee a Chlordane pp-DDT,DDE,DDD Dieldrin Endosulfan I, II Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Hexachlorocyclohexane (total) Methoxychlor Toxaphene ii a Appendix A Table 3 (cont.) Napthalene 1-Methylnapthalene Biphenyl] 2,6-Dimethylnapthalene Acenapthene Acenapthylene Fluorene Phenanthrene 1-Methylphenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Benzo(e)pyrene Benzo(g,h,1)perylene Dibenzo(a,h)anthracene Indeno(1,2,3-cd)pyrene Perylene * Composites of two samples Appendix A Table 4 Sediment Chemistry Results (Dry Weight) for Northeast Petroleum, New Haven Harbor 1993 | % Gravel 0.0 0.0 0.0 0.0 0.0 0.0 a | % Sand 9.5 10.7 10.3 8.35 7.82 12.6 97.7 % Silt/clay 90.54 89.3 89.7} 91.65} 92.18 87.4 | | | 2.3 ee | | AS Cd PESTICIDES (ppm) Aldrin Chlordane pp-DDT,DDE,DDD Dieldrin Endosulfan I, 1 Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Hexachlorocyclohexane (total) Methoxychlor Toxaphene ND ND nanny ND = Not Detected eune sae ND ND ND ND ND Appendix A Table 4 (cont.) ae PAHs (ppm) heen rey | ae ea Face oe B3n |e Bs id eer | ee eee | Napthalene ND 1-Methylnapthalene 2-Methylnapthalene Biphenyl 2,6-Dimethylnapthalene Acenapthene Acenapthylene Fluorene Phenanthrene 1-Methylphenanthrene Anthracene ND ND ND ND ND ND EE el ee a ee Fluoranthene ; : ND ND E : Pyrene ND ND Benzo(a)anthracene ND ND Chrysene ND ND Benzo(b)fluoranthene ND ND Benzo(k)fluoranthene ND ND Benzo(a)pyrene ND ND Benzo(e)pyrene ND ND Benzo(g,h,i)perylene ND ND Dibenzo(a,h)anthracene ND ND Indeno(1,2,3-cd)pyrene ND ND Perylene ND ND ND = Not Detected _ Appendix A Table 4 (cont.) GRAIN SIZE % Gravel 0 0 0 0 0 0 1.67 % Sand 11.4 6.82 7.43 10.4 11.2 69.7 74.5 % Silt/clay 88.6 93.18 92.57 89. : 88.8 26.7 21.6 ee ne a Chlordane pp-DDT,DDE,DDD Dieldrin Endosulfan I, II Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Hexachlorocyclohexane (total) Methoxychlor dias a ~ ND = Not Detected NA =NotGiven Ag Appendix A Table 4 (cont.) Tic a naa ap yea Ey a Napthalene ie 5 ne a oe ie 1-Methylnapthalene 2-Methylnapthalene Biphenyl 2,6-Dimethylnapthalene Acenapthene Acenapthylene Fluorene Phenanthrene 1-Methylphenanthrene Anthracene | Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Benzo(e)pyrene Benzo(g,h,i)perylene Dibenzo(a,h)anthracene Indeno(1,2,3-cd)pyrene Perylene Appendix A Table 5 Sediment Chemistry Results (Dry Weight) for the New Haven Terminal, New Haven Harbor 1993 eee NEW HAVEN TERMINAL | aes a een Aes | GRAIN SIZE %Gravel 2310) 13-8] 213] ene eas %Sand 57.0] 63.8] 62.41 60.4] 66.5 | mSilt/cla 20/6) 1) 018;5\) 325i an 2619 |e d Aldrin Chlordane pp-DDT,DDE,DDD Dieldrin Endosulfan I, II Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Hexachlorocyclohexane (total) Methoxychlor Toxaphene — $658586855655 BRGZaSdeee eae Appendix A Table 5 (cont.) PAHs (ppm) Low Molecular Weight Napthalene 1-Methylnapthalene 2-Methylnapthalene Biphenyl 2,6-Dimethylnapthalene Acenapthene Acenapthylene Fluorene Phenanthrene 1-Methylphenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Benzo(e)pyrene Benzo(g,h,i)perylene Dibenzo(a,h)anthracene Indeno(1,2,3-cd)pyrene Perylene Appendix A Table 6 Sediment Chemistry Results (Dry Weight) for Mobil Oil, New Haven Harbor 1993 GRAIN SIZE % Gravel 3.89 28.3 14.5 % Sand 81.9 yas 82.0 % Silt/cla 14.2 ue a Chlordane pp-DDT,DDE,DDD Dieldrin Endosulfan I, II Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Hexachlorocyclohexane (total) Methoxychlor Toxaphene eo ee Appendix A Table 6 (cont.) Napthalene 1-Methylnapthalene 2-Methylnapthalene Biphenyl 2,6-Dimethylnapthalene Acenapthene Acenapthylene Fluorene Phenanthrene 1-Methylphenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Benzo(e)pyrene Benzo(g,h,i)perylene Dibenzo(a,h)anthracene Indeno(1,2,3-cd)pyrene a Ecyicne Appendix A Table 7 Sediment Chemistry Results (Dry Weight) for Wyatt Incorporated, New Haven Harbor 1993 WYATT AINC ORPORATED i iiaitst2t3 | iaiiiey nr 2 rani 3) iain 4 RAAES 4 =A | Rene 5) TE © | RUAN Pink Tank berth % Gravel 12.7 8.98 18.4 11.3 0.0 3.43 0.5 0.0 % Sand 67.6 70.2 56.3 72.6 69.5 68.3 87.1 34.1 % Silt/clay 19.3 21.6 26.9 16.9 30.8 28.3 12.3 65.9 METALS (ppm) "PESTICIDES (ppm) Aldrin Chlordane pp-DDT,DDE,DDD Dieldrin Endosulfan I, II Endosulfan sulfate Endrin Endrin aldehyde Heptachlor Heptachlor epoxide Hexachlorocyclohexane (total) Methoxychlor Toxaphene eee SSS N66555556655 $686566555556 6586566665 Appendix A Table 7 (cont.) PAHs (ppm) 7S | Pink Tank berth Low Molecular Weight Napthalene 1-Methylnapthalene Biphenyl 2,6-DimethyInapthalene Acenapthene Acenapthylene Fluorene Phenanthrene 1-Methylphenanthrene i High Molecular Weight Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Benzo(e)pyrene Benzo(g,h,i)perylene Dibenzo(a,h)anthracene Indeno(1,2,3-cd)pyrene Perylene ae ie Tees 6 pee he APPENDIX B Disposal and Capping Operations ae ng Appendix B_ Disposal and Capping Operations Appendix B Table 1. Appendix B Table 2. Summary of Disposal Operations of Contaminated Sediments Dredged from New Haven Harbor, October 1993 to January 1994 (Source: Great Lakes Dredging Company) Summary of Capping Operations at the NHAV93 Mound, November 1993 to February 1994 (Source: Great Lakes Dredging Company) fezs'zii | evi‘oer ——_—| J uoneooj ye pousodap [ei Focz'1o9 sf es0‘oop —_—|_ Aong €6A VN 18 pauisodap [e101 Rerounec= Saloeroes | wINMAOAIVEOE. leescztr sd esg‘6g «ss sypafoad Surgpaap ayeatad wo.y [230], I!QOW v6/L/1 cnn ee eee 00S C8E HO SIND v6/8/1 . TO JNO 6/3/1-76/L/1 HO JIND €6/8C/C1-€6/SC/C1 009‘S1 L761 HOS = ae eee nes wnajoned AN €6/ST/ZI-€6/EL/ZI wingjoned SIN E6/EL/ZI-€6/IL/ZI COE LT 006°S Isp Yiog oo1y €6/V1/C1-€6/€1/Cl O0r IZ Z9E‘9I quel yuld €6/6/C1-€6/L/Cl payeiodioouy eA Scie betes a CCS ee Be IT ee [eurwisa, UeARH MON E6/L/Z1-€6/E/ZI JouUevY [V1opsf JVUUT 9} WIOTJ [eJO TL, 000°€ r6C'C jouueyo jerapay JouuT +6/8/1 060°9r Orc'se Jouueyo yeropey JouUT €6/€/Z1-€6/81/11 009°€ 2SL‘Z jouueyo yesopey soUUT €6/81/11-€6/S/11 O€L' 109 €80'09r jouueyo yesepay Jou €6/1€/01-€6/£/01 Kong €6AVHN ajeq, diay, uo1es0'7] [esodsiq auIN]OA 39.1N0S (sso07 jesodsiq SOWYV :99JN0S) 766] Alenuey 0} E66] J9qQ0}9Q ‘JOQIeH UdARH] MAN WOI pospolq SJUOUIIpeg payeurWIEJUOD Jo suotjesiadg jesodsiq jo Arewuins 1 qe q xipueddy umajoneg aN P jouueyo [esiopey | €6/7Z/ZI dej-4 pojerodioouy neam 2? JouuRYo [eIopay €6/01/CI Aemayey /ONUepY X97 2 Jouuey [el1opay | 6/1 E/T GaLaTdNOO LNIOd dLVd oad LVI TVSOdSIG (s807 yesodsiq SOWV :221N0S) p66] Arensga-4 01 €66] JOQUIDZAON ‘PunO|W €6AVHN 94} Je suonesiadg 3uiddeDd jo Arewuins Z AGU, q xipueddy Jauueyo [eropay cos'es CL 668 TEN ECON It [90] (dine EG Ib Bee 5 a It ded-7 esces cL 8£0°6 E19 ES cL 8806 S79'ES cL SCI 6 sep es cL e8p es foe) Ke) = an oss €s ww ~~ “alae io) = + €8S ES SéS'ES CL L90°6 OET ES CL 0£7 6 S9T ES CL $9C 6 OST ES CL SLT ES CL £916 859'S an] wnajoned AN | €6/ZZ/ZI €6/01/Z1 wngjonod AN ¥ 96S 6 Oss ‘ZI Jouueyp elapoy | £6/77/TI £6/01/7I | ce | O1ZOI winajoned AN | €6/ZZ/ZI €6/01/Z1 9LS‘II Orl‘sI wnajoned AN | €6/ZZ/Z1 €6/81/11 OOL ES cL 0076 Ove Es CL SET 6 OOE'ES CL 8006 TWIMad LVN (,W) (PA) dVO Ga LaTdNOO GaLVILINI LNIOd aN NIOA GHNAIOA 40 GouNOs aLvd aLlva Sad SNOT oad LVI TVSOdSIC (1u09) Z 3Jquy, q xipueddy ar pojerodioouy ned Wo SUINTOA [RIO] | weet = | osost Aemayey/onuepy xo] Woy swnyjo, [e1O], | steer O7Z7‘£9 wnojoned AN Wo sUINOA, [BIOL | sra'sos | sas‘t99 | Jouueyo [eIopey Wo SUINTOA [BIOL | cacioos | sssvre | sjusuIpeas poddes jo ouinjo, [e10], TWA LVN a) (pA) dVO ada LaTdNOo GaLVILINI LNIOd aNNTOA ANNTOA 40 GOUNOS aLlva aLvVa 9ad DNOT odd LVI TvSOdSIqd (quo9) 7 a1qu, q xIpueddy APPENDIX C REMOTS® Sediment-Profile Surveys Neate : ; ie ‘ cae : i b : u See beeen Wyner cai Dy es ous an Appendix C REMOTS® Sediment-Profile Surveys Appendix C Table 1. Station Locations and Results of the REMOTS® Baseline Survey Conducted in September 1993 Appendix C Table 2. Dredged Material Thickness from REMOTS® Precap Survey (3- 4 November 1993) Appendix C Table 3. Station Locations and Results of the REMOTS® Postdisposal Survey Conducted 4 November 1993 _ ___aslesees i MOS! 069 INO 11s |6se'es MOS1 069 ie i MOS! 069 MOO! 069 MOO! 069 MOO! 069. is]e6z'es ; MOS 069 (1s ]o8z'es i MOS 069 "1S]Zez'es i MOS 069 M1s]zsz'es i Y10 069 \"1S]9Sz es y10 069 is]zsz'es 419 069 LBQNI|222'€¢ 3 30s 060 I1s]Z0z'es i “30S 069 IT As|Z1z'€s 30S 069 INO 11S]eet es 3001 069 1s}reL ‘es 3001 069 Fis|retes 3001 069 jooojcoo|jcoo jiooojooojocoo|jcoo|jcoeo jooojoocojco0c|jcocojcoo ioocaojcoojcoo|jco0ojcoo iooo|jocoo|jcoo|jooco0o|coo|joo0o liccooljocc0o i OL |_1S]90S'€S i NOSt 689 30S 689 30S 689 ooojooojcoco|joo0oeoo|jocoeo looolooofocooljfooojocoojo0o0 iooojoccoojocoo|jo00occo|jo°00 a) No) (Nn) (No) (No) (oo) | 1s]9ze'es | 1S]ps9'es MSSZE 88-289 I 1S]689'€S MSSZE 88-289 | 1S|s69'€s i MSSZE 88-289 1S]002'¢s MSSZE 88-489 130N1/S99'€S MSOO0E 88-289 (1869's MSOOE 88-289 VOLT Ls|er9'es MSOOE 88-289 13QNI|8b9'€S MSOOE 88-289. l1s]pz9es MSSZZ 88-L89 (1S]S09'€S MSSZZ 88-289 1S ]0e9'€s MSSZz 88-289, I"1s]pes'es MSOS| 88-289 )LS]L6S°€S MSOS| 88-489 295 €S MSOSt 88-489 bes es MSOS 88-289 e1g es MSOS 88-289 61S eS MSOS 88-289 90S €S O3N 88-289 ziSs'es O3N 88-289 pZs'es O3N 88-289 Ooljoocjoo-oj-o0O] (N=) NN) NN) (NN) (NNN) NE) | lS ooljocojooojsoocloooojoo000 iooojooo|jcoo|jco0|jcoco|c9o0o IO OO|JO COIN €66] Joquiaidag ul payonpuosd Asaing suljaseg seSLOWAY U) JO sijnsay pue suoneoo7] uones T 3481 D xipueddy de-||Nd + ABMe-||Nd ‘Moun Jaj}Ue2 ‘(\yBudn saqn}) edojs Uo BewWeD ‘Uad MOS 689 MOS 689 AOS 689, Y19 689 Y10 689 Y19 689 Jeyueo ul ~Moung ‘Aeme-|ind ‘S/W/S/W/S/W Ued D b Ww a mooZz + OO eo ea isl eee ued