Soil Characterization Report_08102020_Final_0004.pdf

Watergate Wetlands Restoration Project

Soil and Sediment Characterization Report

FINAL

620/171203

Delaware Water Gap National Recreation Area — 294871 August 2020

As the nation’s principal conservation agency, the Department of the Interior has the responsibility for most of our nationally owned public lands and natural resources. This includes fostering sound use of our land and water resources;

protecting our fish, wildlife, and biological diversity; preserving the environment and cultural values of our national parks and historical places; and providing for the enjoyment of life through outdoor recreation. The department assesses our energy and mineral resources and works to ensure that their development is in the best interests of all our people by encouraging stewardship and citizen participation in their care. The department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration.

NPS D – 620/171203 / PMIS 294871 / August 2020

Delaware Water Gap National Recreation Area Soil and Sediment Characterization Report FINAL i

TABLE OF CONTENTS

INTRODUCTION

SITE DESCRIPTION AND HISTORY

SOIL AND GEOLOGY

HYDROLOGY

SURFACEWATER, DRAINAGE AND WETLANDS

FIELD ASSESSMENT AND EVALUATION

UPLAND SOIL CHARACTERIZATION

STREAM CHANNEL SEDIMENT CHARACTERIZATION

POND SEDIMENT SAMPLING CHARACTERIZATION

SOIL FERTILITY EVALUATION

DATA VALIDATION

CONCLUSIONS AND RECOMENDATIONS

ACRONYMS AND ABBREVIATIONS

REFERENCES

APPENDIXES

Appendix A—Report Figures

Appendix B—Report Tables

Appendix C—Boring Logs

Appendix D—Laboratory Data (CD Only)

Appendix E—Data Validation ii

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iii

EXECUTIVE SUMMARY

The National Park Service (NPS) proposes to restore wetlands and the natural function of Van Campens Brook at the Watergate Recreation Site by removing artificial dams and human-made ponds and reestablishing the connection between Van Campens Brook and its floodplain. The project would result in a more natural and high-functioning wetland and riparian floodplain system, improved floodplain connectivity within the project area, and more natural fluvial dynamics within Van Campens Brook. In support of this effort, multiple pre-design studies were performed to understand the ecological, biological, and physical processes of the project area and regional landscape.

WSP USA, Inc. (WSP) conducted a soil and sediment investigation to document the chemical and physical characteristics of these materials present at the site. The chemical results were compared to various New Jersey Department of Environmental Protection (DEP) regulatory criteria to evaluate beneficial use options for the soils and sediments that likely will be encountered and managed during the construction of this project.

WSP personnel collected 13 soil samples, 12 sediment, and 2 duplicate samples from the stream channels, ponds, and upland areas (figure 2 in appendix A). The samples were analyzed for base neutrals (BN), polychlorinated biphenyls (PCBs), pesticides, target analyte level (TAL) metals, total cyanide, grain size distribution and fertility parameters, moisture content, and total organic carbon (TOC). Contingent Synthetic Precipitation Leaching Procedure (SPLP) parameters for target compound list (TCL) BN+15, PCBs, pesticides, and TAL metals were also collected. The contingent SPLP samples were not activated because additional analysis was not warranted. Grain size analysis via sieve and hygrometer analysis were also conducted. Five composite sediment samples were collected and analyzed for fertility parameters to assess whether the sediment in several of the ponds can be used for topsoil.

The analytical results were compared to the following DEP standards or background levels to assess potential soil and sediment use in upland or wetland environments:

Beneficial use for soils and sediments in upland areas was evaluated by comparing the sample results to DEP human-health soil remediation standards, including the most stringent standards, the Residential Direct Cleanup Criteria Soil Remediation Standards (RDCSRS) and the Default Impact to Groundwater Soil Screening Level (IGWSSL).

Beneficial use of soils and sediments in wetland areas was evaluated by comparing the sample results to DEP Ecological Screening Criteria (ESC) for the freshwater sediment Low Effects Level (LEL) and Severe Effects Level (SEL).

Metals in soils and sediments were evaluated by comparing the sample results to the ambient metal concentrations established by DEP for the Valley and Ridge physiographic province of New Jersey.

The fertility results in composite sediment samples were evaluated with respect to soil fertility and potential use of sediments for topsoil. These results will be used as part of project design for adding potential amendments and the revegetation plans.

Upland soil sampling results show that BN and PCBs were not detected in any of the 13 soil samples.

Chlorinated pesticides, P,P'-DDT, P,P'-DDD, and/or P,P'-DDE were present throughout the project area and were detected in 12 of 13 soil samples. However, these chlorinated pesticides did not exceed the upland use criteria (RDCSRS and IGWSSL). P,P'-DDT, P,P'-DDD, and/or P,P'-DDE were identified in 2 of 13 soil samples at a concentration exceeding the sediment LEL; however, iv none of the samples exceeded the SEL. Several metals were found at concentrations that either exceeded the IGWSSL and/or the LEL. Manganese also slightly exceeded the SEL in 1 of 13 samples.

Metals detected in the project area were compared with regional ambient metal concentrations established by DEP. The comparison showed that metal concentrations found in soils and sediments at the project area were consistent with ambient conditions. This finding was also consistent with WSP’s field observations; no contamination was observed in any of the samples and surrounding areas. Grain size analysis indicated that the upland soils were predominantly sand with lesser amounts of gravel, silt, and clay.

Sediment sampling results for stream channel samples collected along Van Campens Brook showed that BN, PCBs, and pesticides either were not detected or did not exceed DEP Soil Remediation Standards (SRS) or ESC in any of the four stream channel samples. Several metals were found at concentrations that either exceeded the IGWSSL and/or LEL. However, comparing these results with the DEP’s regional ambient metal concentrations indicated that the metal found in stream sediments were consistent with ambient conditions. This finding was consistent with WSP’s field observations, where no contamination was observed in any of the samples or surrounding areas.

Grain size analysis indicates that the stream sediments were predominantly gravel with the lesser amounts of silt and clay.

Sediment sampling results for samples collected from three ponds to be drained showed that BN and PCBs either were not detected or did not exceed DEP Soil Remediation Standards or ESC.

P,P'-DDT, P,P'-DDD, and/or P,P'-DDE were detected at concentrations slightly above the LEL in two of the samples; none of the results exceeded the SEL. In addition, none of these chlorinated pesticides exceeded the upland use criteria (RDCSRS and IGWSSL). Several metals were found at concentrations that either exceeded the IGWSSL and/or LEL. Manganese also slightly exceeded the SEL. However, a comparison of the results with the DEP’s regional ambient metal concentrations in soils indicated that the metal concentrations found in the sediments were consistent with ambient conditions. This finding was consistent with WSP’s field observations, where no contamination was observed in any of the samples and surrounding areas. The grain size analysis indicated that the pond sediments were predominantly sand and gravel with varying amounts of silt and clay; however, one of the sediment samples showed a predominant grain size of silt and clay with lesser amounts of gravel.

Composite upland soil samples and sediment samples were collected from three of the ponds to be drained. The composite samples were analyzed for a suite of soil fertility parameters, including nitrogen and micronutrients, to evaluate the potential use of these materials as topsoil. The testing results indicated that the composite sediment samples and upland soils contained sufficient nitrogen and micronutrients to support plant growth. The sediments will be suitable for use on-site in proposed wetlands and, if needed, for blending with upland soils to enhance organic content or for topsoil in proposed upland habitats.

The chemical results of the investigation found that the upland soil and sediments in the pond and stream channel can be reused for beneficial use on-site. PCBs were not detected, and BN, if identified, were detected at concentrations well below DEP human-health and ecological criteria.

Metal concentrations identified in the soils and sediments were consistent with ambient metal concentrations in this region of New Jersey. Furthermore, there was no field evidence (staining, photoionization detector [PID] readings, or odors) that the soils or sediments were contaminated.

The metal concentrations detected were below human-health based DEP standards. With exception of manganese, all the metals were below the ecological SEL criteria. Manganese slightly exceeded the SEL in only 1 of 13 soil samples and in none of the 12 sediment samples. Low concentrations of the chlorinated pesticides (P,P'-DDT, P,P'-DDD, and/or P,P'-DDE) were detected in most of the upland soil samples (in 12 of 13 soil samples) and in about half of the pond and sediment samples (6 out of v

12 sediment samples). None of these chlorinated pesticides exceeded the human-health based soil standards (DCSRS or IGWSSL). Although P,P'-DDT, P,P'-DDD, and/or P,P'-DDE were detected in several of the upland soils (2 of 13 samples) above the LEL, none were above the SEL.

Soils in the upland areas will be suitable for beneficial use in upland areas based on their chemical characteristics. A comparison of the sampling results with the human-health based soil remediation standards (DCSRS or IGWSSL) showed that soil constituents detected were consistent with background conditions or were below the soil remediation standards. Upland soils also can be used as fill in the wetland areas based on a comparison with the ESC (LEL and SEL). Chlorinated pesticides (P,P'-DDT, P,P'-DDD, and/or P,P'-DDE) concentrations were the only anthropogenic chemical constituent found in concentrations above the ESC (LEL) and only in a few of the samples (2 of 13 samples). None of these chlorinated pesticides concentrations were found above the SEL.

Upland soils can also be used as fill if the soils are blended with other upland soil or sediments to minimize the chlorinated pesticides (P,P'-DDT, P,P'-DDD, and/or P,P'-DDE) concentrations in the material for used. The grain size analysis of these upland soils was sandy with lesser amounts of silt, clay, and gravel, and are suitable for use as fill.

Sampling conducted during this investigation characterized the upland soils that will be encountered during construction and potentially exposed to the surface once construction is completed. The analytical testing results were compared to DEP human-health based and ecological screening criteria. The results of this investigation showed that upland soils did not exceed the DEP lower exposure limit ecological screening criteria or were consist with regional background conditions.

Potentially exposed soils should not adversely impact human health or the environment based on the findings of this investigation.

Sediment in the ponds and channel will be suitable for beneficial use in upland and wetland areas based on their chemical characteristics. A comparison of the sampling results with the human-health based soil remediation standards (DCSRS or IGWSSL) showed that sediment constituents detected were consistent with background conditions or were below the soil remediation standards. The sediment also can be used as fill in the wetland areas based on a comparison with the ESC (LEL and SEL). The grain size analysis of these sediment was predominantly sandy with lesser amounts of silt, clay, and gravel, and are suitable for use as fill.

The composite testing results indicated that the composite pond sediment samples and upland soils contained enough nitrogen and micronutrients to support plan growth. The sediments will be suitable for reuse on-site within proposed wetlands and, if needed, for blending with the upland soils to enhance organic content or for topsoil in proposed upland habitats.

vi

INTRODUCTION

The National Park Service (NPS) proposes to restore wetlands and the natural function of a stream and its floodplain by reversing human-made changes in and near the Watergate Recreation Site in Hardwick Township, Warren County, New Jersey. The project would compensate for temporary and permanent impacts on wetlands, floodplains, and ecosystem function caused by the construction, operation, and maintenance of a high-voltage transmission line and its 200-foot right-of-way within the Delaware Water Gap National Recreation Area (DEWA).

WSP USA, Inc. (WSP) was hired to perform predesign, schematic design, and design development, and provide construction documents and supplemental services for the NPS DEWA Watergate Wetlands Restoration Project (project) (figure 1 in appendix A). The principal project goal is to generate 33-credit acres of wetland mitigation through reestablishment of palustrine wetland habitat and hydraulic restoration of Van Campens Brook. The project would result in a more natural and high-functioning wetland and riparian floodplain system, improved floodplain connectivity in the project area, and more natural fluvial dynamics in Van Campens Brook.

This report summarizes the findings for the soil and sediment investigation performed for the project to identify the chemical and physical characteristics of these materials present at the site. The results of the investigation will be used to evaluate appropriate beneficial use options for materials to be generated during on-site project construction. This report describes the sample collection methods and field observations, summarizes the data, compares the results with various regulatory criteria, and provides recommendations for beneficial on-site use of soil and sediment materials that will be excavated during proposed construction at the site.

SITE DESCRIPTION AND HISTORY

The approximately 114-acre site is in Hardwick Township in Warren County, New Jersey, and is bordered to the north by Old Mine Road, to the west by a high-tension line right-of-way, and to the east and south by wooded undeveloped land.

The site includes a segment of Van Campens Brook and its associated floodplain, a New Jersey Department of Environmental Protection (DEP) Category 1 waterway and designated trout production stream with a contributing watershed contained solely within NPS property. Historical modifications, including land clearing, grading, and damming of the brook to create a series of ponds, historical farming fields, and homestead sites (now recreational trails and picnic areas), substantially degraded on-site habitat, which was further impaired by non-native invasive vegetation throughout the site.

Settlement at the site began in the early to mid-1700s with the construction of the Van Campens Inn.

Between the time of settlement and the time the site was taken over by NPS, historic Van Campens Brook was dammed to harness water for agricultural purposes and drainage control with non-native plant species brought into the area. In addition, large human-made ponds were created for recreational purposes. Much of the area experienced reworking of native materials to change elevations.

SOIL AND GEOLOGY

According to the US Department of Agriculture, Natural Resources Conservation Service (USDA-NRCS) Web Soil Survey (n.d.) and the DEP NJ-GeoWeb (2015), soils in the study area consist of six soil series and eight soil mapping units, the Chippewa silt loam (ChwBc), Fredon- Halsey complex (FrdAb), Hazen-Paulins Kill complex (HdxpBb), Lackawanna cobbly fine sandy loam (LacBc), Lackawanna cobbly fine sandy loam (LacCc), Oquaga-Lackawanna complex (OpnDh), Wellsboro silt loam (WecBc), and the Wellsboro silt loam (WecCc). In general, the soils at the site are stony silty and sandy loams with slopes ranging between 0 to 35% and are expected to range between 2 and 8 feet in thickness.

An August 2019 Soils Investigation Report by USDA-NRCS office in Hackettstown, New Jersey, indicates that soils to the northeast and southwest of the largest pond appeared to be naturally occurring, but possibly disturbed via earthmoving or soil erosion in the past. Three soil pits excavated in areas of WecBc and the Wellsboro WecCc were found to be composed of fragipan and other restrictive horizons that do not permit water to drain vertically downward, resulting in water collection in low-lying areas and promoting the formation of wetlands wherever the water table reaches the soil surface. It should be noted that the USDA-NRCS report indicates the soils observed around the largest of the ponds did not resemble the soils mapped on this portion of the property

(USDA-NRCS 2019).

According to the Surficial Geologic Map of the Flatbookville Quadrangle, Sussex and Warren Counties, New Jersey, and Pike and Monroe Counties, Pennsylvania (Witte 2012), six distinct unconsolidated deposits underlay the site:

Holocene and late Wisconsinan Stream-terrace deposits (Qst) consisting of stratified to moderately sorted, cross bedded fine sand and silt

Late Wisconsinan Kame (Qk) deposits consisting of stratified to poorly sorted sand and silt with pebble to boulder size grains interbedded in small collapsed hills and ridges presumed to be filled ice-holes and crevasses

Late Wisconsinan Meltwater-terrace deposits (Qmt) consisting of stratified to moderately sorted sand, cobble, pebble, and gravel with minor silt components

Holocene Alluvium (Qal) consisting of stratified to poorly sorted sand, gravel, silt and minor clay, and organic material deposited by the Delaware River and its tributary, Late Wisconsinan non-stratified Till (Qtq) consisting of compact and unstratified, sand, gravel, silt, cobbles, pebbles, and boulders

Late Wisconsinan recessional moraine (Qmbm) deposits consisting of unstratified to poorly stratified sand, gravel and silt deposited at the active margin of the Kittatinny and Minsink Valley ice lobes.

Unconsolidated deposits are expected to reach a maximum depth of 20 feet below ground surface (bgs) before crystalline bedrock is encountered.

During the fieldwork and borings that were advanced by WSP for this study, the lithology of the upland areas was found to be primarily sand and silty sand, with minor components of clayey silt and gravel. Pieces of broken rock were also observed in the sampling equipment throughout the site. It should be noted that the sampling equipment consisted of a narrow diameter (2.5 inch) macro core barrel; therefore, the broken rock is likely cobbles that were broken during the boring advancement.

In addition, a pottery shard was found in boring SB07 at 15 feet bgs, which is indicative of reworked material historically being used to change the site elevation. The sediment boring from within the stream channel and ponds also consisted of sand and silty sand with a slightly higher content of fines, e.g., silt and clay.

According to the Bedrock Geologic Map of Northern New Jersey, the site is underlain by the Upper Silurian Bloomsburg Red Beds, which consist of grayish red, thin to thick bedded massive siltstone and sandstones containing quartz pebble conglomerate, and the Middle to Lower Silurian Shawangunk Formation of dark greenish gray, thick bedded sand stone and conglomerate (Drake et

al. 1997). Bedrock outcrops were observed in the project area and bedrock was encountered within several of the soil and sediment sample locations in Van Campens Brook.

HYDROLOGY

The project area is located within the Van Campens Brook/Dunnfield Creek watershed (US Geological Survey Cataloging Unit 02040104240). The site is in the Upper Delaware Watershed Management Area (WMA 01). WMA 01 drainage predominantly funnels to the Delaware River.

Based on regional topography and geology, groundwater in the vicinity of the site is expected to be encountered within the fractured bedrock along bedding planes and joints and faults. These Upper Silurian Bloomsburg Red Beds do not have high levels of porosity, and perched water is anticipated to be present along the top of the bedrock.

SURFACEWATER, DRAINAGE AND WETLANDS

In addition to Van Campens Brook, two human-made ponds and multiple smaller unnamed ponds are present at the site. The two largest ponds upstream of the earthen dam encompass approximately

7.7 and 2.6 acres. Van Campens Brook is classified as freshwater trout production and protected from any measurable change in water quality because of its exceptional ecological significance, exceptional recreational significance, exceptional water supply significance, or exceptional fisheries resources (FW2-TPC1- DEP 2005a). Regional base level is the Delaware River, located approximately 0.95 mile to the west, and classified as FW-2NT (non-trout).

In general, wetlands are defined according to hydrophytic vegetation, hydric soils, hydrology, and other characteristics. According to WSP’s June 2020 Watergate Wetlands Restoration Project Wetland Delineation Report, 92 wetlands and waters of the US were identified and delineated on-site.

Delineated wetlands include palustrine forested, scrub/shrub, and emergent wetland areas, encompassing approximately 14.22 acres. Water features include palustrine unconsolidated bottom (state open water), upper perennial, intermittent, and ephemeral streams. On-site water features total 19,456 linear feet. Wetlands consisting of Freshwater Pond habitat are located along the larger and multiple smaller ponds, and Riverine habitat is located along Van Campens Brook and its tributaries.

FIELD ASSESSMENT AND EVALUATION

To assess the potential for reuse of existing soil and sediment cut from the site and soils exposed following earthwork, WSP conducted a field investigation that included the advancement of 4 stream channel borings, 8 sediment borings, and 13 upland soil borings. The samples were collected and analyzed in accordance with Louis Berger’s December 16, 2019, Sampling and Analysis Plan (Louis Berger 2019a), which is consistent with relevant portions of the New Jersey Technical Requirements for Site Remediation (New Jersey Administrative Code [N.J.A.C.] 7:26E; DEP 2018) and The New Jersey Field Sampling Procedures Manual (DEP 2005b, updated 2011). WSP also performed work in accordance with the Quality Assurance Program Plan and the Site-Specific Health and Safety Plan (Louis Berger 2019b, c). Task-specific descriptions of field activities performed are provided below.

All sampling locations for the upland soil borings were based on areas that would be cut down to achieve the final proposed site elevations. Sediment locations in Van Campens Brook were chosen based on the location of human-made structures in the Brook, and sediment locations in the ponds were chosen randomly based on the pond sizes. Sample depths were selected based on the need to identify the depth of bedrock across the site and to assess the lithology of the site. Sample intervals were chosen to reflect a 6-inch cut into the proposed native soil at the final grade. The sample locations are depicted on figure 2 in appendix A. All proposed sample intervals can be seen on table 1 in appendix B.

To evaluate appropriate beneficial use options, the analytical results of the soil and sediment samples were compared to the New Jersey Non-Residential Direct Contact Soil Remediation Standards (RDCSRS), the Default Impact to Ground Water Soil Screening Level (IGWSSL), and the DEP Ecological Screening Criteria (ESC). The RDCSRS and Impact to Groundwater Soil Screening Level (IGWSSL) were used to evaluate beneficial use and placement of materials within upland areas. The Low Effects Level (LEL) and Severe Effects Level (SEL) from the ESC were used to evaluate beneficial use and placement of materials within wetland areas.

The metal results for soil and sediment samples were also compared to ambient metal concentrations found in the New Jersey Valley and Ridge physiographic province to help assess whether the concentrations present are consistent with naturally occurring background conditions. The DEP Characterization of Ambient Levels of Selected Metals and Polycyclic Aromatic Hydrocarbons in New Jersey Soils, Year III - Rural Areas of New Jersey Highlands, Valley and Ridge, and Coastal Plain Physiographic Provinces (BEM 2002), the arithmetic mean concentration, and the 90th percentile concentration were used to evaluate metals concentrations.

UPLAND SOIL CHARACTERIZATION

Between April 21 and April 28, 2002, 13 soil borings (SB01 through SB08, and SB10 through SB14) were advanced to collect soil samples to characterize the soils in the upland areas that are expected to be disturbed by the project’s construction. Boring locations can be seen on figure 2 in appendix A.

The borings were advanced by Summit Drilling Inc., of Bridgewater, New Jersey (Summit) with a Geoprobe® 7720DT direct push sampling rig under the direct observation and direction of a WSP geologist. At each boring location, an attempt was made to reach a target depth corresponding to 6-inches below the anticipated final design grade. However, the proposed sample depth could only be achieved at borings SB02, SB10, and SB13; limited sample recovery and rocky soils limited the sample depths at the other locations. At every location, multiple attempts were made to recover enough sample to satisfy the proposed sample interval. It should be noted that refusal due to bedrock was only encountered at SB01 where bedrock was observed at 20 feet bgs. The total depth of boring advancement at each location can be seen on table 1 in appendix B.

At each location, soil samples were collected, field-screened for volatile organics using a properly calibrated MiniRae photoionization detector (PID), and logged in the field using the ASTM’s Unified Soil Classification System. There was no evidence of contamination at any of the sample locations. Soils collected from each sample location were homogenized in a stainless-steel bowl with a trowel. Sampling depths are presented on table 1 in appendix B, and soil boring logs showing detailed lithologic descriptions can be seen in appendix C.

Thirteen soil samples and a field duplicate were collected from 13 samples locations and submitted under chain of custody protocol to SGS Laboratory (SGS) of Dayton, New Jersey. Each soil sample (SB01, SB03 through SB08, SB10 through SB14, and the duplicate) was analyzed for target compound list (TCL) base neutrals (BN) compounds with a library search of 15 tentatively identified compounds (BN+15), polychlorinated biphenyls (PCBs), pesticides, target analyte list (TAL) metals, total cyanide, grain size distribution, moisture content, and total organic carbon (TOC). In addition, contingent Synthetic Precipitation Leaching Procedure (SPLP) samples were collected for TCL BN+15, PCBs, pesticides, and TAL metals in case site-specific IGWSSLs were necessary. The samples were analytical parameters, and other pertinent sampling information can be seen on table 1 in appendix B.

Soil samples collected from all 13 upland sample locations indicate that no exceedances of BN+15 or PCBs were detected. Low concentrations of the chlorinated pesticides, P,P'-DDT, P,P'-DDD, and/or P,P'-DDE, were identified in 12 of 13 soil samples. Exceedances of P,P'-DDT, P,P'-DDD, and/or P,P'-DDE were detected in only 2 of 13 samples (samples SB01 and SB07) and at concentrations that slightly exceeded the LEL. None of these chlorinated pesticides exceeded the SEL, and where detected, the P,P'-DDT, P,P'-DDD, and/or P,P'-DDE concentrations were typically two to three orders of magnitude lower than the SEL. The analytical results and exceedances are summarized in table 2 in appendix B. Activation of the contingent SPLP analysis was not required. The sample locations, exceedances, and metal exceedances, discussed below, are depicted on figure 3 in appendix A.

Metals also exceeded the IGWSSL and LEL standards. Aluminum and manganese exceeded the IGWSSL, while aluminum, arsenic, cadmium, copper, manganese, nickel, silver, and zinc exceeded the LEL. However, except for manganese, none of these metals exceeded the SEL. Manganese slightly exceeded the SEL in only 1 of 13 soil samples. At sample SB12, the manganese concentration detected was 1,150 milligrams per kilogram versus the SEL for manganese of 1,100 milligrams per kilograms. The analytical results and exceedances are summarized on table 2 in appendix B. The sample locations and exceedances are depicted on figure 2 in appendix A, and a complete set of laboratory data packages are provided in appendix D.

Metal concentrations were also compared to DEP-established ambient metal concentrations (BEM 2002) to assess whether the concentrations detected in the soils were consistent with background conditions. Sample comparisons to the ambient mean concentration and the 90th percentile concentration can be seen on table 3 in appendix B. All the metal concentrations detected were typically below the ambient mean and the 90th percentile. For the few exceptions of metals that exceeded the 90th percentile—arsenic, barium, copper magnesium, manganese, nickel and zinc— concentrations reported for these metals were the same order of magnitude or slightly exceeded the ambient values.

As noted above, the metal concentrations found in the soils in the project area were consistent with ambient metal concentrations. Chemical constituents associated with background concentration do not typically need to be remediated by DEP. In addition, IGWSSL for metals, such as aluminum, manganese, silver and zinc are not based on human-health based considerations, but primarily on aesthetic considerations such as taste, odor, and appearance. Aluminum, manganese, silver, zinc, and beryllium can also be found as background constituents. As such, DEP does not require the IGWSSL for these metals (aluminum, manganese, silver, zinc, and beryllium) to be addressed unless there their presence is suspected to be the result of a site discharge. Based on field observations, there was no evidence of an on-site discharge or contamination. Activation of the contingent SPLP analysis was not required because the metal concentrations are associated with natural background conditions and site-specific IGWSSL are not necessary (DEP 2014a).

Analysis of grain size distribution indicates that sand was the predominant component in samples SB03 through SB05, SB08, SB10, SB11, SB13, and SB14, ranging between 43% and 48.2% with gravel, clay, and silt as secondary components. Gravel was the predominant component in samples SB06, SB07, and SB012 ranging between 42.3% and 53.8% with sand, clay, and silt as secondary components. Clay and silt were the predominant component in samples SB01 at 40.7% and SB02 at 56%. In both borings, sand was the secondary component. Grain size distributions can be seen on table 2 in appendix B, and boring logs are provided in appendix C.

STREAM CHANNEL SEDIMENT CHARACTERIZATION

On April 21, 2020, four sediment borings (SED01, SED02, SED07, and SED08) were advanced in Van Campens Brook to characterize chemical and physical properties of the sediments within the existing stream channel. Samples SED01 and SED02 are located immediately downstream of the earthen dam holding the largest pond, while samples SED07 and SED08 are in upstream reaches of Van Campens Brook. Boring locations can be seen on figure 2 in appendix A. An attempt was made at each location to reach a depth of 10 feet bgs with a properly decontaminated hand auger; however, due to the limitation of the hand tools and the large volume of cobbles in the stream bed, the maximum depth achieved was 1.5 feet bgs. All the borings were advanced by Summit under the direct observation and direction of a WSP geologist. It should be noted that drilling via direct push technology could not be performed in Van Campens Brook because of permitting restrictions and physical access issues (e.g., rough terrain and deep flowing water).

At locations SED01 and SED02, bedrock was observed to outcrop within the stream channel, and the samples were collected from areas where the sediment had collected in depressions in the bedrock.

At location SED07 and SED08, refusal was encountered in the form of gravel and cobbles. Sediments at each location were field screened for volatile organics using a properly calibrated PID, visually inspected for any possible signs of contamination, and logged in the field using the ASTM’s Unified Soil Classification System. No evidence of contamination was observed during the sample collection.

Sediments collected from each sample location were homogenized in a stainless-steel bowl with a trowel. Sampling depths are presented on table 1 in appendix B, and soil boring logs showing a detailed description of sediment lithology are provided in appendix C.

All the sediment samples (SED01, SED02, SED07, and SED08) were submitted to SGS and analyzed for TCL BN+15, PCBs, pesticides, TAL metals, total cyanide, grain size distribution, moisture content, and TOC. In addition, contingent SPLP samples were collected for TCL BN+15, PCBs, pesticides, and TAL metals in case site-specific IGWSSL were needed. Aqueous hardness of surface water was also collected at each sediment sample location in case site-specific sediment criteria were warranted. Analytical parameters and other pertinent sampling information are provided in table 1 in appendix B.

Analytical results of the sediment samples collected from the stream channel (SED01, SED02, SED07, and SED08) indicated no exceedances of BN+15, PCBs, or pesticides. Metals exceedances of the IGWSSL and LEL standards were observed. Aluminum was detected in excess of both the LEL and IGWSSL in each of the four samples. Copper was only detected in excess of the LEL in SED01 and SED02 but did not exceed the SEL in any of the samples. Manganese was detected in excess of the IGWSSL in all four samples and in excess of the LEL at SED01. Nickel was observed in excess of the LEL in all four samples, but it did not exceed the SEL in any of the samples. The analytical results and exceedances are presented on table 4 in appendix B and are depicted on figure 2 in appendix A.

The laboratory data package is provided in appendix D.

Soil erosion is a major source of stream and pond sediments. As a result, metal concentrations in sediments were compared to ambient metal concentrations found in soils within the Valley and Ridge physiographic province (BEM 2002). A comparison of the metal concentrations detected in the sediments and ambient soil concentrations is found on table 5 in appendix B. As previously discussed in the “Upland Soil Characterization Section,” the metal concentrations detected were consistent with ambient metal concentrations found in the environment, and no discernable source of potential contamination was identified at any of the sample locations.

Analysis of grain size distribution indicated that sand was the predominant component of each sample, ranging between 55% and 57%, with gravel as the second most predominant component in SED01, SED07, and SED08, ranging between 33 and 39.1%. In SED02, silt and clay were the second most predominant compound at 35.5%. Grain size distributions are shown in table 2 in appendix B, and boring logs are provided in appendix C.

POND SEDIMENT SAMPLING CHARACTERIZATION

Between April 29 and May 1, 2020, eight sediment borings (SED09 through SED16) were completed to collect sediment samples from three ponds at the site that will be drained as part of the project.

Boring locations are shown on figure 2 in appendix A. At each boring location, an attempt was made to reach a target depth corresponding to 6-inches below the proposed final grade. Sediment samples were collected with a vibracore sampler mounted to a pontoon float barge that was maneuvered by an aluminum johnboat, or with a slam bar operated from the aluminum johnboat. However, because of limitations associated with the sampling equipment, the proposed depth could not be reached at all the sample locations. SED10 and SED13 through 16 were advanced until refusal was encountered, which was likely on cobbles or gravel, but did not reach the target depth proposed. The total depth of boring advancement at each location is provided in table 1 in appendix B.

Sediment was collected and field screened for volatile organics using a PID, visually inspected for any possible signs of contamination, and logged in the field using ATSM’s Unified Soil Classification System. No evidence of contamination was observed at any of the sample locations. One soil sample was then collected from each boring using a stainless steel bowl and trowel to homogenize the sample from 0.0 feet bgs (top of the sediment) to the proposed target sampling depth that corresponds to 6-inches below the proposed final grade or to the total length of the boring if the target depth could not be reached. Soil boring logs showing a detailed description of sediment lithology are provided in appendix C. Sampling depths are shown in table 1 in appendix B. Aqua Survey Inc. of Flemington New Jersey performed the work under the direct observation and direction of a WSP geologist.

Each sediment sample (SED09 through SED16) was submitted to SGS and analyzed for TCL BN+15, PCBs, pesticides, TAL metals, total cyanide, grain size distribution, moisture content, and TOC. In addition, contingent SPLP samples were collected for BN+15, PCBs, pesticides, and TAL metals if site-specific IGWSSL were necessary. Analytical parameters and other pertinent sampling information can be seen in table 1 in appendix B.

Sediment samples collected from the ponds (SED09 through SED16) indicated no exceedances of BN+15 or PCBs; however, metals exceedances of the IGWSSL and LEL standards were observed. In addition, the pesticides P,P'-DDD and P,P'-DDE from locations SED10 and SED14 exhibited exceedances of the LEL. One sample, SED13, also exhibited manganese in excess of the SEL. All analytical exceedances are presented on table 4 in appendix B and are depicted on figure 4 in appendix A. The laboratory data package is provided in appendix D.

Soil erosion is a major source of stream and pond sediments. As a result, and as discussed in the “Stream Sediment Characterization Sampling” section, the metal concentrations in sediments were compared to ambient metal concentrations found in soils in the Valley and Ridge physiographic province (BEM 2002). A comparison of the metal concentrations detected in the sediments and ambient soil concentrations is found on table 5 in appendix B. All metal concentrations detected were typically below the ambient mean and the 90th percentile. With the few exceptions of metals that exceeded the 90th percentile—aluminum, barium, chromium, copper, manganese, nickel, and zinc—the metal concentrations reported for these metals were at the same order of magnitude as the ambient values. As previously discussed, in the “Upland Soil and Stream Channel Characterization” sections, the metal concentrations detected in the pond sediments are consistent with ambient metal concentrations found in the environment, and no discernable source of potential contamination was identified at any of the sample locations.

Analysis of grain size distribution indicated that sand was the predominant component is samples SED11, SED13, and SED14, ranging between 44.3% and 63.5% with gravel, clay, and silt as secondary components. Gravel was the predominant component in samples SED10 at 37.5% and SED15 at 67.6%. Sand, clay, and silt were secondary components. Clay and silt were the predominant components in sample SED09 at 49.3%, gravel was the second highest component at 48.5%, and gravel was present at 2.3%. Grain size distributions can be seen on table 4 in appendix B, and boring logs are provided in appendix C.

SOIL FERTILITY EVALUATION

Composite sediment and soil samples were collected to evaluate their potential use as topsoil material. Five composite samples (COMP01 through COMP05) were collected and analyzed for fertility parameters. Two composite samples (COMP01 and COMP04) are representative of pond sediments collected from two of the ponds (pond 2 and pond 10) that will be drained during the construction of the project, while the other three samples (COMP-2, COMP03, and COMP05) are representative of upland soils areas that will be regraded. COMP01 was generated from borings SED09, SED10, SED11, and SED12; COMP02 was generated from SB04 and SB05; COMP03 was generated from SB06, SB07, and SB08; COMP04 was generated from SED14, SED15, and SED16;

and COMP05 was generated from SB10 and SB11. The sample locations are shown on figure 2 in appendix A.

The five composite samples were made from a small aliquot of soil or sediment samples collected from the boring locations. At each of the selected sample locations, an aliquot of homogenized sample was combined in a stainless-steel bowl with the aliquots from other prescribed sample locations. The aliquots were homogenized in the stainless-steel bowl with a trowel into a composite sample. Each composite sample was submitted to SGS and analyzed for select list of fertility parameters, including metals, total Kjeldahl nitrogen, nitrogen nitrate, nitrite, total phosphorus, total suspended solids, and total nitrogen. Analytical parameters and other pertinent sampling information can be seen on table 1 in appendix B.

The composite samples were not compared to any specific regulatory criteria. However, the analytical results were evaluated with respect to soil fertility, potential amendments, and the revegetation plans as part of the project design. All analytical results are presented on table 6 (appendix B), and the individual borings that make up each of the individual sample locations are depicted on figure 2 in appendix A. The laboratory data package is provided in appendix D.

The composite testing results indicate that the composite sediment samples and upland soils contain sufficient nitrogen and micronutrients to support plant growth.

The percent organic matter within the soil was calculated from the sample results for TOC using the equation:

Organic matter (%) = Total organic carbon (%) x 1.72

For the upland soils, the percent organic matter ranged from approximately 0.68 to 1.19%, which is low in comparison to undisturbed soils and within the range of cropland soils. The sediment samples had a higher percent organic matter with an average of 4.68% and a range of 0.33 to 17.72%. The sediments will be suitable for reuse on-site within proposed wetlands and, if needed, for blending with the upland soils to enhance organic content or for topsoil in proposed upland habitats.

DATA VALIDATION

The laboratory data generated by WSP during site activities are currently being assessed for reliability and usability by De Maximis Data Management Solutions (ddms) of St. Paul, Minnesota.

The data quality assessment was performed in accordance with DEP Site Remediation Program (DEP 2014b) The ddms report is provided in appendix E. Conclusions from the ddms report are summarized below. WSP comments are in italics.

Low surrogate recovery was found for several of organic compounds (BN, PCBs and/or, pesticides) analyzed in the soil, sediment, and quality assurance/quality control samples (duplicates and field blanks). Some of the sampling results and detection levels are estimates as denoted by J- and UJ-values.

Estimated concentrations exceeding their respective standards are identified on tables 2 and 4 in appendix B. In addition, estimated detection levels are below the applicable DEP most stringent SRS or SEL ESC with the following exceptions. Antimony’s detection level in soil sample SB11 and in sediment sample SED14 exceeded the IGWSSL and SEL. The detection levels for 3,3’-dichlorobenzidene, atrazine, bis(2-chloroethyl)ether(2-chloroethyl ether), hexachlorobenzene, hexachloroethane, nitrobenzene, n-nitrosodi-b-propylamine and n-nitrosodi-n-propylamine exceeded the IGWSSL in sediment sample SED14. The detection levels for hexachloroethane also exceeded the IGWSSL in sediment samples SED13 and SED15. The elevated detection levels are limited to 4 of 25 samples and are not representative of the concentrations in the soil and sediment.

Due to the low surrogate recovery in the matrix spike/matrix spike duplicate (MS/MSD) sample (less than 10%), the results for (endrin aldehyde) were rejected (unusable) for sediment samples SED09 through SED16 and DUP02. The low surrogate recovery is typically the result of matrix interference.

It should be noted that the laboratory control sample (MS/MSD was acceptable. In addition, endrin aldehyde was not detected in any of sediments samples SED01, SED02, SED07, or SED08.

The detection levels for SED01, SED02, SED07, and SED08 were below the SEL. Furthermore, endrin aldehyde is a breakdown product of endrin, which has not been produced or sold for general use in the US since 1986. Endrin was not detected in any of the soil or sediment samples.

Tentatively identified compounds also were rejected in several soil and sediment samples (SB11, DUP1, DUP2, and SED09 through SED16) because of low/recoveries, laboratory artifacts, and/or lack of confirmation in duplicate samples).

It should be noted that there are no specific soil standards or ecological criteria for the tentatively identified compounds.

The phosphorous results may be higher (biased low) in sediment samples COMP01 through COMP04 because the analysis was conducted outside the 28-day holding time from collection.

Although the holding times were inadvertently exceeded, phosphorous is relatively stable, and there is no regulatory standard. The phosphorous results for COMP01 through COMP04 samples were consistent with the phosphorous concentrations in COMP05, which was run within its holding time.

Grain size distribution and TOC for many of the sediment samples were estimated because of a lack of agreement between paired field duplicate results.

The results may reflect the heterogeneity of the material sampled. In addition. there are no specific soil standards or ecological criteria.

As noted above, the laboratory data are usable and reliable.

CONCLUSIONS AND RECOMENDATIONS

WSP conducted a soil and sediment investigation to document the chemical and physical characteristics of these materials present at the site, which will likely be encountered during the construction of this project. The chemical results were compared to various DEP regulatory criteria to evaluate beneficial use options for these materials.

Thirteen soil samples and 12 sediment samples were collected from the stream channels and ponds (figure 2 in appendix A). The samples were analyzed for TCL BN+15, PCBs, pesticides, TAL metals, total cyanide, grain size distribution, moisture content, and TOC. Contingent SPLP parameters for TCL BN+15, PCBs, pesticides, TAL metals, grain size analysis, and nutrient content were also collected in case site-specific IGWSSL analysis was necessary. The contingent SPLP samples were not activated because the parameters did not exceed standards, or the parameters were consistent with background levels in the environment and did not require further evaluation.

The analytical results were compared to the following DEP standards to assess potential soil and sediment use in upland or wetland environments:

Beneficial use of soils and sediments in upland areas was evaluated by comparing the sample results to the RDCSRS and the IGWSSL.

Beneficial use of soils and sediments in wetland areas was evaluated by comparing the sample results to the freshwater sediment LEL and SEL.

An evaluation of elevated metals in soils and sediments was conducted by comparing the sample results to the ambient metal concentrations established by DEP for the Valley and Ridge physiographic province of New Jersey (BEM 2002)

Upland soil sampling results showed that BN and PCBs were not detected in any of the 13 soil samples. Chlorinated pesticides, P,P'-DDT, P,P'-DDD, and/or P,P'-DDE, were present throughout the project area and were detected in 12 of 13 soil samples. However, these chlorinated pesticides exceeded the upland use criteria (RDCSRS and IGWSSL). P,P'-DDT, P,P'-DDD, and/or P,P'-DDE were identified in 2 of 13 soil samples at concentrations exceeding the sediment LEL criteria;

however, none of the samples exceeded the SEL criteria. Several metals were found at concentrations that either exceeded the IGWSSL and/or the LEL. Manganese also slightly exceeded the SEL in 1 of 13 samples. Metals detected in the project area were compared with regional ambient metal concentrations established by DEP, and the comparison showed that metal concentrations found in soils and sediments at the project area were consistent with ambient conditions. This finding was also consistent with WSP’s field observations, where no contamination was observed in any of the samples and surrounding areas. Grain size analysis indicated that the upland soils were predominantly sand with lesser amounts of gravel, silt, and clay.

Sediment sampling results for stream channel samples collected along Van Campens Brook showed that BN, PCBs, and pesticides either were not detected or did not exceed DEP soil remediation standards or ESC in any of the four stream channel samples.