236639

1

ENGINEERING DESIGN & OPERATIONS REPORT CIBA-GEIGY, TOMS RIVER PLANT INDUSTRIAL WASTE LANDFILL CELL 3

inCORPORHTED

consultants in environmental management

CIB 013 ENGINEERING DESIGN & OPERATIONS REPORT CIBA-GEIGY, TOMS RIVER PLANT INDUSTRIAL WASTE LANDFILL CELL 3

Prepared for:

Ciba-Geigy Corporation Rt. 37 W Toms River, New Jersey

Prepared by:

AWARE Incorporated 80 Airport Road West Milford, New Jersey 07480

June 1987 ENGINEERING REPORT

Page No.

1.0 INTRODUCTION 1-1

2.0 GENERAL INFORMATION 2-1

2.1 Site History and Description- 2-1 2.1.1 Location 2-1 2.1.2 Site Layout 2-1 2.1.3 Site History 2-2 2.2 Environmental Setting 2-3 2.2.1 Land Use and Zoning 2-3 2.2.2 Climate and Meteorology 2-3 2.2.3 Surface Waters 2-4 2.2.4 Site Drainage 2-5 2.3 Existing Industrial Landfill Facility Description 2-5 2.4 Waste Types and Volumes 2-7 2.4.1 Waste Types 2-7 2.4.2 Waste Volumes 2-7 2.5 Easements and Utilities 2-8 2.6 Geology, Hydrogeology, Soils and Geotechnical Aspects of the Facility 2-8

2.7 Permit Requirements 2-9

3.0 LANDFILL DESIGN 3-1 3.1 Excavation Plan 3-1 3.2 Run-on/Run-off Controls 3-1 3.3 Foundation Design 3-3 3.3.1 General 3-3 3.3.2 Stability Analysis 3-4 3.3.3 Settlement Characteristics 3-5 3.3.4 Ultimate Bearing Capacity 3-6 3.4 Landfill Liner System 3-6 3.4.1 Secondary Geocomposite Liner System 3-7 3.4.1.1 Secondary Clay layer 3-7 3.4.1.2 Secondary Geomembrane Liner 3-11 3.4.2 Secondary Leachate Detection System 3-13 3.4.3 Primary Geocomposite Liner System 3-17 3.4.3.1 Primary Clay Layer 3-18 3.4.3.2 Primary Geomembrane Liner 3-19 3.4.4 Primary Leachate Collection System 3-23 3.5 Leachate Generation 3-29 3.5.1 Characterization 3-29 3.5.2 Generation Rates 3-30 3.6 Leachate Disposal 3-37 3.6.1 Leachate Collection Piping 3-38 3.6.2 Leachate Pump Station 3-44 3.6.3 Leachate Force Main 3-44 3.6.4 Leachate Treatment and Disposal 3-52 3.7 Gas Generation and Control 3-52 3.8 Groundwater Monitoring Program 3-53 3.8.1 Sampling and Analysis 3-54 3.9 Closure 3-59

CIB 013 0358 ENGINEERING REPORT (continued)

Page No. 5.0 LANDFILL OPERATIONS 5-1

5.1 Hours of Operation 5-1 5.2 Personnel and Facilities 5-1 5.3 Record Keeping 5-1 5.4 Landfill Equipment 5-1 5.5 Access Control 5-1 5.6 Work Area Control 5-3 5.7 Waste Handling 5-3 5.8 Filling Sequence for the Landfill Facility 5-3 5.8.1 Filling to Intermediate Operations Grade 5-3 5.8.2 Filling to Intermediate Closure Grade 5-4 5.8.3 Filling to Final Closure Grade 5-5 5.9 Contingency Plans 5-5 5.9.1 Fire Control 5-5 5.9.2 Dust Control 5-6 5.9.3 Odor Control 5-6 5.9.4 Severe Weather Conditions 5-6 5.9.4.1 Freezing 5-6 5.9.4.2 Heavy Rain 5-7 5.9.4.3 Snowfall 5-7 5.9.4.4 Electric Storms 5-7 5.9.4.5 Extremely Windy Conditions 5-7 5.10 Equipment Breakdown 5-8

CIB 013 0 ENGINEERING REPORT (continued)

Page No. 5.0 LANDFILL OPERATIONS 5-1 5.1 Hours of Operation 5-1 5.2 Personnel and Facilities 5-1 5.3 Record Keeping 5-1 5.4 Landfill Equipment 5-1 5.5 Access Control 5-1 5.6 Work Area Control 5-3 5.7 Waste Handling 5-3 5.8 Filling Sequence for the Landfill Facility 5-3 5.8.1 Filling to Intermediate Operations Grade 5-3 5.8.2 Filling to Intermediate Closure Grade 5-4 5.8.3 Filling to Final Closure Grade 5-5 5.9 Contingency Plans 5-5 5.9.1 Fire Control 5-5 5.9.2 Dust Control 5-6 5.9.3 Odor Control 5-6 5.9.4 Severe Weather Conditions 5-6 5.9.4.1 Freezing 5-6 5.9.4.2 Heavy Rain 5-7 5.9.4.3 Snowfall 5-7 5.9.4.4 Electric Storms 5-7 5.9.4.5 Extremely Windy Conditions 5-7 5.10 Equipment Breakdown 5-8

013 0360 LIST OF TABLES AND FIGURES

Page No. TABLES

2- 1 List of Required Permits 2-10

3- 1 Wedge Analysis Summary 3-21

3-2 Transmissivity Comparison 3-28 3-3 Operational Stage Leachate Generation Rates 3-32 3-4 post Closure Stage Leachate Generation Rates 3-32 3-5 Rainfall Summary Table 3-34 3-6 Hydraulic Analysis of Collector Pipes 3-41 3- 7 Groundwater, Leachate and Leak Detection Sampling/ Analytical Parameters 3-56 4- 1 Cell No. 3 Materials of Construction 4-2

5- 1 Landfill Equipment 5-2

FIGURES 3-1 Rainfall Summary Table 3-26 3-2 Primary Collection Layer Thickness Graph 3-35 APPENDICES

APPENDIX TITLE

A Cell No. 3 Permit Drawings

B Hydrogeologic/Geotechnical Report

C Landfill Closure and Post Closure Plan

D Cell No. 3 Construction Specifications

E Supporting Landfill Design Calculations

F Geotechnical Characterization of Candidate Soils for Landfill Liner; Clay Compatibility Investigation Phase II, Interim Report

G Cell No. 3 Construction Quality Assurance/ Quality Control (QA/QC) Plan

H Chemical Compatibility Testing of Polyethylene Membranes

I Cell No. 3 Construction Drawings Industrial Waste Landfill Area Leachate Pipeline Outside Landfill Area 1.0 INTRODUCTION

Ciba-Geigy operates an approved and fully licensed Industrial Waste Landfill (New Jersey Department of Environmental Protection (NJDEP) Facility Nos. 1507C and 1507D), at its plant located in Toms River, New Jersey. This Engineering Design Report, the accompanying drawings provided in Appendix A - Cell No. 3 Permit Drawings, Industrial Waste Landfill, and the supporting documentation provided in Appendices B through I describe the methods, materials and procedures which will be used to construct and operate Cell No. 3 and close Cell Nos. 1 thru 7, and must be submitted and approved before NJDEP will issue a new Engineering Design Approval.

This Engineering Report describes the landfill design, construction and operational procedures along with a closure and post-closure plan. This report documents the proposed engineering design developed in response to the submission requirements of 7:26-2.10, and the scope of applicable disposal regulations for sanitary landfills specifically:

7:26-2A.5 engineering design submittal requirements for sanitary landfills 7:26-2A.6 sanitary landfill environmental performance standards 7:26-2A.7 sanitary landfill engineering design, standards and construction requirements 7:26-2A.8 sanitary landfill operational and maintenance requirements 7:26-2A.9 closure, post closure care of sanitary landfills

Pertinent documents accompanying this submittal are provided in Appendix A, Drawings Nos. 6505-100P through 180P of the Cell No. 3 Permit Drawings, Industrial Waste Landfill, NJDEP Facility No. 1907D, Toms River, New Jersey, and other support documentation provided in Appendices B through I.

1-1 2.0 GENERAL INFORMATION

2.1 Site History and Description

In this section the location, physical features, and a brief history of the Toms River Plant site are presented.

2.1.1 Location

The Ciba-Geigy Corporation Toms River Plant is located in Dover Township, Ocean County, New Jersey (Appendix A, Drawing Nos. 6505-100P and 101P). The site encompasses approximately 1,300 acres and is situated about one mile west of the Garden State Parkway. The center of the site is situated at approximately N 39° 59' 10" latitude and W 74° 14' 20" longitude. The site is bounded by the Toms River on the northeast, by Cardinal Drive on the east, by Route 37 and residential/commercial development to the south and west, and by Pine Lake Park, a residential development, to the north. Winding River Park, an outdoor recreational area, borders the Toms River to the east and southeast of the site. The central business district of Toms River is located approximately three miles to the southeast of the site; an industrial park adjoins the site on the west. A residential area, including two senior citizen developments, is located about one mile south of the site.

2.1.2 Site Layout

The approximate limits of the Toms River Plant property are provided in Appendix A, Drawing No. 6505-101P. Approximately three-hundred-twenty (320) acres of the 1,300-acre site are developed; the remainder is largely wooded pineland. The developed area includes the manufacturing or process area of the facility, a wastewater treatment plant with a capacity of 7.5 million

2-1 gallons per day (MGD), and a lined reservoir for emergency storage of wastewater. The bulk of the developed area is located nearly in the center of the property; the surrounding woodland thus serves as a buffer between the active portion of the facility and the surrounding land uses.

The site ranges in elevation from a maximum of about 70 feet above mean sea level in the extreme western area to less than 20 feet above mean sea level adjacent to the Toms River. The site slopes gently to the northeast, east, and southeast, before dropping off sharply towards the river in the north­ eastern section. Except for the wooded area in the northwest and the non-contiguous area east of Oak Ridge Parkway, the entire property is fenced. A description of hydrogeological and geotechnical aspects of the site is provided in Appendix B entitled Hydrogeologic/Geotechnical Report for Ciba-Geigy, Toms River Plant, Industrial Waste Landfill, Cell Nos. 3 & 4, and the accompanying drawings provided in Appendix B - Engineering Design for Cell Nos. 3 & 4, Hydrogeologic/Geotechnical Permit Drawings, NJDEP Facility No. 1507D, Toms River, New Jersey. The distribution of soil types on the site is depicted in Appendix B, Drawing No. 6505-021P.

2.1.3 Site History

CIBA States Limited began construction of the Toms River Division of CIBA States Limited in 1949. Operation of the facility was initiated in 1952 with the production of vat dyestuffs. In 1955, the Toms River Division of CIBA States Limited merged with Cincinnati Chemical Works to become Toms River-Cincinnati Chemical Corporation. Cincinnati Chemical Works, owned by the firms of Chemical Industry Basle, (CIBA), J.R. Geigy, S.A., and Sandoz Limited produced azo dyestuffs and intermediates. The azo manufacturing operations of Cincinnati Chemical Works were subsequently moved to the Toms River Plant during late 1959 and early 1960. Production of epoxy resins also commenced at this time at a CIBA-owned facility at the site. On June 1, 1960, Toms River-Cincinnati Chemical Corporation became Toms River Chemical Corporation owned by CIBA States Limited (which became CIBA Corporation in 1961), Geigy Chemical Corporation and Sandoz, Limited. On October 21, 1970, CIBA Corporation and Geigy Chemical Corporation merged to form CIBA-GEIGY Corporation. On November 2, 1981, CIBA-GEIGY Corporation acquired Sandoz's interest in Toms River Chemical Corporation, which thereafter was merged into CIBA-GEIGY Corporation.

The Toms River Plant manufactures dyes for the textile, paper, leather and automotive industries and epoxy resins and additives for plastics, coatings and high-performance lubricants for the construction, electronics and automotive industries.

2.2 Environmental Setting

2.2.1 Land Use and Zoning

Although, originally founded in a relatively undeveloped area, the Toms River Plant has seen rapid development around its perimeter in the intervening years. This development is characterized by residential development, recreational areas, small commercial establishments, and light industrial complexes as shown in Appendix B, Drawing No. 6505-018P. The commercial areas are located primarily along New Jersey Route 37 to the southwest of the site. The area west of the plant is zoned for industrial use, including light manufacturing and warehousing operations. Winding River Park, a greenbelt park located along the Toms River to the east of the site, is used year-round by area residents.

Residential areas of Dover Township are supplied with water from the Toms River Water Company which maintains 20 wells to the north, northeast, and southeast of the Toms River Plant. Dover Township is connected to the county sewer system. Residences in the Pine Lake Park area of Manchester Township are supplied by private wells and use septic systems.

2.2.2 Climate and Meteorology

The climate of this part of the state is characterized as continental; however, proximity to the Atlantic Ocean results in modifications to the overall temperature, wind, and rainfall patterns.

2-3 The nearest measuring station for temperature data is located in Freehold, Monmouth County, twenty miles north of the Toms River Plant site. Temperatures at the Freehold station range from an average high of 74.2°F in July to an average low of 30.5°F in January. The average annual temperature at Freehold is 52.7°F. Temperatures at Toms River generally follow the same general pattern as those recorded at Freehold.

Precipitation totals generally are evenly distributed throughout the year. Toms River registers its highest average monthly precipitation total in August (4.98 inches) and its lowest in June (3.41 inches). However, year-to-year variations in the amounts recorded in late summer and early autumn may result from the northward passage of storms originating in the tropics. In years that these seasonal storms are experienced, annual precipitation totals tend to be higher than normal.

2.2.3 Surface Waters

The Toms River Plant's eastern property border lies approximately between the 8.25 and 9.75 mile marks on the Toms River. The river originates in Millstone Township, Monmouth County, and empties into Barnegat Bay. No other perennial surface waters are found on the property. The river's flow originates mainly from the water table aquifer and has low pH, hardness, and total solids concentration. The total area of the Toms River drainage basin is 190 square miles (OCPB, 1978). The Toms River is classified as FW-2, non-trout.

A gage station is situated near the Oak Ridge Parkway Bridge and downstream of the cooling water intake and discharge points (USGS, 1982). The drainage area at this point is 124 square miles. The average discharge for the past 53 years is 216 cubic feet per second (140 MGD), equivalent to 23.67 inches of precipitation per year over the drainage basin. Typical seasonal stream flow variations are evident with low flows occurring in late summer and early fall and higher flows common in late winter and early spring. Groundwater base flow is estimated to be approximately 68% of mean annual stream discharge (Anderson and Appel, 1969); accordingly, computed base flow is on the order of sixteen inches per year.

2-4 A flood plain study for the Toms River was prepared for the Ocean County Planning Board by the Philadelphia District of the U.S. Army Corps of Engineers. The study, which included consideration of tidal influences, developed the different flood elevations for the USGS stream gage located approximately 200 feet downstream of the Oak Ridge Parkway bridge. The flood crest elevations for the gage location were estimated to be as follows:

Standard Project Flood = 26.5 feet above mean sea level;

New Jersey Flood Hazard Area Design Flood = 21.8 feet above mean sea level; and

New Jersey Floodway Design Flood = 20.6 feet above mean sea level.

The New Jersey Flood Hazard Area Design Flood is equivalent to a flood with a discharge 25% greater than the 100-year flood. The New Jersey Floodway Design Flood is equivalent to a flood with a discharge of 100 year flood.

2.2.4 Site Drainage

Three gently sloping drainage swales convey stormwater run-off on the Toms River Plant site. An intermittent stream course crosses the borrow area in the northern sector of the property, a drainage swale exits the plant site near the intersection of Cardinal Drive and the Oak Ridge Parkway, and another channel system drains the southeastern sector of the site. Inspection of these drainage swales indicates that little, if any, surface run-off discharges from the site. The swales thus appear to serve essentially as recharge basins for the groundwater system. Permeability characteristics of on-site soils range from moderately to excessively well drained on the higher ground to poorly drained along the river.

2.3 Existing Industrial Landfill Facility Description

The solid waste landfill is located on property owned by Ciba-Geigy Corporation in Dover Township, Ocean County, New Jersey. The site of the

2-5

CIB 013 facility is approximately one-half mile west of the north branch of the Toms River and has been certified by NJDEP as being out of the flood plain of the Toms River. Also, the NJDEP has stated that no riparian interests are involved in this project.

There are no airports within a 2-1/2 mile radius of the proposed landfill. The nearest airport is the Lakehurst Naval Air Station, which is 5.7. miles north of the site. The West Dover Elementary School is the only public building within a one-half mile radius of the landfill. There are no registered wells within a one-half mile radius. There are a number of private residential and commercial buildings within a one-half mile radius. Examination of a recent aerial photograph indicates that there are approximately 127 such buildings within the one-half mile radius. The nearest is at a distance of approximately 1,400 feet from the southeast limit of the landfill.

The landfill is designed to consist of seven distinct cells, constructed and operated in a progressive fashion, keeping pace with the rate of waste generation by the plant.

This document entitled "Ciba-Geigy Toms River Plant, Landfill Closure & Post Closure Plan" and the accompaning drawings are provided in Appendix C:

Drawings 6435-001 thru 007 - Closure/Post Closure Plan Drawings 6505-060 thru 071 - Soil Erosion & Sediment Control Closure/Post Closure Plan

These plans describe the closure method and materials used to close Cell No. 1 and the proposed methods and materials to close Cell Nos. 2 through 7. Appendix B, Drawing Nos. 6505-103P and 104P show the landfill location, overall dimensions, and final disposition. Drawing Nos. 6505-120P, 123P, 124P, 126P, 130P, 131P and 132P provide plan views, cross sections and details of the Cell No. 3.

2-6

CIB 013 0369 2.4 Waste Types and Volumes

2.4.1 Waste Types

Only wastewater treatment plant sludge (WTPS), classified by NJDEP as I.D. 27 Industrial Wastewater Sludge will be disposed in Cell No. 3. This is in accordance with the Administrative Consent Order, Paragraph 25, dated April 25, 1985 between the NJDEP and Ciba-Geigy which states, Ciba-Geigy may "deposit in the landfill wastewater treatment sludge, including sludge resulting from the use of carbon, except if sludge is hazardous waste as defined by New Jersey Regulations". Ciba-Geigy has also petitioned NJDEP to broaden this definition to include other miscellaneous non-hazardous waste streams, provided specific approval is granted by NJDEP beforehand.

2.4.2 Waste Volumes

The dewatered WTPS waste will be generated at a rate of 2,000 cubic yards a month for the first two years of operation. The sludge will originate from the wastewater treatment plant filter press dewatering units, from the closure of the Equalization Basin, and from other wastewater treatment plant units. Upon the completion of the closure operations of the Equalization Basin, the waste volumes will be reduced to 1,000 cubic yards per month.

The dewatered WTPS waste will be generated at a rate of 2,000 cubic yards per month for the first two years of operation. The sludge will originate from the wastewater treatment plant filter press dewatering units, from the closure of the Equalization Basin (pending NJDEP approval), and from other wastewater treatment plant units. Upon the completion of the closure operations of the Equalization Basin, the waste volumes will be reduced to 1,000 cubic yards per month. Cell No. 3 has been designed for a closure capacity of 82,000 cubic yards. Given the information above, Cell No. 3 will be filled to capacity in approximately 58 months. 2.5 Easements and Utilities

There are no easements in the immediate vicinity of the landfill. Jersey Central Power and Light owns a 50 foot easement approximately 450' due west of the landfill. This easement is used for a 8,800 volt underground electric cable.

Utilities serving the landfill include two (2) leachate forcemains, underground electric and water lines as shown in Appendix A, Drawing No. 6505-102P.

2.6 Geology, Hydrogeology, Soils and Geotechnical Aspects of the facility.

Geologically, the site is situated on the seaward edge of the Atlantic Coastal Plain and is underlain by alternating layers of sand, gravel, and clay.

The geology beneath the site consists of layers of unconsolidated sands, silts, and clays of Cretaceous, Tertiary, and Quaternary age. Collectively, these unconsolidated sediments make up the Atlantic Coastal Plain physiographic province. The uppermost formation in the area of the proposed facility is the Cohansey Formation, which is a 75 to 90 foot thick deposit of highly permeable, well-sorted, coarse, medium, and fine sands. Within these sands is a laminated silty clay unit which is continuous over the area of the proposed facility and which forms a water-bearing zone in the overlying sands. The water-bearing sands underlying the Cohansey Clay form the more significant and regional Primary Cohansey Aquifer. Underlying the Cohansey sands is fifteen to twenty feet of the Cohansey/Kirkwood Transitional Zone, consisting of fine sand and silt. Underlying the Transition Zone is the Upper Kirkwood Formation, consisting of intervals of medium fine sand and fine silty sand. The transition Zone, as well as the Upper Kirkwood Formation, acts as an aquitard.

2-8 In addition to the regional hydrogeologic systems described above, the site is characterized by a local perched water zone in the shallow subsurface. The elevation of this shallow water table is dependent on rainfall, with seasonal elevations fluctuating. Appendix B, Drawing No. 6505-029P and 6505-039P provide the contours of this groundwater occurrence in the vicinity of Cell's 3 & 4. A more thorough discussion of the hydrogeologic/ geotechnical aspects of the site is provided in Appendix B.

2.7 Permit Requirements

The permits required for construction of the proposed facility follow in Table 2-1. Ciba-Geigy has obtained all the necessary permits for the landfill. The existing permits cover the entire wastewater treatment plant and site, the landfill of which is the subject of this report. The dates of the permits are indicated in Table 2-1.

2-9

CIB 013 0372 TABLE 2-1

List of Required Permits

Permit Dated

Tree Removal Permit No. 1044 May 2, 1986 Soil Disturbance Permit Docket #1076 May 2, 1986 Flood Plain statement, NJDEP Division of Water Resources, Stream Encroachment Section, John O'Dowd December 15, 1975 Riparian Statement, NJDEP Division of Marine Services, Bureau of Marine Lands Management, James R. Johnson December 16, 1975 CAFRA Permit No. CA75-6-111 January 9, 1976 Dover Township Planning Board File No. DOV-P75.006 February 24, 1976 NJDEP-SWA Registration No. 1507-C October 11, 1977 Variance from Daily Cover Statement, NJDEP Solid Waste Administration, Beatrice S. Tylutki November 30, 1977

2-10 3.0 LANDFILL DESIGN

3.1 Excavation Plan

Clearing and grubbing within the proposed landfill facility area must be done within the clearing and grubbing limit line (CGLL) shown in Appendix A, Drawing No. 6505-104P. Excavation for Cell 3 must be done according to base grades shown on Drawing 6505-120P from the existing contours shown on Drawing No. 6505-102P, in accordance with the Appendix D, Specification Sections 02110 and 02222.

3.2 Run-on/Run-off Controls

During the construction phase of Cell 3, the rainwater falling on the already closed areas of the landfill will be drained towards the edge ditches, which will convey the rainwater to the southeast retention basin. Drainage channel design is based on peak run-off values determined by the Urban Hydrology for Small Watersheds (TR-55). The control and pipe inlet structure for this purpose are designed in accordance with the "Standards for Soil Erosion & Sediment Control in New Jersey", and "Design of Small Canal Structures" published by the U.S. Army. Design flow for this structure is 48 cubic feet per second, determined using Manning's Equation calculated velocities in the earthern ditch did not exceed 3.5 ft/sec. In addition, extra protection with rip-rap of d5o=6" is provided in the ditch at the entrance of the inlet structure as indicated in Appendix C, Drawing 6505-065. A 42" diameter precast concrete pipe structure is used to convey the design flow from the ditch to the southeast retention basin. A steel grate is proposed at the entrance of the inlet to avoid any large debris entering the pipe. The outlet structure apron dimensions and the rip-rap protection are also designed in accordance with the stipulated standards. The details of the control structure and rip-rap protection are also shown in Appendix C, Drawing 6505-071.

3-1 A 42" diameter precast concrete pipe culvert is provided along the ditch at the intersection of the ditch with the access road, the details of which are shown in Appendix C, Drawing No. 6505-071. The southeast retention basin was designed to contain 120 percent of the run-on (from areas around Cells 1 & 2) and run-off (the cap areas for Cells 1 & 2) from a 24 hour, 50 year storm (1.78 million gallons, 5.5 acre-feet). These calculations are provided in Appendix E, Supporting Landfill Design Calculations.

During the operation of Cell 3, the stormwater falling on the exposed sludge will be contained in stormwater retention trenches designed with the capacity to retain the volume of rainwater produced by a 2 day/100 year precipitation event (approximately 750,000 gallons). Rainwater will be contained in the landfill cell and pumped from the cell into the leachate forcemain system (Section 3.6) by a 250 gallon per minute pump available on site. The operations plan, was designed to contain the 2 day/100 year storm within the landfill cell, until intermediate grade is reached. After intermediate grade, stormwater will be diverted to temporary retention basins using procedures described in Appendix A-l of the Closure Plan and is included in Appendix C of this document. Additional details pertaining to the Operations Plan, including the methods for handling stormwater while the facility is operational is provided in Appendix A-l of the Closure Plan. A pumping lag of 12 hrs was assumed in calculating the volume of the storage in the stormwater trenches. During the closure of Cell 3, the northwest berm next to Cell 4 will be opened upon completion of the 2 ft. compacted clay and geomembrane- lined temporary retention basin. By so doing, contaminated water will not be permitted to escape as runoff to unprotected areas on site.

Finally, the future cell areas are considered and the stormwater caught by this completed landfill area is to be conveyed safely to the future northwest and northeast retention basins which are shown in Appendix C, Drawing Nos. 6505-063 and 064. The control and inlet structures for these basins are designed to convey flow of 29 cfs and the details are given in Appendix C, Drawing Nos. 6505-068 and 069.

3-2 Rainwater in the drainage ditches around Cell Nos. 3-7 will flow north and discharge through a 42" drop pipe into two separate sediment control basins (Northeast and Northwest Basins). These basins are sized to contain the run-off (the cap areas for Cell Nos. 3, 4, 5, 6, and 7) from the 24 hour, 50 year storm (1,150,000 gallons, 3.53 ac-ft and 20% sediment storage, 0.71 ac-ft). See Appendix A-2 of the Closure Plan (Appendix C of this document).

In addition to the runoff controls designed for the landfill, a drainage swale designed to handle a 50 year storm was provided for the access road leading to Cells 3 and 4 (See Appendix C, Drawing No. 6505-066). This swale discharges into a naturally occurring swale.

All discharges to existing drainage paths are designed to discharge stormwater at rates less than two feet per second to prevent erosion. Drainage channels conveying stormwater at velocities exceeding 3.5 feet per second were provided with rip-rap protection for erosion control.

3.3 Foundation Design

3.3.1 General

A foundation investigation was performed to determine the underlying soil strata thickness, profile and engineering properties at the proposed landfill site. Five boring locations were selected and the scope included performing Standard Penetration Test (SPT) up to boring depth, ranging from 30 to 40 feet, and installing four 4" stainless steel monitoring wells and one 2" stainless steel piezometer. In addition, various laboratory tests were performed on the soils recovered from various strata to evaluate their characteristics and engineering properties. The selected boring locations are shown in Appendix A on Drawing No. 6505-102P and their coordinates are as follows:

3-3

CIB 013 0376 Corresponding Ciba-Geigy Monitoring Boring Number Well Number South East

B-0282 744-0282 1900 2025 B-1129 744-1129 2610 2110 B-1130 744-1130 3220 2110 B-1131 744-1131 2610 2750 B-1132 744-1132 3220 2750

Samples were recovered using either a two-inch OD split-spoon sampler, or a three-inch Shelby tube driven by a 140 lb. hammer with free fall of 30 inches. Boring logs are presented in Appendix B, Attachment A. In addition to the test boring program, groundwater monitoring wells and a piezometer were installed to comply with the NJDEP requirements.

Groundwater was encountered at depths ranging from 22.5 to 32 ft below the existing ground surface. Perched groundwater was encountered in Boring B1129 at a depth of 8 ft below the existing ground surface.

Representative soil samples recovered from the drilling were subjected to moisture content, Atterberg Limits determination, particle size distribution analysis, specific gravity determination, consolidation, unconfined compression and triaxial permeability testing. Laboratory test results are presented in Appendix B, Attachment A. This report identified the presence of a perched water zone above the Yellow clay layer and defined the limit, depth and areal extent of the yellow clay layer beneath the site.

3.3.2 Stability Analysis

The landfill will be constructed on the compacted in-situ sand (angle of internal friction 0 = 35°) as discussed in Appendix D, Specification Section 02232. Initially, the excavation must be done according to the design

3-4

CIB 013 03 basegrades with side slopes 1 on 3 (approximately 18.5° to horizontal). The stability of this slope of in-situ sand was analyzed using simplified Bishop method. The least value of the minimum factors of safety obtained for various locations of the center of slip circle was found to be 2.1. This value is satisfactory. Stability of the slope must be analyzed according to the different stages of construction. Initially, the stability was analyzed after the placement of the 3 ft secondary clay liner, and the factors of safety obtained for various points increased compared to the previous case, and the least of the minimum factors of safety is 4.5. This indicated the considered slope was stable. Stage by stage stability analysis according to the stages of construction were also analyzed and the details and results are discussed in Sections 3.4.1.2 and 3.4.3.2.

3.3.3 Settlement Characteristics

From the foundation investigation (Appendix B, Hydrogeologic/Geotechnical Report, Section B 3.2.12, Upper Primary Cohansey), the maximum thickness of the yellow clay layer is found to be 12'. The coefficient of compressibility of this layer is 0.2. Using Terzaghi's Time Dependent Consolidation Equation, the settlement of the clay layer was computed, assuming the stress at the mid-point of the clay layer is equal to the load at the surface, since the loaded area is large. This assumption will yield a conservative estimate of the consolidation of the clay layer. The input parameters for the estimate of settlement were selected from the most conservative of the reported soils test results. The aim of the analysis was to very conservatively estimate settlement, and if found acceptable, no further refinements would be necessary. The settlement was computed to be approximately 5" which is acceptable for the Foundation Design. The time required for 100% of this settlement to occur was computed to be 7 months.

The immediate shear strain on the sand will result in a maximum differential settlement of 0.28 inches. The landfill static loads after consolidation will result in a maximum differential settlement of 5.0 inches. The total 5.28 .

3-5 inches of induced differential settlement occurs at the center portion of the landfill and results in: ° a net increased slope of lateral pipes, and ° a 0.25 percent variation in collector pipe slopes, after settlement exceeding 2.0% in all cases. The calculations are given in Appendix E.

3.3.4 Ultimate Bearing Capacity

The in-situ sand foundation or the granular backfilling must be compacted in accordance with Appendix D, Granular Compaction Specification Section 02232. The ultimate bearing capacity of the foundation was evaluated against the working load of the landfill at 100% of its capacity. Using the bearing capacity equation with shape factors, assuming 25' x 550' rectangular area, the factor of safety against ultimate bearing capacity failure was found to be 18.9. This is well above the required factor of safety for a foundation of this nature. The calculations are given in Appendix E.

3.4 Landfill Liner System

The Cell No. 3 containment system design was based on N.J.A.C. 7:26 - 2A.7. Since the proposed facility is located in a highly permeable geologic formation (Hydrogeologic/Geotechnical Report, Appendix B), the design, performance and efficiency of the containment systems shown, at a minimum, conform to the requirements of N.J.A.C. 7:26 - 2A.6(c)2 which state that, "at a minimum, have a containment system consisting of a double composite liner system. The primary and secondary geomembrane liners in the double composite (or geocomposite) liner system shall be in compressive contact with a clay or admixture liner below the geomembrane liner. A leak detection/collection system shall be located between the primary composite liner and the secondary composite liner."

3-6 3.4.1 Secondary Geocomposite Liner System

The Cell No. 3 containment system was designed based on N.J.A.C Regulation 7:26-2A.7. Since the subsurface exploration (see Appendix B) revealed a geologic formation with a permeability greater than 1 x 10~5 cm/sec, a double geocomposite liner system was required. This section will address the secondary liner of the double geocomposite liner system. The primary liner system is discussed in Section 3.4.3.

The secondary liner of this containment system for Cell No. 3 is comprised of a compacted clay and geomembrane composite. The secondary clay layer within this system consists of a minimum of three (3) feet of compacted clay, with a minimum hydraulic conductivity of 1 x 10"7 cm/sec. The secondary geomembrane liner consists of a high density polyethylene (HDPE) membrane posessing a thickness of 80 mils (.08 inches). This geomembrane will be placed in in direct contact with the secondary clay layer.

The remainder of this section will discuss the details of the design regarding each of these components of the secondary geocomposite liner system.

3.4.1.1 Secondary Clay, Liner

The secondary clay liner will be composed of three feet of compacted soil that must obtain a permeability less than or equal to 1.0 x 10"7 cm/sec. A selection process was initiated to determine a suitable source of material for the clay liner. Three sources were found: the Warren clay site, Monroe Township (soil A); Toto Bros. Mine, Monroe Township (soil B); and the County Sand & Gravel, in Mount Holly (soil C). Samples of clay were obtained from each pit and a characterization of the candidate soils" for the landfill liners was performed at Drexel University, Department of .Civil Engineering, under the direction of Dr. J.P. Martin, P.E., Assistant Professor of Civil Engineering. The scope of work for the characterization included determining index properties, compaction, strength properties, consolidation and swell properties, and fixed wall permeability tests. The results of these tests

3-7 were the first part of a two part investigation entitled Geotechnical Characterization of Candidate Soils for Landfill Liner. Part Two of this study investigated the chemical compatibility of soils B and C with a synthesized leachate in a study entitled Clay Compatibility Investigation, Phase II. Interim Report. The results of these studies are found in Appendix F.

The Phase I report indicated that the soils selected from the three pits have very good mechanical and physical properties and would be suitable to function as a compacted clay liner. The soils from all three pits are derived from the Woodbury Formation and are classified according to the Unified Soil Classification System as SM-MC-MH. but behave more like a CL clay of low plasticity and compressibility. Visually the soils are classified as fine sand and plastic silt, bound by trace amounts of clay.

A critical feature of the soils tested is the blocky, shale-like texture of the borrow material. For use as a low permeability clay liner, it is essential that high compaction wet of the optimum moisture content (OMC) be used. The construction of the secondary clay liner will be conducted according to the construction specification drafted by AWARE, Inc. The construction specifications call for the minimum compaction of the secondary clay liner to be 90 percent of the maximum modified proctor density. The secondary clay liner will also be compacted in 6 inch lifts to a final thickness of 3 ft except at the base of the primary sump locations where a thickness of 5 ft will be obtained. The construction of the secondary clay liner will be above a carefully graded and compacted excavation grade (see Cell No. 3 Construction Drawing 6505-120P), covered with a geotextile. The geotextile will control potential pore water pressures, add tensile strength to the clay, and prevent the sand base grade from working into and adversely effecting the integrity of the secondary clay liner. At 90 percent modified proctor density, the moisture content of the three candidate soils tested are 26.7, 30.2, and 24.2 percent, which is approximately 1.5 to 2 times more than the OMC of the soils. Field density and moisture content measurements will be conducted during the compaction of each six-inch lift by using both nuclear moisture-density gauge (Troxler Gauge) and sand cone tests. By maintaining a

3-8 wetter than optimum moisture content, compacting with a vibratory sheep foot-roller, and maintaining the specified modified proctor density, the blocky characteristic of the borrow material can be destroyed, and a continuous homogeneous secondary clay liner can be constructed to the grades shown on Cell No. 3 Construction Drawing No. 6505-123P.

An additional advantage of a wetter than optimum moisture content, beyond reducing the need for field drying and improving the soils workability, is the improved liner stability achieved by the reduction in the soils absortion capacity. The reduction in the absorption capacity of the candidate soils is favorable since it reduces the potential for a dimensionally unstable secondary clay liner. The three candidate soils all possess a low swell potential and, by increasing the percent saturation, the potential for developing a dimensionally unstable clay liner is further reduced.

The permeabilities obtainable with the candidate soils compacted to 90 percent maximum modified proctor density will be in compliance with both the NJDEP Regulations and EPA Guidelines of 1 x 10"7 cm/sec. This is demonstrated by the results of the fixed wall permeameter tests run at moisture contents ranging from 22.9 to 36.0 percent, and the consolidation tests run at overburden pressures ranging from 1,900 to 7,600 psf. At the overburden design stress of 4,000 psf, the permeability was approximately 4 x 10~8 cm/sec.

From the results of unconfined compressive and split cylinder (Brazilian) tests performed on the three candidate soils (see Tables 3 and 4 of Appendix A), it can be concluded that adequate compressive, shear, and tensile strength can be achieved for the construction of a primary or secondary clay liner. The unconfined compressive strengths range from 23.3 psi to 54.39 psi over a range of moisture contents of 21.4 to 36.5 percent. The tests were conducted after one week of sealed curing which most closely approximates the anticipated field conditions. The above range of unconfined compressive strengths classify the three candidate soils as stiff cohesive soils. The tensile strengths of the candidate soils range from 5.0 psi to 8.8 psi under the same moisture and curing conditions described above.

3-9 Phase II of the clay study investigated the effects of leachate, at various confining stresses, on the permeability of soils from Toto Bros (soil B) and County Sand & Gravel (soil C). In order to accomplish this task, the soils were exposed to both water and leachate for extended periods of hydration. The Atterberg limits were performed to measure the effects the leachate had on these soil properties. The Phase II Report concluded that no decrease in the Atterberg limits was observed which would indicate a dessication of the clay particles, and a tendency of the clay structure to flocculate, causing shrinkage cracks. This result would have indicated an increase in clay permeability by several orders of magnitude. The test results did indicate a slight increase in the Atterberg Limits of the soils tested. This may have been the result of the solvents within the leachate "cleaning" the clay particle surface, thus providing more adsorption sites within the clay structure.

The conclusion that may be drawn from the extended hydration Atterberg Limits Test are that the permeability of these soils are controlled by the wide soil gradations, high specific surface area, and high compactibility which yields a soil matrix with small pores and tortuous channels. This is in contrast to most compacted clay liners which derive their low permeabilities almost solely from the electrochemical diffuse double layer which has been shown in some cases to be sensitive to the chemical nature of the permeament. Therefore, it would seem apparent that soils which derive their permeability via gradation and compaction would be excellent candidates for compacted clay liners. All of the soils tested in this program possess these desirable soil characteristics.

Lastly, flexible wall permeameters were used to determine the hydraulic conductivity of soils B and C at various effective stresses while exposed, first to water, then to leachate. The results of these tests indicated that the required liner permeabilities of 1 x 10~7 cm/sec can be achieved with these soils at the specified compaction effort. No effect on the permeability of these soils has been noted at this time. However, additional pore volumes of leachate, beyond the EPA 9100 Guidelines, are being passed through the clay samples to investigate the effect that prolonged

3-10 exposure to leachate has on the hydraulic conductivity of the samples It should be noted that no changes in hydraulic conductivity are anticipated, since most of the effects should have occurred within the passage of the first pore volume. The effluent from the testing will be sent to AnalyticKEM for chemical analysis. This would determine which chemicals, if any, may have an adverse effect on the clay matrix. The results of these additional tests are expected by June 30, 1987, shortly thereafter, a supplemental report will be submitted to NJDEP.

It can be concluded that the soils from any of the three borrow pits would be structurally and hydraulically suitable to function as a primary or secondary compacted clay liner, provided the Construction Quality Assurance and Quality Control Plan, (Appendix G) and Technical Specifications are followed.

A field test patch, will be constructed to verify that the soil selected can achieve the required densities and permeabilities. Additional shelby tube samples will be taken to determine how closely field compaction techniques can duplicate the various soil characteristics determined by laboratory testing. The percent compaction and moisture contents will be field determined, using both nuclear moisture-density gauge (Troxler Gauge), and sand cone tests.

3.4.1.2 Secondary Geomembrane Liner

The secondary geomembrane liner selected was an 80 mil high density polyethylene (HDPE) membrane. The polymer, polyethylene, was chosen for its ability to withstand a wide range of chemical environments while retaining its physical and mechanical properties. To ensure that this polyethylene material was capable of withstanding the exposure to the leachate anticipated within this landfill, EPA 9090 tests were performed on 80 mil HDPE samples from two geomembrane suppliers, National Seal Company (NSC)and Gundle Lining Systems. These liner samples were exposed to a synthezied leachate, which was approved by NJDEP prior to testing. The chemical constituents within this synthetic leachate may be found in Appendix D. The samples were exposed for a maximum of 120 days and tested at 30 day intervals. Samples were incubated at temperatures of 23°C and 50°C during these exposure periods. The results of these tests may be found in. Appendix H. These tests indicated that both the NSC and Gundle materials exhibited little variation in both physical and mechanical properties when exposed to the leachate.

3-11 The selected liner thickness for the secondary geomembrane was determined by considering localized and differential settlements anticipated within the secondary clay layer. Both static and dynamic loading conditions were considered. Using a static load of 4,000 psf, a liner thickness of 22 mils was required. The computed factor of safety was 3.6 which was acceptable. Using a dynamic loading condition (i.e. roller compaction of upper layers) of 65 psi (9500 psf), a liner thickness of 50 mils was required. The computed factor of safety was 1.6 which was acceptable, however, extensive care should be exercised when compacting earthen materials above any geomembrane liner system. For this reason it was decided that the first lift of the primary clay layer be no less than 18" and tracked in via a bulldozer with no compactive effort being applied to this lift. The rationale for this decision is discussed at length in Section 3.4.3.1 of this report. The calculations for this analysis may be found in Appendix E.

The last two design concerns for the secondary geomembrane liner were the determination of the anchor trench dimensions and the side slope stability of the secondary clay layer beneath the secondary geomembrane.

The critical aspects of the anchor trench design are the run out length at the crest of the slope, depth of the trench and finally the trench width. Currently there are two methods available to determine the trench dimensions. The first method, an analytical procedure presented by Dr. Koernerd) in 1986, analyzes the pressure distributions above the liner runout and within the anchor trench. The second method available is simply using the industry standard for anchor trenches which requires a geomembrane runout length of not less than three feet, a trench depth of two feet and a trench width of one foot. Both methods were evaluated, with the most conservative method adopted.

Upon completion of the analytical method it was determined that with a trench depth of two feet, a run out length of .64 feet is required for a factor of safety of 1. Comparing the industry standard with the computed value, it was determined that the standard detail was at least four times more conservative than the analytical approach. Since the anchor trench detail is a crucial element in the landfill design, it was decided that the conservative design approach would be adopted and the industry's standard detail would be utilized for the anchor trench design. The calculations may be found in Appendix E.

3-12 CIB 013 033 The final design concern for the secondary geomembrane liner was the side slope stability of the secondary clay layer beneath the secondary geomembrane liner. The analysis used to determine the stability of this three foot clay layer founded on in-situ sand material, was the Simplified Bishop Method. This method of analysis was used in Section 3.3 to determine the stability of the in-situ material on a 3H:1V slope. The concern with the three foot clay layer was the possibility of sluffing of the clay after the geomembrane is placed, which would rupture and tear the side slope geomembrane. The results of this analysis may be seen in Appendix E. From this analysis it was determined that a deep seated toe failure possesses the lowest factor of safety of 4.5. Typically, a factor of safety less than 1.5 is unacceptable, therefore the above value exceeds that typically used to establish stability and thus the integrity of the secondary geomembrane liner.

3.4.2 Secondary Leachate Detection/Collection System

The secondary leachate detection/collection system for this landfill liner system includes a high drainage capacity polyethelyene netting material (more commonly known as a geonet) to transmit flow to the leak detection sump. The benefits of such a geonet detection/collection system are: ° chemically inert 0 able to convey more flow than 1' sand 0 saves l1 of landfill volume ° easy to install (especially the side slopes)

Given these benefits, the geonet has been incorporated into the design of the secondary leachate detection/collection system.

There are two elements to the design of this layer. The first element has to deal with the amount of expected flow which theoretically should be zero.

3-13 From past landfill projects it has been determined that approximately 70 gal/month (Geoservices, J. Fluet, May 1, 1987) is a reasonable estimate for the amount of flow anticipated. This flowrate is the estimated leakage through the top primary geomembrane liner in Cell 3 and from soil water from consolidation of the clay layer on top of the geonet. The second major element is the time to detect a leak in the sump. This value is important because, if a leak has occurred through the primary liner it is best to know as quickly as possible, so appropriate actions may be taken. These two issues are of paramount importance when designing a leak detection system. Subsequently it will be shown that the transmissivity of the geonet is at least equivalent to the transmissivity of one foot of sand as required by the proposed regulations. The following calculations will compare the hydraulic capabilities of the two materials.

The transmissivity of the sand may be computed from the following equation:

• T = Kb T = transmissivity (ft2/sec) K = hydraulic Conductivity (ft/sec) b = transmission layer thickness (ft)

Thus the transmissivity of 1 foot of sand with a permeability (K) of

3.28 x 10-4 ft/sec (1 x 10-2 cm/sec) is: Ts = 3.28 x 10"4 ft2/sec.

Alternatively the transmissivity of a geonet (TQN) at various overburden stresses may be determined experimentally in a laboratory. The data from such tests is readily available from most manufacturers of these materials. The transmissivity data used for this design was obtained for National Seal's Polynet Material. This data may be found in Appendix E. The computed overburden stress is 3,000 psf for which the transmissivity of the geonet may be estimated at 1 xlO-3 m2/sec or 1 xlO-2 ft2/sec. A factor of safety between the sand and geonet may be computed as follows:

2 F.S. = TGN/TS = 1 x 10" /3.28 x 10~4 £q. 3-1

• o°0 F.S. = 30 This result however is misleading since the upper boundary of the geocomposite is a geotextile overlain by clay and not another geomembrane. Therefore, a reduction factor must be applied to the transmissivity of the geonet. A reduction factor is required because the clay and geotextile will have a tendency to block the pire structure of the geonet, thus reducing the flow capacity. A paper presented by Giroud et al at the International Conference on Geomembranes in 1984 provided experimental data to determine these reduction factors. The results of these tests indicated that given the boundary conditions described above, the transmissivity of the geonet should be reduced by a factor of 5. Therefore, the factor of safety is reduced from 30 to 6. This indicates that the geonet is at least 6 times more transmissive than the required 1 foot of clean washed sand. In addition, it was assumed that no flow reduction occurred within the sand layer from compression of the sand due to overburden load or bacterial growth within the sand layer. These calculations may be found in Appendix E.

From these calculations, the flow capacity of the geonet was calculated and compared to the expected flow of 70 gal/month (.001 gal/min.). The geonet flow capacity was computed on the basis of the preceding transmissivity data. The flow capacity of the geonet was computed to be 0.11 gal/min/ft at a hydraulic gradient of 2.6%. Applying the reduction factor of 5 for compression yields a flow capacity of 0.022 gal/min/ft. The available width of geonet at the inlet to the leak detection sump is approximately 40 feet yielding a total flow capacity of 0.9 gal/min. Dividing the geonet flow capacity by the expected flow yields a factor of safety of 896. This result indicates that this leak detection system has the capacity to accomodate at least 77,000 gal/month, or 38,000 gallons per sump per month.

3-15 The second design element was to determine the time required for a leak to be detected at the sump. This was computed by Darcy's equation as follows:

Q = kiA Eq. 3.2

v = q = ki Eq. 3.3 A

vs = ki seepage velocity Eq. 3.4 N

T = NL time to detect leak Eq. 3.5 ki

where: N = porosity of geonet = .80 L = maximum length of drainage path = 330' i = hydraulic gradient (slope) = 2.6% k = permeability of geonet = .5ft/sec

Applying a reduction factor of 5 to the permeability of the geonet yields a leak detection time of approximately one day. If sand were used, the detection time would be 140 days. It should be noted that the slope of the detection layer influences the detection time. For this reason, no area within the landfill has a slope less than 2.5%.

The last issues regarding the design of this leak detection system are clogging potential and chemical compatibility. Since the geonet is made from the same polymers as the primary and secondary geomembranes, chemical compatibility was not a concern. Regarding clogging potential there are two possible sources. The first source being the restriction of flow in the geonet via the deformation of the geotextile into the voids of the geonet.

3-16 This has been discussed previously and taken into account in the design. The second possible source of clogging would be from the fine clay particles passing through the geotextile. This problem was accounted for in the design of the geotextile. The geotextile was designed to allow leachate to seep through while retaining the fines in the primary clay layer. The method of analysis utilized was developed by Giroud(2) and presented at the 2°d International Conference on Geotextiles 1982. This method is to date the most conservative filter design criteria for geotextiles.

The final component of the leak detection system is the collection sump. The collection sump is a precast concrete HDPE lined structure with an internal storage capacity of approximately 80 gals. The sumps are accessed from the surface via two 6" HDPE pipes capable of conveying a 4" submersible pump to evacuate the sump contents. The sump is surrounded by clean free draining granular material which conveys the leachate from the geonet to the sump. The sump was designed to be chemically compatibile with its harsh environment by being lined inside and out with HDPE. In addition, the sump was designed to hold one month of leachate before the reservoir capacity of the granular material needed to be utilized.

3.4.3 Primary Geocomposite Liner System

The primary liner for Cell 3 containment system is comprised of a clay and geomembrane composite. The primary clay layer has a minimum thickness of two (2) feet with the upper 6" compacted to a maximum hydraulic conductivity of 1 x 10"7 cm/sec. The primary liner consists of a high density polyethelyne (HDPE) membrane possessing a minimum of 80 mils (.08 inches). The primary geomembrane liner will be placed in direct contact with the secondary clay layer.

The remainder of this section will discuss the details of the design regarding each of these components of the secondary geocomposite liner system.

3-17 3.4.3.1 Primary Clay Layer

The primary clay liner will be constructed using the soil chosen for the construction of the secondary clay liner, or in the event that the same soil supply is no longer available an alternate equivalent source may be used. As concluded in section 3.4.1.1 any of the three candidate soils are structurally and hydraulically suitable to act as a compacted clay liner with the condition that the soil chosen be compacted to 90 percent maximum modified procture density and maintain a permeability less than or equal to 1 x 10-7 cm/sec. Section 3.4.1.1 also discusses the leachate compatability, and field test patch requirements for a soil to qualify as a building material for compacted clay liners.

The difference between the two compacted clay liners (primary and secondary) is their orientation within the construction sequence and the inherent construction restrictions. The construction, as discussed in section 3.4.1.1, of the secondary clay liner will be performed by compacting the soil in six inch lifts to a final liner thickness of three feet, while grading the compacted soil according to Cell No. 3 Construction Drawing 6505-123P. The construction of the secondary clay liner is simplified since only a geotextile and the compacted base grade underlie it. In the case of the primary clay liner installation, to obviate questions concerning the integrity of the underlying geotextile, geonet, and geomembrane system following any compaction effort of the overlying primary clay liner, it was agreed upon by the NJDEP to modify the compaction requirements specified for the primary clay liner. Although 90 percent modified proctor density will not be obtained in the first 18 inches of the primary clay liner, the minor loss in the structural stability and permeability is insignificant in comparison to the potential damage to the leak detection system.

The construction of the primary clay liner will not require compaction in six inch lifts as is required for the secondary liner. The primary liner will be constructed by tracking-in and compacting the initial eighteen inches of soil using a bulldozer. Upon obtaining eighteen inches of liner thickness, an additional six inches of liner thickness will be compacted to 90% modified

3-18 proctor density using a sheep-foot roller. Field compaction will be monitored using a nuclear moisture/density gauge and sand cone tests. Shelby tube liner samples will be pushed nine inches and sent to a laboratory to confirm the permeability of the upper portion of the two foot thick primary clay liner. A thorough discussion of the QA/QC procedures may be found in the Cell No. 3 Construction Specifications and QA/QC Document prepared by AWARE, Inc., April 1987 (Appendices D and G respectively).

A final primary clay liner thickness of 2 feet will be smooth rolled to the final grade shown in Appendix A, Drawing 6505-123P in preparation for the installation of the overlying primary geomembrane and leachate collection system.

3.4.3.2 Primary Geomembrane Liner

The primary geomembrane liner selected was an 80 mil high density polyethylene (HDPE) membrane. The reasons for the liner thickness and polymer selection have been presented in Section 3.4.1.2 of this report. The support calculations are included in Appendix E. There were additional design constraints imposed on the selection of the primary geomembrane liner. The additional areas of concern were: ° side slope stability ° hydraulic properties

As discussed in Section 3.4.1.2, the possibility of the secondary clay layer sluffing and jeopardizing the integrity of the liner, was an issue which was analyzed using the Simplified Bishop Method. However, in the case of the primary liner, sluffing of the primay clay layer is also a concern, but the mechanism by which the failure could occur is somewhat different. The primary clay layer, on the side slope, rests on the secondary leachate detection system which is comprised of a geotextile and geonet, which in turn is underlain by the secondary geomembrane liner. The problem arises since the geonet and geomembrane are both made of high density polyethylene (HDPE) which

3-19 exhibits a low friction angle of 16°. As a result, a slip plane exists between the geonet and geomembrane which appears to be the weakest plane in this multi-layer system. Two analytical methods were available to investigate the stability of the primary clay layer after construction. The first method was an infinite slope analysis which essentially considers the situation as a classical sliding block problem. The following equation was used to compute the factor of safty against sliding. F.S. = tan S Eq. 3.6 tan B where: S = friction angle between the geonet and geomembrane 16° B = angle of slope (3H:IV) 18.4°

The factor of safety was then computed to be .86 which is less than 1.0. This result indicates that the primary clay layer is unstable once construction is completed. There are two crucial elements not taken into account in this analysis. The first element is the buttress effect that the soil wedge at the toe of the slope (referred to as the neutral block), has on the structural stability of the clay layer. The second element neglected in this analysis was the strength mobilized by forces within the anchor trench. Therefore, a more rigorous form of analysis was required in order to analyze this slope configuration. The Wedge Analysis was employed, which enabled the investigation of the neutral block's ability to buttress the primary clay layer. In addition, pore water uplift pressures and tension cracks were incorporated into the analysis. The following table is a summary of this analysis. The supporting calculations may be found in Appendix E.

Table 3-1 provides an analysis listing various safety factors for various slope configurations. This analysis indicates that minimum safety factor would be realized by a slope configuration described as a "neutral block", with uplift pressures and tension cracks at the crest. This safety .factor would be 6.2.

3-20 TABLE 3-1

WEDGE ANALYSIS SUMMARY

Slope Configuration F.S.

No Neutral Block 0.86 (i.e., infinite slope analysis)

Neutral Block Only 7.3

Neutral Block & Pore Water 6.7 uplift pressures

Neutral Block, Uplift Pressures 6.2 tension crack at crest

3-21 It should be noted that at the present time there is no published procedure for determining the beneficial effects derived from the anchor trench, therefore, it was not incorporated in the analysis. However, it is apparent from Table 3-1 that the additional stability derived from the anchor trench system is not required since the clay layer has demonstrated its stability without the presence of the anchor trench. To insure the stability of this clay layer, a gebgrid will be placed on top of the geotextile to allow a portion of the load from the primary clay and operations layer to be transferred from the secondary liner and leak detection system, to the anchor trench, much in the same manner that a column in a building transfers its load to a foundation. In addition, the geogrid will aid during the construction of the primary clay layer on the 3H:IV side slopes by presenting a surface with a much higher friction angle.

The next area of concern was the hydraulic properties of the geocomposite liner system. The areas of investigation included determination of leakage due to holes with or without a clay backup and the breakthrough time for leachate to reach the leak detection system. Four scenarios were analyzed in an attempt to estimate leakage rates. They were:

o leakage due to liner permeability o leakage due to the presence of pinholes o leakage due to one hole o leakage thru a geocomposite liner

The leakage rate through the primary geomembrane was evaluted using Darcy's equation and assumes that a free draining material lies beneath the geomembrane which is a worst case scenario. From the calculations in Appendix E, is apparent that for a constant head of 1 foot that 12 gal/mo. would reach the leak detection system. While it is understood that Darcy's equation applies to flow through porous media, this estimate is within an order of magnitude of a much more rigorous type analysis.

3-22

r CIB 013 0395 The next scenario considered one pinhole every 110 ft2. Using Poiseuille's equation for flow through small openings and assuming, once again, a free draining material with 1 foot of constant head on the liner, a flow rate was estimated to be 1,600 gal/mo. for 894 pinholes. It becomes apparent at this point that the permeability, and subsequently the flow through a geomembrane, will be dominated by the presence of holes or openings within the liner. In an effort to eliminate holes or openings within the liner, a comprehensive Construction Quality Assurance Plan (Appendix G) was developed.

One hole with a diameter of .0011 ft2 (1cm2), with the same assumptions used previously, would increase the flow through the liner by 4 orders of magnitude.

The last scenario analyzed attempted to estimate the flow through a geomembrane liner with a clay backup. The method used for this analysis was developed by Y. Fauve(3). The design charts presented in this paper allowed an estimate of the discharge through the geomembrane and clay system to be computed. For a hole 1cm2 diameter, and one foot of constant head, a flow rate of .00083 gal/month was estimated, which is nine orders of magnitude decrease from the scenario with one hole and free draining material.

The importance of this analysis is not in estimating the flow through a liner but more importantly is to demonstrate the effectiveness of a geomembrane and clay composite system. The estimate of flow to the seconary system was previously discussed, and is estimated at 70 gallons a month, a conservative figure by comparison to the flow rates reflective of a composite system. The results of this analysis clearly demonstrate the hydraulic effectiveness of the primary geocomposite liner system.

3.4.4 Primary Leachate Collection System

The design of the primary leachate collection system was divided into three components. The first component of the system was to determine the thickness of the drainage layer. The second component involved determining the required

3-23 transmissivity of this layer. The last component of the primary leachate collection system to be designed was a geotextile separation layer between the collection sand layer and the operational sand layer. The main function of this geotextile is to keep the collection layer free of fines and material which may jeopordize the integrity of the collection system.

The collection layer thickness was computed using the equations presented below: L ([e/k + tanZB]1/2 - tan B) Eq. 3.7 Hma x

= H (Cos B) Eq. 3.8 max _ "mamaxv where: L = maximum drainage path length e = estimate of uniform precipitation k = permeability of drainage layer B = slope of drainage layer

Hmax= maximum water height thickness

Tmax= required thickness of collection layer (in any consistent set of units.)

This method of analysis was recommended by J.P. Giroud of Geoservices as a conservative approach to this problem. Further inspection of equation 3.7 reveals that for small values of slope angle, the cosine of that angle

approaches unity. For the purposes of this analysis Hmax = Tmax. Further inspection of equation 3.8 reveals that two of the parameters, drainage path

3-24 length and slope angle, may be varied to optimize the landfill volume with the hydraulic performance of the collection system. The following figure was prepared relating these two variables provided the soil permeability and rainfall are fixed at 1 x 10-2 cm/sec and 1.28 in/day respectively.

3-25 Figure 3-1 With a maximum drainage path length of 280 feet and a slope angle of 3 degrees, a maximum collection layer thickness of 10.9 feet was required. This result indicates that a material with a much higher permeability is required to accommodate the anticipated rainfall. The rainfall used in this analysis was based on the ten year, seven day event. The seven day duration was used based on recommended EPA Guidelines. The ten year return period was selected, since the maximum expected operational life of the landfill is five years. The permeability of the collection layer is fixed by NJDEP Regulations at 1 x 10-3 cm/sec, however, EPA Guidelines recommend a permeability of 1 x 10-2 cm/sec. Since the EPA Guidelines were more conservative, this value of soil permeability was specified for the collection layer as outlined in Appendix D, Specification Section 02232.

With the collection layer thickness computed (10.9 feet), and the soil permeability selected (1 x 10"2 cm/sec), the transmissivity of the collection may be computed. The supporting calculations may be found in Appendix E. Thus, the minimum required transmissivity of the primary leachate collection layer is 3.60 x 10"3 ft2/sec (3.34 x 10_4m2/sec). Since the 10.9 feet of sand was unacceptable but the calculated transmissivity must still be provided, a high drainage capacity polyethylene netting material (more commonly known as a geonet) was selected to transmitt this flow to the primary collection sump. The geonet was selected from data provided by National Seal Company (NSC) for their product line "Polynet". Since the overburden stress on the collection system was computed to be 3,000 psf, the NSC transmissivity value of 1 xl0"2ft2/sec (1 10"3 cm2/s) was selected as being most representaive of the product line. By dividing the transmissivity of the geonet by that of the required transmissivity of the collection yields a factor of safety of 3.0. This result indicates that not only can the geonet replace the 10.9 feet of sand but its flow capacity is three times greater than the sand collection layer. Table 3-2 compares the transmissivities of the EPA & NJDEP Regulations with that provided by the geonet.

3-27 TABLE 3-2

TRANSMISSIVITY COMPARISON

TRANSMISSIVITY FACTOR REMARKS (ft2/sec) OF SAFETY

Geonet 1 10"

EPA 12" @ 1 x 10-2 cm/sec 3.2 xlO-4 21 Requirements

NJDEP 18" @ 1 x 10~3 cm/sec 4.9 xlO-5 200 Requirements

3-28 This table clearly demonstrates that this geonet connection, system meets and exceeds both Federal Guidelines and NJDEP Regulations. Furthermore, within the two foot sand layer above the geonet, the bottom 18" have been reserved as an additional media through which liquid could be conveyed.

To control fines movement into the 18" of sand in the collection system, a geotextile was designed, using the procedure described in Section 3.4.1.2 of this report. A six inch operational sand layer will be placed above the geotextile for protection of its integrity during landfill operations. The geotextile was designed to allow liquids to pass through, while preventing fine particles of sludge from entering into the collection system. The supporting calculations may be found in Appendix E.

3.5 Leachate Generation

This section of the report presents rainfall data, design criteria, a characterization of the leachate generated, and the selected and calculated leachate generation rates for both the operational life and post closure stages of proposed Cell No. 3. These leachate generation rates were used to design the primary drainage layer, leachate detection sumps, leachate pump station, leak detection drainage system, and the landfill cap.

3.5.1 Characterization

In the design of a leachate containment system, a critical analysis is to determine whether the leachate generated is compatible with the various components that compose the liner system. In order to conduct the clay and HDPE liner compatability testing a characterization of the potential leachate was necessary.

The characterization of the leachate involved sampling, and obtaining analytical data from five representative leachate sources, which include; Cell No. 2 leachate, equalization basin filtrate, equalization basin sludge, contaminated groundwater, and effluent limits. The samples taken were analytically tested for the presence of volatile organics, base/neutrals, and

3-29

CIB 013 0402 acidic compounds. See the analytical results Appendix E, Tables E-l, E-2, and E-3, for a complete list of the parameters tested. From the results of the laboratory testing AWARE Inc. derived a recommendation for a synthesized leachate. This leachate would conservatively represent the leachate that would be generated by the percolation of rainwater through the wastewater treatment plant sludge (see Appendix E, Table E-2). For the compatability testing a factor of safety was built into the leachate characterized by Appendix E, Table E-2, whereby the various volatile organic, base/neutral, and acid concentrations were elevated to levels shown in Table E-3 of Appendix E. It was agreed upon by NJDEP that the concentrations in this proposed synthetic leachate would be adequate for determining the compatibility of the clay and HDPE liners. The best characterization of the actual leachate to be generated from the proposed Cell No. 3 is that which was sampled from existing Cell No. 2, since the method of generation and the fill type (WTPS waste) are very similar to the conditions anticipated for Cell No. 3.

3.5.2 Generation Rates

In developing leachate generation rates for the design of the various components of the leachate collection system AWARE has reviewed daily rainfall data from Toms River, NJ, Station #28816. The data was obtained from the National Oceanic and Atmospheric Administration (NOAA). These data spanned approximately 38 years, between November 1948 and September 1986. In addition, Technical Paper #49 entitled 'Two- to Ten-Day Precipitation for Return Periods of 2 to 100 Years in the Contiguous United States", and Technical Paper #40 entitled "Rainfall Frequency Atlas of the United States", were also obtained from NOAA. These publications were developed by the Weather Bureau in 1964 from 94 rainfall stations across the United States and provided generalized estimates- of rainfall frequency data. While this information was not specific for the Toms River vicinity, rainfall-frequency data were interpolated from these graphs.

3-30 Using the rainfall data, a water balance was calculated for both operational and post-closure stages of Cell No. 3. From the operational stage water balance, a value of 31.18 inches/year of leachate will be generated from an annual precipation rate of 47.31 inches/year. The difference between the two rates is the amount lost to evaporation. If it is assumed that by immediate collection and removal of the generated leachate, the leachate generation rate will approach the precipation rate, a worst case analysis can be conducted. Using 48 inches/year and the landfill area of 140,000 square feet, a worst case leachate volume (excludes evaporation losses) of 4.2 x 106 gallons per year could be expected based on the water balance calculation. See Tables 3-3 and 3-4, and Appendix E, Tables E-4 and E-5 and support calculations. In order to properly design a leachate collection system for peak flow rates, a selection from Technical Papers #40 and #49 of probable worse case storms was made to calculate design flows which represent potential severe storm

3-31 TABLE 3-3 CIBA-GEIGY CELL 3 DESIGN OPERATIONAL STAGE LEACHATE GENERATION RATES

! MONTH PRECIPITATION AREA VOLUME QUANTITY QUANTITY ! 1 1 IN/MONTH FT/MONTH FT--2 FT---3 MG/MONTH GPD !

! JAN 3. 40 0. 283 140000 39667 0. 297 9572 ! ! FEB 3.46 0. 288 140000 40367 0. 302 10785 ! MAR 0.327 140000 45733 0. 342 11036 : i APR 4. 10 0.342 140000 47833 0. 358 11928 ! MAY •j> * tf>3 0. 304 140000 42583 0. 319 10276 ! ! JUN 3. 79 0.316 140000 44217 0. 331 11026 ! JUL 4.40 0. 367 140000 51333 0.384 12388 ! ! AUG 4.60 0. 383 140000 53667 0. 401 12951 ! ! SEP 3.98 . >..••_> A. 140000 46433 0.347 11579 : i OCT 3.69 0. 308 140000 43050 0. 322 10389 ! ! NOV 4 . 09 0.341 140000 47717 0. 357 11899 : ! DEC 4.23 0. 353 140000 49350 0. 369 11909 i

HIGH DAILY QUANTITY = 12951 GPD LOW DAILY QUANTITY = 9572 GPD YEARLY DAILY AVERAGE QUANTITY = 11312 GPD YEARLY LEACHATE GENERATION RATE = 4129138 6PY

TABLE 3-4

CIBA-GEIGY CELL 3 DESIGN POST CLOSURE STAGE LEACHATE GENERATION RATES

! MONTH PERCOLATION AREA VOLUME QUANTITY QUANTITY i 1 1 IN/MONTH FT/MONTH FT---2 FT'\3 MG/MONTH GPD !

! JAN 2.04 0. 170 140000 23800 0. 178 5743 ! ! FEB 2.77 0. 231 140000 32293 0. 242 8628 ! I MAR 2.84 0. 236 140000 33087 0.248 7985 ! i APR 1. 62 0. 135 140000 18900 0. 141 4713 ! ! MAY 0. 00 0. 000 140000 0 0. 000 0 ! ! JUN 0. 00 0. 000 140000 0 0. 000 0 ! ! JUL 0. 00 0. 000 140000 0 0.000 0 1 ! AUG 0.00 0. 000 140000 0 0. 000 0 ! SEP 0. 00 0. 000 140000 0 0. 000 0 ! ! OCT 0.00 0.000 140000 0 0. 000 0 i ! NOV 1.32 0. 110 140000 15423 0. 115 3846 ! ! DEC 3 • 38 0.282 140000 39480 0. 295 9527 !

! HIGH DAILY QUANTITY = 9527 GPD { ! LOW DAILY QUANTITY = 0 GPD ! ! YEARLY DAILY AVERAGE QUANTITY = 3370 GPD I ! YEARLY LEACHATE GENERATION RATE = 1219278 6PY 1

3-32 CIB 013 0405 conditions. The technical papers present us with the means of determining a conservative but realistic storm that will generate a significant portion of the annual precipitation over a short period of time. By designing a leachate collection system based on severe storm conditions we can reduce the duration and magnitude of the hydraulic gradient across the primary liner system. The stormwater flows derived from a 10 year/7 day precipitation event will be attenuated by the 2 foot thick operational sand layer (worst case) or any landfilled Wastewater Treatment Plant sludge. The storage and permeabilities of the operational layer will cause a delay and a reduction in the flow rate entering the sumps. Although leachate flow rates generated by a 10 year/7day storm are reduced after flowing through a porous media, the primary collection pumps have been designed as if the leachate flows to the sumps were runoff. This provides the primary leachate collection system design with an additional factor of safety.

Table 3-5 is a summary of interpolations performed on Figures Nos 12 through 35 contained in NOAA's Technical Paper #49. This table presents in tabular form duration and return period value of rainfall for durations of 2, 4, 7, and 10 days and return periods of 2, 5, 10, 25, 50, and 100 years. Figure 3-2 is a graph of the data presented in Table 3-5. This graph was constructed to minimize inconsistencies in data interpolation between different isopluvial maps, as recommended in Technical Paper #49.

3-33 TABLE 3-5 Rainfall Summary Table Toms River, New Jersey Vicinity

Return Period Duration 2 yr. 5 yr 10 yr 25 yr 50 yr 100 yr 2 day 4.1" 5.3" 6.2" 7.3 8.2 9.3"* (in/day) (2.05) (2.65) (3.1)' (3.65) (4.1) (4.65) 4 day 4.8" 6.2" 7.5" 8.8" 9.7" 10.9" (in/day) (1.2) (1.55) (1.87) (2.2) (2.4) (2.7) 7 day 5.7" 7.5" 9.0" 10.3" 11.5" 12.0" (in/day) (0.81) (1.0) (1.-28) (1.47) (1.64) (1.71) 10 day 6.3"** 8.2" 9.7" 11.0" 13.0" 13.8" (in/day) (0.63) (0.82) (0.97) (1.1) (1.3) (i:38)

Note: * Heaviest rainfall rate ** Lightest rainfall rate FIGURE 3-2

PRIMARY COLLECTION LAYER THICKNESS GRAPH

E = i.28Vdas - K r .81 cn/s SB, i i £ lfij i t : IV.

L(FT.) MfilKflCE PMH

3-35 0408 In order to obtain a clearer sense of an order of magnitude for these values, conversions were applied to present the data in units, of inches/day, in addition to the conventional units of inches. As expected, the 100 year/ two day storm yielded the heaviest rainfall rate and total average daily rainfall quantity, while the 2 yr/10 day storm yielded the lightest rainfall daily rate for the Toms River vicinity. Since the proposed landfill cell currently has a design life of 5 years, a return period of 10 yrs was selected to provide an adequate factor of safety for design. The 7 day duration was recommended to AWARE by an EPA subcontractor (Geoservices), who is currently writing the EPA Guideline Document on RCRA Liner Systems. The selected design rainfall depth for the 10 yr/7 day event was 9.0 inches or 1.28 inches/day (.24 x 10"6 ft/sec). The 10 yr/1. hr peak rainfall depth of 2.2 inches was used to determine quantity of the peak leachate generated in one hour.

The 10 year average weekly leachate flow rates and the 10 year peak hourly leachate flow rates were calculated, based on the corresponding rainfall depth and surface area of the landfill (140,000 ft2). The calculated flow rate for the 10 yr/7 day rainfall would be 78 gpm, while the total quantity generated from the peak 10 yr/1 hr rainfall would be 192,000 gallons. The calculated flow rate and quantity were utilized to design the primary and leak detection layers, leachate and leak detection sumps, the leachate pump station and to lay out the Operational Plan.

Upon closure of the cell the theoretical leachate generation rate will be approximately 50 gallons per year. This generation rate is based on the calculated flow through the geocomposite cap during months with a potential of creating a hydraulic gradient across the PVC and clay cap liners. The months for which leachate generation is possible were determined by the results of the post-closure stage water balance. The months with a positive I-PET value were summed to equal the fraction of the year (7/12 yr) during which a potential and variable head above the cap may exist. In calculating the flow through the geocomposite cap, it was assumed that a constant head above the cap liners of .5 feet existed during the months with positive I-PET values. This is a conservative assumption, and represents a head generated by a post closure perculation rate of 7,300 gal/day (see Appendix E for support calculation). The average post closure percolation rate, calculated using a water balance (Table 3-4), is 6,750 gal/day.

3-36 Due to the impervious nature of the geosynthetic (PVC) membrane a specialized calculation was conducted that determines the flow (Q) through the geocomposite cap by evaluating leakage through a , hole in the geomembrane (Faure, Y. International Conference of Geomembranes). See Appendix E for a model and calculation of the flow through the geocomposite cap. The calculation in Appendix E was simplified by eliminating the primary geomembrane and a geonet which overlay the secondary geomembrane and clay liner of the cap. The primary geomembrane and the geonet will provide an additional factor of safety against leachate generation through the geocomposite cap. Further reduction in the theoretically negligible flow rate can be assumed, but the intended benefit of the dual geomembrane system is to provide a backup in the event of a massive seam failure in one of the geomembranes, there will not be a corresponding significant increase in the leachate generation rate.

It can be concluded from our analysis that virtually all the percolation (13.97 inches or 1.2 x 10^ gallons per year) during the post-closure stage of Cell No. 3 will, upon reaching the geomembrane, run off the geocomposite cap, and into the perimeter landfill drainage collection system. The leachate generation rates will be sharply reduced upon closure and should continue to decline to easily manageable levels provided the structural integrity of the geocomposite cap is maintained.

3.6 Leachate Disposal

The leachate removal system is designed to remove leachate from the primary leachate collection system and the secondary leak detection system (as required). These systems are designed to provide for removal of leachate within the drainage system to a central collection point for treatment and disposal in accordance with 7:26-2A.7 (d) 3i. The leachate collection system consists of laterals installed within the stone drainage envelope, each tied into collection pipes or collectors. The piping system is designed to convey leachate to a stone drainage layer surrounding two wetwells located at low points situated at diagonally opposite sides of the cell as shown in Drawing

3-37 No. 6505-125P. The wetwell contains a leachate pumping station connected to flexible hose discharge piping leading to a forcemain system equipped with leak detection piping. The forcemain system conveys leachate 3,730 feet to the 7.5 MGD capacity (4.0 MGD current flow rate) Ciba-Geigy wastewater treatment plant. This plant has a NPDES regulated ocean outfall discharge. A discussion of how this system complies with the design standards and construction requirements for leachate collection system (7:26-2A.7 (d)), is described in the following sections.

3.6.1 Leachate Collection Piping

The leachate collection piping system consists of an interior grid herring bone pattern, as indicated on Drawing No. 6905-125P. It was designed as a redundant system to the primary geocomposite liner system as discussed in Section 3.4.4, the geonet in the primary leachate collection layer, was designed to convey maximum anticipated flows. The leachate collection piping was designed in accordance with 7:26-2A.7 (d) 3viii (2), "to ensure that the maximum anticipated leachate head generated within the landfill during the operational life of the landfill does not exceed the design head" (1 foot), and to serve as a backup to the geonet system.

The leachate collection piping system consists of 4 inch diameter slotted flexible high density polyethyle (HDPE) pipe. The HDPE piping material used in the leachate collection system has an adequate structural strength to handle anticipated static and dynamic loads and stresses that will be imposed on the pipe by the drainage layer, stone envelope, overlying wastes. Calculations provided in Appendix E summarize the structural analysis of the collection piping for wall crushing, buckling and ring deflection design data. This analysis indicates that the supporting strength (or wall crushing strength) of the pipe is greater than the loads and stresses imposed on the pipe by safety factor of 5.7, which exceeds the 1.5 safety factor requirements of NJAC 7:26 7A.7 (d) 3i. This analysis also indicates a wall buckling safety factor of 3.3, which exceeds the generally accepted recommended 2.0 safety factor. Ring deflection is conservatively no more than the vertical compression of the soil envelope around the pipe. The soil strain around the pipe is 1.7 percent, and the allowable ring deflection for 4 inch SDR 21 pipe is 5.0 percent per NJAC 7:26-7A (d) 3i. Hence, the factor of safety for allowable ring deflection is greater than 3- In addition, the wall thickness of SDR 21 HDPE pipe coupled with 20 inches of sand (operational layer) covered with a geotextile 6 inches below grade developed to distribute loads, possesses the structural strength to support anticipated earth handling equipment (D-6 dozer loads) shortly after the cell becomes operational.

The material used for the collection piping, high density polyethylene (HDPE), is one of the most chemically resistant materials commercially available. Ciba-Geigy has tested 80 mil HDPE liner materials with leachate and the compatitility results are reported in Appendix H, and discussed in Section 3.4.1.2. The SDR 21 HDPE pipe has a wall thickness of (.19 inches) which is 2.3 times the thickness of the membrane tested.

The leachate collector slopes range from 2.2 to 3% as noted in the profiles shown on Drawing No. 6505-125P. The leachate collectors are designed to carry the maximum design flow (158,400 gallons per day per cell [110 gallons per minute]), and 55 gpm per sump.

3-39 Table 3-6 summarizes the hydraulic analysis of selected collector pipe segments. This analysis indicates the following:.

° the collectors have slopes providing self cleaning velocities within the pipe, based on actual maximum flows from the area of drainage as required by 7-.26-2A.7 (d) 3iv. ° the minimum flow velocity exceeds the 2 foot per second requirement based on full flow velocity as also required by 7:26-2A.7 (d) 3iv. ° these collector pipes are capable of handling peak flow rates and required hydraulic design parameters, as indicated in Table 3.6.1

In addition to meeting hydraulic requirements, the system shall be installed true to line and the departure from grade shall not result in excess ponding on the liner. Excess ponding will be alleviated by the geonet system described in Section 3.4.

The piping shall be installed within a washed coarse stone envelope with the envelope wrapped in a geotextile having an equivalent #20 sieve opening. The geotextile shown on the collection pipe detail (see Drawing No. 6505-126P), has been designed to prevent piping of sand fines into the gravel envelope and fulfills the regulatory requirements for keeping collector pipes operational throughout the life of the cell. The collectors contain three slots (.1" x 3"). The gravel envelope material has been sized such that 85% of the material is greater than 2.0 times the slot width of the pipe.

The collector and lateral pipes are installed directly on the geotextile/geonet system as shown in the collector pipe detail. While regulatory provisions require installation of the collectors in a depression constructed within the liner or subgrade, this design feature was not incorporated because the design, as indicated enhances the performance of the geonet system which serves as the primary leachate collection system. Cleanout risers have been provided for the lateral pipelines. These consist

3-40 TABV3-6 HYDRAULIC ANALYSIS OF COLLECTOR PIPES (Selected Segments)

Maximum Flows Maximum Upstream Downstream from Area of Capacity of Upstream Downstream Invert Invert Drainage Pipe Distance Slope Q Actual V Actual Q Full V Full Collector Station Station Elevation Elevation gpm(cfs) fps + Ft. Ft. Ft. % gpm(cfs) fps No. Segment

48.0 68 3 12.5(.056) 3.2 175(.39) 5.5 1 Upstream 0 + 68 50.0 max slope 44.0 77.5 2.6 55U25) 4.6 155(.35) 5 1 Downstream 153 230.5 46.0 45.0 180 2.8 37(.167) 4.3 165137) 5.2 2 Upstream 0 180 50.0 43.46 70 2.2 55U25) 4.6 150(.33) 4.7 2 Downstream 180 250 45.0 min slope

NOTES: ; Reference: Contract Drawing No. 6505-125P SDR 21 pipewall thickness .19", Dia = 4" - .19-.19 = 3.62" = 0.301 2 n Effective Area + .30 /4 = 0.07SF of solid HDPE pipe "risers" extended to the operating level of the cell berm. Each riser will be provided with a removable cap. The collectors can be serviced by perforated 4 inch pipes which are extended from the termination point of the collectors through the stone layer and inside the wetwells (see Section 3.6.2).

The leak detection system relies on a geonet drainage system.

Any leachate transmitted by the secondary geonet will ultimately collect in either of two leak detection sumps underlying and paired with each of the primary collection sumps, (see Appendix A, Drawing 6505-132P). The design flow of leachate into the leak detection sumps is 70 gal/month. The total capacity of the leak detection sumps is 80 gallons, therefore it is anticipated that the sumps will have to be evacuated monthly. In an effort to varify the assumed flow rate and subsequent volume of leachate collected in the sumps, a pressure transducer will be installed to monitor the depth of leachate within the sumps.

he pressure transducer will be lowered down into the leak detection sump, ithin a flush joint 1 inch diameter PVC pipe with a slotted or perforated d, via an existing HDPE 6 inch diameter access pipe. Upon proper Jtallation of the transducer, an operator will connect the transducer cable to a portable insitu dusiter Hermit Data Logger which will give an immediate leachate level reading if leachate is present in the sump. Upon detecting a leachate level that represents approximately the full capacity of the sump, an evacuation procedure is to be initiated.

The evacuation of the leak detection sumps must be conducted through the 6 inch diameter HDPE access pipe. Although the method used to remove the leachate is not critical to any design aspects of Cell No. 3, it is recommended that the evacuation procedure chosen insure that .the 6 inch HDPE access pipe not become blocked off by lowering and subsequent snaring of a pump or suction hose. Unforeseen irregularities that may develop in the access pipe have the potential to snare or wedge a pump with a support cable, discharge hose, and electrical wiring. In an effort to eliminate any blockage of the access pipe, AWARE recommends that the following procedure be utilized.

3-42 To evacuate the leak detection sumps it is recommended that a four inch submersible pump, capable of pumping not less than 20 gpm against 100 feet of head be utilized. The lowering of the pump down into the sump will require the assembly of an insertion sleeve which will be made up of 4 inch diameter threaded flush-joint PVC piping, and a 4 inch PVC slotted well screen. Upon each evacuation of a leak detection sump, the length of threaded flush joint PVC pipe and a 3 foot PVC slotted well screen will be assembled, and slowly lowered down the 6 inch HDPE access pipe to the leak detection sump. After successfully installing the • PVC sleeve, the submersible pump may be lowered through the insertion sleeve, into the leak detection sump. With the pump properly installed, the leachate cap be quickly pumped (recording the volume), into the leachate forcemain for disposal. Upon successfully evacuating the sump, the submersible pump and insertion sleeve can be withdrawn and disassembled. The pressure transducer can then be reinstalled to monitor the level of leachate. With the appropriate type of data logger connected to the transducer the landfill operator can program the data logger to record leachate levels at any prescribed time interval. This data could enable the landfill personnel to determine the rate of leakage into the leak detection sump, therefore, the frequency for which the sump would need to be evacuated......

3-43 3.6.2 Leachate Pump Station

The leachate collection systems are designed to flow by gravity to two sumps, Sump A and Sump B, (Appendix A, Drawing No. 6505-124P), located diagonally opposite corners of the cell. Each sump contains a wetwell, Wet well A and Wetwell B respectively. Leachate enters that sump through a stone layer surrounding the wetwell and enters through an eight inch diameter HDPE pipe stub located at 90° orientations around the wetwell. The wetwell floor is 1 1/2 inch thick HDPE welded to the bottom of the vessel and is 12 inches below the invert of the 8 inch stub, providing for a free flowing head across the liner per 7:26 7A.7 (d) 3viii(2).

The wetwell shall be a six foot diameter prefabricated high density polyethelyne vessel, as shown on Drawing No. 6505-153P. Wetwell heights vary, from 35'-6" to 36'-6", and were designed (see Note 1) on the basis of the vessel extending 2'-0" above the landfill at closure, and the bottom of the wetwell located in the primary clay layer of Sumps A and B respectively, as indicated below:

Wetwell A & B 74.0 ft + 2.0 ft = 76.0 ft. Top El

Wetwell A 76.0 ft -[39.5 Bottom El. + 1.0 Concrete Foundation] Height = 35.5 ft.

Wetwell B 76.0 ft -[38.5 Bottom El. + 1.0 Concrete Foundation] Height = 36.5 ft.

NOTE: 1. (see Appendix A, Drawing No. 6505-150P for wetwell details, and Final Contours on Drawing No. 6505-104P of Closure Plan Appendix C)

3-44 Wetwell side walls shall have a minimum effective thickness to resist the following imposed loading conditions:

o dead load of structure o 1,000 lb equipment load o 100 mph wind load o 120#/cu ft earth load o 80#/cu ft sludge load o 70#/cu ft liquid live load with loads used in the following combinations:

° erection - dead load of structure - one-half wind load ° operation - dead load of structure - dead load of equipment - full wind load - earth load - liquid live load ° final closure - dead load of structure - dead load of equipment - earth load - sludge load - liquid live load

The material of construction of wetwells is high density polyethylene, and as such, is compatible with leachate as demonstrated by compatibility testing provided in Appendix H. Non-HDPE accessories used in the vessels are steel angles and channels (which will be coated with a bitumastic coating), a glass/steel ladder and open mesh cover.

3-45 The 12 inch vertical drop below the stub invert has a capacity of 211 gallons providing a 3.8 minute holding capacity at design flow (55 gpm).

Wetwell working volume 28.26 ft2 x 1.0 ft x 7.48 gal/ft3 = 211

Storage time - 211 gals/55 gpm = 3.8 min.

The wetwell shall be tested for watertightness per requirements set forth in 7:26 2A.7 (d) xii (1) and (3) per QA/QC procedures described in Appendix F.

Each cell contains two (2) pumping stations, Pumping Station A and Pumping Station B. The pumping station consists of a wetwell, pumps, motors, flexible hosing, valves, gauges, level regulators, pipe supports, collection header, and electrical controls, as shown on Drawing No. 6505-150P. Each pumping station contains two (2) submersible dewatering type pumps, per the requirements of 7:26 2A.7 (d) vi which requires two (1 operating, 1 standby) for anticipated design flow rates. Each pump has a capacity to pump 55 gallons per minute at a 72 foot total discharge head. A calculation brief for the pumping station and forcemain design is provided in Appendix E.

Pumps will be UL Approved, as explosion proof, and they will conform to the 1981 National Electric Code, Articles 500, 501 and 502 requirements as suitable for use in Class 1, Division 1, Groups C & D and; Class II, Division 1, Groups E, F & G hazardous locations. Class 1, Division 1 location is one in which ignitable concentrations of flammable gases or vapors exist under normal operating conditions.

Pump operation and controls have been designed to comply with 7:26 2A.7 (d) 3xii (4) which require automatic sound alarms giving warning of high water and pump failure incidents. Should leachate levels reach "high water alarm" float switch levels (elevations 3 feet above the wetwell bottom liner), a control panel mounted alarm light and alarm horn will be energized. A failure will be indicated by a float-switch provided on the discharge piping, which is activated by flow and automatically stops the pump which fails to activate after a preset time period, and sounds alarm at the main building, where someone is on duty 24 hours per day. In addition, an outdoor strobe light is mounted on the emergency generator station.

3-46 CIB 013 0419 The wetwell can be accessed by a staircase and walkway leading to the top of the wetwell. Pumps are equipped with lifting cables and can be removed by steel winches located on the top of the staircase. The wetwell can be accessed on an annual basis, per the regulatory requirements, by the ladder attached to the wetwell wall.

The pump station wetwell structure will be capable of protecting pumps and electrical equipment in accordance with applicable provisions of 7:26 2A.7 (d) 3xiii, specifically items (1), (2), (3), & (4) of the provisions, which require, respectively:

item (1), explosion proof equipment for pumps, motors and electrical controls item (2), adequate lighting item (3), separate and independent sources of electrical power item (4), automatic sound alarms

Regarding item (1) above, the pump station wetwell structure will be capable of protecting pumps, motors, and/or electrical equipment in accordance with 7:26 2A.7 (d) 3xxiii (3), which requires the facility to be constructed in accordance with the National Electric Code, "Special Occupancy Hazardous Location", Volume 6 of the National Fire Code, "Explosion Venting", Volume 14 by the NFPA. Steps taken to provide for compliance include provisions for explosion proof pumps tested and approved by both Factory Mutual & Underwriters Laboratories, and certifications that the pumps conform to the National Electric Code for use in Class I, Division 1, Groups C & D. Class I, Division 1, is a location in which ignitable concentrations of flammable gases or vapors exist under normal operating conditions, a condition not anticipated

3-47 but designed for. In order to allow a Class I, Division 1 designation for the wetwells, the flexible cord shall be of the type approved for extra-hard usage and be provided with suitable seals (approved sealing fittings/conduit) where the flexible cord enters the explosion proof motor casing. Normally, flexible hosing is only permitted for connections between portable lighting and utilization equipment and the fixed portion of its supply circuit. The leachate pumping station is considered "portable utilization equipment", since it fits the definition of Article 501-11 which states that these units are "electric submersible pumps with means for removal without entering wet-pit" (wetwell). Pumps and appurtenances can be removed by chain attached to winches located on the wetwell stairway platform. An additional safety feature designed into the pumping system is thermal overload protection (thermocouple) in the unit provided. Level switches and flow switches will be explosion proof. All piping insulation and accessories (insulation, jacket, facing adhesive, cement, tape and cloth), will have a composite fire and smoke hazard rating per ASTM E-84M, NFPA 255 or UL 273.

The wetwell is explosion proof and is designed for use as a Class I, Division 1, Group C & D facility. Steps taken to provide for compliance include provisions for remote location of electric panels, and equiping local control stations with explosion proof protection. The control panels for wetwell A and B are approximately 200 and 700 feet away from the respective units and housed in the auxiliary pump station structure, which also houses the 100 kw emergency generator.

Regarding Item (2), the wetwell will be provided with UL Approved, explosion proof lights affixed to the stairway on the wetwell platform and on the inside sidewalls of the structure.

Regarding Item (3), two separate and independent sources of electric power shall be provided. The normal feed source originates from Building 741 and is primarily in underground conduits. It is also furnished aboveground in a cable tray system and in rigid conduits along the wetwell structure. It is supplied by explosion proof 2 x 3 foot electric conduit tray into the wetwell. The alternate source is 100 kw oil driven unit housed in emergency generator stations located near the landfill.

3-48 Regarding Item (4), automatic-sound alarms operating independently of the pump station power will be installed to give warning of high water, power failure or breakdown. If the pump, for any reason fails to operate, an alarm and warning light is activated in the Building 743 computer control room, where someone is on duty 24 hours per day. In addition, a strobe light on the outside wall, facing east, of the emergency generator building is activated. Each pump has indicator lights on the control panels and Building 743, which indicate whether or not the pump is operational.

Additional descriptions and details of the wetwells of leachate pumping stations are provided on Drawing No. 6505-150P, Appendix A.

3.6.3 Leachate Forcemain

The forcemain for Cell No. 3 is described on HR Drawings E 43533 through E 43837 provided in Appendix I of this submission. The forcemain consists of an approximate length of 3,730 feet of high density polyethelyne (HDPE) pipe. The forcemain is designed to convey leachate and leachate contaminated stormwater to the Ciba-Geigy Treatment Plant (WWTP).

Leachate is pumped through the 3 inch lightweight, woven polyester-reinforced, polyurethane hosing, with PVC/nitril rubber cover from the pump outlet. After discharge, it flows into a 4 inch manifold supported from the grating of the wetwell. From the manifold it flows through insulated/heat-traced 4 inch HDPE piping suspended from the staircase and walkway. The forcemain enters two precast concrete manholes, where pipe sizes increase from 4 inches to 6 inches, and the piping is provided with a PVC leak detection piping system varing in size from 6 to 8 inches. Piping in the treatment plant area is above ground carbon steel pipe.

The leak detection piping flows by gravity to one of 16 manholes on the forcemain, routed to the WWTP. The HDPE piping has been designed to resist lateral thermal expansion by anchor blocks secured to precast manholes by rebar.

3-49 This design was based on the four conditions indicated below:

Condition 1 Dry weather flows from Cells 3 and 4 Q total = 220 gpm

Condition 2 Stormwater contaminated leachate flows from one cell Q total = 250 gpm

Condition 3 Stormwater contaminated leachate flows from one cell Q = 250 gpm + Dry weather flows from Cells 3 and 4 Q = 220 gpm

Q total = 470 gpm

3-50 Condition 4 Stormwater contaminated leachate flows from one cell Q ='250 gpm + Two pumps operating in each sump Q = 440 gpm

Q total = 690 gpm

While Condition 4 flowrates exceed maximum anticipated design flowrates (1 pump, 55 gpm per sump), (2 sumps per cell x 2 cells + 220 gpm), the pumps and forcemain system have the capacity to handle two pumps operating per sump. The controls were designed to activate the standby sump pump in a "cascade" mode, in case the initial pump could not handle flows. This condition represents a maximum flowrate of 690 gallons per minute.

The Appendix E flowrate and headloss analyses indicates that wetwells A & B in both Cells 3 and 4 could continue to operate while a separate stormwater pump or mud hog is surcharging the system to remove stormwater per procedures outlined in Section 4.0. A total system discharge head of approximately 68 feet existing in the pipeline system during maximum flowrate conditions (Condition 4), indicates that the dewatering pumps in Cell 3 and 4 would be capable of pumping at or close to their maximum rated flowrate capacity (pumps designed to deliver 55 gallons per minute at a 72 foot total discharge head). System velocities under maximum flowrate conditions would range from slightly less than 2 to 5 feet per second. Under normal dry weather flow conditions (Condition 1), system TDH would be less and pipeline velocities would drop below 2.0 feet per second.

3-51 3.6.4 Leachate Treatment

Leachate discharged through the forcemain system enters the primary neutralization tank at the Ciba-Geigy wastewater treatment plant. Leachate flows under maximum anticipated flow rate conditions represent less than ten percent of WWTP flows. However, under dry weather normal operating conditions, after the landfill is covered with sludge, daily operating flows are anticipated to be far less (3 to 5 gallons per minute) which is less than .1 percent of WWTP flows. Leachate receives biological treatment and polishing with granular activated carbon. Polished wastewater is sent for discharge into a NPDES permitted ocean outfall, and is in compliance with NJAC 7:14A. Leachate and leachate contaminated stormwater from Cells 1 and 2 have been treated at the WWTP in much larger quantities at this facility since 1981.

3.7 Gas Generation and Control

The gas generation rates expected from this landfill may not be compared to those gas generation rates typically found in most municipal landfills. Landfill gases (largely methane and carbon dioxide) are formed as a result of the last stage of biological decomposition, that stage being methanozenic decomposition. This stage begins upon depletion of oxygen within the landfill, and is characterized by formation of carbon dioxide, water, and methane.

In order for this stage to proceed, organic matter within the waste must be present for decomposition to occur. Since organic waste is absent at this site, it may be concluded that almost no methane gas will be produced. This theory was experimentally tested in a 15 month study completed in 1978, for an environmental impact statement prepared for landfill Cells 1 and 2. This study concluded that the sludge to be landfilled in Cells 1 through 7 would produce no methane. (Ref. Environmental Assessment Council, Inc. Toms River Chemical, Environmental Impact Statement for the proposed lined landfill, Appendix N, Determination of Gas Generation Potential of Sludge to be Landfilled at Toms River Chemical, 5/24/78).

3-52 Even though methane gas generation is not anticipated, a passive gas venting system has been conceptually designed for Cell No. 3, the details of which are provided in Appendix C, Landfill Closure and Post Closure Plan, Section 4.5.

This venting system is primarily composed of two components. The first component is a gravel-filled trench, wrapped with a geotextile. The trench will be located along the centerline of the landfill cell as shown in Appendix C, Drawing No. 6505-062. The second component is passive point gas vents spaced every 50 feet within the cap. Methane gas monitoring will be performed during and after closure of the cell. The point gas vents will be monitored quarterly for evidence of methane production within the landfill.

3.8 Groundwater Monitoring Program

The existing monitoring system at Cells 1 and 2 of the landfill facility consists of nine wells. Five of these wells are currently being used to monitor the ground water. These wells are located in Appendix B, Drawing No. 6505-016P and are identified along with benchmark monuments in both local and New Jersey Geodetic Survey grid systems. Two of these five wells (0102 and 0122) are located hydraulically upgradient of the facility and three wells (0107, 0105, and 0123) are located hydraulically downgradient.

Recent hydrogeological studies of the landfill area have confirmed the existence of a shallow, unconfined water-bearing zone which has been termed "the Upper Cohansey Water-Bearing Zone". During the course of the recent investigation, monitoring wells and piezometers were installed in this zone to determine hydraulic gradients and existing water quality. Data from these wells indicate minor degradation of water quality in this zone due to an upgradient waste disposal area.

In order to ensure effective monitoring of the potential impact from the new landfill cell, the designated monitoring system for Cell 3 will include five of the recently installed, shallow monitoring wells, as well as one existing monitoring well. Three of these wells (744-1129, 744-1130, and 744-1133) are representative of "background" water quality, while three wells (744-1131, 744-1132, and existing well 744-0123) are representative of "downgradient" conditions. Locations of these wells are provided on Drawing No. 6505-016.

3-53 CIB 013 0426 All wells used for monitoring of the solid waste landfill are clearly marked and protected from construction and operation traffic by appropriate signs, outercasings, fencing and posts. The landfill manager and construction superintendent are fully aware of all well locations and the importance of ensuring their integrity. It is the responsibility of these individuals to inspect the well locations during landfill operation to verify their operability.

3.8.1 Sampling and Analysis

During landfill operation, all existing and new wells at the facility will be analyzed for the parameters listed in Table 3-7 as specified in N.J.A.C. 7:14-10.12, as modified in items 3 (a), (b), and (c) in the State of New Jersey Department of Environmental Protection permit issued January 19, 1979 under Facility Registration Number 1507D.

Ciba-Geigy will follow the Ground Water, Leachate and Leak Detection Sampling and Analysis Plan included in Table 3-7. The plan, which will be kept at the facility, will include procedures and techniques for:

° Sampling Protocol - including smapling instrumentation and approved methodologies, sampling frequency, sample storage and preservation requirements, and chain-of-custody procedures. ° Analytical Protocol - approved field and laboratory methods, and quality assurance/quality control procedures. 0 Data Management Criteria - including recommended procedures for data storage and retrieval, appropriate statistical analyses, and data reporting.

In order to develop as much data as possible for comparative purposes, monthly monitoring of these wells for the routine parameter list will be conducted during the initial year of monitoring. Monthly analyses will allow

3-54 development of a substantial database for statistical evaluation purposes. Moreover, monthly sampling will enable statistical comparison of a given monitoring well to its own history as well as to the designated background wells.

The statistical test to be employed is the "Cochran's Approximation to the Behrens-Fisher Student's t-Test" using the averaged-replicate method. This method will be applied on a quarterly basis to the monthly data averaged over the quarter. Each monthly value will be the average of the replicate values, thus accounting for analytical and/or instrument variability.

3-55 TABLE 3-7 GROUNDWATER, LEACHATE AND LEAK DETECTION SAMPLING

ANALYTICAL PARAMETERS

Ground Water

Alkalinity Chloride (CI) Hardness (as CaCo3) Iron (dissolved) Phenolic compounds (as phenol)

Sulfate (S04) Total Dissolved Solids (TDS) pH Specific Conductance Lithium (Li) Lead (Pb) Mercury (Hg) Chromium (Cr) Calcium (Ca) Magnesium (Mg) Total Organic Carbon (TOO Toluene Dichlorobenzene Chlorotoluene 1,2,4 Trichlorobenzene

Leachate Collection and Leak Detection Systems

pH Specific Conductance Total Organic Carbon (TOO Phenolic compounds (as phenol) Lead (Pb) Lithium (Li) Chromium (Cr) Mercury (Hg) Toluene Dichlorobenzene Chlorotoluene 1,2,4 Trichlorobenzene For each parameter specified for analysis, the arithmetic mean and variance based on -four replicate measurements on samples obtained monthly will be calculated. These results will be compared with the initial background arithmetic mean using the Student's t-test at the 0.01 significance level to determine statistically significant increases (or pH decreases) over initial background.

If the comparisons for the upgradient wells show a significant increase (or pH decrease), Ciba-Geigy will report this information to the New Jersey Department of Environmental Protection annually for each ground water monitoring well. This report will outline the statistical evaluations performed for the parameters. If the comparisons made for a downgradient well show a significant increase (or pH decrease), Ciba-Geigy will immediately obtain additional ground water samples from those downgradient wells where contamination was discovered, split the samples in two, and obtain analyses of all additional samples to determine if the significant difference was due to laboratory error.

If the additional analyses confirm the significant increase or decrease, Ciba-Geigy will provide, within seven days, written notification to the department that the facility is affecting ground water quality. Within fifteen days following this notification, Ciba-Geigy will develop and submit a plan, certified by a geologist or hydrogeologist, for a ground .water quality assessment. This ground water quality assessment will be capable of determining:

1. Whether contamination has entered the ground water

2. The rate and extent of migration of contaminants in the ground water

3-57 3. The concentrations or values of parameters corresponding to or indicating contamination

4. The number, location, and depth of wells

5. Sampling and analytical methods for the parameters to be determined 6. Evaluation procedures, including any use of previously gathered ground water quality information

7. A schedule of implementation.

After receiving Department approval, Ciba-Geigy will implement the assessment plan. As soon as technically feasible, a determination on whether the facility has impacted ground water will be made. Within fifteen days after this determination is made, Ciba-Geigy will submit to the Department a written report containing an assessment of ground water quality.

If it is determined that the facility has not adversely affected ground water quality, the initial ground water monitoring program will be reinstated. However, if it is concluded that the facility has contaminated the ground water, Ciba-Geigy will continue to make determinations as specified in N.J.A.C. 7:14A-6.10 (c) 2 and 3 on a monthly basis until facility closure or until remedial action has reduced levels of contamination to a level which mitigates the environmental impact. In compliance with the NJDEP regulations, Ciba-Geigy will cease to make these determinations if the ground water quality assessment is implemented during the post-closure care period.

3-58 Unless a ground water quality assessment, as described above, is underway, Ciba-Geigy will at least annually evaluate the data on ground water surface elevations to determine if the number and locations of upgradient wells are adequate. These records on ground water surface elevations will be kept on-site throughout the active life and post-closure care period and the results reported in accordance with N.J.A.C. 7:14 A-6.ll. Ground water surface elevations will be recorded prior to the collection of samples from each well.

If, at any time, the ground water protection standard is exceeded, Ciba-Geigy will institute a compliance monitoring program or a corrective action program identified in N.J.A.C. 7:14 A-6.15.

3.9 Closure

The multi-cell closure plan (Appendix A, Drawing No. 6505-103P) presents the initial and final operational sequences proposed for the industrial waste landfill. In conformance with the continuous landfilling methos, the development of this facility will be phased and integrated so that one section will be in operation while another section is being constructed. Depending on the operational stage, partial closure measures may be required to maintain and protect environmental quality.

Following the construction of future landfill sections, wastes will be placed above the floor of the landfill until disposal activities within these sections reach final elevation shown in the Engineering Plans. During the operation of a landfill Cell No. 3, construction of the subsequent proposed landfill Cell No. 4 should commence. This activity should be completed by the time disposal activities in the operational landfill reaches final elevation. At this point, the final cap will be placed on the operational Cell No. 3 while waste disposal takes place in a subsequent cell.

3-59 Thus the closure at this facility is comprised of the following elements:

1. place an intermediate cover of sand over the waste 2. install those items of the leachate collection system not already constructed (piping, manholes, and gravel) 3. place additional sand in the active cell to bring it up to a closure grade 4. install the landfill gas collection system, a gravel trench 5. expose existing geomembrane in the side berms and adjacent cell's cap 6. install geocomposite capping system, attaching it to the exposed berm and cap geomembrane 7. install soil cover and seed 8. evaluate Post-Closure Cost Estimate and Financial Plan, adjust escrow account as necessary 9. implement Post-Closure Plan.

The geocomposite capping system mentioned (item 6), will be installed as follows (in ascending order, refer to Figure 2):

° filter fabric (to provide separation of waste gas vent layer) ° 12" of sand cover (sand to provide a means of gas venting) ° filter fabric (to provide separation between the clay and sand layer)

3-60 ° 12" of compacted clay (tertiary liner), permeability 10~'cm/sec. 0 30 mil geomembrane (secondary liner system) ° High capacity drainage net (to provide a leak detection system . for the primary liner) ° 30 mil geomembrane (primary liner system) ° 1' of sand cover (to provide drainage for rainfall), permeability greater than 10_3cm/sec ° 18" of soil and 6" of topsoil (to provide vegetative growth, proper run-off condition and protection of primary liner system.

The accompanying Cell No. 3 Permit Plans (Appendix A) illustrate the manner in which the final cover will be graded and keyed into the perimeter embankment berms of the landfill. This installation procedure will provide for encapsulation of the waste in each section.

All surface contours will be graded to a maximum slope of 3% on the top, 4:1 and 3:1 sideslope, and designed to collect run-off and direct it to a perimeter drainage system. The cover material will consist of sand and clay loam capable of supporting a non-food chain vegetation which does not have an extensive tap root system, but which will provide adequate cover to prevent erosion. Preparation procedures for planting will include fertilizer, seed, and mulching. Refer to Appendix C, Soil Erosion and Sediment Control Plan.

3-61 4.0 LANDFILL CONSTRUCTION

4.1 General

The landfill construction plan for the Ciba-Geigy landfill consists of the major components such as drainage control, sediment control, excavation and grading of the landfill base, landfill baseliner, leachate collection system, pump stations and storage facilities, landfill gas control system, final cover and top seeding. Many, aspects of construction will be occuring at any one time.

4.2 Installation Methods and Procedure

The purpose of this section is to provide a description of the installation methods and procedures to be followed in the construction of the facility. Topics discussed in the following section include materials required, equipment utilized and the scheduling of construction events.

4.2.1 Materials

The major materials required to construct the facility are summarized in Table 4-1. Additional Technical details on these materials are provided in Appendix D, Cell No. 3 Construction Specifications (Specifications), and in Appendix G, Cell No. 3 Construction Quality Assurance/Quality Control (QA/QC) Plan.

4.2.2 Equipment

The equipment utilized to install the materials and construct the facility will be the contractors' responsibility. In selecting the equipment, the contractor must insure that the equipment will perform in such a manner as to meet or exceed all the parameters of the construction specifications.

4-1 TABLE 4-1 QELL NO. 3 MATERIALS OF CONSTRUCTION

Material Description Material having permeaiblity of 1 x 10-7 cm/sec, at Clay a compaction of 90 percent of the modified proctor. Medium to coarse sand having a permeability of Sand lxlO-2 cm/sec, with relative density of 94% Dr 86%. Crushed natural washed stone (type GP) graded with Stone a maximum particle size LT 2 inches. Non-woven filter fabric with an E.O.S. of 100+ used to prevent piping of clay subbase into sand and Geotextile (Type 2) clay into the geonet. 80 mil, high density polyethylene material serving as primary and secondary membrane for both Geomembrane geocomposite liner systems. Foamed and extruded polyethylene netting, minimum nominal thickness of 160 mils designed to convery Geonet leachate with a minimum transmissivity of 3.9 x 10"4 m_2/sec.

Geogrid Prestressed polyethylene material with a tensile strenth of 2000 lb./ft. installed over secondary geomembrane composite side slope for stabilization of the slope configuration.

Piping 4 to 6 inch SCH 80 slotted HDPE piping for leachate collection.

Pumps Six (6) explosion proof dewatering type pumps (two [2] shelf spares) capable of delivering 55 gallons per minute at a 72 foot total discharge head.

Geotextile (Type 1) Woven filter fabric used for material separation and roadway stablization having a permittivity of 1.2 x 10"6 sec. and an E.O.S. of 20.

Enkamat Soil erosion matting applied for erosion control. Hydroseeding A pure live seed mixture applied at a rate of 100 lbs./acre contained in hydroseed mixture with amendments, fertilizer, mulch, tacking agents, etc. TABLE 4-1 CELL NO. 3- MATERIALS OF CONSTRUCTION (Continued)

Topsoil Six inches of topsoil to be furnished in areas where hydroseeding is indicated.

Concrete Cast in place reinforced concrete for wetwell foundation.

Staircase & Walkway Two (2) painted structural steel ASTM A36 staircases and walkways fabricated into largest practical units compatible with shipping and erection at site, with grating, floor plates, hand rails, etc.

Wetwell Two (2) prefabricated high density polyethylene wetwells, each six-foot diameter, 35-36 feet high. 4.2.3 Work Sequence

The schedule of construction events are described in Appendix Dr Specification Section 01005, Part 1.04 and incorporated in this document as Table A.

The major construction events are as follows:

4.2.3.1 Site Preparation

Remove all plant life, debris, and asphaltic material and dispose of at a legal disposal facility to be designated by Ciba-Geigy. Site preparation is described in the Appendix D, Specifications Section 02110.

4.2.3.2 Subgrade

Backfill or excavate areas to meet the Engineering Design Drawings. Proof-roll base grades using a sheepsfoot or smooth drum roller. Subgrade is described in the Appendix D, Specifications Section 02232 and in the Appendix G QA/QC Plan.

4.2.3.3 Liner & Drainage Layer

A double composite liner consisting of a primary and secondary leak collection/detection system as well as a primary and secondary geomembrane and clay composite system. The geomembrane will be an 80 mil high density polyethylene (HDPE) that will be field seamed using the extrusion or fusion process (Section 02233). The three-foot clay layer (secondary clay layer) will be placed and spread by dozer and compacted by sheepsfoot roller to a density of 90% modified Proctor to insure a maxium permeability of 1 x 10-7 cm/sec. Prior to compaction, the clay shall be mixed by disc-harrowing to maintain a consistency in the soils placed in six inch lifts. Shelby Tube permeability samples will be taken at a rate of one per 1,000 cubic yards in place as well as density and moisture tests performed at a rate of 1 test per 2,500 ft2 in every 6 inch lift compacted after the second lift (Specifications Section 02231 and QA/QC Plan Section 4.2). The primary clay layer will be backfilled systematically with the first lift being not less than 12 inches, 4-3 placed and spread by a dozer. The top 6 inches of the primary clay layer will be backfilled and compacted using procedures and sampling protocol described for secondary clay layer (Specifications Section 02232 and QA/QC Plan, Section 4.3). The primary leachate collection sand layers will be placed and spread using a dozer with compaction provided around leachate piping and appurtenances as required. The sand will be tested at a rate of one 200 pound sample for every 2,500 in-place cubic yards of material. In addition, density tests will be taken on a 50 foot grid pattern on every 6 inch lift after the second lift of each layer. This layer shall have a minimum permeability of 10_3cm/sec. (Specifications Section 02232 and QA/QC Plan Section 4.4 and 4.5).

4.2.3.4 Collection Pipes

Polyethylene pipe, geonets and the primary sand layer will convey leachate to the leachate pump station. The pipe shall be SDR 21 slotted HDPE pipe and will be welded using the butt fusion method and bedded in the primary leachate collection sand layer (described above, Section 3.4 and QA/QC Plan Section 4.9). Geonets will be installed in the leak detection and leachate collection system (Specification Section 02233, Part 2.03 and QA/QC Plan, Section 4.6).

4.2.3.5 Sumps, Pump Stations (Wetwells) and Pumps

The pump stations/wet wells will be manufactured of HDPE and delivered to the site as prefabricated units. A crane will be required to set the units on the "poured in-place" concrete pads (foundations). Installed in each unit will be two (2) explosion proof, submersible type dewatering pumps as shown in Appendix A, Drawing No. 6505-150P. Pump stations/wet wells are also described in the QA/QC Plan, Section 4.7. In order to access the pump stations/wet wells and pumps, a steel staircase and walkway will be erected. The Foundations will be concrete pads that will be poured in-place. The structure consists of painted ASTM A36 steel ascending from the landfill berms, supported by a latticed steel beam structure set in a reinforced concrete pad on the berm and a steel column " set in a reinforced concrete foundation in the landfill sump area. Bridge accessories include, metal stairs, handrails, platform, grating, floor plates, pipe tube railings and portable winches to. handle equipment. See the Specifications Sections 03001, 05120, 05510, 05521 and 05530; QA/QC Plan Sections 4.11 and 4.12; and Appendix A, Cell No. 3 Permit Drawings Nos. 6505-126P to 6505-150P.

4.2.3.6 Leachate Treatment and Disposal

Permanent pumps (Appendix A, Drawing No. 6505-150P) will be used to remove and discharge leachate to the on-site wastewater treatment facility. The leachate will be pumped via an insulated HDPE Forcemain varying in size from 4 to 8 inches, inserted in PVC leak detection piping sloped by gravity to precast manholes (See Appendix A, Drawing No. 6505-104P, Appendix I and QA/QC Plan Sections 4.9 and 4.10).

4.2.3.7 Gas Ventilation System

The construction of the methane gas ventilation system will consist of the excavation of a trench, backfilled with gravel, and wrapped in a geotextile. SCH 40 PVC pipes, perforated at the bottom, (within the gravel trench) will vent gas to the atmosphere. The methane gas ventilation system is described in Appendix C "Landfill Closure and Post Closure Plan", Section 4.5.

4.2.3.8 Monitoring Wells

The monitoring system consists of six newly installed and/or existing 4 inch diameter stainless steel wells employed to monitor ground water at the site. These wells are located in Appendix B, Drawing No. 6505-102P. A more detailed description of the installation of the landfill monitoring wells and the monitoring plan is described in Appendix B, Attachment B and Appendix C, "Landfill Closure and Post Closure Plan", Appendix B, Section 2.0

4.2.3.9 Caps, Surface Drainage and Erosion Control

The cap will consist of Filter Fabric, 12 inches of sand cover for gas venting, filter fabric, 12 inches of clay compacted to 10"7cm/sec permeability, a 30 mil geomembrane secondary liner, a high capacity drainage 4-5 net, a 30 mil PVC liner, 1 foot of sand cover for drainage of rainfall and 24 inches of cover material. Top sand drainage layers will have a permeability of greater than or equal to 10_3cm/sec. Sand and clay materials will be installed in six inch lifts and the cover material will contain a minimum of six inches of topsoil to provide for vegetative growth.

Surface drainage and soil erosion controls consist of drainage ditches and retention basins designed on the basis of the 24 hour, 50 year storm, with all discharges to existing drainage paths designed to discharge stormwater at rates less than two feet per second. Rip-rap was provided for inlets to drainage basins and applied to drainage swales where velocities exceeded 3.5 feet per second. Rip-rap will be installed in three layers, each layer equivalent to 3 times the D50 thickness. Erosion control mats will be applied to all ditches installed in fill and all disturbed areas (basins, drainage swales, pipe outlets, etc) will be stabilized with seeding. Any areas disturbed for more than 30 days will be temporarily seeded.

Additional technical information pertaining to the installation of the landfill final cover (CAP), surface drainage and erosion control are described the "Landfill Closure and Post Closure Plan" under Appendix C.

4.3 Construction Contingency Plan

The Purpose of this section is to provide a description of the Construction Contingency Plan (CCP) to be used for the construction of Cell No. 3. The following sections will describe the procedures to be followed when deficiencies in material or workmanship are encountered during construction per the requirements set forth in NJAC 7:26-2A.5. The CCP will also describe the methods to be utilized to correct those deficiencies encountered during the construction of Cell No. 3. Topics discussed in the following sections include defective materials, inspection failures and severe weather conditions. It should be noted however, that this document should be used in conjunction with the QA/QC Plan and Technical Specifications.

4.3.1 Defective Materials

Table 4-1 represents the major groups of materials to be used during the construction of Cell No. 3. 4-6 CIB 013 0441 The specific materials to be used may be found within the contents of the Specifications and the QA/QC Plan. This section will address the procedures for dealing with materials which are either non-conformant to Specifications, or damaged while in storage or during placement.

4.3.2 Earthen Materials

Earthen materials for this project will consist of sand, stone and clay materials. In all cases these materials will be visually inspected for changes in color, texture and foreign matter. In place materials will be tested by one or more of the following methods:

a) Particle Size

b) Moisture Content

c) Nuclear Density

d) Hydraulic Conductivity

The QA/QC testing program to be implemented for inspection of earthen materials is given in greater detail in the QA/QC Plan Sections 4.1 through 4.5. In all cases, material found to be in non-compliance with Specifications 02231 and 02232 will be removed, replaced and retested in accordance with the QA/QC Plan. Materials found to be defective prior to installation must be replaced or repaired by the Contractor.

4.3.3 Geosynthetic Materials

The geosynthetic materials for this project will consist of geotextiles, geonets, geogrids and geomembranes. In all cases these materials will be visually inspected for obvious defects and flaws. All field seams on geomembranes will be 100% non-destructively tested and partially destructively tested in accordance with the QA/QC Plan; Section 4.6. Field seaming devices will be required to perform trial seams in order to assure that the device is functioning in accordance to the Specifications and the QA/QC Plan.

Materials found to be defective prior to placement will be discarded and replaced at no cost to the Owner. Material found to be defective after installation may be either patched, spot welded, or reconstructed in accordance with Section 4.6 of the QA/QC Plan.

4.3.4 Miscellaneous Materials

This section will address those materials which do not come under one of the previous two categories of materials. This section is divided into piping and concrete material defects.

4.3.4.1 Piping Materials

This subsection applies to both HDPE and PVC piping materials. In all cases, piping materials will be visually inspected for obvious defects and flaws prior to placement. Any defective material will be removed and replaced at no cost to the Owner.

Upon installation of the piping material, but prior to backfilling or permanent anchorage, pressure tests will be conducted to insure the integrity of the in-place material. Those segments of piping found to be defective will be removed, replaced and retested at no cost to the Owner. Details of the test procedures and specifications may be found in Sections 4.7 through 4.10 in the QA/QC Plan and in Specifications, Sections 15260 and 15410.

4.3.4.2. Concrete

All precast concrete materials will be visually inspected per Section 4.11 of the QA/QC Plan for cracks, breaks or imperfections. Any precast material exhibiting any of the obvious mentioned defects will be either repaired if permissible or discarded and replaced at no cost to the Owner. 4-8 All poured in-place concrete and associated reinforcing will be visually inspected, per Section 4.11 of the QA/QC Plan, and slump tested for consistency. Cylinder samples will be cured and tested for strength parameters. Any concrete not in compliance with the Specifications, Section 03001 will be removed, replaced and retested.

4.3.5 Inspection Failures

Inspection failures for synthetic or natural materials will be handled in accordance with the QA/QC Plan and Specifications. In summary the areas in which the failure occurred will be retested by an appropriate method to verify the materials non-compliance. If this additional testing confirms the original findings several options are available to correct the situation.

These options would include, but not be limited to the following remedial actions:

a) reconstruction

b) localized repair

c) replacement All of the above repairs would be followed up by retesting for specification compliance.

4.3.6 Severe Weather Conditions

Various unusual weather conditions can directly or indirectly adversely impact the construction of Cell No. 3. Some of these possible climatic conditions and associated remedial measures are presented in the sections to follow. These climatic conditions would adversely effect the placement of the clay material and the geomembrane panels. 4-9 4.3.6.1 Extreme Cold

Geomembrane placement will not proceed at an ambient temperature below 40°F unless otherwise authorized. Generally, extreme low temperatures will not adversely impact in-place geomembrane panels, however, due to the high coefficient of thermal expansion of HDPE, large shrinkage of the in-place panels may be anticipated. Stockpiled HDPE should be unaffected.

Under no circumstances should an attempt be made to incorporate frozen clay material within a clay lift. Stockpiled frozen clay should be allowed to stand until the material has had time to thaw, at which time it may be used in construction. In-place clay which is frozen will be scarified to the depth of a non-frozen layer. The material will be allowed to thaw, followed by recompaction; or removed and fresh, uniform material put in its place.

4.3.6.2. Extreme Heat .

In-place or stockpiled geomembrane material will be affected by extreme heat conditions. High temperatures will allow the geomembranes to expand. This should not adversely impact the installation nor the performance of the geomembrane.

In-place clay lifts may excessively dry out and desiccate as a result of extreme heat. Severely desiccated in-place clay material will be removed, replaced and retested. If in-place clay lifts are to be left exposed over weekends or long holidays, temporary plastic coverings may be required to prevent desiccation. Stockpiled clay material which becomes desiccated may be either reworked or discarded and replaced at the discretion of the Soils Quality Assurance Manager.

4.3.6.3 Heavy Rains

Geomembrane placement will not be performed during any amount of rainfall or excessive moisture (i.e., fog, dew, etc.).

4-10 Clay compaction will not proceed during heavy rains. In-place material will be allowed to dry and be recompacted or removed and replaced at the discretion of the Soils Quality Assurance Manager. Stockpiled clay should be smooth drum rolled and sealed to minimize moisture infiltration.

4.3.6.4 Snow

Geomembrane placement will not be performed during or after any snowfall.

Clay compaction will not proceed during snowfall. Upon termination of the snowfall, the snow will be cleared, and the clay layer examined for evidence of freezing. If the clay is frozen the contigencies outlined in Section 5.1 of this document may be employed.

4.3.6.5 Electric Storms

No geomembrane nor clay compaction will proceed during an electric storm. Construction will be suspended for the duration of the storm.

4.3.6.6 Excessive Winds

Geomembrane placement will not proceed in the presence of excessive winds. In-place panels should be secured via sandbags.

4-11 5.0 LANDFILL OPERATIONS

5.1 Hours of Operation

The landfill will be open between 9:00 a.m. and 3:00 p.m., Monday through Friday for operations. The site will be closed every weekend of the year and seven holidays.

5.2 Personnel & Facilities

The personnel involved in the regular operation of the landfill will be one (part-time) dumptruck operator, one dozer operator, one landfill supervisor and the wetwell equipment operators (part-time).

5.3 Record Keeping

The daily volume of wastewater treatment plant sludge (WTPS) trucked to the landfill will be entered in a logbook worksheet by the dumptruck operator and it will be authorized by the landfill supervisor. Proper record keeping is essential to monitor the quantity of sludge dumped and the rate of filling of sludge. Annual reports will be submitted to NJDEP. These reports will include quantity of sludge landfilled, leachate quantities pumped and landfill elevations and remaining capacity (estimated).

5.4 Landfill Equipment

The types and details of equipment given in Table 5-1 will be involved in the operation of the landfill facility.

5.5 Access Control

Vehicular access to the landfill will be along the access road indicated in Drawing No. 6505^104P and controlled by a gate with chain and lock positioned across the entrance of the road. There will be no unlocked alternate route to the landfill.

5-1 CIB 013 0447 TABLE 5-1 LANDFILL EQUIPMENT

EQUIPMENT FUNCTION DESCRIPTION MODEL

dumptruck transport and dump the capable of dumping up to Autocar Dynoso solid waste on the the inclination of 45° unit landfill site to horizontal

dozer spread and grade the capable of moving in the track mounted dumped waste in the sludge D4-LGP caterpillar landfill with 30" width blade

submersible collect the leachate capable of handling 3/16" EBARA 100 ESU dewatering from the primary solids up to 2% solids 67.5 pump collection system by volume with capacity of 55 gpm at 67 TDH

pump motor activate the pumps capable of making 20 NEMA MGI-Type B starts per hour for equivalent 24 hrs/day with 3 phase supply, 3 hp 460 volts, 60 Hz

alarm system Dalarm pump failure/ capable of energizing see Dwg.6505-152 2)high water level alarm light and horn see Dwg.6505-152

stormwater pump out the storm­ portable, high pressure Peabody-Barnes pump water centrifucal pump of Model No.4030 HCC 220 gpm capacity

to During working hours, landfill personnel will control access to the site.

5.6 Work Area Control

Arrangements and preparations for the supply of cover material, control of elevation and drainage, proper waste deposition, and general maintenance will be the responsibility of the landfill supervisor.

5.7 Waste Handling

The waste should be handled with care to prevent any spillage during transport of waste to the landfill site.

5.8 Filling Sequence for the Landfill Facility N , The filling sequence for the proposed landfill is described in Appendix C, Landfill Closure and Post-Closure Plan, AWARE Drawing 3-1. This drawing shows the steps to be followed for the successful operation of the facility. A brief description of the fill sequence is presented below.

5.8.1 Filling to Intermediate Operations Grade

a) Make the initial access to the landfill for the bulldozers from the northern side of the cell as shown in Cell No. 3 Construction Drawings, Industrial Waste Landfill, Ciba-Geigy Toms River Plant, Operational Road (Cell No. 3 Permit Drawing No. 6505-104P).

b) Fill to elevation 48.0, those areas below this elevation.

c) Line the base and slopes of the landfill with a foot of sludge to prevent the stormwater entry into the primary collection system.

d) Landfill waste along the entire length of the cell, filling the center portion of the cell, keeping the bottom width 100 ft., filling 5-3 to elevation 56.0. Stormwater retention capacity shall be left on either side of the filling operation (Appendix C, Drawing No. 3-1, Section C-C).

e) Remove the access for. the dozer from the northern side of the landfill. Keep the ditches clear for the stormwater storage on all sides of landfill as outlined in the Operations and Maintenance Manual, Appendix C, Appendix A-l (stormwater control plan).

f) Construct access road on the west side near the truckwash area.

g) Continue landfilling from the west side and build the access road eastward as the cell becomes filled. Slope the access road (not to exceed 10:1) to obtain the intermediate grade shown on Appendix C, Drawing No. 3-1. During this landfilling stage, it is essential that the sideslopes do not exceed 1.5:1 and that the ditches are free of additional waste.

5.8.2 Filling to Intermediate Closure Grade

a) Landfill waste in individual piles on the platform area established by the intermediate grading. An area will be kept free to enable dozer to complete the final grading.

b) Landfill waste adjacent to the access road area creating individual piles.

c) Construct the temporary retention basin and runoff collection ditches for storm water before pushing additional waste into the retention trench areas. Open-up the spillway in the berm shown in Appendix C, Drawing 3-1.

5-4 5.8.3 Filling to Final Closure Grade

a) Make the final grade of the landfill by pushing individual piles of waste down into the runoff collection ditch area. The final grade is shown on Appendix C, Drawing No. 3-1.

b) Initiate preliminary Capping of Cell No. 3.

5.9 Contingency Plans

5.9.1 Fire Control

The possibility of an outbreak of fire is a contingency which must be addressed at all landfills, regardless of the low fire potential of proposed Cell No. 3. This material is a carbon-based material containing a moisture content of 50 percent or more. Hence, the likelihood of fire associated with handling this material is negligible.

The landfill supervisor is responsible for initiating and maintaining all fire-fighting activities. Requests can be made of local fire-fighting units to assist in any outbreaks which may occur. The Rules of the Division of Waste Management require that, whenever fire, smoldering, or smoking occur, immediate notification must be given to the police and fire departments having jurisdiction in the area. Additionally, the Divisions of Waste Management and Air Pollution Control must be informed.

The use of the on-site Fire Brigade will offer the best means of fire control especially considering the non-flamable nature of the Wastewater Treatment Plant Sludge. Water can be used to extinguish any fire. The four inch truckwash forcemain may be utilized as a water supply if necessary. If, at any time, additional assistance is required, local fire-fighting units should be called in. All fire fighting procedures should be posted'in the operations trailer.

5-5 5.9.2 Dust Control

The Ciba-Geigy Toms River Plant, Industrial Waste Landfill site is surrounded by woodland and grassland. Under these conditions, the incidence of blowing dust would be minimal and virturally have no impact on the vicinity. Whenever dust may become a nuisance, water will be applied to access roads or other points subject to heavy traffic. Similar measures can be taken if a dust problem develops at the landfill.

5.9.3 Odor Control

Odors generated from the Wastewater Treatment Plant sludge have not developed to levels that would impact the surrounding landfill vicinity or downwind communities. The isolation of the landfill from the Surrounding communities significantly reduces any potential impact. If odors should become an off-site problem, the source should be monitored and proper remedial action should be taken immediately.

5.9.4 Severe Weather Conditions

Various unusual weather conditions will directly affect the operation of the landfill and must be dealt with accordingly. Some of these possible climate conditions and associated remedial measures are as follows.

5.9.4.1 Freezing

Freezing conditions should not disrupt the landfill operations with the exception of a potential failure of a section of heat traced leachate forcemain. The freezing of the pipeline will not cause the pipe to leak due to the properties of HDPE. Thawing and replacement of the heat tracing tape is all that is required for remediation. The filling and grading of Wastewater Treatment Plant sludge can be conducted during freezing temperatures.

5-6

CIB 013 0452 5.9.4.2 Heavy Rains

It is recommended that operations such as grading the WTPS waste during heavy rain be postponed. The strength properties of the WTPS waste, upon saturation will deteriorate and may not support a bulldozer.

The dumping of the WTPS waste can continue through heavy rain with the condition that the dumping area is kept clean to insure that runoff drains freely to the stormwater containment system. It is crucial that any WTPS dumped during a heavy rainstorm not distrupt the stormwater containment system. Stormwater Control is thoroughly discussed in Appendix C, Appendix A-l.

5.9.4.3 Snowfall

The available plant and landfill equipment should be adequate to remove accumulated snow from access roads and operational areas. It is advisable to arrange snow banks in a manner which promotes adequate drainage when melting occurs. Wherever possible, snow banks should drain downslope away from the landfill. All snow that comes in contact with WTPS waste should be pushed, or piled and left to melt and drain into the stormwater containment system.

5.9.4.4 Electric Storms

The open area of a landfill is particularly susceptible to the hazards of an electric storm. If necessary, landfilling should be suspended for the duration of the storm and, to guarantee the safety of all field personnel, refuge should be taken in a trailer, rubber-tired vehicles, or adjacent buildings.

5.9.4.5 Extremely Windy Conditions

The consistency of the WTPS waste, and past Cell No. 1 and 2 operating experience suggested that the operation of Cell No. 3 should be virtually unaffected by windy conditions.

5-7

CIB 013 0453 5.10 Equipment Breakdown

In the case of landfill equipment malfunction, there is sufficient equipment as backup within the plant to adequately maintain pertinent landfilling operations. If a piece of equipment is likely to be out of service for a long period of time or the onsite backup equipment breaks down, additional machinery can be rented. In the event the primary leachate collection sumps are inoperable for a day or more, a backup replacement pump or pumps can be installed.

5-8